I was a kid during WWII and afterward talked with a tanker who was in one of them in North Africa. Blown out of the turret twice. He said that if a shell didn't penetrate the hull, most of the crew were killed anyway as the concussion knocked all the rivets loose and they spanged about inside just like bullets.
“...In Lima, OH, they were turning out a tank ever 4.5 HOURS....”
There's a great book titled "Freedom's Forge" (read synopsis) that tells of the mind-boggling efforts that we made in ramping up for war as well as on-the-fly innovations when it finally hit. One was in the production of Sherman tanks where "the Fisher Tank Arsenal used a new welding technique that saved four-fifths machining time, bent the slabs into shape with a 480-ton metal press, and for final assembly, hoisted them on 30-ton jigs, rotating them like ducks on a spit." You put down the book and feel proud to be an American.
[Sidebar] Another innovation - the Swedes took 3 1/2 hours to rifle a 40mm anti-aircraft barrel. Our engineers used broaching and turned them out in 15 minutes.