Post By LFLondon
The machines that made the Jet Age (Heavy Press Program)
The machines that made the Jet Age (Heavy Press Program)
The machines that made the Jet Age - Boing Boing
I began my forging die apprenticeship in a shop that had several presses that came from Germany after WW2. The largest was 16000 tons, small by todays standards, but keep in mind that it was supposedly built in 1933.
Thanks for the feedback, Ernie. You must have made machining history with
Originally Posted by ErnieD
those machines. Assuming all the equipment that came from Germany after the war ended did not go only to government shops I wonder what the procurement process was for corporations who wanted them. Did the government arrange for removal and shipping to corporate location to be reimbursed upon delivery.
I was born at the beginning of WW2. It is a shame that the Russians got anything from Germany after the war, personnel, equipment, archives and especially land, same with their theft of most of Finland's Karelia. The USA, UK, postwar European allies should have formed a union to rebuild Europe and erect their own wall to keep the Russians out.
I wonder how much equipment was left in Germany to help restart their economy and continue important R&D and manufacturing.
I was impressed with the photos, in a way a wake up call about how things are manufactured. Interesting to note the vastly improved structural quality of parts made in cold forging as opposed to cast or hot forged.
Originally Posted by RC99
There is another collection of photos of some of these big presses in another PM post in the archives of this subforum with pictures of components produced by them.
US high schools should offer a course that illustrates and documents the major achievements of American industry during its history up to and including the present. This should generate a number of career choices that otherwise might not happen, including many who might opt for trade schools.
See also this Atlantic Monthly article:
One of America’s great machines comes back to life.
By Tim Heffernan
Iron Giant - Magazine - The Atlantic
Enjoyed the article and seeing the big presses. It was interesting to learn something about their history, never heard any of it while in the trenches.
Too bad the article doesn't mention the "waffle" was heated to forging temperature in the big furnace next to the press (shown on the right in the floor photo) before loading into the press. Got the impression the author was more interested in his political twist to the story and gee whizz than presenting technological history.
An aerospace part I worked on in the early/mid-70s was the largest 7075 forging to that date and made in the Alcoa Heavy Presses. Sure would have been fun to see it done, only saw photos.
That is impressive, Dave, to say the least.
Originally Posted by DaveE907
There was no mention of preheating the workpieces before forging in the articles I read. They should do a better job of editing before publishing.
It does seem a bit of a stretch to think of one of those titanium blanks automagically cold forming (metal flowing like liquid) into a perfect part in the press despite the pressures involved; hard to see how precise specs could be maintained that way and splits, fractures, cracks avoided.
Here's the caption under the titanium parts photos:
"Press-forging minimizes waste metal compared to machining, and by realigning the metal’s internal crystalline structure along natural lines of stress, results in much stronger parts than casting would produce. Photos: Library of Congress "
Your Alcoa Heavy Press is the one that recently has been upgraded and restored for continued use.
Alcoa: News: News Releases: Alcoa Celebrates the Redesign of Iconic Forging Press in Cleveland
"February 13, 2012
Alcoa Celebrates the Redesign of Iconic Forging Press in Cleveland
Advanced press solidifies Alcoa’s Cleveland Works as a premier forging producer
CLEVELAND--(BUSINESS WIRE)--Alcoa announced today the completion and restart of its redesigned 50,000-ton forging press at the company’s Cleveland Works. A $100 million dollar investment that Alcoa announced in 2009, the new press strengthens Alcoa’s position as the preeminent supplier of large aluminum, titanium, nickel and steel forgings to the aerospace, defense, energy and industrial markets.
“Combining our advanced alloy and manufacturing process technology with our state-of-the-art 50,000 ton press capabilities, we will be unmatched,” said Eric Roegner, president, Alcoa Forgings and Extrusions, at a special celebration shared with federal, state and local legislators, community and industrial leaders, and employees. “Our unique press offers the ability for Cleveland Works to double its capacity to serve our customers in the commercial and defense aerospace markets as well as industrial and energy markets.”
The multi-million dollar investment involved the complete redesign and modernization of the 50,000-ton press, a 92-foot structure – with five stories above and seven below the ground – that began production in 1955.
“As one of only five existing heavy closed die forging presses in the United States, this national historic engineering landmark is strategically important to our nation’s defense and Alcoa’s commercial competitiveness,” said Roegner. The press was originally installed as part of the Air Force Heavy Press program following World War II and has been used to build parts for nearly every military aircraft, helicopter, and tracked and combat vehicles from the 1950s through present day."
I don't know about making machining history. By todays standards everything was crude. We had a planer, a horizontal boring mill, a vertical mill, 3 Hydrotels, 3 ( can't remember the name) horizontal duplicators and various smaller equipment.
Often times we would make dies for open forging of shapes. These forgings would then be sent to the vendor and they would mill them to final shape and size. One job that i will never forget is a die to make rough forgings for the Boing 707 window frames. These were basically a rectangle bent to a radius approximating the fusalage shape.
I made the dies on the planer. To cut the shape I made a template from sheet metal, mounted it to the rail of the planer, made a tracer finger from sheet metal and attached it to the cutting head. A flashlight was hooked up using wire between the template and the finger. After facing off the die block and establishing a center line, lining up the template and finger, I would touch the tool off to the face adjust the finger to the template until the light came on then start the table, engage the cross feed, then bump the verticle feed crank up or down depending on wether or not I was cutting the convex or concave die half,until the light came on ad infinitum. I remember that there was a lot of that bumping of the crank before the job was done.
One note, this all happened sometime around 1954-1958 and facts are hazy. I remember that the tracer finger and template had to be insulated from the machine but I don't remember how I accomplishet that.
I used that template,finger, flashlight on the lathe to cut large spherical radii in the end of punches for backward extruding some sort of a vessel.
Ah, the good old days,
By the way this shop was run for the government.
Last edited by ErnieD; 02-21-2012 at 09:40 AM.
Reason: add text "By the way this shop was run for the government"
Thanks for sharing part of your work history, Ernie. That was fascinating. I'd say you definitely made history.
Originally Posted by ErnieD
I've only started reading this thread and plan on reading it through. Very interesting stuff. Thanks for posting this part of our country's industrial history.
In the comments section of the companion article a fellow was trying his hardest to knock these as 'nostalgic relics', claiming with "dirt cheap CNC now presses like these are worthless". Some better educated commenters tried to explain just how wrong he was, but to no avail.
After reading the article about the author bashing old machines. I think he is off his rocker. I do service work on old machines. Old machines by far are more over built than the current machines being made. At our shop we machined 8 tubes that are at the base of the machine. I knew a guy that worked in the die shop at Alcoa and he told me that that machine uses water as the pressure fluid. At first I did not beleave him. Then he explained why they use water. Water has a better heat transfer characteristic than oil. Oil can't dissipate heat as fast as water can. At least by the volume of fluid needed to run this machine. This is all I know about the press. As most of you know forging is not dead. Their is to much stuff that need to be forged in order for everything to function in society.