After a couple of days on the surface, the point of no return came, to the accompanying holler of ‘Diving stations, diving stations’ being piped throughout the boat. You then knew that it was time to get accustomed to the new world awaiting below. The captain would tell the OOW and lookouts to come down, and the lookouts would stand at the bottom of the conning tower, relaying the cries of the OOW to the captain as he shut, clipped and pinned the upper and lower lids of the tower. This was the final symbolic act before every patrol. Once the lower lid had been shut and pinned, the captain would spend a few moments at the periscope taking in reports that the boat was ready to dive, while I would be sitting in the control room either on the CEP* or on the fire-control panel, ready to start plotting any contacts once we were below the water.
The captain would then place the dive in the hands of the XO, with ‘Number 1, dive the submarine’ being the usual instruction. To dive a submarine, the main requirement is to achieve negative buoyancy so the boat is heavier than the water outside and thus sinks. This is done by opening the main vents and filling the ballast tanks with water, which allows the boat to be controlled when diving.
When a submarine is on the surface, its ballast tanks are filled with air to create buoyancy so that the submarine’s density is less than the water surrounding it and it floats. When under the waves, the trim tanks are used to maintain the correct balance of water to create neutral buoyancy so the boat has the same density as the sea outside and thereby achieves its cruising depth, one that could easily be sustained for a complete circumnavigation of the world’s oceans. A quantity of compressed air is always kept in reserve for use in the event of an emergency surface procedure. Managing the trim requires years of experience to get right – and obviously the faster you go, the harder it is. Keeping a boat evenly trimmed underwater at speed is akin to trying to control an aircraft in the sky, with the rudder, foreplanes and the afterplanes looking after the direction and depth of the boat.
Although it’s not that noticeable, there’s a slight incline forward and a trace of movement when you’re diving, a bit like descending in a very slow-moving lift. I remember on my first patrol being ever so slightly underwhelmed by the whole experience, the crew exuding a sense of professional nonchalance, everything slow and laborious. I was expecting more of a Das Boot-style dive at speed, with everyone hurtling to the front of the boat to weigh it down. I mentioned this to the coxswain at the time, telling him I thought it was a tad unsatisfying, to which he responded with a cool stare and said, ‘Humph, you’re a cunt.’ Wise words indeed.
We would descend to around 100 feet and then immediately head back up to periscope depth, just to check the planes and integrity of the ship-control workings. Meanwhile, the captain sought assurances from the rest of the boat that there were no leaks, and while whirling around on the periscope he’d perform continuous sweeps of the horizon, checking for contacts. This wasn’t the time for anything to go wrong. No fucks-up, not here, not now.
When the skipper was comfortable with the nature of the reports coming back to him, it was time to go. The periscope was lowered, and then it was goodbye world. Everyone knew the submarine was now going to take on a bow-down angle and had to ensure everything was stowed away – this should have already been sorted on work-up, but you never can tell what might suddenly come loose – particularly something weighty that might prang someone on the head; one time a junior mechanic got struck by a flying monkey wrench on dive that had been left on top of the ship’s systems console, receiving a sore head and a cut ear for his trouble.
There was a small symbol of the boat on the console in various degrees of pitch that had to be monitored. There would be another round of post-diving checks throughout each department, which would each then report back to the XO confirming there were no leaks. Sooner or later the boat would reach our operational patrol diving depth, which remains secret as it could jeopardise present or future submarine operations.
The workings of the ballast and trim tanks took place in the control room at the systems console, opposite to where I kept my watch. Forward of the missile compartment, this was the engineering heart of the boat. And while the reactor and all the associated systems were controlled back aft in the manoeuvring room, the systems console was good old-fashioned submarine engineering and controlled by the PO or chief stoker, along with a junior-rate stoker who’d help him out. I got a migraine just looking at all the controls and switches. One wrongly pulled switch, and chaos could ensue.
When we first dived on patrol, the submarine was at its maximum weight, burdened with three months’ food and supplies. Gradually, food supplies got eaten, the sewage tank filled with waste and needed to be evacuated, so seawater was taken in to create fresh water and help in the production of oxygen. This all had to be considered when attempting to keep the submarine neutrally buoyant. Water was pumped by the use of the trim pump from forward to aft, or vice versa, to compensate for any increase or decrease in weight. This was done pretty constantly throughout the patrol, with small adjustments of water distribution here and there to make sure the submarine kept to an even keel.
The hover pump – yes, the submarine could hover – was controlled from the systems console as well and was used in the missile-firing procedure since the boat had to be stationary while firing, and it did this by the activation of the hover pump. The hydraulics system was located here too. Hydraulics is basically high-pressure oil that flows through various pipes from a central pumping plant to help operate certain equipment on board such as the steering gear, the planes, periscopes and masts, together with various flood and vent valves. The advantage of hydraulics is that its noise signature is very low, maintenance is straightforward for skilled engineers and the system does not get degraded by contact with seawater.
The systems console was the bread and butter of the forward engineering on the boat, and the marine engineers who looked after it took everything in their stride, were never stressed, always of a cheerful disposition and never ones for moaning, despite the difficult, hot and cramped working conditions. They’d be diving the boat one minute, sorting out the hydraulics the next, operating the laundry and clearing the toilets if they were backed up with shit, not to mention maintaining the battery if we needed back-up diesel power. All in a day’s work without complaint, 24/7, week in, week out.
Watching the dolphins and constellations already seemed a long time ago. We were in the depths now, with 80 days ahead of us, hidden and cut off from the world – but for the communication from the Command Centre at Northwood. Even though the public back home were unaware of the fact, this Cold War was actually very hot for the Polaris crews. Since 1968 when the patrols started, the officers and men of all the deterrent patrols – across Polaris and then Trident – have been on a constant war footing. Our response would have been quick and indeed brutal if the signal ever came, although I never really thought about it a great deal at the time, bizarre as that seems.
I could deal with the long absences, not being one to miss family and friends too much. It might sound harsh and uncaring, and I hadn’t really recognised this part of me before I went out on patrol, but I was never overcome with feelings of homesickness – I suppose I must have been a bit of a loner. Maybe it was because I realised that if I was to survive weeks on end under the sea, all those people who were closest to me were best forgotten about.
* Contact evaluation plot.