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 Post subject: Re: M26 Pershing:
PostPosted: Mon Jan 15, 2018 10:00 pm 
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MKSheppard--
That was an impressive history of the Navy's mid-war to 1945 Scout/Dive/Torpedo bomber program. How does the Boeing F8B fit into the story? Despite its "Fighter" designation, it had an internal bomb bay, and I think was designed with torpedo carrying as one of its missions.


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 Post subject: Re: M26 Pershing:
PostPosted: Tue Jan 16, 2018 6:27 pm 
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I have yet to do the torpedo/level bomber history.

I do have some information on the F8B.

It was a unsolicted Boeing proposal based on what they thought a fighter should be.

See, from the Tigercat Competition in 1941 to the second jet fighter competition in about 1945; the USN held NO design competitions at all.

Everything was the result of very informal procedures --- e.g. BuAer calls up someone, or they call BuAer up.

In the case of the F8B, it was a very long term aggressive Boeing proposal that kept getting resubmitted to BuAer until BuAer basically put their hands up and said "OK, try it, just stop bothering us" basically.

It tangentially connects with the torpedo/level bomber history....but I don't have the time to write it up (yet) thanks to North East Snow Emergencies. :cry:

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 Post subject: Re: M26 Pershing:
PostPosted: Tue Jan 16, 2018 9:47 pm 
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MKSheppard--
Thanks for reply!
What follows is a story I think I've told before: forgive me if I've told it too recently.
Many years ago, as an undergraduate philosophy major with a hobby curiosity about Boeing aircraft, I looked up "Boeing" in the university library card catalogue… and found a card for a "book" with the Boeing corporation as its author(!), entitled "The Philosophy of Fighter Design." With my combination of interests, OF COURSE I looked for it in the stacks. Turned out it was a pamphlet of … this was a long time ago, and I'll hazard a guess: if you find out my memory is faulty, don't say I didn't warn you … eight pages (carefully given hard card stock outer covers by the library), in simple prose with cartoonish illustrations. I forget the exact publication date, but it was around the latter part of WW II, and it seemed reasonable to conclude that the company had issued it in an effort to drum up popular or congressional support for the F8B.

The argument (we philosophers are good at spotting arguments!) went something like this. There are lots of very different roles fighter planes have to fill. Ideal characteristics for one might not be ideal for another. THEREFORE a variety of different fighter aircraft, optimized for different roles, should be developed and acquired.

An argument that the designers of an aircraft with characteristics out at one far end of the general "fighter" envelope might want to make… (One role for a naval (thought I don't remember the pamphlet as making explicit reference to naval fighters) fighter would be Kamikaze-killing. Maybe the best option for this at the time would have been the Grumman F8F: fast, manoeuvrable, with an absolutely astonishing climb rate… and small and light enough that it could be procured and deployed in large numbers. I very much doubt that the F8B could have matched it for this application! But if it is reasonable to have different aircraft for different roles… Then maybe the Navy should get F8F and also a heavy strike fighter capable of carrying a torpedo in an internal bomb bay.)
… Although I was a dyed-in-the-wool Boeing fan, I thought the argument was unconvincing: WW II experience seemed to show that you couldn't depend on being able to field role-optimized fighters in the right places at the right times, and that an aircraft that could serve multiple roles was more valuable. Case in point the P-47, equipped with a turbocharged engine for high-altitude fighter-escort duty, that in practice (ETO) was also a good ground attack aircraft.

Philosophical moral: even one's heroes sometimes give fallacious arguments when their own interests are in question.


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 Post subject: Re: M26 Pershing:
PostPosted: Tue Jan 16, 2018 11:22 pm 
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The funny thing about that is I'm pretty sure the F8B was intended to be the Do Everything Fighter. One aircraft, all roles, no waiting.

(Or, less charitably, the American Firebrand...)

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 Post subject: Re: M26 Pershing:
PostPosted: Sat Jan 20, 2018 1:52 am 
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BONUS to the VSB history!

I have a memmo somewhere where the Navy bitches that the AAF has Class I priority on R-3350s, while the USN only can get Class III Priority for R-3350s for the BTD.

-------------------------------------------

The history of the torpedo bomber begins with the development of the TBD Devastator, as it was not only the US Navy's first monoplane torpedo aircraft, but also the first to have horizontal bombing as a secondary mission to the primary mission of torpedo attack.

Image
TG-2

In 1934, the Navy's TG-2, which was a R-1820-86 powered torpedo biplane that weighed 8,271~ lbs gross, with a maximum speed of 128 MPH and a 300 mile range was becoming obsolete (first flight 1931), so the Navy began a program to replace it.

The future Fleet Admiral Ernest J. King (at that point Rear Admiral King, Chief of BuAer) signed on 13 September 1935 a memorandum laying out the proposed procurement program -- once the XTBD-1 had successfully flown, a RFP would be issued for quantities of 27 to 120 planes. The same procedure would be repeated for it's competitor, the Great Lakes XTBG-1.

Fortunately for Douglas Aircraft, the first XTBG-1 crashed during initial flight testing, delaying tests until the second prototype was flying.

Starting in 1937, the TBD began to equip the US Navy's VTB squadrons. During the service life of the Devastator (so named in 1941), there were no major changes, other than an abortive attempt by the Naval Aircraft Factory in 1939 to produce a single TBD-1A prototype seaplane.

Twin Engines Rise Briefly -- 1937

On 9 February 1937, LCDR A.M. Pride forwarded the plans and characteristics of BuAer Design #145, a twin engined design utilizing the XR-1535-92 Twin Wasp Junior, proposing it as a possible VTB aircraft.

By April 1937 the results of a comparative spotting survey between the TBD-1 and #145 by the Ships Installation desk were done -- #145 could be spotted on WASP, RANGER, YORKTOWN, ENTERPRISE, LEXINGTON and SARATOGA with only a few handling restrictions.

Despite this, nothing ever became of #145, but the twin engined bug would refuse to die out over the coming years.

A change in role, and Twin Engines Again -- 1938

From the inception of the USN's "Class Desk" system on 15 July 1932, torpedo carrying planes were placed in "Class VB-VT".

On 24 February 1938, "Class VTB" was created, recognizing that they had a horizontal bombing capability in addition to their torpedo carrying capability.

Later in June 1938 BuAer rejected a twin engine design proposed that same month by a Mr. A. Garr of Roxbury, MA. The design was a tricycle landing gear plane of 15,000~ lbs gross weight and 282 MPH @ 1,000 ft top speed, with a landing speed of 65 MPH. The reasons for rejection were due to:

A.) Too Heavy.
B.) The company was an unknown to the Procurement Division.

The 1939 VTB Competition

On 10 March 1939, Type Specification SD-114-6 for Class VTB airplane was released.

The general specifics the Navy were looking for were:

Quote:
a.) The missions of the aircraft represented by this design are to attack heavy surface craft with bombs or torpedoes, to serve as heavy smoke layers, and without bombs or torpedoes, to conduct scouting operations and attack light surface craft with gunfire. The principal features desired in the design are briefly summarized in the following sub-paragraphs:

1.) Maximum Stalling Speed with power off, 70 mph (statute) with one MK XIII torpedo (normal torpedo condition) less 1/2 fuel.....It is essential that the airplane have good stability and control about all three axes at low speed in the landing condition and that stalling shall be followed by nosing over without tendency to dive or fall off on one wing....

2.) Range at Economical Speed - Range at economical speed carrying one MK XIII torpedo or as bomber (3 - 500# bombs) shall be not less than 1000 miles (statute).

3.) High Speed - Highest practicable, and at least 300 mph with normal fuel load.

4.) Take-Off shall be as short as possible and not more than 325 feet in a 25 knot wind with normal torpedo load (Mk XIII torpedo) and fuel for 1000 miles range at economical speed.

5.) Service Ceiling - Shall not be less than 30,000 feet, beginning with normal torpedo load........

6.) Armament - All guns shall be located as near the center line as possible in order to effect high concentration of fire. The torpedo and bombs shall be carried internally ......

7.) Radio - Scouting radio equipment and rotation direction finder .... shall be carried in loading conditions.

8.) Power Plant - Single engine, mechanically supercharged............may be either air cooled or liquid-cooled, the air-cooled preferred.

9.) Strength - In accordance with appendix XXXI of Type Specification SD-114-6.

10.) Minimum Weight and size are desired but weights up to 12,500 pounds will be considered in normal torpedo....

11.) Dimensions - Overall height with wings folded shall not exceed 17 feet under static conditions on its own landing gear. The limiting overall dimensions ..... with wings folded.......are 41 feet by 48 feet with a clearance not less than 12" all around. The overall length shall not exceed 39 feet and the span shall not exceed 60 feet.

12.) Miscellaneous Designs Features -The gunner is designated also as radio operator, since he is the only one available for this assignment when the assistant pilot-bomber is at the bomb sight. It would, however, be desirable to have the radio accessible to both the gunner and the assistant pilot-bomber. The intention is not to have the radio inside the gun enclosure, but the radioman should have easy access to it from the enclosure ........
Depending on the space within the fuselage and the relative locations of assistant pilot's seat, rear gun enclosure and radio, the possibility of providing an auxiliary seat for use of the gunner-radioman when not in the gun enclosure is suggested, though not required.


