With the discussion about SP 786 cylinder repairs below, I wonder if repairs have yet been attempted on NP 4-6-2 No. 2156 in the Twin Cities? Last I knew, they were thinking about trying a "cold" process, which I took to be some type of epoxy-type repair. Any updates on that project?

bobyar2001@yahoo.com

The narrow-gauge Baldwin 4-4-0 currently in the Tweetsie shop had a burst cylinder casting that the owners wanted repaired during the overhaul. They consulted with the Tweetsie shop foreman and he told them "The old man Coffey would have said to jerk the damn thing offa there an' braze her up". Well, the corporate mechanical engineers didn't think that would work and some Canadian outfit sold them this "cold process with metal stitching", basically a glue and sew it back together process which was extremely expensive. It took a couple of months for the casting to come back and when it did it was worse than when it left--wouldn't hold a line pressure hydro.

So they jerked the damn thing offa there and brazed her up. They heated the entire casting for a couple of days then did the braze repair. So far it appears to be a great sucess with no additional cracking.

They talked about recasting the cylinder but could not find anybody who would take the job and run with it. They cost was over 50 grand, with no guarantees, and Tweetsie would have to set the core boxes.

Has anybody recast a cylinder casting in modern times other than the Chinese? The Strasburg guys made a new one I think, but they are the only one I know of.

Little River Locomotive Company
ken290@hiwaay.net

> Has anybody recast a cylinder casting in
> modern times other than the Chinese?

British outfits have made five modern cylinder castings that I know of, and possibly quite a few more. Three of these are for the new A1 4-6-2 now being erected at Darlington. These are what we would call medium-size cylinders with piston valves. The middle one includes the frame spreaders and the saddle for the smokebox, and of course the exhaust passages for the nozzle. The Brits also made new cylinders for the poppet-valve experimental 4-6-2 Duke of Gloucester by back-engineering from the originals, which had been hacked off and sectioned as museum exhibits. After new drawings were prepared, the original drawings came to light, and the new drawings were found to be almost identical.

I believe that all these castings were done from wooden patterns, although a lot of the castings for the A1 are being made with lost foam. If I remember right, no more than one or two tries was needed for the complicated Duke cylinders, and I don't think any of the A1 cylinders had to be cast more than once.

Aarne H. Frobom
The Steam Railroading Institute
P. O. Box 665
Owosso, MI 48867-0665

froboma@mdot.state.mi.us

It is hard to think that the same country that did the huge integral-cylinder cast engine beds from late steam days can't find a foundry to do a little slide-valve 10 x 14 cylinder isn't it!

We may have to go back to the old country!

Little River Locomotive Company
ken290@hiwaay.net

I'd just like to locate the patterns for an AEREA 5x9 Journal box!


lamontdc@adelphia.net

> I wonder if repairs have yet
> been attempted on NP 4-6-2 No. 2156 in the
> Twin Cities?

whose engine is it? MTM?

hi-plains@juno.com

Yes, at the Jackson Street Roundhouse. Was on display at Como Zoo in St. Paul for many years before that.

whose engine is it? MTM?


bobyar2001@yahoo.com

Bob:

I thought MTM had acquired a second NP Q-3 Pacific, #2153. Perhaps this one is in better shape?

shawsinoly@aol.com

Ken:

That's interesting about the cold stitch repair not working. I know a lot of people push this for repairing cracked auto engine blocks, especially on older, rarer cars. I've read a lot about it, and some people swear by it (see link below to one manufacturer). Basically, you drill a series of not-quite-touching holes and thread them with a special tap. You then screw in specially threaded plugs. The threads are supposedly contoured to actually "pull" the two sides of the crack together. Next, you drill a second set of holes at the intersections of the first set of plugs, tap them, and screw in more inserts. When you're through, the crack has been replaced by a line of "stitch" plugs. These guys claim it is extremely difficult to weld or braze large cast iron parts properly, and that's why "stitching" is better.

Do you know who did the work on the cylinder from the engine at Tweetsie? I'm just wondering if "cold stitching" is that crappy, or if the guys who did the work did a sorry job.

