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HM Submarine Ocelot Digital tour

Stop 1


Welcome to the HMS OCELOT digital tour.  For the best experience, please remain at the stops when accessing the information provided and watch your step as you proceed around the dock.

HMS OCELOT was the last warship built for the Royal Navy here at Chatham.

HMS OCELOT was the 54th submarine built at Chatham.  Construction began on the 17th November 1960, and she was launched into the River Medway on 5th May 1962.

An O-Class submarine is a diesel-electric submarine. She has two large diesel engines on board, but these engines do not power the submarine. Instead, they are connected to two large electric motors which create electricity.

HMS OCELOT has travelled around the world. In 1964 she joined the Third Submarine Squadron based in Scotland. During her first three years she travelled over 90,000miles operating around the UK, the Mediterranean Sea and the Baltic.

These OCLEOT 50 information panels give more details about HMS OCELOT’s construction here at the Dockyard.

Stop 2

Acquisition and Preservation

For the best experience, please remain at the stops when accessing the information provided and watch your step as you proceed around the dock.

On de-commissioning in September 1991, HMS OCELOT was prepared for disposal by the Royal Navy, her life as a Royal Navy submarine was over. Important equipment and materials were removed to refit other submarines that were still in service.

At this time, the Chatham Historic Dockyard Trust was able to acquire HMS OCELOT into their collection, to celebrate the rich history of submarine construction by the Royal Naval Dockyard at Chatham.

Over the next 3 years HMS OCELOT was restored internally. Missing equipment was sourced through visits to other Naval bases, dockyards and shipbreakers.

Following her time in No2. Basin, HMS OCELOT was moved to this location, No.3 Dock. Support stands were positioned on the floor of the dock, then the caisson was opened allowing the River Medway to flood in. The submarine was manoeuvred into position above the supports, then the caisson was closed.



Normally ships are kept with water in the dock, just like HMS CAVALIER and HMS GANNET. This allows the water to support the shape of the hull, removing pressure and stress on the frame. However, a submarine does not need this support as it is constructed as a steel tube that can support itself.

Hear the memories of HMS OCELOT’s arrival at The Historic Dockyard Chatham by Richard Holdsworth MBE – former Director of Heritage, Public Engagement and Learning.


how HMS OCELOT looks today…

Stop 3

Propulsion and Steering

For the best experience, please remain at the stops when accessing the information provided and watch your step as you proceed around the dock.

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.

Stop 4

Navigation and Communication

For the best experience, please remain at the stops when accessing the information provided and watch your step as you proceed around the dock.

The large tower in the middle of the submarine that looks like a shark’s fin is called… ‘The Fin.’

The Bridge is an area at the top where the crew could stand and look out over the sea. Inside the Fin is the Conning Tower.

The shortest tube at the front which becomes thinner towards the top is the Attack Periscope. This was sometimes called the Captain’s Periscope. A periscope uses mirrors, to allow the crew to look around when the submarine is submerged. The thin profile allows the attack periscope to cut through the water easily, creating little disturbance in the water and is more difficult to spot. This would have been used when HMS OCELOT wanted to remain unseen, when in close range of an enemy vessel. The second tube is the regular search periscope. This was larger and could be used to scan the horizon when the submarine was further away from an enemy vessel.

The third tube is for radar transmission, this would have been used with the onboard radar systems to track ships or aircraft.  The fourth and longest tube is the Radio Communication mast. In the 1960s messages were sent and received using radio waves.

Below the Fin at the bottom of the Conning Tower is the Operations Room. Here all of the systems of the submarine could be controlled.

The Chatham Historic Dockyard Trust’s current Chairman, Admiral Sir Trevor Soar, was one of the commanders of HMS OCELOT during her time in service. Hear his memories of the Control Room onboard HMS OCELOT.

Hear Sir Trevor’s memories of navigation onboard HMS OCELOT.

Next to the Control room was the Captain’s Cabin. The captain was the only person on board to have his own room, however it was very small. It is said that one of the former captains of HMS OCELOT was so tall that he had to have a small hole cut into an internal wall, so that he could lie down flat with his feet poking through the hole!

Hear Sir Trevor’s memories of life onboard HMS OCELOT.

The Perisher

The Submarine Command Course (SMCC), previously known as the Commanding Officers Qualifying Course (COQC), and informally known as The Perisher because of its supposed low success rate, is a training course for naval officers preparing to take command of a submarine.

Stop 5

Stealth and Secrecy

For the best experience, please remain at the stops when accessing the information provided and watch your step as you proceed around the dock.

There are no windows on the submarine. Underwater the water pressure would be too great, there would be little light and nothing really to look at. If the crew needed to ‘look around’ when they were submerged, then they would use sound waves, just like a dolphin would use echo-location to find a fish.

Sonar was a highly effective system of locating vessels in the local area. HMS OCELOT almost always ran in ‘passive’ mode, which was listening to what was around. While capable of transmitting, this was hardly ever used as it would give away the submarine’s presence and location.

Former Commanding Officer, Admiral Sir Trevor Soar, shares his thoughts on HMS OCELOT’s sonar system:

Stop 6

Attack and Defence

For the best experience, please remain at the stops when accessing the information provided and watch your step as you proceed around the dock.

A torpedo is a large underwater missile that can be fired from the submarine while submerged. These doors are where the torpedoes exit the submarine when fired.

When constructed in the 1960s, HMS OCELOT had 8 torpedo tubes, 3 on each side at the front (bow) and two at the rear (stern).

Originally the submarine would have carried up to twenty-four ‘Mark 8’ torpedoes. Six in the torpedo tubes and 18 on racks in the torpedo compartment. Mark 8 torpedoes had a range of up to 3 miles. We have an example of a Mark 8 torpedo on board. It is so large, that often visitors just walk by without noticing it, until it is pointed out to them. Throughout her time in service, HMS OCELOT also carried Mark 22 torpedoes. These would have been used against both submarines and ships.

The rear torpedo compartment was converted to sleeping quarters for the maintenance crews – engineers, mechanics and electricians. This became known as the Stoker’s Mess. This was a hot and noisy space, with lots of vibrations as it was behind the engine room and next to the propellers.

HMS OCELOT went through many refits in her time of service. During one of these refits, the torpedo tubes were removed so that a new passive towed array sonar could be added.