Limiting shells

There are four shells in total, consisting of north and south top/bottom pairs.

Gaps

The shells have toroidal breaks at φ=0°/section P-A/west and φ=180°/section H-I/east and poloidal breaks at θ=0°/HFS midplane and θ=180°/LFS midplane.

Penetrations

The shells have round vertical penetrations.