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Thread: Navy Blacksmiths at Work
08-12-2007, 11:53 AM #21
That Davy-United(2nd pic) looks almost identical to the original picture posted.From that,I'd think you were correct about it being steam over hydraulic.
08-12-2007, 01:16 PM #22
Okay, I'm convinced.
So then the question is, how fast does the cylinder operate?
I have done a wee bit of forging with a hydraulic press, and find the slow speed of mine means that the dies draw all the heat out of the workpiece very fast, especially with smaller workpieces.
This means you need a lot more power than with a fast hammer, as with a hammer, the force of the blows can actually impart heat to the part- allowing you to work a hot part for quite some time.
With anything under about 2" diameter, however, a hydraulic press is a one shot deal- you need to get all the work done within the first few seconds, before your work piece gets completely cold. So if you have a lot of extra capacity, and can keep pressing with mucho tonnage even as the work cools, it can work.
But as someone who does a fair amount of hot work, I have to say that the press I have, with its slow speed ram, is certainly no direct replacement for a hammer. For certain tasks, where one, very hard "press" can do the job, its great. But for something that really requires a few hundred, lighter, directed hits to do the job, like say pulling a long taper, my press, anyway, is miserable.
If this press had a relatively quick return time, maybe it could substitute for a real power hammer.
But if not, then it seems like an awful lot of weight, cost, and space for a machine that has limited utility.
And set up the way it is, with forging dies, it was not being used as a general shop press, pushing out bearings and the like- it is obviously dedicated to forging.
I have to assume that at the time, which was the peak of industrial forging, there were guys on these ships who really knew their way around forging big stuff. And they probably would have figured out ways to do what they needed. And they probably also did a lot more multistriker hand forging than they would if they had a real hammer.
08-12-2007, 02:29 PM #23
The Davy-United press was rated at 150 tons, stated to be suitable for working 6 inch ingots, and equivalent to a 15 cwt (¾ ton) steam hammer. The same source shows a similar press but with the lifting cylinder mounted on top (this was used for rapidly raising the ram after each stroke. On the one in my photo, the lifting cylinder is inside the body, and operated the links next to the slots either side of the press ram). Interestingly, the one in my photo was specially made for minimum height, for use in a naval repair ship. The photo of the standard (taller) 150 ton press shows it in use making big shackles in India, and the operators are barefoot!
Surprisingly, the 150 ton press could work at up to 120 strokes per minute for the ‘rounding-up operation’. I assume that this is a finishing process for round components where the stroke only needs to be very short?
08-12-2007, 02:52 PM #24
Ok, I"ll go with the steam over hydraulic press too. I wouldn't have thought a steam/hydo press would be very efficient because of the slow return, but I guess a quick return speed could be made to happen.
What is you opinion of a fly press? I've never run a trip hammer or such, but I can see some advantages to a flypress, especially a LARGE one.
Page "page8 big boy presses" shows some of the big ones I was thinking about. Page 9 also shows a line drawing of a large flypress.
Check Mr. Starver's description at the bottom of page 8.
08-12-2007, 07:36 PM #25
Great contributions , fellas !!!
on the heat-loss issue.
it's just like people .
A skinny dude in the drink , in the winter will die in minutes.
A hefty may have a chance based on mass / surface-area ratio.
that's a big chunk in the first pic.
ain't gonna go cold in an instant.
And the friction of the forging in the part partially replentishes the heat lost to the surroundings.....thats how forge-welding takes place ( the heat-rise from the welding blows momentarilly raise the metal to molten in just that imidiate region of the blows).
what small forging I have done frustrated me to the point of putting
heat under the anvil stand
and taking the anvil to about 250 ish. F
back to the skinny dude.
Thanks all for the additional pics.
08-12-2007, 07:49 PM #26
As Ries said, fast forging puts heat into the workpiece. I learned this from a former neighbour who was a smith in the local steelworks. He described in detail how they forged big shackles from bar in about 10 minutes (when you think of the wages, £bugger-all per hour at the time, that must have made made for a very cheap product). I asked about the reheating time, and he gave me 'a look', before explaining that it didn't need reheating when worked under the steam hammer.
08-12-2007, 10:22 PM #27
150 strokes per minute from hydraulic is amazing- of course, it is a design optimised for just that.
At 150 BPM, its very competitive with a steam or mechanical power hammer- especially at 1500 lb ram weight.
