I can’t post the pix here because the magazine is copyright, but it’s worth the money to get a copy. Here’s a similar photo I found on the net to give you an idea of what I’m talking about.
One photo shows employees of the General Machinery Corp. standing in front of, and on, one of the engines. It looks to be about four stories tall, not all that unusual for large steam engines of the era. But what blows my mind is the story about how these things are machined and the photos of the machines that did the work. One shot shows a 20-foot boring mill boring a cylinder. There is a man standing on the table, and the machine is about six times taller than he is. If he’s six feet tall, that makes the machine about 36 feet tall. The man needs a ladder to get up onto the table. The boring bar is almost as big around as his torso.
The story says that at its peak this factory turned out one complete engine every day and a half.
What is also incredible is the accuracy they maintained. The crankshaft weighed 40,000 pounds and the six 14 1/4” dia. journals were turned to plus .000, minus .002. And the whole crank was straight and true over its 21-foot length to .004. The 18,500 lb. low pressure cylinder with a diameter of 70 inches and a length of 65 inches is bored to ±.002 over its length. The bolt holes for the crank bearing caps are bored to ±.0005 over 15 3/4 inches and the 18.25-inch spacing between the holes must be within ±.001.
Just looking at the machines makes you wonder how they made them and got them true.
Check it out.
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* Engineers & Engines Magazine
Box 10
Bethlehem, MD 21609
