How Larne helped win the battle against U-boat scourge during First World War
The German submarines posed a huge danger to Allied shipping around the coast of Ireland. Co Antrim author Guy Warner reveals in detail in his new book how airships and vessels, from little trawlers to destroyers, combined to defeat the enemy
I first became interested in the subject a number of years ago. It stemmed from the fact that my grandfather, grandmother and great aunt all served at Larne Naval Base during the First World War. My first book was titled Airships Over The North Channel and told the story of the airship station at Bentra in Whitehead.
I returned to the National Archive at Kew and carried out more research, the fruit of which was a second, revised and expanded edition now titled Airships Over Ulster. Both of these touched upon the role of Larne Naval Base, as the airships were under the control of the Senior Naval Officer in the town.
I then began to think of a further development of the story, putting the tale of the airships in their context as part of a much larger national effort. So I went back to Kew twice more and uncovered a vast amount of material about the 1914-18 war at sea as it specifically related to Ireland.
Much of what I have uncovered has never been presented in a book before and has hitherto been hidden history. Many of the 400-plus photos have never been published previously. The work of the RN, RNAS and, latterly the RAF, USN and USNAS in Ireland was crucial to winning the war at sea and the eventual victory of the Allies. Last year I also assisted the museum staff in Larne and Carrickfergus in devising and setting up exhibitions on this subject. It has been very hard work, but very rewarding and satisfying to shed light on an important but overlooked part of our history.
The Great War of 1914-18 brought many technological innovations which served to add to the horror and carnage of the conflict. The war at sea was not immune from these developments as battle was engaged not only on the surface but also by underwater craft and in the air above. Ireland went from being a naval backwater to the forefront of a major theatre of the war. In 1914 nobody thought that the U-boat would prove to be such a key weapon or that naval forces based in Irish ports and airfields would be crucial to winning the war.
Ireland first entered the war in a naval sense when the Royal Navy's Grand Fleet moored in Lough Swilly for a month in the autumn of 1914 while the anti-U-boat defences at Scapa Flow were being upgraded. While there, on October 27, 1914, the new battleship HMS Audacious was sunk by a mine laid off Tory Island by the German auxiliary minelayer SMS Berlin. As a direct result of this catastrophe minesweeping trawlers were sent to Buncrana and also to Larne.
Naval bases were established in both locations. In 1914 Larne was a thriving market town and seaport with a population of around 9,000. Its situation on the north-east coast of Co Antrim gave it a strategically important position on the North Channel between Ireland and Scotland. Any vessel passing through the northern end of the Irish Sea en route to Glasgow, Belfast, Dublin or Liverpool, as well as many minor ports, was subject to the jurisdiction of the naval forces based in Larne. The sea route from Stranraer to Larne was also the shortest crossing between Great Britain and Ireland. Larne's Olderfleet Hotel became a naval headquarters under the direction of the Senior Royal Naval Officer.
The challenge faced by British forces in the U-boat war should not be underestimated. U-boats first penetrated the North Channel, the Irish Sea and the Atlantic coast of Ireland in early 1915. A considerable proportion of the Royal Naval Reserve was sent to ports all around the coast of Ireland. The RNR was largely made up of trawlers and drifters and their crews who were drafted into service.
By the spring of 1915 more than 100 of these small but sturdy vessels were based in Larne. In due course they would be equipped with 3-inch or 6-inch guns and fitted with wireless telegraphy sets. While based at Larne these small ships would have their coal bunkers replenished between patrols, their boilers would be cleaned, repairs made, the crews rested, supplies would be taken on board and the necessary command and control would be given.
The largest ship to be based in Larne in 1915 was the former London and North Western Railway Kingstown to Holyhead mail steamer TSS Hibernia, which was requisitioned by the Admiralty and renamed HMS Tara. Supported by a flotilla of four destroyers - HMS Dee, HMS Dove, HMS Garry and HMS Thorn - HMS Tara patrolled the North Channel, inspecting merchant vessels and keeping them clear of danger areas.
Anti-submarine nets were laid from the north coast of Ireland to the Mull of Kintrye and were patrolled ceaselessly by relays of drifters. As the North Channel was too deep to net to the bottom, the object was to make the submarines use up their batteries by keeping them submerged for as long as possible. Two lines of nets were laid 20 miles apart, "a light flexible curtain of thin steel wire woven into six or 10ft meshes and supplied in lengths of 200 yards. These were laid clipped together. The submergence of the glass buoys on which the nets were hung or the automatic ignition of a calcium light betrayed immediately the presence of a submarine".
