Some years before World War I, British admirals considered the submarine to be the weapon of inferior nations, un-English and not very gentlemanly. Their thinking was stuck in the Nelson era when great fleets of surface ships came together and fought it out at close quarters, with the strongest and fastest, invariably the British, winning the battle. The whole concept of the submarine – which crept up on its prey un-seen, fired a salvo of deadly torpedoes then slipped silently into the sanctuary of the depths – was considered ‘jolly cowardly.’ There was such little enthusiasm for the undersea vessel that the British Navy’s submarine building and training programme lagged far behind that of other countries. Germany, on the other hand, had developed the diesel engine to a very high standard to give their u-boats superior surface speeds, which was very important.

When World War I started an incident occurred on the Dutch Coast that jolted the British Admiralty out of its complacency. It seems fair to say, with the benefit of hindsight, that it drove them in their anxiety just a little crazy. In September 1914 the cruiser HMS Aboukir was torpedoed by the German submarine U9 and sunk. Two other British cruisers, HMS Cressy and HMS Hogue, came to the aid of the sinking vessel but were also torpedoed and sunk. Of the 2,200 men comprising the crew of the three ships, 1,450 were lost. To lose three cruisers and so many men in a single afternoon to a lone small u-boat made the British Admiralty sit up and take notice. When, less than a month later, the U9 sunk the cruiser HMS Hawke and killed another 500 British sailors, the Admirals began to panic.

In order to upgrade their submarine fleet they started an ambitious building programme, with various companies building a number of different classes of vessel. In their haste, the Admiralty fell into the trap of accepting a design that had previously been turned down as impracticable – the steam submarine. The Director of Naval Construction, Sir Eustace Tennyson-d’Eyncourt, had previously produced this design for what he described as a submersible destroyer. Because it was driven by steam on the surface it could do 24 knots, allowing it to keep up with the surface ships of the fleet.

Today, now that the submarine has found its true place in warfare as a lone menace lurking in the depths, it seems incredible that the Admirals of that time thought of submarines more as part of their surface fleet, albeit with the added ability to submerge.

The vessel Sir Eustace designed was enormous compared to any previous submarine and in fact larger than any destroyers. It was over 100 metres long, displaced over 1,700 tonnes (2,600 tonnes when submerged) and had seven propulsion units: two oil fired steam boilers for the surface, four electric motors for underwater and an auxiliary diesel motor for the transition from electric power to steam. In 1913 the design had been rejected as unworkable, but two years later, with the Admiralty in a panic, they reluctantly agreed to build it. The design would form a class of submarines known as k-boats, which would eventually come to suffer more serious accidents and calamities than any other class of ship in the world.

Of the 17 of these submarines built, one sank on her first day at sea, three were lost in collision and a fifth disappeared without trace. Between them, the boats suffered a total of 16 major accidents and numerous minor ones. The loss of life was correspondingly high, the 300 deaths being caused not by enemy attacks but by accidents with the submarines themselves. Only one of the k-boats actually saw battle. She fired a torpedo at a German u-boat, but although it struck dead centre below the conning tower it failed to explode.

By the beginning of 1917 a number of the k-class boats had been completed and were at various stages of their acceptance trials. All reported difficulties, mainly due to the number of hatches or holes that had to be closed off before the submarine could dive. ‘The k-boats,’ as one crude stoker put it, ‘have got more holes than a French tart.’ On 29 January the ominously numbered K13 left Fairfield shipbuilding yard at Govan on the Clyde and proceeded downriver. She had a crew of 53 onboard and 27 men from the builders and subcontractors. Commander Goodhart from K14, which was still under construction, was also present.

Right from the beginning, things started to go wrong. Someone inadvertently turned off the power to the steering and the submarine broached to port, putting her sharp bows onto a mud bank. The ebbing tide turned the submarine sideways to block the river. The SS Sonnava, a steamer, tried to get past the submarine’s stern but ended up wedged between K13 and the dredger Shieldhall, which was lying alongside a wharf. The Sonnava went full astern on her engines and managed to get clear, allowing the K13 to complete the full turn, pull her bows out of the mud and proceed down river backwards. After that rather inglorious exit from the Clyde she proceeded to the trial area where she completed some surface manoeuvres before commencing her diving trials. She was accompanied by a small steam vessel, the Comet, which acted as tender.

