INTRODUCTION

Before 1914, the Royal Navy, confident of its supremacy at sea, gave little consideration to either the production and laying of mines or to sweeping minefields. Serious losses of warships and merchantmen to enemy mines forced the hasty organisation of sweeping flotillas of converted trawlers, paddle steamers and tugs, reinforced later by purpose-built vessels. As close blockade of enemy ports by surface warships was impossible, in part because of enemy minefields, the British resorted to sowing their own mines around Heligoland and off the Jade and Ems, initially to inhibit sorties by the High Seas Fleet but, after the introduction of submarine warfare against shipping, increasingly to block the exits of U-boats. In addition to mining by submarines and converted minelayers in the Bight, the British sought also to close the Straits of Dover and Otranto to the U-boats, using nets and surface and air patrols as well as mines. Despite prodigious efforts, none of these measures met with much success. At best they represented an inconvenience to the enemy. The Germans swept marked channels regularly and natural forces swept away other mines. Moreover, the standard British mine was notoriously ineffective, though by the time the Americans came into the war, the Admiralty had begun to copy the much more reliable German pattern [272].

The Americans, imbued with an offensive spirit, a desire for instant solutions and an unquenchable faith in the ability of modern technology to solve any question, at once pressed for the wholehearted introduction of mine and net barrages at every narrow point, especially the northern outlet of the North Sea. Their somewhat accidental discovery of a wonder mine and ingenious proposals emanating from the Coast and Geodetic Survey of the Department of Commerce were seized upon by the zealous Assistant Secretary of the Navy, Franklin D. Roosevelt. Stressing the high potential efficacy of barriers across the Straits of Dover and Otranto and, most importantly, between Scotland and Norway, he urged Wilson, the Navy Department and the visiting Balfour mission to adopt the scheme and the American antenna mine. A North Sea Barrage would lie nearer British bases than German and therefore it could be patrolled and defended without undue difficulty and would pose the Germans an intractable and demoralising problem. Roosevelt presented the idea with all the zest and imagination for which he was noted.