About this detail of the Tiger
The main gun of the Tiger 1 was elevated by a hand-driven gear wheel. To save space, the gear wheel was put on the right-hand side of the gun, under the coaxial MG. This gear wheel and its gearbox were mounted on a solid metal structure known as the 'box' [4] .
This photo shows the box in the Bovington vehicle, with its original blue/grey paint. It is made of 16mm steel plate. At the extreme right, a portion of the box (under the gun balance cylinder) is painted black; I don't know the reason for this. On top of the Box is the outline of a wrench that was lying in the dust for years. The loader's seat was normally bolted to the box, but in this photo it has been removed.
This diagram shows the box from above. It is attached to the top of the turret ring by 6 bolts. Some of these bolts are countersunk into the box, in 40mm holes. In this drawing the number of bolts in the turret ring is doubled; in other words, this is not one of the first 200 turrets.
This shows the dimensions of the box. The red lines represent the axes of the turret. The box was screwed into a metal plate welded to the turret ring. In this example, the ends of the plate protrude past the edges of the box: the 'APG' Tiger (hull #31) is built like this [2] .
Looking from directly behind the box, we can see the two holes for attaching the loader's seat. The right-hand end of the box, under the balance spring, is made lower than the rest.
This diagram shows the box as seen from the side. The upper side of the box had a large hole where the gear wheel casing was attached. The lower end of the box had bolt holes for attaching the bridge.
This photo shows the bottom of the box as seen from outside the turret. The large hole is covered by the gear wheel casing.
The information above applies to turrets with drum cupolas. When the Tiger's turret was redesigned with a ring cupola, the box was also redesigned [1] .
[1] DW to Tiger 1
[2] Survey of Tiger 250031, by Stephan Vogt
[3] Survey of Tiger 250122, at Bovington museum, by David Byrden
[5] Factory drawing 2AKF31861U1B11: Turmgehause (overall turret armour)