A formal RFP was issued by BuAer on 25 March 1939, resulting in the submission of the following designs by 24 August 1939:

Grumman "A"/"B"
Brewster "A"/"B"/"C"
Vought "A"/"B"/"C"/"D"
Douglas "A"
Hall "A"
Vultee "A"/"B"

By 20 September 1939, discussion in BuAer centered upon the following designs in the following order:

Grumman "B"
Brewster "A" (or) Vought "C"

By 21 October 1939, BuAer had gone into detail on each remaining design;

"Grumman A, with the R-2600, 2 speed engine, is eliminated from consideration by the low performance at high altitudes."

"Grumman B, with the R-2600-B-658, two-stage engine, supercharged to 22,000 feet, is the best all-round design."

"Vought C, with the R-2800, 2 speed engine, has higher speeds than Grumman B or Brewster A at all altitudes up to 19,400 feet, and is faster at 16,000 feet by approximately 14 mph and 17 mph respectively than the above designs. From a performance standpoint, this airplane is outstanding for torpedo and normal bombing operations..... It has approximately the same weight as the Grumman and is over three hundred pounds heavier than the Brewster. For carrier adaptability, it rates below the Grumman........ This design is preferred over the other Vought proposals."

"In conclusion, it is recommended that the first award be made to Grumman for his design B, and that at least two airplanes of that design be purchased in order to provide valuable insurance for rapid completion of the trials. .........and it is recommended that the second award be made to either Brewster for Design A or to Vought for design C, .......An important factor favoring the Vought C is the use of the R-2800, 2 speed engine, which does not tie this competition down to one engine, although it is to be remembered that it suffers a speed penalty above 19,400 feet.”

Following a brief flirtation with ordering both R-2600 and R-2800 versions of the Grumman proposal (Grumman replied that they could make a R-2800 version, but not at the cost wanted by BuAer), on 3 November 1939, it was decided in conference to procure:

2 x Grumman "B" Designs with R-2600
1 x Vought "C" Design with R-2800

The TBF/TBM Avenger

Contract 72974 was executed to cover procurement of both Grumman prototypes, with the mockup held on 8 July 1940.

Because of urgent demands from the fleet, on 30 December 1940; Grumman was issued a contract (#76928) to procure 325 x TBF-1 (R-2600-8 Two Speed) and 1 x XTBF-2 (R-2600-10 Two Stage); because production of the R-2600-10 was not sufficient enough to meet contract delivery dates.

First flight of the XTBF-1, BuNo 2539 was on 7 August 1941; it crashed on 28 November 1941 and flight test duties resumed with the second XTBF-1, BuNo 2540.

On 2 January 1942, Contract #91367 was issued for 1,965 TBF-1 aircraft. The first 1,200 were built as TBF-1s and the remaining 765 were finished as TBF-1Cs.

On 23 March 1942, due to the need to have Grumman put all their productive energies into the F4F/F6F programs, the Eastern Aircraft Division of General Motors Corporation was issued Contract #98837 for 1,200 TBM-1/TBM-1C. This contract was later increased to 1,500 aircraft.

Several more contracts for more and more TBM's were issued over the years, but the key red letter date was on 10 December 1943, when a VTB Design Branch letter transferred complete engineering responsibility for the TBF/TBM Avenger to Eastern Aircraft.

On 21 October 1944 the head of VTB design recommended that the following recommendations be made in order to reduce the weight of TBM-3 aircraft.

(a) Remove the turret and tunnel gun.
(b) Remove all radio communication equipment except on VHF transmitter and receiver.
(c) Install only the following electronic equipment:

1. Radar
2. AN/APN-1
3. AN/ARC-1
4. IFF
5. Interphone
6. AN/APG-17

(d) Relocate radio-radar operator in second seat.
(e) Fair canopy demanded by removal of the turret.

Additionally, if a strengthened wing was also provided in conjunction with the weight reduction program, it would provide a 5g aircraft with improved bombing performance.

The TBU/TBY Sea Wolf

Following the construction of XTBU-1 BuNo 2542 under Contract #73253, signed 22 April 1940, production of the TBU was not undertaken as BuAer considered Grumman more suitable than Vought-Sikorsky as a source of production aircraft, and because the initial performance calculations showed that the TBF and TBU would be almost alike in performance.

However, as detail engineering proceeded on the Avenger, it became apparent that Grumman's plane was becoming increasingly overweight and that production TBFs would be well below the expected performance.

For this reason, BuAer decided to execute a production contract on the TBU, via a planning directive issued on 12 June 1942, calling for 1,100 aircraft.

Unfortunately, due to the high priority of the F4U program at Vought (and the resultant slow progress of production engineering of the TBU), it was decided to transfer the TBU to Consolidated Vultee, via letter of intent signed 31 October 1942 calling for 1,100 TBY-1 with the R-2800-20 "B Series" engine to be built at Consolidated's Allentown, PA plant.

However, the engineering, test, and design responsibility was to rest with Chance-Vought even though production of the TBY-1 was to be at Consolidated Vultee Aircraft. So, accordingly, Contract N0a(s)-622 was executed with Chance-Vought for them to have engineering, test, and design responsibility until the delivery of the 301st airplane, or final acceptance by the Navy of the first airplane, or until Jan. 1, 1945, whichever of the three conditions was fulfilled first.

By October 1942, BuAer was investigating the possibilities of installing the R-2800-22 "C Series" engine in the TBY to boost performance. Following a meeting with the Director of Planning on 30 March 1943, it was decided that all production TBY aircraft would have the "C Series" engine and that Chance-Vought would engineer the changeover.

The following day on 31 March 1943, a conference was held to inform all of BuAer's desire regarding the "C Series" engine. Unfortunately, Chance Vought replied that it would take them ten months to engineer the engine changeover, and so it was decided to keep the "B Series" engine on the TBY-1 and change the engines on the 301st TBY delivered, at which point Consolidated would have all engineering responsibility.

By 1 November 1943, Consolidated contacted the VTB Desk and stated they were ready to install the "C" in the first TBY-1 if an acceptable agreement for responsibilties/contract gurantees could be made with Chance Vought. Despite efforts by the VTB desk, no agreement could be reached with Chance Vought, so the original plan for engine changeover was continued with.

The VTB desk, highly desiring the "C Series", scheduled a conference on 7 December 1943 which resulted in Consolidated agreeing to install the C Series on the first TBY-1 and assume all responsibility for only the engineering work done by Consolidated on this engine installation. The changeover of the engine changed the designation from TBY-1 to TBY-2.

From December 1943 to September 1944 engineering/design responsibility slowly shifted to Consolidated, but actual progress was slow, resulting in a BuAer conference on 10 July 1944 which resulted in a shakeup of key personnel in Consolidated, resulting in the first TBY-2 aircraft's first flight on 20 August 1944.

It was at this point an event occured which showed the lengths that BuAer was willing to go to bat for the Sea Wolf.

On 21 August 1944, the Director of Military Requirements sent a memo to the Assistant Chief, BuAer regarding the W-11 Working Schedule (31 July 1944) voicing concern over the planned shifts in aircraft:

F4U-1D to F4U-4 in January 1945
F6F-5 to F6F-6 in July 1945
FG-1 to FG-4 in November 1945

due to concerns over the status of the "C Series" engine; and recommending that the F6F-6 be cancelled; so that F6F-5 production could be extended until it was sure that the F4U-4 was working.

A month later in September 1944, the worries came true.

F6F-6 production, which had been scheduled to start in July 1945 with 105 planes a month, had production of 100+ planes a month pushed back to October 1945 because of "expected delays in receipt of proven 2800-C-2 stage engines".

This may have been caused by the Curtiss-Wright Lockland, OH engine plant that was producing the R-2600 being rescheduled to build R-3350s for the B-29.

At this point, the USN took almost all of it's R-2800 "C Series" programs and shot them in the back of the head.

F6F-6? Dead, with 500 propellers ordered for it transferred to the F4U-4 program.

SB2C-6? Dead.

The only survivors were the F4U-4 and the TBY-2.

[The Final History of the TBY-2 has to be pieced together, TBD]

The 1942 VTB Program

Following the 21-22 January 1942 conference in which the scouting mission was transferred to the VTB class:

It was the opinion that the scout-mission should be transferred to the VTB type of airplane, making a conception of the single-seat dive bomber possible. The advent of radar had placed such a burden upon the radar operator that it was believed he could not be expected to serve as a look-out and rear gunner. This indicated the three-seater for use as a scout with radar search equipment. It was realized that this would make necessary a revision of the numbers of each type to be carried in the carriers, but only three types are needed. The proposed types would be VF, VBT, and VTSB.

A memorandum was issued on 29 January 1942 stating that a new twin engine torpedo scout bomber be designed with tricycle gear to meet this changed requirement and that Douglas Aircraft be assigned the project.

The 1942 Douglas Entry, SKYPIRATE

On 9 February 1942, BuAer confidential letter C-1660 was sent to Douglas Aircraft Company asking for proposals for an experimental torpedo scout bomber.

