G Class: Overseas Submarines
These boats were designed on the lines of the Italian submarines of the time. As with the F Class, they were built with a double hull in an attempt to improve on the saddle tank design. In reality, they provided little improvement over the popular and highly successful E Class.
The G class were the first British submarine to have 21" torpedo tubes. The original design called for 1 bow and 1 stern tube. However, it had been shown that 2 bow tubes gave a greater chance of success in attacks so the bow was altered to accommodate 2 tubes. This posed a problem with weight so the older 18" bow tubes were fitted. There were also two 18" beam tubes.
Other armament included a 3" Deck Gun.
A total of 14 boats were completed between 1915 and 1917. The first 5 boats, G1 to G5 were all built at Chatham.
During the war, operating in Home Waters, the class had two notable successes when G2 sank U 78 and G11 UC 43.
Four of the class were lost in the war. The first G9 having attacked (unsuccessfully) HMS Pasley by mistake, the Pasley turned and rammed the submarine. Only one survivor from G9 was picked up. Both G7 and G8 failed to return from patrols. G7 was the last submarine loss of the war. The last of the four boats, G11, was wrecked 11 days after the armistice. All 10 G Class surviving the war, were sold between 1920 and 1928.