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Liberty ships were pre-fab cargo ships with sections bolted together at the seams. Some did come apart at sea but the majority being successful made the risk worthwhile.

Liberty Ship Technical Specifications

Speed: 10.5 knots (12 mph), presumably even when fully loaded.
Gross weight (i.e., weight of empty ship): 7000 tons
Cargo weight (applicable to ship’s “full load displacement” rating):7000 tons
Full load” Displacement (Gross weight + full-load cargo weight):14,000 tons
The so-called “Deadweight” (i.e., amount of Cargo, and the ship’s own Fuel, etc., which the ship could carry on emergency missions if seas didn’t become too rough, or in calm lakes, etc.): …… 10,500 tons
Size:430 feet long; 57 feet beam (max width); 27 feet draft (depth into the water).
Power: total 2,500HP, from reciprocating steam engines.
Fuel: Oil
Crew: about 56 to 80; ((about 12 to 25 of those would likely be Navy personnel (guards) to man the ship’s several defensive guns. The number of these guns per ship increased during the war))

Quick! Name that plane!!! rofl.

I like these fact-sheets - they're fun to read. Thanx.

Some did come apart at sea but the majority being successful made the risk worthwhile.

Except for the crews on the ships that came apart at sea. [:(]

ORIGINAL: Orm

Some did come apart at sea but the majority being successful made the risk worthwhile.

Except for the crews on the ships that came apart at sea. [:(]

And for that reason they were modified to lessen the risk of failure. Also they were called Victory ships, but the name never stuck.

ORIGINAL: rustysi

ORIGINAL: Orm

Some did come apart at sea but the majority being successful made the risk worthwhile.

Except for the crews on the ships that came apart at sea. [:(]

And for that reason they were modified to lessen the risk of failure. Also they were called Victory ships, but the name never stuck.

Thought Victory was a separate class - later than the Liberty. Think they were a bit faster as well.

The John Brown Saturday photographed by my friend Gary in the Chesapeake Bay.

Not bolted, welded.

Early ships were lost due to poor quality of steel used in construction. Somebody made nice buck out of those dead sailors.

"Titanic Effect" I might call it.

The SS American Victory is a Victory class ship that was restored and now is a museum ship in Tampa, FL.

I have taken a tour of her.

She is still ship worthy and they occasionally take her out on short fundraising cruises.

If anyone is in the area I would recommend the SS American Victory as a stop.

Her official website with further details is here:
http://www.americanvictory.org

ORIGINAL: IdahoNYer

ORIGINAL: rustysi

ORIGINAL: Orm


Except for the crews on the ships that came apart at sea. [:(]

And for that reason they were modified to lessen the risk of failure. Also they were called Victory ships, but the name never stuck.

Thought Victory was a separate class - later than the Liberty. Think they were a bit faster as well.

Some Victory ships were used after the war. I worked with a man who served on one as a engineer (at the time I worked with him he was already retired, but he was loaned in at age 73 because of his experience in engineering)

As for what Pelthunter said, I don't think they were trying to be cheap... Welding was new technology in shipbuilding and a weld is hard too check without the correct equipment..... With inexperienced welders nasty things can happen (such as the breaking up of ships....)

One Constance Tipper delved into the issue of claimed failed welding and it was proven false accusation.

Ships were broken due to sub-standard steel used in construction. And why would you use sub-standard steel in building ships, hmm?

Sources, people. Lets have sources [:)]

Well, perhaps "sub-standard" is too strong a term. Perhaps "grade not really suited for cold weather climates" is better description.

"Constance Tipper was one of the first women to take the Natural Sciences Tripos, in 1915. Her major research contribution was to discover why during the Second World War the Liberty Ships were breaking in two.

Working from the Engineering Department in Cambridge, Tipper established that there is a critical temperature below which the fracture in steel changes from ductile to brittle. The Liberty Ships in the North Atlantic were subjected to such low temperatures that they would have been susceptible to brittle failure.

The full implications of her work were not realised until the 1950s but after that, the ‘Tipper test’ became the standard method for determining this form of brittleness in steel."

Forum for some reason does not allow me to post links.

ORIGINAL: pelthunter

One Constance Tipper delved into the issue of claimed failed welding and it was proven false accusation.