The suggested design (by BuAer) was to be a twin engine, three-man design for torpedo dropping, high altitude bombardment and long range scouting.

Douglas proposed four designs:

Twin Engine Turbocharged
Twin Engine Two Speed Supercharged
Single Engine (R-4360 Two Speed Supercharged)
Single Engine (V-3420 Turbocharged)

BuAer chose the single R-4360 design and issued a letter of intent, followed by the mockup board on 15 March 1943; followed by a formal contract on 31 October 1943 for two XTB2D aircraft and one static test article.

In December 1943, Douglas was asked for costs involved in providing 23 additional aircraft, and on 10 January 1944 Douglas replied with a detailed cost proposal. This was accepted by DCNO on 25 March 1944 and included money for design and fabrication of production tooling to produce 100 aircraft a month with delivery dates estimated from June 1945 to December 1945.

Ultimately, on 28 July 1944, DCNO cancelled it, giving weight and size reasons as his rationale; but these had been issues as far back as 13 April 1943:

Quote:
SUBJECT: Operation of XTB2D vs TBF on CV9 Class -Comparison of.

1. The XTB2D could be operated on the CV9 Class carriers subject to certain restrictions. The arresting gear installed in this class carrier is designed to arrest airplanes up to a weight of 16,000 lbs. with an engaging speed of 85 mph. Later ships of the class will have CV41 type higher capacity arresting gear in-installed. Which ships will be so outfitted cannot be stated until design of CV41 gear is complete and production data at hand. The present flight deck is designed for load of 14,000 lbs. per wheel with a distance of 12 ft. between wheels. Later ships will have reinforced flight deck structures for airplanes of approximately 20,000 lbs. landing weight. The centerline elevator clearances are only one foot since the airplane is 46 ft. long compared to elevator length of 48 feet. The centerline elevators have sufficient capacity at the slower speed cycle (53 sec.). The deck side elevator capacity is 13,000 lbs. and there are no plans on foot now to increase its capacity.

2. Spotting studies indicate the following comparisons:

Flight Deck
18 x TBF
12 x XTB2D

Hangar Deck
18 x TBF
10 x XTB2D

XTB2D's will not bypass (one past the ether) in the hangar alongside the uptakes due to the narrowing of the hangar at this point.

5. Weight of aircraft carrier on CV's is becoming more critical every year. During the past year the total weight of the carrier complements increased 50%. Even by reducing the VTB squadron complement from 18 planes to 12 planes the weight will still be increased by using the XTB2D airplanes.


Additionally, in order to fit on existing elevators on the CV-9 class; the tail of the TB2D was shorter than it should have been from a stability standpoint.

Finally, the VTB branch history says:

Further justification was offered in that it was the opinion of certain Individuals in the Navy that the mission of torpedo dropping by aircraft was becoming of secondary importance as a tactical operation. Recent battle reports and observations have indicated, though, that they are tactically important and that torpedo bombers should still be regarded as one of the primary offensive weapons to be used against enemy surface vessels.

The cancellation of the production contracts didn't end the fabrication of the two XTB2Ds ordered though, as the Navy felt that it still needed hard data on aircraft of this size for operation from aircraft carriers.

On 2 October 1944, despite the cancellation of the XTB2D, Douglas submitted a proposal outlining the installation of a jet engine in the second Skypirate, along with the removal of the tunnel gun, bombardier's tub, and Emerson turret and assorted armor.

Basically, a BTD-ized version of the Skypirate that would gain an increase in Vmax at sea level with a torpedo of 73 MPH.

The 1942 Lockheed Vega Entry

On 10 June 1942, the head of the VTB design desk visited Lockheed Vega to discuss twin engine VTB aircraft to be built by Lockheed. Vega undertook preliminary design studies and on 23 July 1942 replied to BuAer with the findings of their investigations; and said that in effect, they were too overloaded with work to actually do any concrete work in a reasonable amount of time.

Lockheed Vega's design number for this project may have been V-141.

The 1942 Grumman Entry

BuAer, despite having selected the single engine Douglas entry for the TB2D, still desired twin engines; this being a long running bugaboo. So they requested a proposal from Grumman on a twin engined VTB to the same specifications.

On 21 December 1942, Grumman submitted a preliminary design study, followed by a more detailed study on 19 March 1943.

Grumman's design was a a twin-engine, tricycle gear airplane with an internal bomb bay capable of holding two torpedoes. Power plants were two R-2800 "C-Series" engines. Gross weight would have been 34,515 (!!) lbs, clearly something meant for the MIDWAY class from the beginning.

A letter of intent was issued on 6 August 1943 for two XTB2F prototypes. The mockup took place from 1 to 5 May 1944, upon which the Navy began to have second thoughts.

A significant battle then broke out by 20 May 1944 in BuAer over the merits of the TB2F design, comparing it to the TB2D design and what cancelling it meant -- it was big, it was heavy, it overloaded catapults, etc.

A major point was that if it was cancelled, the Navy would be committing themselves to small, short ranged (relatively speaking) carrier aircraft.

In the end though, a stop work order was issued on 14 June 1944.

Enter the Slim-Fast Version of the TB2F

The very same memo that contained the stop-work order for the TB2F also contained a request that Grumman study and submit a design for a torpedo scout aircraft with the following characteristics:

Quote:
Twin engine, tricycle landing gear, monoplane with catapult and arrested landing provisions.

Bomb bay capable of containing one MK-13 Mod. 3 torpedo.

Fuel capacity in self sealing internal tanks for 400 mile combat radius.

Four fixed .50 cal. machine guns. APS-4 radar in the nose. Armor protection for pilot and one crew man.

Maximum gross weight with all above equipment -28,000 lbs.

Maximum span - 60 feet spread, 34 feet folded.

Maximum over-all length - 46 feet.

Maximum tail height - 16 feet.

Maximum wing loading - 48 lbs/sq. ft.

Vmax Sea Level - 380 mph.

Vstall power off - 85 mph.

Take-off in 25 knots - 450 feet.


Heavy suggestion was made that the characteristics could be met in a modified F7F-2 type aircraft.

In response, Grumman submitted Design 66 (G-66), and it was reviewed by BuAer in conference on 24 June 1944.

Essentially, it was the F7F-1 modified to have a bomb bay holding a torpedo. No other changes were made, resulting in a high wing loading, resulting in a takeoff run of 466~ feet when the plane was loaded with a torpedo and 700 gallons of fuel.

VTB Desk felt that the F7F-1 modified to carry an external torpedo offered better characteristics as a VTB aircraft.

Grumman responded with a revised design on 21 July 1944 which was a modification of the F7F-2 and differed by having a slightly larger wing to reduce wingloading and had the following specifications:

Takeoff distance with a torpedo was reduced to 351 feet
389 MPH @ Sea level @ WEP
423 MPH @ Critical Altitude @ WEP
17,562 lbs empty
Would not exceed the 26,000 pound weight limit for CVB class carriers when loaded with a torpedo.

The design was designated the XTSF-1 on 22 July 1944 via Confidential Aviation Planning Directive 65-A-44:

Quote:
NAVY DEPARTMENT
Office of the Chief of Naval Operations
WASHINGTON 25, D. C.

Op-31-X-HCM
(SC)A4-3/W
Serial 0157731

22 July 1944

CONFIDENTIAL

AVIATION PLANNING DIRECTIVE 65-A-44

From; CNO

To: ComAirPac
ComAirLant
Chief, BuAer

Subj: XTSF-1 Model Aircraft; designation of.

1. The design for a new torpedo-scout carrier airplane submitted by Grumman Aircraft Engineering Corporation has been accepted.

2. The new design is a twin-engine, mid-wing, single tail airplane, essentially a modification of the F7F-2 night fighter, incorporating a fuselage change to provide for a bomb bay to carry either a torpedo or a gasoline tank. It is designed for use ashore and aboard aircraft carriers.

3. The model designation for this airplane shall be XTSF-1.

D. S. CORNWELL
By direction


In Grumman's 21 July proposal, they said that they could build the two prototypes in six months following authorization. To expedite this, a partial mockup was held on 2 October 1944 at Grumman.

On 12 October 1944, VTB desk recommended 23 additional articles of the TSF be procured and production be investigated. Additionally, a decision was also made to procure the two existing XTSF aircraft with a fuselage nose large enough to accomodate the SCR-720; allowing a night intruder version to be developed in the future if the need is so desired.

Unfortunately, things quickly soured for the TSF. A conference was called in December 1944 and it was stated that:

(A) Grumman does not want to proceed on XTSF at any priority.

(B) Grumman does not have sufficient engineering on XTSF for transfer to any other contractor.

(C) Grumman desires complete cancellation of the contract. Due to weight and installation changes, the original concept of similarity between the F7F and XTSF had rapidly disappeared. Practically a complete redesign of the landing gear and center section would be required.

It was decided during the conference that:

(1) The XTSF-1 contract be immediately terminated.

(2) All consideration of turning this identical airplane over to another contractor be dropped.

(3) a new proposal for a scout attack torpedo bomber from some other contractor to compete with XTB3F be obtained. Douglas was recommended. This new design to be either twin, single or composite engine.

(4) Proceed with investigation of F8B for attack purpose.