Funnels were folded down and sealed and the four large openings that supplied air for the boiler fires were sealed with huge mushroom valves. All other hatches were closed and the submarine dived. When she surfaced the captain, Lieutenant Commander Herbert, conferred with his engineer officer, Lieutenant Lane, and they decided that as there were now 900 litres of water in the boiler room, there must be a small leak. Lane also had some serious concerns about the operation of the mushroom valves and asked Frederick Searle, the Admiralty overseer, to take a look at them. After an inspection, Searle assured Lane there was nothing to worry about.

At 3.15 pm, after the officers and builders had enjoyed a leisurely lunch aboard the Comet, the second dive was commenced. When they got down to six metres Lane sent the Chief Engine Room Artificer into the boiler room to see if he could identify the leak that had previously plagued them. He returned shortly to report that the boiler room was flooding freely. The captain ordered the vessel to surface but the K13 was already too heavy. She went to the bottom in about 15 metres, where almost at once water entered the electrical circuits, caused short circuits and started a fire that threatened to eat up their limited supply of oxygen. When the fire was extinguished they assessed their situation. A total of 31 men, including Lane, were almost certainly drowned in the flooded after section. Still alive in the forward part of the submarine were 49 men.

Fortunately, their dive had been observed by the captain of another submarine, who was concerned at what he saw and quite quickly raised the alarm. In Glasgow, however, the rescue arrangements were slow to get going and it wasn’t until 2 am the following morning that the submarine was located on the bottom. The rescue vessel Gossamer carried a diving suit but no diver. When a young diver did eventually reach the scene, the very old diving suit burst on him when he entered the water. When a new dive suit was obtained the diver went down and tapped on the submarine’s hull, receiving a message in Morse code: ‘all well before engine room bulkhead.’

Hours later, when it appeared to the trapped men that nothing had happened to effect their rescue, the captain decided on a brave plan. At low water Captain Herbert and Commander Goodhart climbed up into the conning tower and closed the lower hatch. Although they had no escape breathing apparatus, the intention was to flood the tower, open the upper hatch and allow Goodhart to swim to the surface with a message. Herbert’s job was to close the hatch and drain down the tower for later use.

Meanwhile, on the surface, it was decided to sweep a heavy wire under the bow of the submarine in order to lift it high enough for the sailors to escape through the torpedo tubes. This was being done when Herbert burst to the surface in a flurry of bubbles, having been propelled after Goodhart by the outrush of air from the conning tower. Herbert was half drowned, but alive, whereas Goodhart had become entangled in the bridge overhang and never made it to the surface.

The rescuers, alerted by Herbert to the seriously dwindling air supply inside the K13, renewed their efforts to connect up an air hose. The fresh air revived the men somewhat and they set about filling the depleted air storage cylinders. This then allowed them to blow the forward ballast tanks, which raised the bow of the submarine to within a metre or two of the surface. At the same time divers removed, modified and refitted a plate from the hull, allowing a 10-centimetre pipe to be connected. Once the inside hatch was opened, and after a cloud of foul air had escaped, voice communication was established and hot drinks passed to the weary men. Then a diver’s air line was passed down the tube, allowing the atmosphere of the boat to be further re-vitalised with clean air.

The experts were keen to lower the submarine back down and do a proper salvage job with lifting pontoons but many of the officers argued that they wanted their men out as soon as possible. They won the argument and the wire under the bow of the submarine was hauled in to bring the forward torpedo tubes above water. When the wire began to slip, however, the operation was halted and the situation re-assessed. It was then decided to cut a hole in the hull with an oxy-acetylene torch but progress was halted once again when the space between the outer and inner hulls was found to be full of water. As fast as the rescuers bailed the water out the more flooded in and hours of delay followed while they tried to overcome this problem, putting tremendous psychological stress on all concerned. With the bow of the submarine only just above the water, the rescuers were aware that the rising tide could undo all their good work and seal the fate of the men in K13.

