Liberty ships?

[dextadriver]

I have a big interest in machines of ww2
Earlier I was reading online about liberty ships
Each ship was built in just a few days
What would have caused cracking in the structure of some ships
Some ships broke in half and sank
But a lot of ships were unaffected
What could be reason?
Poor quality steel in wartime?
Poor quality welding?
Thanks

 

[optima21]

they wernt expected to last, they were a disposable item. they were just built as fast as possible as the allies needed ships to be made faster than the germans could sink them. dont think there would have been much quality control on them.

maybe this should help you

War Factories , Series 1, Episode 7 - German Aviation on UKTV Play

The untold secret story of war production that shaped the Second World War.

uktvplay.co.uk

 

[brightspark]

Technical Problem Identification for the Failures of the Liberty Ships

The U.S. Liberty Ship Building Program in World War II set a record—a total of 2700 Liberty Ships were built in 6 years, in order to support the battle against Nazi-Germany. However, numerous vessels suffered sudden fracture, some of them being split in half. This paper demonstrates and...

www.mdpi.com

 

[DAPPH]

Italian welders with leanings to Mussolini sabotaging things same happened in a lot of American war factories pre the USA joining in . ? The shipyards were almost stopped by Mafi types in control of the unions

 

[DaveB]

The total welding of ships was new.
The old rivetted construction could 'flex' a bit in rough seas which the welded construction could not.
Add in a design weakness with the square corners to the cargo hatches being a stress raiser.
Then the fact that the particular steels used go through their brittle transition at close to 0 C and the North Atlantic is regularly prettu cold.

Once a crack started it never got caught by a rivet hole, rivet holes were typically 1 inch or bigger and form excellent crack stoppers !!

 

[Tom O]

I don’t know if it’s true but I have heard that earlier shipbuilding welders were paid by the rod and sometimes welded rods in place .

 

[Ross365]

I was told by a member of staff in a University metallurgy department that it was a materials problem associated with very low temperatures.

 

[Burdekin]

Brittle fracture.

 

[addjunkie]

I don’t know if it’s true but I have heard that earlier shipbuilding welders were paid by the rod and sometimes welded rods in place .

That was common place in the 70s yards when they were on piece work.

Brittle fracture.

Id agree, the North Atlantic in winter isnt a kind place, having spent a bit of time out there, look at the great circle route to Murmansk and youll see how far North they go. Chuck in low temperature , in experienced welders working at pace, I can see how they cracked up. I remember covering this many years ago at college briefly, cant remember if it was covered in Naval Architecture or somewhere else.

I did a trip on a bulk carrier running Iron Ore from Seven Islands to-the Uk, we welded cracks / doubling plates up every port!

If your really interested in getting up close and personal to a liberty ship, there is one with sea worth condition with a triple expansion steam engine in San Francisco astern of the WW 2 American sub.

USS Pampanito - Wikipedia

en.wikipedia.org

SS Jeremiah O'Brien - Wikipedia

en.wikipedia.org

 

[Erie Fred]

Italian welders with leanings to Mussolini sabotaging things same happened in a lot of American war factories pre the USA joining in . ? The shipyards were almost stopped by Mafi types in control of the unions

Evidence ?

 

[Tinbasherdan]

Brittle fracture, sometimes onset by poor control over the HAZ when welding. Remember welding ships was relatively in its infancy in those days! Have a look at the uss schenectady (sp?) broke its back just sitting at the quay

 

[addjunkie]

Brittle fracture, sometimes onset by poor control over the HAZ when welding. Remember welding ships was relatively in its infancy in those days! Have a look at the uss schenectady (sp?) broke its back just sitting at the quay

She was a T2.

T2 tanker - Wikipedia

en.wikipedia.org

 

[Tinbasherdan]

She was a T2.

T2 tanker - Wikipedia

en.wikipedia.org

Different ship type, same issue!

 

[Burdekin]

That was common place in the 70s yards when they were on piece work.

Id agree, the North Atlantic in winter isnt a kind place, having spent a bit of time out there, look at the great circle route to Murmansk and youll see how far North they go. Chuck in low temperature , in experienced welders working at pace, I can see how they cracked up. I remember covering this many years ago at college briefly, cant remember if it was covered in Naval Architecture or somewhere else.

I did a trip on a bulk carrier running Iron Ore from Seven Islands to-the Uk, we welded cracks / doubling plates up every port!

If your really interested in getting up close and personal to a liberty ship, there is one with sea worth condition with a triple expansion steam engine in San Francisco astern of the WW 2 American sub.

USS Pampanito - Wikipedia

en.wikipedia.org

SS Jeremiah O'Brien - Wikipedia

en.wikipedia.org

Brittle fracture was the failure mechanism, cold water temperatures would make it more prevalent.

 

[julianthegypsy]

Any crack on a riveted ship would stop when it got to the end of a panel. Once welded, it could just keep going through the next panel etc...

 

[500e]

I read somewhere they did not stager the plates so the Crack could follow the weld

 

[prepman]

Technical Problem Identification for the Failures of the Liberty Ships

The U.S. Liberty Ship Building Program in World War II set a record—a total of 2700 Liberty Ships were built in 6 years, in order to support the battle against Nazi-Germany. However, numerous vessels suffered sudden fracture, some of them being split in half. This paper demonstrates and...

www.mdpi.com

Fascinating. I would also like to state emphatically that I was not involved in any of the welding.

 

[DAPPH]

Evidence ?

T'was a TV prog years ago about the massive industrial threat of power control & strikiing posed by certain trade unions on the war effort .

 

[Morrisman]

Brittle fracture, sometimes onset by poor control over the HAZ when welding. Remember welding ships was relatively in its infancy in those days! Have a look at the uss schenectady (sp?) broke its back just sitting at the quay

SS Schenectady - Wikipedia

en.wikipedia.org

 

[Morrisman]

Evidence ?

A few minutes on the internet throws up no end of info about the deals the US govt cut with the mafia run ship building industry early on in WW2.