(5) Proceed with increase in performance program on XTB2D-1. [the aforementioned jet boost program I believe].

(6) Continue XTB3F at highest priority.

December 1944 - Enter the Boeing F8B

In response to the request of a Military Requirement's directive for an engineering study of the XF8B, VTB Design Branch submitted a letter for the signature of the Chief of BuAer that requested such a study by the Boeing Aircraft Company.

The letter requested a study of the following modifications:

Quote:
(a) Remove the two-stage engine and substitute an R-4360-4 single stage, variable speed, single rotation, 0.25, #60 shaft.

(b) Remove the dual rotation propeller and substitute a suitable single rotation propeller for the engine of (a) above.

(c) Modify control surfaces and empennage to provide for single rotation propeller.

(d) Move pilot's cockpit forward and provide 15° down vision over the engine cowl.

(e) Incorporate second seat behind the pilot for radar-radio operation, with sufficient armor protection against .50 cal fire, from a 45° cone from the rear, oxygen equipment, radar controls and scope, seat and safety belt.

(f) Provide installation provisions for external mounting of a Mk 13-3 aircraft torpedo with lug suspension either under a wing or on the centerline of the fuselage, whichever location involves the lesser modification to the present design design.

(g) Provisions for carrying APN/APS-4 detachable radar package under the right hand wing as far outboard as is possible to obtain maximum radar vision ahead and above.

(h) Provide installations for carrying the 11.75" rocket projectile "Tiny Tim," under each wing and additional alternate provisions for four 5" HVAR rockets under each wing.

(i) Provide installations for carrying one twin .50 cal Douglas machine gun package, or one Mk 1 single .50 cal container, or one Mk 3 single 20 mm cannon, under each wing.

(j) Provide installations for carrying one 150 gal. drop tank on each wing.

(m) Recalculate structural strength to establish the resulting design load factor. The minimum strength considered acceptable for this type of aircraft is 5g at a gross load for a normal attack condition. This loading will consist of full internal protected fuel, two man crew, one 2000 lb. bomb, six .20 mm fixed cannon with 200 rounds per cannon, and all radio and radar equipment installed.


TO BE CONTINUED....

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 Post subject: Re: M26 Pershing:
PostPosted: Sat Jan 20, 2018 2:03 am 
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There's a lot more I need to add to the TBM/TBY chapters but it's 2 AM Eastern here...so tomorrow, then guys. Consider the above a rough first draft. :P

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 Post subject: Re: M26 Pershing:
PostPosted: Sat Jan 20, 2018 11:03 pm 
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I just found Lockheed's proposal for the Torpedo Scout Bomber (aka Skypirate) that they gave the Navy and then said "sorry, we can't do this."

Vega Aircraft Corp., Model V-141 Torpedo Scout Bomber, Preliminary Design Study, Part I/II

in a finding aid I found at NARA almost ten years ago.

Will have squeeematics of that later this week (I have to go to the Archives on Monday, put in a pull request, and then wait till Tuesday to see what I got).

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 Post subject: Re: M26 Pershing:
PostPosted: Sat Jan 20, 2018 11:09 pm 
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Allen Hazen wrote:
Many years ago, as an undergraduate philosophy major with a hobby curiosity about Boeing aircraft, I looked up "Boeing" in the university library card catalogue… and found a card for a "book" with the Boeing corporation as its author(!), entitled "The Philosophy of Fighter Design." With my combination of interests, OF COURSE I looked for it in the stacks. Turned out it was a pamphlet of … this was a long time ago, and I'll hazard a guess: if you find out my memory is faulty, don't say I didn't warn you … eight pages (carefully given hard card stock outer covers by the library), in simple prose with cartoonish illustrations. I forget the exact publication date, but it was around the latter part of WW II, and it seemed reasonable to conclude that the company had issued it in an effort to drum up popular or congressional support for the F8B.


That book exists in NARA II:

ARCID 6827849, Box 52: Boeing Aircraft, Philosophy of Fighter Design

:mrgreen:

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 Post subject: Re: M26 Pershing:
PostPosted: Sat Jan 20, 2018 11:29 pm 
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This is the Douglas "A" entry for the 1939 VTB.

Attachment:
Douglas 1939 VTB.png
Douglas 1939 VTB.png [ 166.67 KiB | Viewed 373 times ]

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PostPosted: Sun Jan 21, 2018 3:15 am 
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Location: BM-9, BB-30
The Super-Devastator is strong in that one...

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Here is the original 1943 schedule for the Curtiss BTC:

Quote:
RG 72
NM-52 Entry 67
General Correspondence, Confidential 1922-44
Box 1447
Declassified via NND 730026

------------

Aer-PRD-6372-PML
VBTC1/A4

1 MAY 1943

C 8880

From: Chief of the Bureau of Aeronautics.
To: Navy Representative, Aircraft Scheduling Unit,
Steele High Building, Dayton, Ohio. 138432
Attention: Lt. (Jg) G.C. Ealer.

SUBJECT: Proposed Production Schedule for BTC-1 Airplanes.

1. The following information is submitted in accordance with the telephonic request of Lt. (Jg) G. G. Ealer on 30 April,

[OCR: edited it slgihtly from the tabular format to make it work here]

February 1944
XBTC-1 #1 (1 aircraft)

March 1944
XBTC-1 #2 (1 aircraft)

XBTC-2 #1
May 1944 (1 aircraft)

XBTC-2 #2
June 1944 (1 aircraft)

BTC-1
July 1944 (1 aircraft)
August 1944 (3 aircraft)
September 1944 (6 aircraft)
October 1944 (15 aircraft)
November 1944 (25 aircraft)
December 1944 (40 aircraft)

2. The above information is in accordance with the proposed 8M Schedule for the year 1944 only. However, this program will possibly be delayed due to the SB2C situation at this time. It is understood that Curtiss personnel is being shifted from the XBTC-1 to the SB2C program which will necessitate a change in the schedule for the XBTC-1.

3. Attention is invited to the fact that this information is very tentative and accordingly is subject to change at any time.

MORRIS DUANE
Lt. Comdr., U.S.N.R,
By Direction Chief of Bureau

Lt. (Jg) A. A. Clagett,
1 May 1943
Phyliss Lotreck

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PostPosted: Fri Jan 26, 2018 6:41 pm 
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Dragging this back onto tanks:

The Ordnance Department: On Beachhead and Battlefront states

But Barnes did not want the 90-mm. on the M4 tank. He believed that the gun was too heavy for the tank; that it produced "too much of an unbalanced design."
(Barnes, MS on 90-mm gun; and Ltr to Gen. Campbell, 11 Oct 44, sub: History of Tank Guns. Both in Folder, Tank Guns (Over-all), Barnes file, OHF)


I looked in both folders in that box; followed by looking at the bottom of the box to see if it wasn't at the bottom and didn't find the 90mm gun memo. It may have gone missing at some point; but it's probably CCed somewhere else, possibly in the design history book for the Sherman.

---------------------

NARA II
RG156
NM-26 Entry 646A
Box 778A
Declassified Via NND 735001

ALL COMMUNICATIONS SHOULD BE ACCOMPANIED BY CARBON COPY AND ADDRESSED TO

WAR DEPARTMENT
OFFICE OF THE CHIEF OF ORDNANCE
WASHINGTON, D. C

TO INSURE PROMPT ATTENTION
WHEN REPLYING REFER TO:

____________NO. _____________

ATTENTION OF
__SPOTH__

11 October 1944

MEMORANDUM FOR Major General L. H. Campbell, Jr.

Subject History of Tank Guns

1. EARLY DEVELOPMENT: Until about the middle of 1940, tanks were assigned to the Infantry as the using arm and matters concerning the armor and armament for these vehicles were referred by the Ordnance Department to the Infantry. Over a period of many years, the Ordnance Department endeavored to have the thickness of armor and the power of guns in tanks increased. The War Department General Staff, however, had placed weight limitations of 7½ tons on light tanks and 15 tons on medium tanks until January 1956 and July 1938, respectively, at which times these limitations were somewhat relaxed.

The normal tank armament of that period consisted of caliber .30 and caliber .50 machine guns. In 1928, the Ordnance Department had recommended the use of a 1.85" gun for tanks, and one such gun was built and installed in the medium tank and successfully tested in 1929. In 1938, the 37mm gun, M5, was placed in the turret of the medium tank. In 1937 the latest medium tank produced by the Ordnance Department for the Infantry was the Medium Tank, T5, which was designed in 1936-37. This tank was standardized in July 1938 as the M2. It was further improved and redesignated M2A1 in June 1939. A number of these tanks had been manufactured in 1939. They mounted the 37mm Gun, M5, in the turret, four caliber .30 machine guns in the sponsons, and two in the front plate.

2. 75mm GUN: In January 1939 the writer recommended the use of a 75mm weapon in tanks and set up a project to have the 75mm Howitzer, M1A1, installed in the pilot Medium Tank, T5 - Phase III. This was done, and the firing at Aberdeen Proving Ground in August 1939 indicated that the 75mm Howitzer was greatly superior to the 37mm Gun and more effective than all the machine guns combined.

