In the case of a British line of eight battleships attacked “beam on,” the chances of a hit for torpedoes which reach the British line may be assessed roughly at seven to nine, taking the length of a ship as 600 feet, and the distance from the bow of one ship to the bow of her next astern as two and a half cables, that is 1,500 feet, thus giving a total length of ships of 4,800 feet, and the total of the interval between them as 6,300 feet.
A German destroyer usually carries six torpedoes, and at long ranges one may calculate the chances of hits on the above reasoning at between three and four per destroyer, provided all the torpedoes are correctly fired at such a range as to ensure that they reach the British battle line, and provided that the British ships can take no effective steps to avoid the torpedoes.[O]
[O] Few British destroyers carried more than four torpedoes up to the year 1917, although they mounted a much heavier gun armament than their enemies.
It has been said that the element of chance is a large factor in torpedo warfare of the nature herein discussed. By this it is meant that skill is not a factor that can produce a decisive effect when dealing with torpedoes, as in the case of guns dealing with guns. It is true that skilful manœuvring may enable a ship to avoid a torpedo, if sufficient warning of its approach is given, and if its position with reference to any track it is leaving can be correctly judged. When experience at the Jutland Battle showed that under favourable weather conditions the track of German torpedoes was visible for some distance, great care was taken to avoid all mention of this in the dispatches so that future use could be made of the fact.
Another factor in this matter was the knowledge that our enemy was almost certain to possess a very considerable superiority over us in the number of destroyers likely to be present during a Fleet action. This was a question which had given rise to anxiety in the minds of the then First Sea Lord and myself before the War; we had discussed it on more than one occasion when the destroyer building programme was being considered.
Our fears were realised, particularly during the first two years of the War.
The relative position of the two Fleets in this respect at different periods is shown in the following table, so far as it is known to me:—
| Date | British destroyers with the Grand Fleet, including Flotilla Leaders[P] | German destroyers probably attached to the High Sea Fleet | Additional German destroyers, less than 12 years old, that could join the High Sea Fleet at Germany’s selected moment |
| August 4th, 1914 | 42 | 88 | 20 |
| October 1st, 1914 | 42 | 88 | 20 |
| January 1st, 1915 | 42 | 88 | 30 |
| April 1st, 1915 | 58 | 88 | — |
| July 1st, 1915 | 65 | 88 | — |
| October 1st, 1915 | 65 | 88 | — |
| January 1st, 1916 | 66 | 88 | 50 |
| April 1st, 1916 | 74 | 88 | — |
| May 31st, 1916 | 80 | 88 | 70[Q] |
[P] The Harwich force, as a whole, is not included in the figures in column 2, since I never expected that it would be able to concentrate with the Grand Fleet.
[Q] No account is taken in column 4 of German losses in destroyers.