Finally, at around 7.30 pm, the valve controlling the water level between the outer and inner hull was found to be only partly closed. Once this had been properly shut off the water level dropped sufficiently for the dockyard engineer to commence cutting a hole in the pressure hull. First Lieutenant Singer, who had taken command after Herbert had left, gave the go-ahead for the men to start escaping. ‘Civilians first, lads,’ he reminded them. It took just over an hour to get all the men out. They had been trapped for 57 hours with an air supply that had been calculated to last only eight hours.

When the submarine was finally lifted it was found that one of the mushroom valves had failed to close properly, allowing the boiler room to flood very quickly. It was also discovered that the engine room hatch had been opened and bodies that should have been there were missing. It was later deduced that Lieutenant Lane and another man, John Steel, had managed to open the engine room hatch and make their escape. They did actually reach the surface, but then either drowned or succumbed to air embolism – a blowing-up of the lungs – by holding their breath on the way up. Two heads had been seen in the water by a young chambermaid at a nearby hotel, but no one had believed her at the time. About a month later, Arthur Lane’s body was recovered from a mud bank in the Clyde. Steel’s body was never found.

The K13 was raised, rebuilt and re-commissioned as K22. About the only real change the Admiralty made as a result of the disaster was to never again give the number 13 to any submarine. At the court of enquiry it seemed that people in high places preferred to hold a dead man accountable for the disaster rather than allow any criticism of their holy cow, the k-class of submarines. The blame was put absolutely on the shoulders of Lieutenant Lane, even though the evidence shows he was the only man to have concerns about the operation of the mushroom valves. He was also the one to send someone to check for leaks in the boiler room and alert the captain to the flooding. Had he raised the alarm a few seconds earlier, allowing the submarine to surface before it was too heavy, he would have been a hero. Instead, even in death he was obliged to take the full blame for the death of so many, a weight that his widow bore for him.

Although the sinking of the K13 was the most serious of the k-boat problems thus far, the rest of her sister submarines were having their own difficulties. One of the problems, referred to as ‘loss of suction’ concerned the diesel oil that fed the boilers. Contained in tanks whose bottoms were open to the sea – which helped to maintain consistent buoyancy as the fuel was used up – the oil would mix with salt water in rough weather and emulsify. This had the alarming effect of putting out the boiler fires and leaving the submarine without motive power until the boilers could be relit. Just about all of the k-class submarines stopped suddenly at one time or another after losing suction. As they were often in convoy at the time, there were more than a few near misses when following ships almost collided with stationary vessels.

There were many other faults with the k-boats. For a start, they were not buoyant enough in the forward end, which allowed the waves to push the bows under. Quite a few dived involuntarily before all were eventually modified. Another poor design feature was that in rough weather waves would wash down the funnels. K-boats were the only submarines in the world where the stokers and engineers wore oilskin coats and sou’wester hats on watch. K1 developed so many and varied faults that her acceptance trials, which would normally have lasted no more than week, took five months. K2, on her first attempt at a dive, suffered a massive electrical malfunction that resulted in a fire and explosion. On her second attempt, some months later, the mushroom valves stuck open because the hydraulic oil used to close them had solidified in the cold conditions. Miraculously, she managed to regain the surface before disaster struck. K5 went down with all 57 of her crew. The cause was never established, but being a k-boat there were plenty of possibilities to choose from. K6 refused to resurface after a dive until some hurried underwater repairs were completed. K14 sprang a leak and almost sank while at anchor. K3 dived out of control and hit the seabed at 70 metres, well below her official crush depth – the depth at which a submarine could possibly begin to implode. K15 dived stern first and was almost lost.

The k-boats were troublesome both on the surface and underwater, particularly as they dived. If the trim tanks (small fore and aft ballast tanks) were not correctly balanced the submarine would get out of control and continue to dive no matter what the crew did to correct her. With a crush depth of only 45 metres and a length of over 100 metres, the bow could be at a dangerous depth before the stern had even left the surface. Another common fault was that their forward hydroplanes jammed below 25 metres, which led to a number of them sticking their noses into the mud after an involuntary dive. All these faults and near disasters were reported to the Admiralty but were either hushed-up or regarded as teething troubles. There were a number of senior Admirals who had backed the idea of steam-driven fleet submarines and they had no intention of changing their minds at that late stage.