In 1939 the question arose as to -what tank should be put into production in the war emergency. It was argued that the Medium Tank, M2A1, was a completed article which had been thoroughly-tested and was, therefore, the tank for quantity production. Steps along this line were taken, and the Chrysler Corporation, which was selected to manufacture the tanks, sent its engineers to Rock Island Arsenal and was first provided with a set of drawings of the M2A1 tank.

The writer advised against the manufacture of the M2A1 and insisted that a new tank be designed to mount the 75mm Gun. General Wesson decided to go ahead with this recommendation and to hold up production until the new design could be completed. It was desired to put the 75mm Gun in the turret. The Chief of Infantry disapproved this recommendation but permitted the installation of the 75mm Gun in the sponson in place of the machine guns.

The first 75mm Gun, M2, was made short, as the Infantry did not want the tube to extend beyond the front of the tank. This brought about the design of the well-known M3 tank, called the "General Grant," with the 75mm Gun, M2, in the sponson. The M3 was the first medium tank manufactured in quantity for this war. This tank proved itself in Egypt at the battle of El Alamein. Without the 75mm Gun in the sponson, however, the tank would have been under gunned and would not have had sufficient firepower to be effective on the battlefield at that time.

Although the 75mm Gun demonstrated its effectiveness insofar as firepower is concerned, it was soon demonstrated that the sponson-mounted gun was not nearly as effective as a turret-mounted gun would be. As soon as the M3 Tank was placed in production, steps were taken to redesign it by placing the 75mm Gun in the turret. The gun was lengthened and the muzzle velocity increased from 1,850 f/s to 1,970 f/s, making it a more effective weapon. The gun was later standardized as the M3. The new tank was designated as the T6.

The pilot T6 Tank was completed at Aberdeen Proving Ground in August 1941. General Devers, then Chief of the Armored Force at Fort Knox, witnessed tests of the pilot T6 Tank at Aberdeen on 3 September 1941 and immediately gave his approval. It was therefore decided to standardize the T6 as the M4 and put it into production on the basis that the change would be made in such a way that there would be no loss of production. Production of the M4 Tank began in March 1942.

3. 105mm HOWITZER: It was planned at the same time to design the M4 Tank turret so that the 75mm Gun, the 105mm Howitzer, or other armament could be mounted interchangeably. The 105mm Howitzer had previously been placed on the M3 Tank chassis to make up the 105mm Howitzer Motor Carriage, M7, called the "Priest" by the British. The M7 had been sent to Egypt to the British in time for use against the Germans at El Alamein and in subsequent actions. Since the 105mm Howitzer was already available on the M3 chassis in the form of the M7 Howitzer Motor Carriage, the mounting of the 105mm Howitzer in the M4 Tank was delayed owing to the press of other projects. The project for mounting the 105mm Howitzer in the tank turret was later revived, and the pilot was successfully proof-fired at Aberdeen Proving Ground in December 1942. The Howitzer was standardized as the M4, and the mount as the Combination Gun Mount, M52, These units are now in production.

4. 76mm GUN FOR MEDIUM TANK, M4: After the Medium Tank, M4, had been put into production, it was felt highly desirable to provide this tank with a more powerful gun so that it would be still more effective against enemy armor. The 75mm Gun, M3, with which the M4 Tank was being equipped, was an ideal gun against personnel because of its excellent high-explosive shell. However, it was desired to install a gun which would also have more effective armor-piercing qualities.

It was planned that only about 25 percent of the M4 Tanks be equipped with this gun, since it was not considered necessary for all tanks to have such high-powered weapons.

The design of the 76mm Gun, T1, was made in this office, and Watervliet Arsenal was given an order on 14 July 1942 for two pilot guns. These pilots were completed and successfully tested at Aberdeen Proving Ground on 12 August 1942. After these tests, the Chief of Ordnance recommended by memorandum to the Commanding General, Army Service Forces, on 21 August 1942, that 1,000 of these guns be manufactured quickly for mounting in M4 Tanks for the African theater. The gun had been so designed that this could be done without any major modification of the turret. This project was approved, and an order for 1,000 76mm Tank Guns was placed in August 1942. The 76mm Gun is in reality a 3" Gun specially designed for tank use. Since it required a very slender round of ammunition with a cartridge case different from that of our standard 3" Gun, it was called "76mm" to prevent mixing of ammunition in service.

The first production 76mm Gun, M1A1, mounted in a pilot tank, was successfully fired at Aberdeen Proving Ground on 26 September 1942. In a letter dated 21 November 1942 (File SP 472.1), the Armored Force stated that the M4 Tank mounting a 76mm Gun was an untried weapon which was not tested by the Armored Force and recommended that no quantity production of this weapon be undertaken until pilot models were thoroughly tested and their suitability for Armored Force use determined. The Ordnance Department was specifically instructed to procure no more than 12 tanks mounting a 76mm Gun. Later the entire project was dropped.

On 19 February 1943 the Armored Force stated at a meeting attended by representatives of the Army Ground Forces and the Chief of Ordnance and his staff, in Detroit, that the manufacture of 216 Medium Tanks, M4, mounting the 76mm Gun would be requested.

The letter file requesting this manufacture was indorsed to Headquarters, Services of Supply, on 1 March 1943 for more information. Headquarters, Army Ground Forces, approved the diversion of 17 medium tanks to mount the 76mm Gun to equip one Medium Tank Company only. On 21 August 1943 Headquarters, Armored Command, recommended the procurement of 1,000 medium tanks equipped with the 76mm Gun. The first production tanks mounting the 76mm Gun, made as a consequence of this recommendation, were completed in January 1944.

5. 3" and 90mm TANK GUN: When development of the 60 ton Heavy Tank, M6, was begun in May 1940, the writer chose the 3" high-velocity gun as its principal weapon. At that time this was the most powerful gun which had been mounted in a tank by any country. The first Heavy Tank, M6, using the 3" Gun, T12 (later M7), was completed, demonstrated, and accepted on 8 December 1941.

In the realization that still heavier guns would be required on the battlefield as time passed, design was undertaken in September 1942 of a 90mm high-powered gun which would have the ballistics of our 90mm antiaircraft gun but the same outside diameter as the 3" tank gun, M7, so that it could be used in the Heavy Tank, M6. Furthermore, based on the work done by the Heavy Tank, M6, steps were taken in February 1942 to place the 3" gun from the heavy tank in an open turret on the M4 chassis as a self-propelled gun mount. This design was completed and standardized as the 3" Gun Motor Carriage, M10, on 4 June 1942.

The 3" Gun Motor Carriage, M10, was placed under heavy production, and it was planned that eventually the 90mm tank gun, T7, would be developed primarily for the Heavy Tank, M6, and could also be utilized in the Gun Motor Carriage, M10, without extensive redesigning. The design of the 90mm tank gun, T7, was completed in December 1942. It was mounted in the 3" Gun Motor Carriage at Aberdeen and demonstrated to the Secretary of War and officers of the War Department and Army Ground Forces on 10 February 1943. After these demonstrations, attempts were made to interest the Army Ground Forces in the 90mm gun, but these attempts failed. On 3 October 1943, a letter was received from the Army Service Forces stating that our recommendation for the immediate manufacture of 500 90mm gun motor carriages based on the M10 chassis was disapproved.

As the Ordnance Department felt it absolutely essential that a gun more powerful than the 3" tank gun be available on the battlefield to oppose the German 88, this matter was pressed with the Army Ground Forces. Upon a recommendation that at least 1,000 of these units be manufactured, an order was received from the War Department to proceed with the manufacture of 500 units known as the 90mm Gun Motor Carriage, T71. The gun was therefore standardized as the M3 in September 1943. Because of the lack of interest shown by the Using Arms, the 90mm Gun Motor Carriage, M36, was not standardized until June 1944.

It had been planned also to mount this gun in the T20 series of tanks, the design and development of which were started in May 1943. The Army Ground Forces, however, felt that the 76mm gun had sufficient power, and they were not interested in the 90mm. Permission was obtained, however, to mount the 90mm Gun, M3, in 40 Medium Tanks, T25, and 10 Heavy Tanks, T26, experimentally.

Upon completion of these units, little interest in them was shown by the Ground Forces. Consequently a demonstration was conducted at Aberdeen for the Secretary of War, the Chief of Staff, and officers of the General Staff and Army Ground Forces. The greatly increased effectiveness of the 90mm gun over the 75mm and 76mm guns was concurrently demonstrated. As a result of these demonstrations, decision was personally made by General Marshall to place the Heavy Tank, T26, in production with the 90mm gun. At the present time, orders have been issued for the quantity production of these weapons and both Fisher and Chrysler Corporation are tooling. Production will be started by Fisher in October 1944.

6. 105mm GUN: By September 1943, the very powerful 105mm Gun, T4, had been designed and a pilot manufactured for antiaircraft use. Since this gun can fire a 42-lb. armor-piercing projectile at 2,900 f/s, 5.5 inches of armor at 30 inclination can be penetrated at a range of 2,000 yards. These ballistics were considered very suitable for an antitank or self-propelled weapon. To adapt a weapon of this power to tank mounting, the T5E1 gun was provisionally laid out in late 1943 and the super tank design to carry this gun was started in September 1943, but Army Ground Forces would not approve manufacture although it was approved by the Commanding General, Army Service Forces, The project suggested the manufacture of 25 tanks, now known as the T28, in order to have them available should they be required for use against heavy fortifications which might be encountered in France and Germany. Finally, on 26 April 1944, after long delay on the part of the Army Ground Forces, approval was given for the manufacture of five T28 tanks to weigh 80 tons with a frontal armor on the basis of 10". These tanks are now under manufacture.

