During World War II, the Wehrmacht used three remotely operated demolition tanks: the light Goliath (Sd.Kfz. 302/303a/303b), the medium Springer (Sd.Kfz. 304) and the heavy Borgward IV (Sd.Kfz. 301). The Borgward IV was the largest of the vehicles and the only one capable of releasing its explosives before detonating; the two smaller vehicles were destroyed when their explosive charges detonated.
Borgward originally developed the B IV as an ammunition carrier, but it was found unsuitable. It was also tested as a remote minesweeper, but was too vulnerable to mines and too expensive. During the Battle of France, German engineers from the 1st Panzer Division converted 10 Panzer I Ausf Bs into demolition and mine clearing vehicles, using them to place timed charges on bunkers or minefields without losing the vehicle. The Waffenamt found the idea valuable, and ordered the B IV’s development as a remote-controlled demolition vehicle. The first vehicles were delivered in 1942.
The Borgward IV was much heavier than the Goliath, and carried a much larger payload. The Borgward IV was operated by radio and the Goliath was wire guided, due to the Borgward IV’s much longer range a driver in the vehicle would bring it independently to its destination before dismounting and conducting it to its target by radio. When it reached the target, the vehicle would drop the charge and leave the danger area. This put Borgward IV operators in great danger. While the Borgward IV was armored, its armor was inadequate by 1942-43, and its larger size than the Goliath made it much easier to spot.
The more interesting for me is the last variant : near the end of World War II, approximately 56 Ausf. Bs and Cs were converted to the Panzerjäger Wanze, armed with six RPzB 54/1 anti-tank rockets. In the last days of the war, these vehicles fought some minor skirmishes against Soviet armor and saw some action at the Battle of Berlin.
The UE, which was a British munition carrier and artillery tractor, was also modified in a similar way in the end of the war. Several such machines participated in the battle of Berlin.
(One machine can be added as a premium and other as a researchable free analog)
