Submarines are able to travel the world’s oceans undetected for months at a time. Here you can see the aft end of HMS Ocelot which is the rear of the submarine, and some of the special features that allow submarines to be controlled in the water
When the huge ballast tanks are filled with water, the submarine increases in weight and this creates negative buoyancy, so the force of up-thrust holding it at the surface is reduced. The submarine sinks to the seabed.
There are two hydroplanes at the front of the submarine (currently raised) which control the depth of the submarine. These would drop down like small fins or wings to help the submarine change depth.
When preparing to dive quickly, a Klaxon would be sounded in the Control Room. This was part of the rapid dive process which would submerge the submarine in approximately 1 minute.
You will notice that the two large propellers that would have turned to move the submarine forwards are missing. It is believed that HMS Ocelot’s propellers are stored in a secret location.
The propeller shaft is connected to motors which are powered by the batteries within the submarine. The 2 large diesel engines onboard, each producing 3680bhp, are connected to two 2,200kW electric motors. These motors generate electricity which is fed into the batteries.
HMS Ocelot could travel at a full speed of 18knots (21mph) while submerged, and 14 knots (16mph) when surfaced, but at these speeds when submerged, the batteries would only last 35 minutes before having to be recharged by the engines.
Cross the caisson and turn left to find stop 4