USS San Francisco (C-5) - World War I

World War I

With the April 1917 entry of the United States into World War I, San Francisco began laying antisubmarine nets in the Hampton Roads area. In June, she shifted to New York, whence she conducted experimental deep water minelaying operations; and, during August, she underwent overhaul at the Portsmouth Navy Yard. In mid-September, she moved back down the coast to New London, Connecticut where she provided net laying services until ordered to Norfolk for training duty later in the fall. From December 1917-March 1918, she underwent an extensive overhaul; and, in April, she became flagship of Mine Squadron 1.

In early May, the squadron assembled at Newport, Rhode Island. On the 12th, the ships sailed for the United Kingdom. On the 26th, units of the Royal Navy escorted the ships into Inverness. San Francisco joined the Allied effort of creating the North Sea Mine Barrage across the North Sea to restrict German submarine traffic into the Atlantic by:

• planting 153 mines during the 1st minelaying excursion on 7 June,
• planting 170 mines during the 3rd minelaying excursion on 14 July,
• planting 170 mines during the 4th minelaying excursion on 29 July,
• planting 170 mines during the 5th minelaying excursion on 8 August,
• planting 166 mines on 12 August to field test sensitivity settings for the antenna fuze detonating relay of the Mk 6 mines,
• planting 160 mines during the 6th minelaying excursion on 18 August,
• planting 170 mines during the 7th minelaying excursion on 26 August,
• planting 170 mines during the 8th minelaying excursion on 7 September,
• planting 170 mines during the 9th minelaying excursion on 20 September,
• planting 170 mines during the 10th minelaying excursion on 27 September,
• planting 170 mines during the 11th minelaying excursion on 4 October,
• planting 170 mines during the 12th minelaying excursion on 13 October, and
• planting 170 mines during the final 13th minelaying excursion on 24 October.