Hey there boys and girls, if you think a wheel turning lathe for steam engine drivers is a big machine, put six bucks in an envelope and send it to Engineers & Engines magazine for the Feb/March ‘19 issue* and take a gander at what was used to make the triple expansion engines for WWII liberty ships. This will really blow your brains out.
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.
_______
* Engineers & Engines Magazine
Box 10
Bethlehem, MD 21609
Big machine tools that will blow your brains out
- Greg_Lewis
- Posts: 3021
- Joined: Wed Jan 15, 2003 2:44 pm
- Location: Fresno, CA
Big machine tools that will blow your brains out
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
Re: Big machine tools that will blow your brains out
I've always loved seeing that huge stuff.
Fred V
Pensacola, Fl.
Pensacola, Fl.
-
- Posts: 1852
- Joined: Tue Dec 06, 2016 4:05 pm
- Location: Elmwood, Wisconsin
Re: Big machine tools that will blow your brains out
Also interesting is that they selected a piston design over a more efficient and lighter turbine because the piston engine used mature technology that any shipyard could handle. This implies that those tolerances were considered routine.
Re: Big machine tools that will blow your brains out
I was told by one of the John W. Brown crew that gear making required for turbines was in short supply and needed for warships, therefore piston engines. I spent quite a bit of time in the engine room on a cruise. It is amazing how quiet that monster is even at full throttle.
Re: Big machine tools that will blow your brains out
you should see the size of the tools used to make the gun that went on Battle ships, steam powdered hammers to forge gun tubes, the mills to make the breech, the shaper to make the mount, the lath was so long a man rode the tool holder to watch the cut. Town I grew up in had a company called YUBA in Benicia California. They made dam gate ,gold dredges, etc. had some of the biggest machine tool I have ever see.
stay on the shine side of the rail
-
- Posts: 809
- Joined: Wed May 31, 2006 2:13 pm
- Location: Laguna Niguel CA
Re: Big machine tools that will blow your brains out
Boeing had a milling machine with a travel of around 100 feet or so; I saw it about 30 years ago. Yes, the machinist rode the carriage. They milled down the interior of the aluminum wing skins to reduce the thickness for weight savings. They were left full thickness where they mated to the ribs and spars. Ball-end mills were used to make a better transition from thin to thick to avoid the stress consequences of sharp corners.
Re: Big machine tools that will blow your brains out
Wonder how much faster you could build a live steamer using something like this? https://youtu.be/NC63Xx2N1-8?t=1m9s Probably a near million dollar machine.
Re: Big machine tools that will blow your brains out
Here's some modern large tooling:
Building-sized milling machine to make full-sized foam molds for boat hulls, and other BIG stuff, too.
https://www.janicki.com/capabilities/equipment/
Founded by former Univ. of Washington, Seattle, Mechanical Engineering students.
~RN
Building-sized milling machine to make full-sized foam molds for boat hulls, and other BIG stuff, too.
https://www.janicki.com/capabilities/equipment/
Founded by former Univ. of Washington, Seattle, Mechanical Engineering students.
~RN