The driver and radio operator of the Tiger 1 were both provided with hatches at their positions in the hull. These hatches were designed by Henschel and had no similarity to the hatches in the Krupp-designed turret. Their basic design was already finalised in the earliest known drawing of them [1] .
This is an extract from that drawing. It shows two circular hatches, of diameter 560mm, both located 900mm from the tank's center line. That is significantly farther outboard than the seats of the crew members underneath them. Coincidentally, the hull is 1800mm wide internally, so one half of each hatch opening is above a sponson. These position were chosen so that the hatches would not foul the turret.
Externally featureless hatches, as drawn here, were built into the first Tiger prototype "V1" [4, see p.41] . All subsequent production and prototype Tigers had a periscope holder built into each hatch.
These are the basic dimensions of the hatch and the new armour cover that was added to protect the periscope [2] [3] . The periscope's position was inconvenient but was forced by the locking mechanisms on the bottom of the hatch. In fact, the need to fit this hatch influenced the design of the periscope housing itself.
This model shows how the top of the periscope fit under the steel cover with only a millimeter to spare.
Although the hatch appeared to be 30mm thick, its underside was cut down to make it 25mm, the same thickness as the hull roof. This sketch also indicates how the periscope holder and periscope fit into the hatch.
[1] Drawing J2877
[2] Survey of Tiger 250122, at Bovington museum, by David Byrden
[3] Der Panzerkampfwagen VI und seine abarten, Walter J. Spielberger, Motor Buch Verlag
[4] DW to Tiger 1