7. 90mm TANK GUN - SUPER-VELOCITY: On 17 March 1944, the design of the super-velocity 90mm Gun, T15, was undertaken. This gun was designed to use a standard 90mm projectile in a new case. The new case has the same exterior diameter as the standard case, but its length has been increased to provide a greater powder capacity. This gun was designed to give a velocity of 3,200 f/s with single-base powder. The design was also such that it could be used interchangeably with the standard 90mm tank gun, M3, except of course, for ballistics. The gun is very long (70 calibers) and would require the use of a new equilibrator and stronger parts in the mount. However, this gun can be mounted in me T26E1 Tank.

The pilot gun was delivered to Aberdeen on 1 September 1944 and is now being used to develop powder. If the war continues, several hundred of these guns will be manufactured for mounting in the T26E1 Tanks in order to provide a gun of greater firepower.

8. LATEST DEVELOPMENTS: The T26E1 tank is the Ordnance Department's 1945 model tank. In order to have a still later model tank available should the war continue into 1946, design of two new tanks, the T29 and the T30, was started in September 1944. It is planned to mount the 105mm high-powered tank gun referred to above in the T29 Tank. This gun will also be bored experimentally as a 90mm weapon to give a muzzle velocity of 3,500 f/s with a 24-lb. projectile. The proof tests will indicate whether the 90mm caliber or 105mm caliber would be more desirable.

The T30 Tank contemplates the use of a newly designed 155mm Gun Howitzer. The undersigned started the design of this gun in October 1944. This gun will fire a 95-lb. armor-piercing projectile to penetrate 6 inches of armor at 30° inclination at a range of 2,000 yards. It would also be a powerful field gun, firing the 95-lb. high-explosive shell. The ability of this 155 mm Gun Howitzer to fire armor-piercing ammunition and high-explosive ammunition interchangeably would make it a very effective weapon.

/S/
G. M. BARNES
Major General, Ordnance Department
Chief, Research & Development Service

REFERENCES

1. First Partial Report on Test of 1.85" Tank Gun, T1 - 24 Jan 1930

2. OCM Item 14967

3. First Report on Installation and Test of 75mm Howitzer in Medium Tank, T5-Phase III -6 May 1940

4. First Report on Assembly of Medium Tank, T6 - 9 Dec 1941

5. First Report on Medium Tanks, M4, 105mm Howitzer Installation - 17 June 1943

6. OCM Item 18503

7. First Report on Test of 76mm Gun, T1 -24 Aug 1942

8. OCM Item - 18865

9. Final Report on 76mm Gun in Medium Tank, M4 -30 Dec 1942

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 Post subject: Re: M26 Pershing:
PostPosted: Fri Jan 26, 2018 6:44 pm 
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NARA II
RG156
NM-26 Entry 646A
Box 778A
Declassifed Via NND 735001

HISTORY OF TANK DEVELOPMENT BY
ORDNANCE DEPARTMENT IN WORLD WAR II

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

HISTORY OF TANK DEVELOPMENT
BY ORDNANCE DEPARTMENT IN
WORLD WAR II

I am writing these notes on tank development during World War II from memory, as an indication of how difficult it is to get any true picture of what actually occurred during this period from any official records. Similar remarks would also hold for any other important era of development such as for example, artillery. If the Ordnance Department is going to get a true story of the important developments of materiel during World War II it seems to me it would be necessary to get the personal experiences of the several officers who had the responsibilities of these various projects and then using these personal histories as background to fill in the voids from the official records.

Nearly every important development in materiel during the war was covered by an O.C.M. and is thus recorded history. What is lacking from these official documents is the thinking which led up to these projects. The O.C.M. was the method by which the Ordnance Department kept the line of the Army informed as to what it was doing and obtained their concurrence as they went along. Thus it could not be said that the Ordnance Department branched off on its own without consulting the using services. It is not, however, generally understood that it was necessary for the Ordnance Department during this period to take the lead in the development of ordnance equipment. Each branch of the Army had a Service Board for testing equipment. Unfortunately, the officers of these boards were not sufficiently experienced in the work of research and development to be of real help to the Ordnance Department except as a check on the final results which had been secured. Due to the fact that Ordnance personnel spend their service careers in the study of ordnance materiel it is to be expected that their knowledge of weapons exceeds that of line officers whose careers are concerned with the tactical use of equipment.

It is not well understood that tactics are usually written around a particular weapon. Thus, field operations ordinarily do not generate ideas leading to new materiel. A new piece of equipment must first be produced, such as for example, a machine gun, before the tactics can be devised for the exploitation of the capabilities of the weapon. For these reasons it is necessary for the Ordnance Department to take a strong lead over the using services in the development of new equipment and then to get the help of the using services in determining where the weapon best fits into battlefield operations.

TANK HISTORY DURING WORLD WAR II

Since I was in charge of the new tank development program for the United States Army in writing this history it is necessary for me to refer to actions which I personally took in regard to this program. I am not actuated from any motive of trying to bring out the importance of the part I personally played in this history but rather to explain exactly what did happen. It will be seen plainly that my statements are far different from the recorded history of tank developments in World War II.

In 1939 the Ordnance Department had worked out a tank known as the medium tank M2A1. This was the type of tank which was desired by the Infantry at that time. I might say that this was before the formation of the Armored Service and at that time the tank was considered primarily an infantry weapon. The M2A1 tank carried a 37 MM gun in the turret and as I remember, some six machine guns. The 37 MM gun was thought of, as an anti-tank gun to protect the tank against other tanks but the real purpose of the tank at that time was thought of as a machine gun nest. Somewhere about 1940 or perhaps 1941 (I would have to look up the date) the Ordnance Department contacted Mr. K.T. Keller of the Chrysler Corporation asking them to manufacture the medium tank in quantity production for the Army, and in fact to build a new plant for that purpose - that plant is now the Detroit Tank Arsenal.

During 1939 the writer was assigned to the technical staff of the Ordnance Department and had conducted tests at the Aberdeen Proving Ground to determine the effectiveness against infantry of machine guns vs. high explosive 75 MM shells. These tests showed clearly that the 75 MM gun was much more effective against personnel at all ranges than machine gun fire.

Mr. K. T. Keller went to the Rock Island Arsenal in 1940 to get the drawings for the M2A1 medium tank to be manufactured in the new plant and to start tooling. He obtained such drawings and went back to Detroit to go to work. In the meantime, the writer had been transferred to General Harris' office and made Chief Engineer of the Ordnance Department in charge of all research and engineering for the Ordnance Department. The writer visited Rock Island Arsenal and inspected the design of the M2A1 tank. He returned to Washington and reported to General Wesson and General Harris that this tank was entirely unsuited for modern warfare. It could not survive on the modern battlefields due to lack of fire power. He further stated that the tank would be obsolete before it could be sent overseas. It would be necessary to introduce a 75 MM gun into the tank if it were to be useful. He recommended that all work on the M2A1 tank be immediately stopped and that an entirely new tank be designed. Although this meant stopping all work at the Chrysler Corporation this recommendation was approved by General Wesson and General Harris and the undersigned was authorized to design a new tank for the United States Army.

The writer wished to put the 75 MM gun in the turret and entirely replace the 37 MM gun. However, the using service which was still the Infantry at that time would not go along with the displacement of the 37 MM gun. As a compromise, the best the writer could do was to leave the 37 MM gun in the turret and put the 75 MM gun in the sponson, opposite the driver. This tank so designed was called the M3 or General Grant. The Infantry demanded that the gun barrel not extend beyond the tracks. This shortened the gun and made it in reality a howitzer. It still was an effective weapon as compared with the 37 MM gun which the Infantry retained in the turret.

The writer transferred the design of this tank from Rock Island Arsenal to Aberdeen Proving Ground and placed Colonel Christmas and Colonel Colby in direct charge. Later Colonel Christmas was re-assigned, leaving Colonel Colby in charge of this design. As soon as the design of the tank was completed it was successfully tested and approved by the Tank Board and put into quantity production.

The writer believing that the tank was still deficient in fire power immediately started the design of another tank on his own initiative. A high velocity 75 MM gun was put in the turret entirely replacing the 37 MM gun. In the meantime, experiments had been completed on welded armor and on the use of cast armor. This new tank was designated the M4 and later the General Sherman. A week or so prior to the completion of the design of the M4 tank General Jacob Devers was appointed in charge of the Armored Service. He was immediately contacted was asked to come to Aberdeen Proving Ground and inspected the M4 tank to be completed. General Devers and members of his staff reviewed the M4 tank and approved it making as I remember but one correction which was the position of the escape hatch.

