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DaveyJ576 · 10-20-10, 10:05 PM

As to which boats were welded, it goes like this:

Riveting had been the joinery method of choice since the dawn of steel ships in the 1890's. It was well understood as a process and when brand new it provided a strong seam. The problem arose in that over time, bending and flexing moments weakened and tended to separate a riveted joint. This has obvious negative implications for pressure hull strength and was a constant headache when it came to fuel tanks. All submarines up to the V-boats leaked fuel for this reason and the older the boat got the worse the problem got. A slick of leaking fuel trailing behind the boat tended to give away its position to prowling destroyers. Seams had to caulked whenever the opportunity presented itself and it was a constant and ongoing chore.

Stodgy and conservative naval architects and engineers at the Government yards were quite aware of this new process of welding, but were very mistrustful of this technique. They felt that there was not enough operational experience with this technique (and they were right to an extent) to trust it completely. They thought a welded seam would crack, rather than flex as a riveted joint would. Riveting was what they knew and they were going to stick with it.

On the other hand, in the 1930's Electric Boat was very keen on re-establishing itself as a submarine manufacturer and distinguishing itself from the Government owned yards. During the height of the Great Depression, it was also very interested in making itself profitable. Therefore, it embraced welding as a means to these ends. Not only would welding provide a stronger and more durable seam (the EB engineers felt) but it also saved a lot in labor costs.

EB had been shut out of the submarine building business for a almost 11 years while the Government yards (Portsmouth and Mare Island) got the contracts for the V-class. So, when given the chance to build what would become the Cuttlefish, they jumped at it and were eager to once again prove their efficacy as a submarine builder. They desperately wanted to demonstrate welding to the Navy. Distrustful of the technique, the Navy allowed them some leeway and EB used welding to join together seams for the fuel tanks only. The rest of the boat was riveted. Subsequent tests and trials showed that the experiment was quite successful; the Cuttlefish's fuel tanks were tight and remained so. EB was happy with the results and made a wholesale shift to welding.

The designers at Portsmouth were not yet convinced and were not ready to make the shift to welding. For the next series of boats, (the Porpoise/Shark/Perch class) the Government yards continued with riveting and the EB built boats were welded. Operational experience with these boats and shock tests performed on caissons eventually won over the Government designers and all subsequent boats were welded.

So the breakdown goes like this:

All submarines up to Cachalot (SS-170): riveted
Cuttlefish (SS-171): partial riveted and partial welded
Porpoise (SS-172) & Pike (SS-173): riveted
Shark (SS-174) & Tarpon (SS-175): welded
Perch, Pickerel, & Permit (SS-176-178): welded
Plunger, Pollack, & Pompano (SS-179-181): riveted
All subsequent boats from all yards: welded

The riveted boats were mostly pulled from front line duties as quantities of Gatos started to show up in theater. Except for Narwhal, Nautilus, & Pollack they were pulled back to the states for training duties, still useful to the end.

BTW, Porpoise & Pike were the last full double hull fleet boats. EB reintroduced the partial double hull (the outer hull merged with the pressure hull at each end at the torpedo room bulkheads) when they built Shark. All subsequent fleet boats had the partial double hulls.

10-20-10, 10:05 PM	#18
DaveyJ576 Officer Join Date: Nov 2008 Location: Norfolk, VA Posts: 241 Downloads: 30 Uploads: 0	Welding As to which boats were welded, it goes like this: Riveting had been the joinery method of choice since the dawn of steel ships in the 1890's. It was well understood as a process and when brand new it provided a strong seam. The problem arose in that over time, bending and flexing moments weakened and tended to separate a riveted joint. This has obvious negative implications for pressure hull strength and was a constant headache when it came to fuel tanks. All submarines up to the V-boats leaked fuel for this reason and the older the boat got the worse the problem got. A slick of leaking fuel trailing behind the boat tended to give away its position to prowling destroyers. Seams had to caulked whenever the opportunity presented itself and it was a constant and ongoing chore. Stodgy and conservative naval architects and engineers at the Government yards were quite aware of this new process of welding, but were very mistrustful of this technique. They felt that there was not enough operational experience with this technique (and they were right to an extent) to trust it completely. They thought a welded seam would crack, rather than flex as a riveted joint would. Riveting was what they knew and they were going to stick with it. On the other hand, in the 1930's Electric Boat was very keen on re-establishing itself as a submarine manufacturer and distinguishing itself from the Government owned yards. During the height of the Great Depression, it was also very interested in making itself profitable. Therefore, it embraced welding as a means to these ends. Not only would welding provide a stronger and more durable seam (the EB engineers felt) but it also saved a lot in labor costs. EB had been shut out of the submarine building business for a almost 11 years while the Government yards (Portsmouth and Mare Island) got the contracts for the V-class. So, when given the chance to build what would become the Cuttlefish, they jumped at it and were eager to once again prove their efficacy as a submarine builder. They desperately wanted to demonstrate welding to the Navy. Distrustful of the technique, the Navy allowed them some leeway and EB used welding to join together seams for the fuel tanks only. The rest of the boat was riveted. Subsequent tests and trials showed that the experiment was quite successful; the Cuttlefish's fuel tanks were tight and remained so. EB was happy with the results and made a wholesale shift to welding. The designers at Portsmouth were not yet convinced and were not ready to make the shift to welding. For the next series of boats, (the Porpoise/Shark/Perch class) the Government yards continued with riveting and the EB built boats were welded. Operational experience with these boats and shock tests performed on caissons eventually won over the Government designers and all subsequent boats were welded. So the breakdown goes like this: All submarines up to Cachalot (SS-170): riveted Cuttlefish (SS-171): partial riveted and partial welded Porpoise (SS-172) & Pike (SS-173): riveted Shark (SS-174) & Tarpon (SS-175): welded Perch, Pickerel, & Permit (SS-176-178): welded Plunger, Pollack, & Pompano (SS-179-181): riveted All subsequent boats from all yards: welded The riveted boats were mostly pulled from front line duties as quantities of Gatos started to show up in theater. Except for Narwhal, Nautilus, & Pollack they were pulled back to the states for training duties, still useful to the end. BTW, Porpoise & Pike were the last full double hull fleet boats. EB reintroduced the partial double hull (the outer hull merged with the pressure hull at each end at the torpedo room bulkheads) when they built Shark. All subsequent fleet boats had the partial double hulls. Last edited by DaveyJ576; 10-21-10 at 04:29 PM.