United States H-class submarine

The United States H-class submarines were Electric Boat design EB26A and EB26R design coastal patrol submarines used by the United States Navy.

The first three submarines of the class were laid down in March–April 1911 as USS Seawolf (SS-28), Nautilus and USS Garfish, and were renamed H-1, H-2 and H-3 while still under construction on 17 November 1911, as part of a forcewide submarine redesignation. They were commissioned in December 1913/January 1914.

In 1915 the Imperial Russian Navy had ordered 18 H-class submarines built to a modified EB602 design. Ordered from the Electric Boat Company, they were to be built in Canada at a temporary shipyard near Barnet, Vancouver, British Columbia to avoid US neutrality concerns, which had derailed the delivery of ten similar submarines to the British. The shipyard was owned by the British Pacific Construction and Engineering Co. Twelve were delivered, and served as the American Holland-class submarines, but the shipment of the final six was held up pending the outcome of the Russian Revolution of 1917, and the boats were stored in knockdown condition at their construction yard. All six were purchased by the United States Navy on 20 May 1918 and assembled at Puget Sound Navy Yard before being commissioned as H-4 to H-9 in late 1918.

USS H-1 (SS-28) ran aground and was wrecked off the coast of Mexico on 12 March 1920, while the remaining eight submarines were decommissioned in late 1922, and laid up in the Reserve Fleet. Finally stricken from the Navy List in 1930, they were sold for scrap in 1931 and 1933.

Design
These vessels included some features intended to increase underwater speed that were standard on U.S. submarines of this era, including a small conning tower and fairwater, and a rotating cap over the torpedo tube muzzles. For extended surface runs, the small fairwater and its open bridge was augmented with a temporary piping-and-canvas structure (see photo). USN tactical employment of these submarines in this era did not require "crash dives", so the considerable time it took to dismantle and store below the temporary bridge structure was not considered a liability. Experience in World War I showed that the piping and canvas structure was inadequate in the North Atlantic weather, and USN submarines serving overseas in that war (E, K, and L-classes) had the forward structure of the fairwater modified with a metal "chariot" shield. Starting in 1918-1919 with lessons learned from overseas experience, U.S. submarines had bridges more suited to surfaced operations in rough weather.

The streamlined, rotating torpedo tube muzzle cap eliminated the drag that muzzle holes would otherwise cause. In the stowed position, the submarine appears to have no torpedo tubes, as the holes in the cap are covered by the bow stem. This feature remained standard on Electric Boat designed submarines through the O-class, with the exception of the L-class and the USS M-1. The L and M-class boats pioneered the use of shutter-style doors for the torpedo tubes, which then became the standard for all USN submarines starting with the S-class patrol submarines of the 1920's.

The EB26A design originally built for the USN (H-1 to H-3) had a watertight bulkhead separating the torpedo room from the forward battery compartment. The six boats of the H-4 to H-9 group were built to the EB602L design (EB26R for the USN) for export to Russia. When seized by the U.S., they were completed to that slightly modified design. The biggest difference being that they did not have the bulkhead between the torpedo room and the forward battery, essentially making it one large compartment.

Since the acquisition of the H-4 to H-9 group was delayed, other types had already been acquired by the USN so these last six boats were assigned hull numbers that fell into the middle of the S-class (147-152)

Boats

 * USS H-1 (SS-28) (originally Seawolf), laid down 22 March 1911, launched 6 May 1913, commissioned 1 December 1913. Wrecked, 12 March 1920.
 * USS H-2 (SS-29) (originally Nautilus), laid down 23 March 1911, launched 4 June 1913, commissioned 1 December 1913. Decommissioned, 23 October 1922, sold for scrap 1 September 1931.
 * USS H-3 (SS-30) (originally Garfish), laid down 3 April 1911, launched 3 July 1913, commissioned 16 January 1914. Decommissioned, 23 October 1922, sold for scrap 14 September 1931.
 * USS H-4 (SS-147), laid down 12 May 1918, launched 9 October 1918, commissioned 24 October 1918. Decommissioned, 25 October 1922, sold for scrap 14 September 1931.
 * USS H-5 (SS-148), laid down 12 May 1918, launched 24 September 1918, commissioned 30 September 1918. Decommissioned, 20 October 1922, sold for scrap 28 November 1933.
 * USS H-6 (SS-149), laid down 14 May 1918, launched 26 August 1918, commissioned 9 September 1918. Decommissioned, 23 October 1922, sold for scrap 28 November 1933.
 * USS H-7 (SS-150), laid down 15 May 1918, launched 17 October 1918, commissioned 24 October 1918. Decommissioned, 23 October 1922, sold for scrap 28 November 1933.
 * USS H-8 (SS-151), laid down 25 May 1918, launched 14 November 1918, commissioned 18 November 1918. Decommissioned, 17 November 1922, sold for scrap 28 November 1933.
 * USS H-9 (SS-152), laid down 1 June 1918, launched 23 November 1918, commissioned 25 November 1918. Decommissioned, 3 November 1922, sold for scrap 28 November 1933.