In the meantime, the Detroit Tank Arsenal had been producing the General Grant tank at a very high production rate as had several other manufacturers within the United States. The problem now was how to change from the General Grant to the General Sherman tank without losing production. This was successfully worked out so that while the production of the General Grant tank was continued its production was gradually decreased while the production of the General Sherman tank was increased as rapidly as possible until finally a point was reached where the manufacture of the General Grant tank could be discontinued altogether.

The importance of the 75 MM guns in both the M3 and M4 tanks was quickly proven on the battlefield in Africa. The British had been driven back month by month by General Rommel until the Army had reached the outskirts of Cairo. The British Eighth Army was in a critical position. Appealing to the United States our Government sent every available M3 and M4 tank to the British Eighth Army in Cairo. Luckily these tanks arrived before the battle of El Alamein. The arrival of the American tanks was kept a secret and the Germans did not know that the British had received some 350 of these tanks. When the Germans attacked at El Alamein with their armored divisions they ran headlong into these American tanks with 75 MM guns. As a result the German Armor was destroyed, General Rommel was defeated and the British Eighth Army was saved. The lesson is, that if the M2A1 tank had been manufactured as desired by the Using Services the battle of El Alamein would have been written differently in history.

In 1940 while the M3 tank was being designed the writer felt that the American Army should have a heavy tank mounting a more powerful gun and carrying thicker armor. For that reason the development of a new heavy tank for the Army was undertaken. This tank was to carry very heavy armor in front and due to the weight of this armor and the size of its armament the tank would be of the heavy class weighing in the neighborhood of 60 tons. Since it was desired to maintain the same mobility for the heavy tank as was possible with the medium tank the design required the use of a very large engine.

After study, the Wright Whirlwind engine of 1000 horsepower was selected. This introduced new tank problems because no automotive vehicle at that time had used such a large engine and it was very doubtful whether a geared transmission could be built to carry the torque loads imposed. The writer called upon the Ordnance Automotive Advisory Committee, composed of leading engineers from the automotive industry. Colonel H. Alden was Chairman of this Committee which was sponsored by the Society of Automotive Engineers, As a result they recommended the development of three types of transmissions; electric, hydromatic and torque converter plus a two speed gear assembly. All these transmissions were built. The electric transmission which was designed by the General Electric Company proved an outstanding success.

It enhanced the tank performance greatly and improved its cross-country mobility and maneuverability. The torque converter transmission with two speed drive was also successful although difficulty was encountered in the steering differential which depended upon the use of band brakes. This difficulty was later overcome. The first tank was tested successfully at the plant of the Baldwin Locomotive Works the day after Pearl Harbor, 1941.

The Ordnance Department was given an order for 3000 of these tanks and both General Motors and Baldwin Locomotive Works undertook tooling and production. This tank project immediately ran into difficulty. Both the Army and the Engineer Corps opposed its use. The Engineer Corps had no bridge capable of supporting a tank of this weight. The Armored Service likewise was opposed to the use of a heavy tank feeling that the medium tank was superior for all around use. Unfortunately, word about the heavy tank leaked out through the War Production Board and information concerning it was published in the newspapers. This was well ahead of the construction by the Germans of the tiger tank and it is quite possible that its development was brought about by the knowledge that the American Army possessed a 60 ton tank. The writer equipped the heavy tank, which was known as the M6, with a very high velocity 3" gun. In fact, this gun was our high velocity anti-aircraft gun for which ammunition was available. At the time, it was believed that this gun was of heavier caliber than any used by any country.

The writer feeling that a still heavier gun was necessary to face battlefield developments designed a new 90 MM gun. The gun made use of high strength alloys so that its outside diameter was no greater than that of the 3" gun it replaced. The new 90 MM gun was successfully tested in the turret of the M6 tank.

In the meantime, the Army directed that the production of the M6 tank be cancelled. The Army stated that due to lack of shipping space, it was much better to ship two medium tanks M3 or M4 than one 60 ton heavy tank. In the meantime, production was stopped after the completion of some 44 of these tanks. The Army was thus deprived of the use of a heavy tank until the latter months of World War II. This nearly lead to a scandal as in the meantime the Germans had produced their famous heavy tiger tank, the armor of which was so thick that the 75 MM gun in the M4. tank could not penetrate it.

Our troops in the European theatre gradually came to the realization that they were being out-gunned by the German tiger tank and that the 75 MM gun in the M4. tank would not adequately defeat the armor of the German tiger tank. As the Using Services had turned down the heavy tank, I had studies made to find out what could be done to improve the fire power of the medium tank, M4. As a result of these studies the writer designed a new gun of greater fire power than the 75 MM. This was the largest gun which could be placed in the turret of this tank without redesign of the latter. It worked out to be a high velocity 3" gun. Since the chamber of this gun had to be long and slender, due to dimensional limitations of the turret, the chamber was different from that of any other 3" gun in service. Difficulties would occur in the field if another 3" gun were introduced with a different cartridge case. To avoid this I called this 3" gun a 76 MM gun. It increased the fire power of the M4 tank but, of course, did not entirely bridge the gap between the 75 MM and the 90 MM gun.

In order to further increase the penetrating ability of the 76 mm gun, high priority was given to a project for developing a special shell for the 76 mm gun, which would further increase its penetration. This round was based on the use of a tungsten carbide core, using an aluminum outer wall to surround the tungsten carbide and providing a steel base. This round gave increased penetration and was known as the 76 mm HVAT round. As these rounds were manufactured they were transported by air to Europe and then to the Armored Divisions in the field. Thus each M4 tank in Europe soon had a moderate supply of this special ammunition.

While the Services deprived themselves of the early use of the heavy 60 ton tank and 90 mm gun a great deal of good for the Services came out of this heavy tank project. I took the turret from the heavy M6 tank, lightened its armor and further lightened the armor of the M4. tank. A new type of vehicle for the Army was thus created. These vehicles were known as tank destroyers. They were lightly armored M4 tanks carrying 90 MM guns in open turrets. Thousands of these tank destroyers were manufactured and sent to several theatres. Our troops were thus provided with a powerful tank destroyer capable of handling any German tiger tank encountered in the battlefield.

As soon as it became evident that it was impossible for the Ordnance Department to build the heavy tank M6 for the service the writer undertook the design of a new tank which would carry the high velocity 90 MM gun designed for the M6 tank. It would be of a low silhouette so that the weight would be kept to about 40 tons with adequate armor. This project was immediately frowned upon by the Using Services and especially by General Leslie McNair who was head of the Ground Forces. The writer therefore went to General Brehon Somervell and explained to him the advantage of the new design and secured permission to complete the design and manufacture of a pilot tank. The pilot was completed _____?

The writer arranged for an immediate tank test to be held at Aberdeen Proving Ground. At this test armor plates of 3" and 4" in thickness were set up at an angle of 30 degrees to the vertical. The 4" plate corresponded to the thickness and angularity of the front of the tiger tank. Officers of the Army General Staff, Ground Forces, were invited to this test. The principal guests included Mr. Stim[p]son, Secretary of War; General Marshall, Chief of and General Moore and other officers of the Ground Forces; General Devers and high-ranking civilians and officers of the General Staff. Trenches were dug about 100' from the plates and the guests were invited to put on combat clothes including steel helmets and enter these trenches. A General Sherman tank at a range of 2000 yards first attacked the 3" plate which it defeated. General Sherman was then fired against the 4" plate representing the front of the German tank. The ammunition bounced off this plate. The newly designed heavy tank with the 90 MM gun, later known as the General Pershing, next attacked these plates. It successfully defeated the 3" plate and likewise defeated the plate, all projectiles bursting behind the plate as required for tank destruction.

Taking a plane back to Washington from this test General McNair told the writer he would never approve a heavy tank for the United States Army. This matter was taken up with Mr. Stimson and as the result of the day's test Mr. Stimson and General Marshall approved the building of the new heavy tank. A large production program was given to General Motors Corporation.

The writer obtained permission to take the first 20 of the new tanks overseas to have them battle-tested. The writer visited General Eisenhower's headquarters at Versailles and obtained permission to introduce the 20 tanks upon arrival directly on the battlefield. General Eisenhower assigned these new tanks to the First Army and the 3rd Armored Division, commanded by the late Major General Maurice Rose who was shortly thereafter killed in battle. The tanks were demonstrated to the officers and the men of the First Army after a two weeks training period. The tanks then went into action against the Germans. Wherever German tiger tanks could be found they were knocked out by the new American tank which was declared by General Rose to be exactly what the Army wanted.

The writer before returning to the United States visited all Army commanders in the field and acquainted them with the capabilities of the new tank. I found that all American Army commanders were alarmed over the situation resulting from the superiority of the German tiger tank. As a matter of fact, tank personnel were reaching a point where they were becoming afraid to fight in the M4 tank due to its lack of fire power. They received the new heavy tank with open arms and wondered why such a tank had not been available to them earlier. They did not realize that this was due entirely to the action of General McNair as Commander of the Ground Forces. The arrival of the General Pershing tank on the battlefield was most opportune and solved what would otherwise have been a very serious situation for our Army. In the meantime, tank production had been growing in the United States so that before the Armistice some 3000 (?) of these tanks had been completed.

