A good view of the Portsmouth Navy Yard .
The large shipbuilding shed in the foreground housed 5 building ways that allowed construction to be continued year-round. As can be seen to the left, some boats were constructed in drydocks, as well.
Photo scanned from: "The Fleet Submarine in The U.S. NAVY "- John D. Alden
Portsmouth had the largest capacity for submarine construction during the Second World War. 108 submarines were assigned to be built here during the war and 80 were completed. In order to streamline construction, large sections of the submarines were pre-fabricated in the shops before the keel was laid. Thus the ships were on the building ways and in the basins for a minimum amount of time. Indeed, the yard set a record of fifty-six days from keel laying to launching for USS Cisco (SS 290) in 1942. Later in the war another record for construction was established when the USS Sea Poacher (SS 406) went from keel laying to commissioning in 173 days. Portsmouth built boats were favored by wartime commanders for their up-to-date equipment. As a side effect of their rapid construction however, they were also considered less finished and less neatly arranged than boats build in other yards of the period.