Ships were broken due to sub-standard steel used in construction. And why would you use sub-standard steel in building ships, hmm?

Very true. It was the steel at fault, not the weld, although it took a while to figure this out because you can't exactly examine the on the bottom of the Atlantic.

ORIGINAL: Numdydar

Sources, people. Lets have sources [:)]

Freedom's Forge detailed this during the chapters on Henry Kaiser and the shipyards. There was a lot of wheeling and dealing, a lot of subcontracting going on during those years. Most produced excellent products and led to the overwhelming mass of good quality, efficiently produced material that the Allies piled into both theatres. Some of the stuff didn't go so well, as could be expected when everything, including the mass production techniques used to make the stuff, was new.

I don't remember the book mentioning a company that was particularly at fault for the steel, but I'm not sure it was intentionally bad steel made to profit from the war. Some of the steel plants were brand new too and probably had growing pains, but this is not from a source, just conjecture based on other details in the book about other industries and factories that didn't get it right in the beginning.

http://www.amazon.com/Freedoms-Forge-American-Business-Produced/dp/1400069645

Ah. Here is more. About Constance Tipper.

It was more a design flaw than either a problem with the process of welding or a 'poor' quality steel. It wasn't known that a different grade of steel might be needed for a welded ship as opposed to a riveted ship, or that a ship's steel under strain from load, weather and especially cold might become brittle instead of ductile.

[font="Trebuchet MS"]Liberty Ship Design Flaws
Many early Liberty ships were affected by deck and hull cracks and indeed several were lost. About 1,200 ships suffered from cracks during the war (about 30% of all Liberty-class ships), and 3 were lost when the ship suddenly split in two. Though the work force was largely untrained in the method of welding ships together, it was not worker error that caused these failures. Rather, the failures were caused by a design oversight.

The cause of the failures was discovered by Constance Tipper, an engineering professor at Cambridge. She found that the grade of steel used to make Liberty ships suffered from embrittlement, in which materials become brittle. Ships operating in the North Atlantic were often exposed to temperatures below a critical temperature, which changed the failure mechanism from ductile to brittle. Because the hulls were welded together, the cracks could propagate across very large distances; this would not have been possible in riveted ships.[/font]

http://www.brighthubengineering.com/marine-history/88389-history-of-the-liberty-ships/

It wasn’t sub-standard welding. Only a very few ships broke up. The cause was extensively investigated and found to be a load-stress failure at the aft corner of the #2 cargo hatch. The technical reports are freely available and very informative. They even show pictures for the linguistically challenged.

The fix was to relocate two frames and add a longitudinal stringer. Ships already in service were surveyed for the tell-tale stress cracks and then retrofitted with a diagonal frame member.

No Liberty ship with the modification and no Liberty ship with the retrofit ever broke up on voyage, despite being overloaded by as much as 20-25%, thus putting unbelievable stress on the ship girder.

Victory ships were built using exactly the same construction methods. They simply had a different hull form and a more robust powerplant. Many of these are still in service in outlying corners of the world, 60 years later.

A high school friend's father bought and ran 4 surplus Liberty ships between New York (cargo was coal) and Rio (cargo was lumber). I was invited to work one summer and was tempted, but didn't bite.

Sorry Obvert, but that's not what Constance Tipper said. She found a metalurgical break point with respect to temperature. It had nothing whatever to do with "quality" of steel. The ships that broke, described above, broke on a longitudinal/torque stress point. It had nothing to do with steel, but had everything to do with wracking stress points. Yeah, she found that, under certain stresses, and under certain temperature conditions, $hit would get wierd.
And it was fixed.

But her stuff, if it was that important, would have found its way into the Fleet Program. But it didn't, and so there you be.

Isn't the Internet lovely? So many conspiracies and so little time. [:D]

As it was stated, her work was not really recognized for what it meant until 1950s.

Perhaps because she was, well, a she. Like many of the welders blamed for bad weld jobs. Women, sheesh.

ORIGINAL: tocaff
A high school friend's father bought and ran 4 surplus Liberty ships between New York (cargo was coal) and Rio (cargo was lumber). I was invited to work one summer and was tempted, but didn't bite.

You should have. I grew up with Lyke's in Tampa. I learned about the sea from them. Went to Europe when I was 12 on Adabelle Lykes. Yikes. JWE