It is gratifying that our troops in Korea have had a tank heavier than the M4. In the early days of Korea our troops were equipped only with American light tanks and during that period suffered heavily due to the fact that they were out-gunned by the Russian heavy tanks (T34.). However, as soon as our heavy tanks arrived at the Korean battlefield the situation was reversed. General Collins has reported that American tanks have won every engagement. The General Patton tank is the General Pershing tank with some modifications.

In 1945 the writer designed a new heavy tank for the Army mounting a higher velocity 90 MM gun, a still heavier tank mounting a 120 MM gun and a new 155 MM gun. All of these pilot tanks have now been completed and are being used as the basis for future new tank development for the Army.

It is hoped that these brief notes on tank development may help the writers of Ordnance history to better understand the recorded history of tank development during this period.

June 12, 1951

G. M. Barnes
Major General U.S.A. (Ret'd)

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 Post subject: Re: M26 Pershing:
PostPosted: Fri Jan 26, 2018 7:15 pm 
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In these two letters, I'm reading quite a bit of axe-grinding and self-back patting.

Plus the development of things because they're neat and new, and how dare the people actually using them tell me what they need.

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 Post subject: Re: M26 Pershing:
PostPosted: Fri Jan 26, 2018 7:19 pm 
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First letter is official, second letter is written as a retired guy.

I could always check out Stimson's diary (on microfilm at U of Maryland) for the dates around the test of the T2x series at Aberdeen to see Stimson's take on it. There's also George Marshall's papers.

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 Post subject: Re: M26 Pershing:
PostPosted: Fri Jan 26, 2018 7:24 pm 
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From:
George C. Marshall WW2 Correspondence on Microfilm
“Directives – Miscellaneous, 1941--1944.” folder

[1944 Jan 21]

WAR DEPARTMENT
OFFICE CHIEF OF STAFF
WASHINGTON

General Hardy – Consider this as confidential between us. What is your view?

GCM


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THE JOINT CHIEFS OF STAFF
WASHINGTON
21 January 1944

MEMORANDUM FOR THE CHIEF OF STAFF:

Subject: Production of 250 Heavy Tanks Armed with 90 mm Guns.

1. The Joint Production Survey Committee has under independent consideration the question of whether production of 250 heavy tanks (T-26) armed with 90 mm guns (four battalions) recently ordered by the War Department prior to service test, should be continued.

2. Recent action of the War Department was based on recommendation of ETO and contrary to recommendations of NATO, AGF and ASF.

3. There are some facts which you personally should know now as a member of the Joint Chiefs of Staff, which I believe should not be presented by the committee to the Joint Chiefs of Staff as a body, inasmuch as OWM may ask for copies of some of our reports.

4. If the history of the development and procurement of self-propelled gun carriages is ever investigated by the Truman Committee it may result in considerable criticism of the War Department on the ground of uneconomical procedure and lack of foresight. As I have been a party to this procedure in almost all instances, due to the urgent military necessity of getting self-propelled firepower on the battlefield as quickly as possible, I should like to review it. I have concurred because the Ordnance Department has always maintained that production will be hastened by authorizing procurement of relatively large quantities of newly designed equipment prior to test by the using arms or on the battlefield. This has proven to be unsatisfactory in the cases shown on the attached list. (Note: Tanks are regarded as armored self-propelled gun carriages).

5. Contract terminations resulted in considerable loss to the United States without getting any satisfactory carriages on the battlefield.

6. It is now proposed to take another chance with the procurement of 250 heavy tanks armed with 90 mm guns (T-26), at an estimated cost of $26,850,000, although this tank has some important untried innovations and has not been tested by the using arms. The urgent military necessity for this tank does not exist in the degree it did in the other cases as its only advantage is that it has heavier armor.

Assuming the unlikely probability that no deficiencies are found in test it will not be available in Europe prior to October or November 1944.

7. No individual recommendation is made as the Committee has postponed their report until General Eisenhower has made recommendations from ETO instead of General Devers.

P.C. Moore,
Major General, USA

---

Item
Number Authorized
Remarks

1. 3/4 ton truck with 37 mm gun
5,280
Unsatisfactory on battlefield; trucks dismantled and used for other purposes.

2. 60 ton tank, Electric Drive
2,086 reduced to 230
Unsatisfactory in field test; contract terminated after 40 were completed.

3. Light tanks with 75 mm tank gun (urged by General Devers)
3,000
Unsatisfactory in field test; contract terminated after 7 were produced.

4. Cletrac mount for 3" gun
1,580
Unsatisfactory in field test; contract terminated with no production

5. Armored car, wheel tracked (T-13)
2,000
Ordered by higher authority; unsatisfactory in field test; contract terminated with no production.

6. New carriage for 76 mm gun (T-70)
1,000 increased to 3,200
Not yet ready for battlefield after many months of correcting defects.

7. Light tank with new 75 mm gun (T-24)
1,000 increased to 1,800
Still correcting defects after much loss of time.

-------------------

WAR DEPARTMENT
WAR DEPARTMENT GENERAL STAFF
OPERATIONS DIVISION
WASHINGTON
22 January 1944

GENERAL MARSHALL:

My view is that we should go ahead with this project unless Eisenhower reports unfavorably. In that case the project should be dropped. Devers was anxious to have these tanks. They were set up as an operational requirement. The Germans are making and using heavy tanks. It is another case of having to go ahead without waiting for long field tests. We may make a mistake and be blamed for. it – as General Moore indicates. That is far better than not having a weapon that is needed.

/S/
T.T.H

GO AHEAD. GCM

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OCS
FMcC
3542

January 24, 1944

MEMORANDUM FOR GENERAL MOORE:

In connection with the attached memorandum, General Marshall desires that this project go ahead if General Eisenhower reports favorably. I think he feels that he would rather be in the position of having us take a chance on making an error than to take a chance on not having a weapon that is badly needed.

sgd FMcC

FRANK McCARTHY
Colonel, General Staff Corps
Secretary, General Staff

jes

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 Post subject: Re: M26 Pershing:
PostPosted: Fri Jan 26, 2018 7:32 pm 
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In fairness to Barnes, based on Nicholas Moran's book can openers, he is the primary reason the 90mm M36 made it to combat in time to be useful. He was the only one to push its development and understood you had to design these things before they were needed.


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 Post subject: Re: M26 Pershing:
PostPosted: Fri Jan 26, 2018 7:36 pm 
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Nathan45 wrote:
In fairness to Barnes, based on Nicholas Moran's book can openers, he is the primary reason the 90mm M36 made it to combat in time to be useful. He was the only one to push its development and understood you had to design these things before they were needed.


They still had to sell the 90mm M36 as "anti-concrete fortification buster" to get it past McNair. Same thing for the T28 Heavy Tank (nee T95 GMC)

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 Post subject: Re: M26 Pershing:
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Thanks for finding these letters btw MKShepard


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NATIONAL ARCHIVES II
RG 156
NM-26 ENTRY 646A
BOX A773
DECLASSIFIED VIA NND 735001

------

WFBeasley/jk
22 February 1945

Col. S. B. Ritchie
Acting Chief of Research & Development Service

Chief, Tank & Motor Transp Div, Res & Dev Serv

Redesignation of Heavy Tank, T28 as Gun Motor Carriage, T95

1. I am returning herewith General Campbell's memorandum regarding the change in name of Heavy Tank, T28, with suitable indorsement for returning it to General Campbell to advise him of the action taken. The draft which was discussed with General Campbell and which was used in preparing the stencil is made an inclosure to the return memorandum indorsement.

2. As previously discussed with you I believe we should have in the Military Dictionary, TM 20-205, suitable definitions for tanks and gun motor carriages and suggest something along the following lines:

A tank is defined as a self propelled vehicle of the full track type, mounting a cannon and one or more machine guns, armored to provide complete protection for the crew and equipment against weapons of tank gun caliber at battle ranges.

A gun motor carriage is defined as a self-propelled vehicle of full track, half track or wheeled type, mounting a cannon, including vehicles which mount a combination of automatic weapons for A.A. use. Additional machine guns may or may not be provided. In the larger types external outriggers are used for stability. The armor normally employed does not provide complete coverage and is generally designed to give protection against small arms and fragments. These vehicles may or may not include open top turrets.


W. F. BEASLEY
Chief, Tank & Motor Transport Division

1 Incl.
Memo 7 Feb 45 fm Gen Campbell w/1st Ind reply & incl. T487

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WFBeasley/jk
6423

1st Ind (Memo)

Research & Development Service, 22 February 1945

To: Major General L.H. Campbell, Jr, Chief of Ordnance

1. Your instructions to change the name of Heavy Tank, T28 to indicate it as a Gun Motor Carriage, are being carried out.

2. The subcommittee report, draft T-487, subjects "Carriage, Motor, 105mm Gun, T95 – Redesignation from Tank, Heavy, T28 and Recording of Development and Characteristics Recommended" has been prepared in stencil font and delivered to the Ordnance Committee for circulation for signatures. The rough draft of this item which was discussed with you, is attached for your information in the event you desire to check the language used.

S. B. RITCHIE
Colonel, Ordnance Department
Acting Chief of Research and Development Service

1 Incl.
OCM Draft T-487

Subject: Vehicles under construction at Pacific Car & Foundry Co.

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