In 1936 the Wehrmacht put out a requirement for a heavy recovery vehicle.
The SdKfz 9 was the largest halftrack used during World War II. It was designed as a heavy recovery vehicle for tanks. Eventually an artillery tractor version was made. The tractor version was used to tow the heavy artillery and some heavy engineering equipment which included bridging equipment that was towed.
The recovery version of the SdKfz 9 had stabilizing legs and a crane. For really large tanks such as the Tiger I two SdKfz 9s had to be used for towing.
Some of the heavy artillery towed:
- 128 mm FlaK 40 (Luftwaffe anti-aircraft gun)
- Krupp 210 K 38
- 240 mm K 3 (had to be towed in 5 loads)