Then came the night in which two k-class boats sank, three were so badly damaged they could not be repaired until the war had ended, and almost 100 men drowned or were seriously injured. It was 1918 and the Grand Fleet – all naval ships of war in the area – was performing an exercise devised by Vice Admiral Beatty. Known as Operation ECI it was comprised of 29 battleships, 15 cruisers, 18 light cruisers, as many as 30 destroyers and two flotillas of k-class submarines, each led by a light cruiser. They formed up and proceed through darkness and mist down the Firth of Forth, showing only dimmed-down blue stern lights and keeping radio silence.

All the vessels passed down the Firth and through the many anti-submarine defences without incident. When they came abeam of May Island they were supposed to make a slight alteration of course and increase speed to 21 knots. Unknown to them, however, there were two minesweepers in the darkness ahead that had not been informed of the Grand Fleet’s movements. The result was that K11, suddenly confronted with the vessels, was obliged to drastically reduce speed and veer off course. K17, in turn, took violent evasive action to avoid colliding with K11. The third in the line, K14, narrowly avoided collision, careered out of line and heeled over when her rudder jammed. When it eventually freed itself the captain tried to regain his place in line and inadvertently crossed in front of K22 (the formerly unlucky K13). She sliced her knife bows into K14, killing two men and flooding the forward part of the boat. K22 was also badly damaged at the bow and her forward torpedo room was flooded.

In the meantime, the leading cruiser, Ithuriel, carried on into the night with three of the submarine fleet following behind, unaware of what had happened. The flooding K22 sent a coded message to inform Ithuriel of the collision, rigged some lights and fired red signal rockets to warn the following destroyers that they were dead in the water and in real danger of being run down. The leading cruiser, HMAS Australia, passed the stricken submarines without incident and the captain ordered HMS Gabriel to detach and give assistance. The last cruiser in line, HMS Inflexible, struck K22 at 18 knots, battering nine metres of her bows and tearing off the starboard ballast and fuel tanks. Unaware of the seriousness of the impact, Inflexible carried on eastward while K22 rocked and floundered in her wake, flooded forward but remaining afloat.

The Ithuriel received a message about the collision but due to a mistake in decoding there was some confusion about who had struck what. Eventually she and her following submarines turned to assist, and promptly met the rest of the outgoing ships head on. For 20 minutes Ithuriel made numerous turns to dodge the cruisers and destroyers, but the submarines, too ponderous to turn quickly, narrowly avoided disaster many times. Then, inevitably, HMS Fearless slammed into K17 just forward of the conning tower, knocked the submarine sideways and swept on by. K17 was mortally damaged but no one was killed or injured. The captain ordered everyone up onto the conning tower and upper deck in preparation to abandon the vessel, and when she slid below the surface, less than 10 minutes after the impact, the crew was washed into the sea.

HMS Fearless had stopped by this stage and was lighting the scene with a searchlight. Far from helping, this caused yet more confusion as the following submarines pulled out of line to avoid collision. K4 slowed and headed right in front of K6, whose sharp bow sliced deep into the K4’s pressure hull. She began to sink at once. K7, meanwhile, the last submarine in line, switched on her navigation lights and went full astern on her engines. The captain managed to avoid colliding with K6 but ran over the already sinking K4. The k-boat voodoo was working horribly well that night, and K4 disappeared beneath with all hands.

To complete the disaster, three more battleships and a number of destroyers came onto the scene where many of the 56 men from K17 were floundering in the water. When the ships had passed, only nine of the men were still alive and at least one of those died later from injuries received. Despite the fact that no enemy had been present that night, so many vessels and men were lost in such a short time that the calamitous Operation ECI came to be known as the Battle of May Island. The night had been an unmitigated disaster for the k-boats, although the court of enquiry found that everything was due to human error. No fault could be found with the boats themselves or the system of operating such hard-to-manoeuvre steam submarines amongst a surface fleet. Even after the end of the war it seemed that the Admiralty had not learned any lessons, as they ordered six more k-class boats.

Admiral Fisher had decided that the large k-boats were a stepping stone to even larger underwater dreadnaughts carrying guns similar to that on a battleship. K18, which was being built at the time, was converted and fitted with a gun forward of the conning tower, re-powered with diesel engines instead of steam, re-classified as a submarine monitor – a vessel able to make a shore attack from the sea – and given the title M1. Although she was completed before the end of World War II, she never saw action.

