1st February 1917
Unrestricted German Submarine Warfare
In April, German U-boats sank 555,056 tons of British merchant vessels. The shipyards in Belfast and Londonderry received many orders to replace the hundreds of ships that had been lost. During 1918 alone, Belfast shipyards launched 201,070 tons of merchant shipping. Belfast Lough and Lough Foyle were seen as safe havens from U-boats, so major repair and refit work was the main contribution of the Northern Irish shipyards to the Allied war effort. Labour was in short supply during the war, so existing workers had to work long hours in Harland & Wolff. It was not uncommon for workers to put in over 80 hours in one week.