# Riveted plates on old ships **URL:** \ **Category:** Factual Questions\ **Created:** [April 22, 2012, 6:35am UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563 "2012-04-22T06:35:14Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Chickenwrangler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chickenwrangler/32/91_2.png) [@Chickenwrangler](https://boards.straightdope.com/u/Chickenwrangler)\ **Post date:** [April 22, 2012, 6:35am UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/1 "2012-04-22T06:35:14Z")
Lots of interest in the Titanic at the moment which reminds me of a thought I had some time ago about all those rivets you see on the hulls of old ships. I understand that a hot rivet is hammered through holes in two steel plates and as the rivet cools it pulls the two plates together. Ok I get that, but was that good enough to make the plates watertight or did they have to use some kind of sealant/coating to stop leakage? 🙂 ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [April 22, 2012, 7:38am UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/2 "2012-04-22T07:38:57Z")
My observation, as a complete non-expert: those steel plates are painted – above the water line partly for appearance, but below the water line to retard corrosion of the steel plates. That paint is laid on fairly thick, and would by itself seal any small gaps between the plates. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [April 22, 2012, 12:34pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/3 "2012-04-22T12:34:55Z")
Not sure. Boilers were made this way, and had to be water and gas tight at high pressure after many cycles changing hundreds of degrees in temperature – a much tougher requirement. I know a mechanical engineer who is also a steam locomotive engineer, and will ask him! ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [April 22, 2012, 2:41pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/4 "2012-04-22T14:41:32Z")
There’s a bygone shipbuilding trade called caulking. The caulkers were charged with caulking those seams to make them watertight. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [April 22, 2012, 3:48pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/5 "2012-04-22T15:48:32Z")
> [@gotpasswords](#): > > There’s a bygone shipbuilding trade called caulking. The caulkers were charged with caulking those seams to make them watertight. After they were riveted ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [April 22, 2012, 4:23pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/6 "2012-04-22T16:23:57Z")
> [@Snnipe\_70E](#): > > After they were riveted And on a quick read, it’s not the same as the caulking that was done on wooden ships - actually driving old rope-strands or tar into the seams between planks. It seems to involve deforming the edge of a riveted plate to make it into a snugger fit with the next. ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 22, 2012, 7:08pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/7 "2012-04-22T19:08:37Z")
> [@Malacandra](#): > > And on a quick read, it’s not the same as the caulking that was done on wooden ships - actually driving old rope-strands or tar into the seams between planks. It seems to involve deforming the edge of a riveted plate to make it into a snugger fit with the next. Well, don’t leave us wondering. 😕 _ **How** _ was the edge ‘deformed’, and how was it accomplished? Was it done before or after the plates were riveted together? ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [April 22, 2012, 7:29pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/8 "2012-04-22T19:29:06Z")
> [@JBDivmstr](#): > > Well, don’t leave us wondering. 😕 > > _ **How** _ was the edge ‘deformed’, and how was it accomplished? Was it done before or after the plates were riveted together? Wiki sez: > [@](#): > > In riveted steel or iron ship construction, caulking was a process of rendering seams watertight by driving a thick, blunt chisel-like tool into the plating adjacent to the seam. This had the effect of displacing the metal into a close fit with the adjoining piece.[1] Originally done by hand much like wooden vessel caulking, pneumatic tools were later employed. With the advent of electric-arc welding for ship construction, steel ship caulking is truly a lost art. and mentions that the same thing was done with boilers. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [April 22, 2012, 7:51pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/9 "2012-04-22T19:51:57Z")
One thing this leaves me wondering: A quick check shows that both arc welding and oxy acetylene welding were developed in the late 19th century. How come they were still using riveted hull and boiler construction well past WW I? The Queen Mary, laid down in 1930, was riveted. Steam locomotive boilers were still riveted in the 1920s. ---