Somewhat confusing the issue is the fact that presses are usually rated in tons of pressure, while hammers are rated in pounds of ram weight- so most blacksmiths dont have immediate, in their head ideas of what 150 tons will do, but can tell you that 1500lbs is a VERY large hammer.
I am unaware of currently available hydraulic presses with anywhere near that speed. Most common, under $1 Million dollar presses are designed for single stroke work, and speed is not a factor at all- I doubt my enerpac based press could do better than 5 strokes a minute.
Its a matter of the common industrial uses of presses being totally different from what these were designed for.
And nowadays, there is virtually no market for large forging hammers, or presses. The chinese are the last men standing in the big hammer industry- all of the american, english, and continental european players are gone, most for 20 years or more.
Big presses are still made, of course, but not for open die forging like these are.
I know a lot of blacksmiths that would love to get their hands on a machine like this- but I wonder if ANY still exist?
I have never heard of one.
A lot of common forging techniques benefit from many lighter blows, rapidly delivered.
"rounding over" could be referring to returning a piece to round profile after tapering it- tapering is done in square shapes, then the piece will be made into an octagon, and then a round again.
As for fly presses, they are great tools- but, like a hydraulic press, they do not replace a true power hammer, but supplement it.
A flly press can do all kinds of stuff, cold and hot, such as cutting, bending, punching, slitting, and some forming.
They would not be great for tapering, or other really heavy duty rearrangement of mass, however- for that, nothing beats a hammer, whether its mechanical, steam, or air powered.
08-13-2007, 06:49 PM #28
"And nowadays, there is virtually no market for large forging hammers, or presses. The chinese are the last men standing in the big hammer industry- all of the american, english, and continental european players are gone, most for 20 years or more.
Big presses are still made, of course, but not for open die forging like these are."
Reis- You need to come to Scot Forge before you start making statements like this. In the next few years we are likely to become a 1/2 Billon dollar company. Within the last two years we have designed and built in the good ol' USA two large open die forging presses. One is 5500 ton, the other 3000 ton. We have desginged, built, and will be installing a 2000 hydraulic upsetting press at the facility where I work in the next few months. We have capital investments for the last 2 years that top $40 million. Since our company has no debt and large cash reserves, all that investment was done without the need to take a loan from the bank. Additionally, Scot Forge is 100% employee owned so we as employee-owners all reap the financial benifits of the strong market and debt free management philosophy.
Some of our competitors are doing the same thing in terms of equipment additions and upgrades. I will conceed that the very largest open die forging press (14000 tons) is in Japan at Japan Steel works, but you can make some awfully big forgings on the presses I work with. That big press has a backlog of about 3 years. There are also a couple of 10,000 presses still being operated by some of our competitors, such as Lehigh Heavy forge. By the way, our presses can deliver up to 400 blows per minute when in the planishing mode, which is used for final finishing of a forging.
There are a number of companies in Europe that also are players in the open die market. Most open die forgings are not shipped accross the ocean, at least the ones that we make, so you may not be aware of the prescense of the European players, but there out there. Asia does also have a thriving open forging buisness, but again, not a lot gets shipped from them into the US due to cost and more importantly, lead time.
The market for large forgings is as good today as it has been for probably the last 20 years and it is projected to be so into the forseeable future. What is defintily dying out is the use of industrial blacksmiths forging on hammers less than 1000 lbs to make and repair equipment for production facilities. That used to be a common job in every maintainence department in most foundaries, forge shops, etc etc. Now, most of the items those men made are either mass produced or fabricted. Most ornamental blacksmiths don't need or want to run a hammer over 500 or so pounds so the market for hammers in the range of 500-2000 is quite dry. However, we just purchesed a 10,000 hammer from another industrial shop because it is larger than any of the current hammers we have and we can take advantage of the additional capicty of the machine.
As for hydraulic presses that an ornamental blacksmith can use, these are being made commercially up to around 25 tons. There is a man here in WI who makes them up to 40 ton. If you want bigger than that, you probably will have to make it yourself or find someone to do it for you, but it can be done.
08-13-2007, 07:47 PM #29
Patrick, I would love to come to Scot Forge.
And I certainly wasnt trying to write your company out of history- I am very aware of it, and hold what you guys do in awe.
But I was mostly referring to the fact that Nazel and Chambersburg are out of business, Alldays and Onions and Massey are no longer making hammer after hammer, that Beche no longer makes air hammers.
