http://www.youtube.com/watch?v=aaIkpJe0Sls/to this video it shows a Rheinmetall 60cm 040 Karl selbstfahrenden morser of the battlefield forgotten hope secret weapons modification that can lower and lift the vehicle to protect the running gear from recoil
the lowering and the lifting of the vehicle should had been and to the Mendeleyev Tank of the battlefield 1918 modification
to the landships.com site it writes that it was planned for full or partial lowering of the hull to protect the running gear from enemy fire