The second k-boat to be converted to the M designation of M 2, was built as a seaplane carrier with a large hangar for its aircraft. Tragically, both these two vessels were fated to disappear with all hands.

In 1925 M1 was diving in Lyme Bay, Devon, when she failed to surface. The SS Vidar, a Swedish ship, later reported striking an underwater object in the same area at the same time. Inspection of the Vidar found only slight damage to the bow, but flakes of camouflage green paint – identical to that on the M1 – were found on the ship’s hull-plates. It was surmised that the Vidar had struck the M1, but how could the ship be only slightly damaged while the submarine, with a thick pressure hull, be so badly damaged that she sank?

The mystery remained unresolved until 1999, when an ex-navy diving colleague of mine – now Britain’s foremost wreck hunter, Richard Larne – set out to rediscover the last resting place of the M1. Richard, with a team of deep divers aboard a converted landing craft, found the wreck using sonar. When the divers descended the 72 metres, using special three-gas mixtures instead of ordinary air, they discovered that M1 was virtually intact with little sign of collision. But the huge gun was not in its place and it was later found some distance away on the seafloor. Richard reasonably concluded that in a one-in-a-million chance the Vidar had struck the M1 squarely on the breech of the gun, knocked it out of its mounting and left a large hole down which water gushed at about a tonne a second. The shell room directly below the gun would have flooded first, where the watertight doors may well have held the first onslaught of water. As the submarine sank lower and the water pressure increased, the doors and the bulkheads would have collapsed, drowning all the men very quickly.

After the demise of the M1, this class of submarine was reduced to two – M2, a seaplane carrier, and M3, a minelayer. One day in 1932, after the M2 had signalled she was diving, nothing was ever heard from her again. When a coastal vessel, the SS Tynesider, put into the nearby port, her master asked the harbour master if it was usual for submarines to dive backwards. The harbour master didn’t know but thought it unlikely and he reported their concerns to the naval authorities. It took eight days to locate the submarine, by which time all hope of saving the 60 crewmen had gone. One man did escape from the M2 during or after she sank, but his body was later found on the shore.

The court of enquiry deduced that when the M2 had surfaced the hangar door was opened a little too soon, allowing a large wave to enter and make the submarine heavier, allowing more water to flood in and sink her. However, k-boat officers had a different idea, born from long experience with the killer submarines. They suggested that as the M2 reached the surface and the hangar door was opened, the rear hydroplanes malfunctioned and taking the stern on an involuntary dive, which soon filled the hangar with water and making her dive stern first as had been witnessed. After this disaster M3, the remaining submarine of its class, was scrapped, bringing an end to the tragic saga of the k-boats…almost.

In 1960, I was a member of the Naval Air Command diving team stationed at a dive base at Portland in Dorset. One of the members of the team, Leading Seaman Mike Rice, knew the story of the M2, had obtained the exact co-ordinates of her final position and was keen to organise an expedition to relocate and survey the wreck. We were careful not to mention to the navy what our intentions were because we knew they would not be keen on us interfering with a wreck that contained bodies. Keeping it all quiet, we used navy equipment and a civilian boat during our summer leave period to search for the last resting place of the M2.

By good management, or perhaps good fortune, we found the wreck on the third day of a seven-day expedition and spent the rest of the time looking over what was a very large submarine. She lies upright on an even keel, heading west. The large cylindrical aircraft hangar with its rectangular door sits open, with the little aircraft either washed out of her or so corroded that she is now a part of the shambolic hangar deck. We discovered an open hatch to the interior of the submarine, which was later sealed-up by a navy contractor to prevent anyone from entering. We discussed whether we should enter but decided that as it was an official grave-site it would be disrespectful to disturb the remains of those that lay at rest there. This turned out to be a wise decision as someone reported our diving activities to the navy and we were called to account for our actions. We supplied a fairly detailed drawing and report on the submarine and stated that we had not entered the interior out of respect.

We received an official telling off for using navy dive gear in an unofficial capacity but that was the end of the matter for us. The navy then sealed the M2 up so that no one could enter in the future.

Thirty or so years later, Richard Larne and his expedition located the M1 and proved that her loss had been caused by a weakness in the design of the gun mounting. For me, that brought to a close the unhappy story of the k-boats and their later m-class conversions.