Friday, 25 July 2014
Mobility Trials Part 3
This one is less of a complete report, and more a mishmash of off-roading and various associated activities I have accumulated.
CAMD RF 81-12086-97
"Figure 13. The moment before fording.
Figure 14. The moment before fording. The tractor begins tilting forward at a point before the third road wheel."
These two photographs are from trials of the Ya-13F light artillery tractor. While it is not particularly important to know at what point a tank begins tilting forward as it enters a sharp incline, a vehicle that is meant to be towing something behind it is a different matter entirely.
Towing a gun? Easy. What about towing a tank?
Towing was done twice, after the tank travelled 432 km and 767 km. The total distance of towing was 20 km. In the first case, an IS-122 and a KV-85 were towing an IS-122. In the second, an IS-122 towed an IS-122.
In both cases, the tank was towed over a dirt road trampled by tanks, and partially on an asphalt highway covered in packed snow, at 1st and 2nd gear, with external temperature between -5 and -9 degrees.
During towing, the engine's temperature was normal. The water temperature stabilized at 65 degrees. The oil temperature stabilized at 72 degrees.
Photo #27: IS-122 and KV-85 tanks tow an IS-122 tank on a road trampled by tanks."
CAMD RF 38-11369-351
A SU-100 undergoing mobility trials, showing the perils of a gun that is too long on bumpy terrain. The end of the gun is covered to prevent mud from getting in, but the sack cannot hide the distinctive shape of the muzzle brake. This is no ordinary SU-100, but a SU-122P, a SU-100 with a D-25 gun.
The sack was there for a very good reason.
"Fig. 2. The 122 mm SPG D25-SU-122P hits the ground with its barrel when descending from a bump with the gun elevated at 12 degrees."