A few snipets of info and eye candy from what I am working on...(In short, casual form) T40/M9 Tank Destroyer/Self-Propelled Gun (1941-42):><O:p></O:p> The T24, an Early Attempt<O:p></O:p> The U.S. Army expressed a need for a vehicle capable of stopping and destroying enemy tanks. The new vehicle, dubbed the "Tank Destroyer", would have the same armor protection and general mobility of a standard tank, but would be heavily armed with enough punch to decimate enemy armored formations. Up until 1941, the only vehicles available were modified trucks and half-tracks, which lacked greatly in the mobility, firepower and armor departments.<O:p></O:p> During the summer of 1941, Baldwin Locomotive Works began development of a vehicle to fill the need for a true tank destroyer. They began with the chassis of an M3 Lee medium tank, added a modified superstructure with an open, hexagonally-shaped top, and armed the vehicle with the M1918 3-inch gun. <O:p></O:p> The Ordnance Department accepted the vehicle for testing at Aberdeen at the end of the summer, designating it the T24 gun motor carriage. However, the extremely high silhouette of the vehicle was thought to detract from its ability to stalk its prey, and gun was found to be lacking in range and accuracy. The T24 was returned to Baldwin for adjustments. <O:p></O:p> The M9, America's First Tank Destroyer<O:p></O:p> What Baldwin later returned to the Army was basically a somewhat improved T24. Indeed, it was the T24 pilot vehicle, simply modified with a slightly lower superstructure and some minor improvements to the weapon and related systems. The vehicle was accepted for testing at Aberdeen once more, this time under the designation of T40. The Ordnance Department was still far from impressed, but a surprise attack on Pearl Harbor by the Japanese, and the subsequent entry of the United States into the war prompted the vehicle's adoption as the Army's first standardized full-track tank destroyer. It was christened the 3-inch Gun Motor Carriage, M9, and a production contract was awarded for 1,000 examples.<O:p></O:p> View attachment 23777 However, as the vehicle was not truly up the Army's standards, the contract was cancelled only four months later, in April 1942. The M9 had simply proven too slow, and furthermore, its 3-inch main armament was not available in sufficient quantity. As the vehicle had a basis on the M3 Lee medium tank, the silhouette was also above the minimum for a vehicle intended as an ambush predator. The Tank Destroyer Board finally abandoned the project at the end of the summer of 1942, officially due to the insufficient mobility and speed of the vehicle. Three photos: The first two of the T24, the last of the M9 (T40), after being modified with the 105mm howitzer to become the T32 pilot vehicle. Hope you all enjoyed, its still just research notes for the most part, and I left out most of the smaller details. If anyone can add to this thread, it would of course be great. Any more pics? Any more info? Love to hear it. Next installment tomorrow morning - lunchtime for those of you in the UK.
And the T24/T40 design would contribute to the T32, which was the pilot vehicle for the famous M7 Priest 105mm HMC. Anyway, heres the next one, another beauty that never made it... M5 "Cletrac" 3-Inch Self-Propelled Gun (1942):><O:p></O:p> Early in 1941, the U.S. Tank Destroyer Board was experimenting with different designs for a self-propelled anti-tank gun. Brigadier General Andrew Bruce, commander of the Tank Destroyer Force, was a strong proponent of self-propelled weapons. However, when the Ordnance Department sent out requirements for a self-propelled, full-track carriage for the M3 3-inch anti-aircraft gun, which was much improved and plentiful compared to the older M1918 weapon, the results were less than impressive. General Bruce did everything in his power to assure that this horrid machine would not reach the hands of his troops or anyone elses. <O:p></O:p> <O:p> </O:p> <O:p></O:p> The new machine, designed and built in 1941 at the Cleveland Tractor Company, where it was nicknamed the "Cletrac", was a failure. It was slow, offered no armor protection for the gun crew, was certainly not the most stable in the world, it had very poor reliability, and, perhaps most importantly, loved to catch fire. The chassis was based on Cleveland's successful M2 high-speed tractor, also called the Cletrac (as were all of their products), and used at Army Air Corps bases for towing aircraft. View attachment 23794 The gun was mounted at the rear of the 12-ton vehicle, with a large, angled armored gun shield surrounding the barrel, which stretched forward to the front of the vehicle. The M3 weapon was an improvement on the M1918 3-inch gun, and was used mostly for anti-aircraft purposes. For use against ground targets, it could deliver a shell more than nine miles, firing up to twenty rounds every minute for short bursts. The crew had 33 rounds at their disposal, stored beneath the gun mount at the rear. <O:p></O:p> <O:p> </O:p> <O:p></O:p> The M5 Cletrac had a crew of four. The 22,570-pound machine was 15 feet long, 8 feet 3 inches wide and 5 feet tall. The Cletrac was not long compared to its width, and like the M2 HST, it had hard rubber-padded steel tracks. A 404ci Hercules inline six-cylinder gasoline-powered truck engine provided 150 hp to the Clark five-speed manual transmission; steering was through a controlled differential unit. The Cletrac could attain a 24mph top on-road speed. The crewmen operated at the rear, with no armor protection, and were therefore exposed to the enemy. <O:p></O:p> <O:p> </O:p> <O:p></O:p> The Ordnance Department, in their usual infinite wisdom, loved the design and convinced the War Department to adopt the Cletrac. They did so; the Cletrac was designated the M5, and 1,580 vehicles were ordered in January 1942. As Cleveland Tractor was gearing up for production, the Cletrac was further tested at Aberdeen Proving Grounds in July 1942, where it was finally proved that it would not be acceptable as a tank destroyer or a self-propelled gun. In fact, the machine itself had been largely destroyed in the vigorous Aberdeen testing. The M5 was therefore declared obsolete before ever being issued to an Army unit. It therefore never fired a shot in anger. Again, the short version here. Mostly just research so far. Alot of details left out, things one can gather from the photographs (ie, suspension, superstructure, etc..) But you get the gist of it. I find the machine beautiful, and I officially WANT ONE. The town green is, after all, very near my house. Im sure no-one would mind...
Finally got around to reading this properly. Good stuff mate. Despite the high silhouette the T24 somehow 'looks' right. And I have a bit of a thing for Cletracs , something pleasingly Heath-Robinson about them. Nice shots. (BTW, the weird smilies that appear are formatting marks from whatever program you store your notes on being picked up as smiley 'shortcuts' by the forum - If you click 'Go Advanced' below the posting window, and then tick the box marked 'disable Smilies in text', it should make them disappear.) ~A
Thanks for the tip, VP. I did notice that, and I went back in to take the smileys out. All in all, this forum is very self-explanatory and user friendly. The pictures shown are original Army testing photographs. Interesting is the fact that the M5 was tested throughout the war for different systems. The first pic shows an experimental muzzle brake. Just an example of how a failed machine can be put to use somehow... By the way, if anyone has any other pics of these two machines, post them - I would love to see them.