And yes, I was thinking of the 250 to 2000 lb range of hammers, what a big dog like you would call maintenance sized machines.
If you want a 1000lb, or a 2500lb hammer, new, you are pretty much stuck ordering one from china, these days.
And my point is partially made by the fact that at Scot, you will be designing and building your own hammers- so no "market" has entered into it, whereas 50 years ago, you would probably have been buying them from Chambersburg.
I didnt say there was no industrial forging industry- in fact, I am constantly reminding people there is, as many people are convinced nothing is forged any more.
I was merely talking about the regular commercial availability of hammers that are big to me, while small to you.
I do have a 50 ton hydraulic press, that I use for forging- but it sure doesnt do 150 strokes per minute.
Is the guy in Wisconsin you are referring to making high speed presses suitable for open die forging?
If so, I wanna know more.
08-14-2007, 10:22 AM #30
With regard to the presses being made in Wisconsin- yes they are suitable for open die forging. Contact Ric Furrer through forgemagic for more info. He has one of these presses and should be able to give you his impression of its capabilites. I will see if I can find the contact info of the maker. His name is Chuck Schaffer. Ric should also be able to provided contact info for him.
I suspected you were reffering to the smaller hammers and presses, but I couldn't tell for sure and I didn't want people to get the idea that open die forging is no longer performed in the USA. You are definitley correct about the availability of hammers and presses and that is in part why we build our own.
08-14-2007, 08:15 PM #31
With the discussion of the large hammers, I was trying to find photos of the big (125,000T IIRC) forging hammer Carpenter Metals built a few years ago. Couldn't find anything on their web site. Any one have any insight as to that hammer?
Meco3Hp Fly-presses do indeed have a place in the forge, but, like Reis said they compliment a power hammer but don't replace it.
08-16-2007, 12:25 AM #32
At first glance I thought it was an electro-(rotary)-pneumatic type like the old nazels or the modern chinese "striker", but, I suppose direct use of steam would be more efficient. Sure is a handsome looking machine reguardless...
08-16-2007, 01:33 AM #33
So back to vibration on ships...
If the hammer in the OP is somehow like a 1500# ram (!?!?) 150BPM drop hammer, then it would most likely make a pounding like one. (Is it single or double acting? The steam over hydraulic could be just for lift...)
A ship 466x60x19ft displacement, if square (which it wouldn't be) would displace 17k tons. We can probably assume 10k tons.
The issue wouldn't seem to be vibration of the ship, but rather, local reinforcement of the floor under and around the hammer.
Vibration and concussion on ships wasn't a new problem - they'd been carrying guns for some time, and those pose all sorts of problems...
08-16-2007, 05:18 AM #34
My first impression of the photo was that it was a press and not a hammer, the C frame is very substantial as is the ram. A press will not create the pounding of a hammer as the ram is slower and lighter, the vast majority of the forming forces will be contained within the press structure. There will still be some shock when the ram contacts the work, if this were a problem then mounting the press on compliant mounts would almost elminate any shock without any major performance degredation. Compliant mounts reduce the floor loading as well.
Steam over hydraulic would be silly for 1500 lb lift 1500lb with 250psi steam would be a cake walk for a 4" cylinder with a 1" rod. And the cylinder in the picture at the RHS is a lot bigger than 4", looks like 12 - 14" driving a 3" hydraulic piston. It actually looks like it is hydraulic on the downstroke amd steam return, the 6" cylinder on the press frame is probably the return, note the light linkages.
08-23-2007, 11:19 AM #35
This machine is a C frame forging press, don't know the manufacturer, Davy as shown in one of the photos made them as well, we own a 200 ton model self contained Davy C frame. We brought it from BHP here in Newcastle when they closed down the steelworks. It was converted from steam hydraulic to electro hydraulic in the early 80s. When it was converted its capacity was increased to 250 ton. Small stuff compared to scot forge, but they are one of the biggies in the world of forging. Scot forge has one of the best websites I have found for a forging company, when you make billions each year I suppose you can afford a good website. Our press is rated to 800mmdia x 500mm thick for rings and discs and up to 350mm dia for forging shafts, although BHP used it for forging ingots and blooms measuring 400mm x 600mm.
I knew that many old ships used to carry smiths on board but this is the first time I have seen any photos of such.
02-09-2013, 08:11 PM #36
wow you certainly had the last word there phil!
02-11-2013, 02:16 PM #37