aft peak

Slight indentation to the aft peak tank.

It may be possible to drain the aft peak via the main engine room by means of an easily accessible, automatically closable fitting.

Aft peak tank air pipe holed.

AFT PEAK (Double bottom tank is preferable)

The aft peak tank and bilge were filled with concrete (presumably for stability) and this extra weight could not be shifted to another area of the vessel from where the vessel was taking on water.

In addition, she had six centrifugal pumps for moving 100 tons of water in five minutes between the fore and aft peak tanks to adjust her trim and release the icebreaker from compressive ice.