Hi Simon.
It seams to be very good. Seeing the hatch I just came to remember an intricate system of rods connecting the steelhatches to the wooden deck hatches so they could be opened in one operation. Anyhow this system was used for the galley hatch and fwd torpedo loadinghatch which were crewaccesses while alongside. Pictures below, on one of the photos you can see a guy operating one of the external valves from the deck by the T bar.
Tore