Good Steaming,
Hugh Odom
The Ultimate Steam Page
http://www.trainweb.org/tusp

> The narrow-gauge Baldwin 4-4-0 currently in
> the Tweetsie shop had a burst cylinder
> casting that the owners wanted repaired
> during the overhaul. They consulted with the
> Tweetsie shop foreman and he told them
> "The old man Coffey would have said to
> jerk the damn thing offa there an' braze her
> up". Well, the corporate mechanical
> engineers didn't think that would work and
> some Canadian outfit sold them this
> "cold process with metal
> stitching", basically a glue and sew it
> back together process which was extremely
> expensive. It took a couple of months for
> the casting to come back and when it did it
> was worse than when it left--wouldn't hold a
> line pressure hydro.

> So they jerked the damn thing offa there and
> brazed her up. They heated the entire
> casting for a couple of days then did the
> braze repair. So far it appears to be a
> great sucess with no additional cracking.

> They talked about recasting the cylinder but
> could not find anybody who would take the
> job and run with it. They cost was over 50
> grand, with no guarantees, and Tweetsie
> would have to set the core boxes.

> Has anybody recast a cylinder casting in
> modern times other than the Chinese? The
> Strasburg guys made a new one I think, but
> they are the only one I know of.


Lock-N-Stitch Inc.
whodom@awod.com

Yes, they have. Not sure about its condition, nor if it has been moved yet.

> Bob:

> I thought MTM had acquired a second NP Q-3
> Pacific, #2153. Perhaps this one is in
> better shape?


http://us.f141.mail.yahoo.com/ym/login?.rand=1q5p7b1cgo83n
bobyar2001@yahoo.com

Seems there is no technical reason we couldn't weld fabricate a cylinder and valve using modern quality control and welding technology. Has anybody out there tried it?

Dave

irondave@bellsouth.net

I was over at Jackson Street yesterday and observed the work being done to NP 2156. So far it has been moved inside the roundhouse and has been sandblasted inside and out. An ultrasonic test of the boiler shell has also been done, and everything looks good. The "$10,000" repair to the cylinder casting has not yet been performed, but "will be done soon" according to the musuem volunteers there. Also, according to the musuem volunteer conducting the roundhouse tour, the repair will be good for over 2000 psi when completed (this is what he said...take it or leave it). It also has some sort of warranty in case of failure.

The other NP 4-6-2 that has been acquired by the MTM has not yet been moved out of East Grand Forks.

It appears as if NP 328, which was to be overhauled and returned to service before 2156, may be cosmetically restored instead and placed on display inside the roundhouse. Sections of the boiler have proven to be thin - too thin for operation. This after the musuem spent a good deal of $$$$ and two years to tear it down for rebuilding.

Jeff Terry

Heber Valley Railroad
jterry618@msn.com

As a learning experience there is probably no good reason against it. If for example you started with seamless tubing ... available up to 26"OD x 1.5" wall, available in a wide variety of steel grades. This material could be used for the cylinder or cylinder liner and the piston valve chamber and would guarantee a strong pressure vessel. The steam passages would have to be machined blocks to maintain streamlined flow. All welds would be x-ray tested. The advantage over casting is the rejected section could be ground out and rewelded. I witnessed the production of nuclear waste containers in England and believe me the technology involved is about 25 times that required for a fabricated cylinder block. Rings of course would have to be made of a compatible material to minimize wear.


lamontdc@adelphia.net

Dave,
In my opinion, it would be next to impossible to make a pair of cylinders using a welding process.
The stress caused by the uneven heating and cooling would almost definitly lead to warping, and if it didn't it would produce an end product which is not strong enough.

cheers,
Steve


SPLoco35@AOL.com

Interesting differences of opinion here.

In reading RED DEVIL, 3450 was altered through th steam chests by cutting away a large section and welding in a new piece. A pearlitic iron liner was then installed.

I rode on a modern steam passenger locomotive in Australia a few years back that had a completely fabricated engine and saddle if i correctly understood my hosts at the time.

So, maybe if we instituted high quality control, normalized assemblies and than machined and lined?

Hugh, please tell us what is going on in the rest of the world. Does Winterthur cast or fabricate?

Dave

irondave@bellsouth.net