The H-class submarines had a length of 150feet overall, a beam of 15feet and a mean draft of 12feet. They displaced 358LT on the surface and 467LT submerged. The boats had a crew of 2 officers and 23 enlisted men. They had a diving depth of 200feet.[1]
For surface running, they were powered by two New London Ship & Engine Co. 4750NaN0 diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 170hp Electro Dynamic Co. electric motor. They could reach 14kn on the surface and underwater.[1] On the surface, the boats had a range of 2300nmi at and 100nmi at submerged.[2]
The boats were armed with four 18-inch (450 mm) torpedo tubes in the bow. They carried four reloads, for a total of eight torpedoes.[2]
H-4 was launched on 9 October 1918, and commissioned on 24 October 1918. Stationed at San Pedro, California — first with Submarine Division 6 (SubDiv 6) and then SubDiv 7 — H-4 participated in various battle and training exercises along the West Coast with her sister H-boats. These exercises were interrupted by occasional patrol duty off Santa Catalina Island and periodic overhauls at Mare Island.
In company with the two sub divisions and tender, H-4 sailed from San Pedro on 25 July 1922 and reached Norfolk, Virginia on 14 September via Magdalena Bay, Corinto, and Coco Solo. She decommissioned there on 25 October. H-4 was struck from the Naval Vessel Register on 26 February 1931 and sold for scrap on 14 September.