About this detail of the Tiger
The turrets installed on the first 50 or so Tiger B were inherited from the cancelled VK4502 [2, see chapter 5] . Their main armour walls stood about 110mm clear of the hull roof. On the VK4502 this gap would have been protected by armour on the hull top [2, see 4.1] , but on the Tiger B it formed a shot trap.
In March 1943, Henschel sketched a protective armour ring ( "Turmfugenschutzring" ) to surround the base of the turret [2, see 5.1] . This particular design was not used. Later, a stronger ring was designed; it was added as a change to the hull roof design drawing [1] on 14 January 1944. These rings were built on new Tigers from April 1944.
The ring was 100mm tall and had a sloped outer face. The bottom edges were bevelled for weld. The ring was not needed (and could not fit) on tanks with the production turret.
It was held to the roof by steel pegs, welded at the top. I cannot confirm that they were also welded at the bottom, but this seems logical. The ring then could not be removed from the hull roof. The part number of the peg was 021E49501-278.
The ring formed a complete, uniform circle around the turret. It was made of 12 identical segments, each with 3 pegs. They were not welded to the adjacent segments; there was about 3mm clear space between them [1] . The part number of the segment was 021E49501-277.
Two of the peg positions were close to a weld line that ran across the hull roof. According to the German design drawing, these positions should not be used if slight variations in manufacture put them too close ( "Wenn Loch auf Schweißnaht kommt, dann nicht gebohrt" ). This means that some Tigers had open holes in these positions, as suggested in the diagram above.