**Author:** ![Kenm](https://avatars.discourse-cdn.com/v4/letter/k/bc79bd/32.png) [@Kenm](https://boards.straightdope.com/u/Kenm)\ **Post date:** [April 22, 2012, 9:13pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/10 "2012-04-22T21:13:33Z")
> [@yabob](#): > > How come they were still using riveted hull and boiler construction well past WW I? The Queen Mary, laid down in 1930, was riveted. Steam locomotive boilers were still riveted in the 1920s. Welding wasn’t as strong as riveting. James Burke, in his TV series Connections from the mid-'70s, discusses the first all-welded ships built in the 1940s, Liberty ships. Burke says [**here**](http://www.youtube.com/watch?v=kGPawxh-E34) (YouTube) that all-welded ships weren’t as strong as riveted ships, but they weren’t expected to last more than five years. From the video clip that includes the Liberty ship Jeremiah O’Brien: > [@](#): > > ". . . They’re doing something nobody has ever tried before. The Liberty is an all-welded ship. That’s another reason why during World War II, this ship is such hot stuff. > > "The point about welding ships is it’s faster than joining the bits together with rivets. But not as strong. . . . > > . . ."We’re here assembling wartime ships because the Curies’ crystal electric guage got used by Lengevin to develop sonar that helped knock out German U-boats attacking the ships you’re looking at being put together faster than the U-boats can sink them. > > “The first ship takes 256 days to get built; by 1942 they’ve got it down to an incredible 15 1/2 hours.” ---
**Author:** ![Mk\_VII](https://avatars.discourse-cdn.com/v4/letter/m/5f9b8f/32.png) [@Mk\_VII](https://boards.straightdope.com/u/Mk_VII)\ **Post date:** [April 22, 2012, 9:26pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/11 "2012-04-22T21:26:14Z")
British shipyards were very slow to introduce welded hull construction, even in the 1940s many warship hulls were still riveted. The post-war slump meant many yards closed altogether and those that remained had cautious, ageing management who were reluctant to innovate. The hard times also lead to often bitter industrial relations and some strange trade-union demarcation dividing lines. As to watertightness - frequently they weren’t. Single-riveted seams often loosened in rough weather, particularly in small ships like destroyers where captains might drive them hard in rough weather if they dared. The mess-decks (normally in the forepeak) could be miserable places in an Atlantic storm, with water streaming in from the loose rivets on the deck as well. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [April 22, 2012, 10:59pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/12 "2012-04-22T22:59:36Z")
> [@yabob](#): > > One thing this leaves me wondering: > > A quick check shows that both arc welding and oxy acetylene welding were developed in the late 19th century. How come they were still using riveted hull and boiler construction well past WW I? The Queen Mary, laid down in 1930, was riveted. Steam locomotive boilers were still riveted in the 1920s. To expand on what was already said… The metallurgy and welding technology just weren’t mature enough. One thing that riveted seams did better was stop cracks. Here’s a [rather famous photograph](http://matdl.org/failurecases/Other_Failure_Cases/Liberty_Ship) of a liberty ship that split clean in half because of metal stress issues in combination with few barriers to crack propagation. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [April 23, 2012, 1:09am UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/13 "2012-04-23T01:09:54Z")
I had a teacher at the maritime academy whotold the sstory of being on a liberty ship that started to crack inhalf at sea. Acording to the teacher they managed to get the two bow hooks back to the stern and the stern hook up to the bow. Then they put tension on both to hold the ship together until they could get to the nearest safe port. I was also on a T-2 tanker that was of the complete welded hull design. Some time after WWII sshe was put in dry dock and a line was cut down the hull and butt strapped over. This way if a crack started it would travel only to the butt strap and there it would stop. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [April 24, 2012, 8:07pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/14 "2012-04-24T20:07:59Z")
> [@Napier](#): > > Not sure. Boilers were made this way, and had to be water and gas tight at high pressure after many cycles changing hundreds of degrees in temperature – a much tougher requirement. > > I know a mechanical engineer who is also a steam locomotive engineer, and will ask him! My expert says there is no caulking or gasketing in boiler riveted joints, and that the contraction of a hot rivet is an essential part of the process of sealing the joint. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [April 24, 2012, 9:36pm UTC](https://boards.straightdope.com/t/riveted-plates-on-old-ships/619563/15 "2012-04-24T21:36:36Z")
> [@Chickenwrangler](#): > > Ok I get that, but was that good enough to make the plates watertight or did they have to use some kind of sealant/coating to stop leakage? Typically a pneumatic caulking operation was performed along the bottom edges of the overlapping plates, causing the steel to flow plastically into the riveted joint. No sealant required.