Between these nets were four or five lines of net drifters, supported by patrols. Day and night the little steamers kept under way, continuously towing their nets. In addition there were surface patrols for five miles at each end, which meant that to pass through, a U-boat had to stay submerged for 30 miles.
The Admiralty decided that accommodation for officers could be provided by converting part of the drifter's fish hold or by adding a cabin to the upper deck. This work was carried out in Belfast. Much other work on the drifters and trawlers was undertaken by the Larne Shipbuilding Company (which had been established in 1878 near the Olderfleet Castle and would survive until 1922). The company was taken in hand, "extensive additions were made to the facilities and a great many extra hands were engaged". As many as 150 armed trawlers and drifters at a time were based in Larne.
Additionally, the Royal Navy developed a fleet of airships to patrol the seas. The new submarine-searching or submarine-scout craft became known as the SS Class and was crewed by the Royal Naval Air Service (RNAS). No other contemporary aircraft could match the airships' endurance or slow speed capability. They could patrol for hours on end and used wireless telegraphy to communicate with their bases, who could then direct warships towards a potential target.
Success depended on close co-operation between the naval airmen and the warships operating from Larne Naval Base. The surveillance and detection capabilities of the airships helped keep U-boats below the waves, where they could see less, had to travel much more slowly and used up valuable battery power. It is a well-documented fact that the U-boats crews loathed the airships.
In October 1915 Bentra, just outside Whitehead, was established as a sub-station of RNAS Luce Bay airship base in Scotland under the command of the Senior Naval Officer at Larne Naval Base. Rations for the men stationed at Bentra were provided by the Army Service Corps via the 6th Royal Fusiliers at Carrickfergus Castle. Duties included convoy escort and also accompanying the Larne-Stranraer steamer, the Princess Maud.
Crewed by young men barely out of their teens, the SS and later SSZ class airships made long patrols over the sea of up to 10 hours duration. It is hard to imagine now just what it would have been like for the crews of the airships, suspended beneath a gasbag in an open cockpit, between a few hundred and a few thousand feet above the cold, grey sea.
One of the pilots, Flight Sub-Lieutenant Thomas Elmhirst, only 19 years old at the time, later wrote: "It should be noted that conditions were cramped and confined on board, exposed to the cold and at the mercy of the elements. This would not be a pleasant experience when returning from a long patrol - tired, hungry and cold."
Other devices and weapons which would be deployed at sea - even in the smallest vessels - from 1916 onwards included the hydrophone and the depth charge.
The hydrophone consisted of a receiver which, when lowered into the water, picked up the vibrations of a U-boat's propellers and passed the sound by means of "communicating wires and headphones to a trained listener stationed on deck".
These were non-directional at first until the development of directional hydrophones in 1917. An Ulsterman from Hillsborough, Lieutenant Hamilton Harty RNVR, renowned as the conductor of Manchester's Halle Orchestra, used his musical ear to great effect tuning the equipment and matching pairs of hydrophones. The depth charge was a 300lb bomb fitted with a hydrostatic device to detonate it at a pre-set depth, therefore allowing a submarine to be attacked when submerged. The development of depth-charge throwers rather than simply rolling them over the stern increased their range and efficiency and chances of success.
For vital supplies - foodstuffs, oil, munitions - and, from 1917, troops from America to cross the Atlantic from the US to the Allies, ships had to pass the coast of Ireland, either to the north or south. The situation became critical in the spring/early summer of 1917 - losses of merchant shipping to the German U-boats were unsustainable.
In June 1917 First Sea Lord Admiral Jellicoe warned the War Cabinet that the shortage of shipping was becoming so serious that it would be impossible to continue the war into 1918 if the losses carried on at the same appalling rate, having reached a peak of 834,594 tons in April.
The introduction of the convoy system in 1917 was critical to winning the war at sea. It was increasing in intensity, and for the vessels and warships based in Larne and at Bentra, 1918 would be a critical and dramatic year, which would bring considerable success.
The full story of the war at sea from bases all around the coast of Ireland 1914-18 is told in Guy Warner's new book U-boats Around Ireland, published by Colourpoint Books of Newtownards, price £18