Upon returning from London in mid-October, 1917, Admiral Mayo, of our Atlantic Fleet, brought back the outline of a proposed minelaying operation. The paper was quite informal—unsigned, undated, bearing in pencil across the top, “Admiralty would be glad to learn whether Navy Department concur in the plans as shewn.”
The field was to be 230 miles long—the distance from Washington to New York—divided into three parts, the middle section, of 135 miles, called Area A, allotted to us, because the reach of the new American mines was greater than ordinary—three of them covering the same extent as eight mines of other types. Thus numbers and effort were saved.
There would be three “systems,” each consisting of one or more rows of mines just below the surface, dangerous to any craft, and other rows at intermediate and extreme depths, so that, whether running on the surface or at ordinary submergence or as deep as 240 feet, a submarine had the odds against her. In the absence of patrol vessels to drive them down, submarines would naturally run on the surface, and so the rows of upper level mines were made more numerous than those at deeper levels. The stroke of a mine is sudden and powerful, and while a vessel on the surface may survive it, to a submerged submarine it is usually fatal. All classes of vessels shy at a minefield, and that the Germans shared this aversion was shown by captured papers, which made it clear that the submarines dreaded nothing so much as mines.
The scheme was unprecedented, and that its great magnitude would involve a mass of detail requiring very careful adjustment was evident on the most cursory examination. Some who heard of it regarded it as impossible, and foolish to attempt. As to the new mines, the very basis of the whole project—since a complete unit would not exist for several months, the statement of Rear Admiral Ralph Earle, Chief of the Naval Bureau of Ordnance, that the mines would be forthcoming in season, had to be based upon tests of the mine only by parts, with the assumption that all would function properly when assembled. Action upon that assurance would at once involve upward of forty million dollars, which made his stand a bold one, inviting unmeasured odium, should the mine after all fail. To await the mine’s final proving, however, would have been fatal to any possibility of beginning the barrage before 1919.
The task of laying the barrier would be hazardous in itself, with constant danger of interruption by the enemy. A single minefield in the open sea, or widely separated ones, presented no extreme difficulties, but to lay a series of them so close together as to leave no considerable gaps between, made a problem for which no really practical solution was yet visible.
For four days the project was under consideration by the Naval General Board at Washington. Time pressed, the need was great, the new mine very promising. The attitude of our officers was favorable. My own expressed view, based on three years’ experience in mining, was that, though much greater difficulties and magnitude would develop even than yet foreseen, the scheme was nevertheless feasible, was within our minelaying experience in principle, and, though it could hardly be more than half or a quarter effective, it was well worth doing. The British Admiralty’s approval and belief in the practicability of the scheme was implied in the original paper, but an explicit confirmation was asked and obtained by cable, on the basis of their three years’ war experience and knowledge of North Sea conditions. And so the plan went to the Secretary of the Navy bearing the General Board’s approval, as promising a sufficient degree of success to warrant undertaking it.
CHAPTER THREE
The Bases in Scotland
The British Minelaying Squadron was to operate from Grangemouth, near Rosyth, on the Firth of Forth. As a mine assembling and operating base for the American Squadron, the British naval authorities decided on Inverness and Invergordon, in the Scottish Highlands, situated on Inverness Firth and Cromarty Firth, respectively, which empty into Moray Firth about eight miles apart. One base would have been enough and in some respects more convenient, but the limited transportation means across Scotland necessitated two. To require the slow mine carriers to navigate the difficult passages around the north of Scotland would prolong their exposure to submarines and cause more escort duty for destroyers, so it was decided to discharge their cargoes on the west side, at points which gave a short haul across Scotland—Fort William, at the western terminus of the Caledonian Canal, and Kyle of Loch Alsh, where one crosses to the Isle of Skye. The cargoes were transported by canal motor-barge and by the Highland Railway.
