Lieutenant Commander Allen Buchanan to Admiral Sir Lewis Bayly, R.N., Commander, Naval Forces, Southern Ireland
U. S. S. DOWNES.
27 February, 1918.
From : Commanding Officer.
To : The Commander in Chief.
SUBJECT: Hunting submarines in Irish Sea.
1. In accordance with your verbal order, there is herewith submitted for your consideration some suggestions in connection with hunting submarines in the Irish Sea, more particularly in Area 4.
The line between Kish and Holyhead is will [i.e., well] patrolled with trawlers, yachts, etc.
The approaches to Liverpool between the Skerries and Isle of Man should be more completely covered. The trawlers, minesweepers, etc., in this area work more in an East and West line along Mersey #1 and Mersey #2, while shipping in entering and leaving does not follow so exactly these lands [i.e., lanes], especially by the time the meridian of the Skerries is reached. It therefore results that shipping not conforming strictly to the lanes is subject to an attack by a lurking submarine. Not only directly North of the Skerries, but the area to the Northward and Westward is not so well patrolled.
Weather conditions are believed to exercise a great influence on the movements of the submarines. During rough weather the submarine will seek a lee in order to recharge, or to lie on the bottom. Such conditions he can find on the East coast of Ireland in the blight [i.e., bight] between Rockabill and Haulbowline and between Haulbowline and St. Johns. These areas should be well covered with trawlers, and especially drifters. The submarines could then be detected arriving or leaving. The destroyers should naturally cover this area as well.
It is believed that the trawlers, drifters, etc., are much more efficient in licating [i.e., locating] the submarine than the destroyers can possibly be. It is a chance only when a destroyer sees a submarine; we are easily picked up and the submarine has ample time to dive and hide. The submarine is not so careful in hiding from a trawler or steamer. As a case in point a steamer spoken by the DOWNES at 1845 sent out an Allo at 1900. There can be no doubt that the submarine sighted the DOWNES and waited until we had resumed our patrol before appearing.
The destroyer is the main force of attack, they have to [i.e., the] mobility and the armament, and a submarine o[n]ce sighted can be sever[e]ly handled. The chief problem is the definite lication of the submarine, so that depth charges may be dropped in place. Even after location within a limited area, the submarine has so many courses and sppeds [i.e., speeds] open to him that it is most difficult for one destroyer to cover the many possibility. For this reason the destroyers should be kept concentrated as much as possible, and when a submarine is located within a limited area, the boats can work together, giving a much greater chance of successful attack than the arit[h]metical increase in number of boats would indicate, because the greater number can much more quickly exhaust possible lines of retreat.
The patrols already established are the main force of search, and as such should realize the great inportance of early information reaching the hunting destroyers. The Senior Naval Officers in Liverpool, Holyhead and Kingstown were all unofficially requested by me to so inform their patrols, which they most heartily agreed to do, so that such reports did come thru to us better the latter part of my stay. Perhaps an Official communication from the Commander in Chief might be a help,altho it is most desired not to intimate that the Senior Nav[a]l Officers were not willing to do all in the power, because the contrary is the case. In every instance they were most willing and courteous and
officer offered ai rd and assistance far beyond our needs.
Radio stations on shore, equipped with direction indicators, would be a great help. Every night are intercepted radio messages being exchanged between enemy submarines. A radio station is needed at Holyhead.
Destroyers should make freer use of Holyhead and Kingstown during quiet times. This, to enable Commanding Officers to confer and plan their future movements, and also to get more in touch with the patrol authorities at these points. In addition, it is a rest for the personnel. Hunting is much harder work than convoy duty, altho infinitely more interesting and attractive to Officers and men.
Ships for hunting game should be selected so far as possible with the best equipment for locating, and best armament, especially depth charges. And further among those of the same equipment, those whose personnel are most keen for the duty should be taken.
It is not considered advisable to constantly change vessels on this duty. The hunting duty is a little different from convoy work, and one only learns by experience, which is the harders [i.e., hardest] thing to pass on to another.
Above all, every effort must be made to coordinate the work of the patrols and the destroyers. At present we are working on parallel line to the same end; we must work along the same lines, the one force supplementing the other, the inherent efficien[t] qualities of one type being used to supply the deficiencies of the other.
/s/ Allen Buchanan.