Did German WW2 U-boats have a lathe on board?

Yes they did. This one is from U-505, captured in WW2 and presently on display in Chicago Illinois. read more

As the war ended the Operation Regenbogen order went out for Germans to scuttle their U-boats to prevent capture but 136 U-boats were recovered by the Allies. Most were used for testing, especially the Type XXI, which was the most advanced submarine in the world at the time. read more

In the first few years of World War I, the U-boats took a terrible toll on Allied shipping. In early May 1915, several New York newspapers published a warning by the German embassy in Washington that Americans traveling on British or Allied ships in war zones did so at their own risk. read more