This casing starts on the Boat Deck and goes down to the Tank Top level. This provides the Reciprocating Engine Room with ventilation. It was on the aft end of the Boat Deck and was inside the Engineer's promenade.
This was basically a vent that opened up on the Boat Deck. It went all the way down to the engine room
This deckhouse consisted on two tank rooms and a smoke room for the engineers. The top of the deckhouse formed a skylight which could be opened or closed to inclement weather at sea.
The tank rooms acted as portable water storage and it was put on the Boat Deck to maintain pressure on the water systems.