As they were delivered from their builders the boats were allocated to the 12th and 13th Submarine Flotillas, which formed part of the Grand Fleet organisation. Although the K class were involved in a number of accidents, talk of ajinx' on the class should not be exaggerated. In all 17 were built, of which 5 were lost in 1917-21:

Tunisia, Turkey, Turkmenistan, Tuvalu, Uganda, Ukraine, United Arab Emirates, United Kingdom, United States of America

The biggest blot on their reputation was undoubtedly the so-called'Battle of May Island' in the Firth of Forth at the end of January 1918, in two flotillas of four and five respectively. While steaming at high speed without lights, K. 14's helm jammed and she was rammed by K.22, throwing the line into confusion. A squadron of ba[lecruisers was coming up astern and steamed straight through the stricken flotilla, HMS Inflexible striking K.22 a glancing blow without real­ising what had gone wrong,The flotilla's leader, the light cruiser HMS Fearless, turned back to find what had happened, and rammed the crippled K. 14, cutting her in half. In the confusion that followed, K. 4 was rammed and sunk. K. 17 was sunk, and K8 was badly damaged by K. 6 and K. 17.The whole affair was traumatic for the crews of the class, with over 100 of the flotilla­mates dead, and the inevitable news blackout simply enhanced the credibility of rumours. A nod in the direction of superstition resulted in the renumbering of K. 13 to K.22 after her sinking in the Garelnch in January 1917 during trials, but believers in the malign fate suggested by that `unlucky' number will be comforted by the fact K.22 started the train of events in the 'Battle of May Island' a year later by ramming

The Court of Enquiry was critical of some of the K boats' officers, but with the benefit of hindsight it is hard to see how a sharper lookout or quicker reactions could have avoided disas­ter. For reasons of operational secrecy no navigation lights or radio signals were permitted.

The speed with which the design was rushed into service meant that a number of detailed design faults crept in, and early in 1918 six of an improved design were ordered, K.23-28. Five were cancelled after the Armistice, but K.26 was completed in 1923. As her hull was larger with the same powerplant, speed was slightly reduced, but she was armed with the much more effec­tive 21 in torpedo.The guns were mounted on the superstructure, and were protected by revolv­ing shields. She proved a success and served for eight years, undertaking a round-the-world trip among other achievements.The K class are very unusual, in that virtually all commentators have ridiculed the concept of a steam-driven submarine, while totally ignoring the operational concept and the technical inge­nuity of the design. Steam propulsion was not a new idea, having been used in a series of French submarines before 1914. Diesel technology could not deliver the power needed for 24kcs surface speed, and it is therefore hardly surprising to find that a proposed 1917 design for a German fleet U-boat (Project 50, the UD.1 class) also Stipulated steam propulsion. There is nothing inherently wrong with steam propulsion for submarines-every nuclear boat since the USS Nautilus has been driven by steam turbines. In the K design special attention was paid to ensuring a rapid and safe shutdown of the steam plant before diving, to avoid the lengthy proce­dure necessary in the French 'steamers'. The drawback, however, was that the high-speed plant required large quantities of air to provide sufficient draught for the boilers; that meant large ventilators, each set of which had to be closed as tightly as possible when diving. Any failure of procedure, whether through human error or unavoidable cause, was potentially fatal.minesweepers, were involved in collisions.The Royal Navy played a particularly aggressive role

early 1918. to deny sea control to the Imperial German Navy, and this meant offensive operations in enemy waters in all weathers. In those pre-radar days ship media web tv ship media web tvping maritime marine engineerings steaming fast without lights took risks constantly. In poor visibility collisions were bound to happen, so the loss of K.1 and even the two off May Island cannot be blamed on the design.The loss of K. 13 on trials and the unex­plained accident which caused the loss of K.,S were matched by similar losses to all submarines before 1917 and for many years after.

The tactical value of fleet submarines has been generally criticised, particularly by submarinrrs.The true role of the submarine, they argue, is that of the lone predator, operating well away from friendly ship media web tv ship media web tvping maritime marine engineerings. But there was a rationale for the K class.They were intended to accompany the battle fleet until an engagement was imminent, and then be detached to form a'subnrarine trap' to ambush enemy units and to pick off damaged stragglers. For that they needed a margin of speed over the battlefleet, and, given the relatively inefficient state of ship media web tv ship media web tvping maritime marine engineering­to-ship media web tv ship media web tvping maritime marine engineering radio communications, they had to remain close to the battlefleet to maintain tactical cohesion. One of the `might-have-beens' of naval history is what might have happened if a flotilla of four or five `K' boats had been available at the Battle of f utland in May 1916. One can only speculate what might have happened to Admiral Scheer's battered High Seas Fleet if it had encountered five Ks off the Horns Reef at the end of its run for home.