[MarkSheppard]

Firepower by Hunnicutt says:

14 SEP 1944: OCM 25117 recommends development of a new heavy tank series with four pilots.

They are

2 x T29 (105mm T5E1 Gun)
2 x T30 (155mm T7 Gun)

7 DEC 1944: US Army Ground Forces (AGF) recommends that Ordnance develop a modified Pershing with heavier armor due to success of the M4A3E2 "Jumbo". The "interim" solution was to produce the T26E5 "Jumbo" Pershing with thicker armor and a modified final drive with a lower gear ratio and the ultimate solution being a new design (aka T32).

8 FEB 1945: OCM 26606 recommends construction of four pilots of a heavy assault tank using as many M26 pershing components as possible to be the "objective" assault tank. The tank is designated T32.

1 MAR 1945: OCM 26825 recommends procurement of 1,200 T29 heavy tanks.

MAR 1945: T32 pilot production approved.

10 APR 1945: T32 mockup almost completed; and 80% of drawings for the pilots had been released.

12 APR 1945: 1,152 T29 were approved for procurement.

Late APR 1945: Four additional T29 series pilots were authorized, with one of them getting the 120mm T53 Gun and being designated T34.

17 MAY 1945: OCM 27662 recommends that two T30 Pilot tanks be equipped with the 120mm T53 Gun, derived from the 120mm AA Gun, and so designated as T34 Heavy Tank.

31 May 1945: T34 pilot production approved.

9 AUG 1945: OCM 28680 recommends that T32 Pilots #3 and #4 be completed to a modified design (T32E1) with rolled front hull armor plate, no bow machine gun and the drivers' hatches were changed to a pivoting design, allowing them to be opened without intefering with a traversing turret.

AUGUST 1945: World War II Semi-Formally Ends with Surrender of Japan. Program significantly cut back -- it may have been actually cut back after V-E Day. More research at National Archives is needed.

23 AUG 1945: OCM 28848 approves actually building ten T29 pilots for postwar evaluation.

DEC 1945: The first T29 Pilot #1 is redesignated T29E1 and diverted to General Motors for the development of a modified Allison V-1710 engine as a tank engine.

LATE 1945: T30 power train changed from Wartime Ford GAC to the air cooled Continental AV-1790-3 engine.

15 JAN 1946: T32 Pilot #1 completed and shipped to Aberdeen.

19 APR 1946: T32 Pilot #2 completed and shipped to Aberdeen.

14 May 1946: T32 Pilot #3 (T32E1) completed and shipped to Aberdeen.

19 JUN 1946: T32 Pilot #4 (T32E1) completed and shipped to Aberdeen.

10 JUL 1947: OCM 31654 reduces T29 pilots to just eight.

24 JUL 1947: OCM 31668 authorizes diversion of one T30 pilot as the T30E1, to test out a semi-automatic power assisted loader. (You still needed to place the shell on a ramming tray).

OCT 1947: First T29 arrives at Aberdeen (T29E1)

1 APRIL 1948: OCM 32107 designates the T29 Pilot #2 with the new T5 Turret as the T29E2. It had a MIT-designed computing gun sight that was tied into a hydraulic traverse/elevation system.

APRIL 1948: Second T29 Arrives at Aberdeen, along with first T30.

MAY 1948: Third T29 Arrives at Aberdeen. This tank was equipped with the T31E1 rangefinder and was designated T29E3. The T31E1 was a 9 foot stereoscopic rangefinder.