Robert wrote;

"WRM has sent a bunch of work there. None of it was ever stitched. It was all welded.
"

I'm very glad to hear that you had success with the welding done by the Lock and Stitch folks. But they do in fact say that it is nearly impossible to weld interior cracks inside of most cast iron pieces.

Cast iron comes in about 100 flavors, but they all have one thing in common, the compressive strength (how hard you can push on it until it breaks) is much higher than the tensile strength (how hard you can pull on it).

There are indeed some repairs that can be done on cast iron around the edges by welding.

But the problem with interior cracks is that the piece heats up and expands (even when properly preheated before welding) and then the weld is properly performed. Then as the piece cools (even if very slowly, and properly annealed) the interior areas "pull" against the exterior areas and cause the casting to crack again (eventually).

When cast iron is properly poured and it has a chance to cool slowly the compressive and tensile stresses get a chance to "average" out, and the resulting casting is very long lived for systems in compression (i.e a cylinder head bolted onto a cylinder body and compressed when steam or a diesel fuel explosion occurs inside). But cast iron is never a good choice when you want to pull (all of the time or just half of the time) on a metal piece, like a piston rod, or locomotive frame.

The whole reason the Lock and Stick folks came up with the stitching pins was to overcome this characteristic problem with cast iron (and aluminum to a lesser extent).

Steel on the other hand has basically the same compressive and tensile strength so it can withstand the expansion/contraction inherent with heat from welding. And you can pull on it just as much as you can press on it. This is why barbed wire was never made out of cast iron.

Cheers, Kevin.

Referring to the drawing in my original post, here is a photo a weld. I’ve got seven to upload, but I’m not sure how the size is, so this one is a trial.

This is weld #1. It has a crack in the weld, extending below the weld on the inside of the frame, fireman's side.  The crack starts on top, and extends through the oily spot. This is immediately behind the cylinder saddle.  Note the "filler" that has been welded into the "V" part of the frame.  This filler is not present on the engineer's side. Photo taken looking up from the service pit, looking at the inside of the frame.

Sorry, I cannot really place the weld compared to your first posting as #1.
Apart from that regarding the filler plate welded in the triangular hole, is it
welded in fully, closing the hole, or only partial. In the last case, does crack #2
start from there? An extra picture would help.
Kind regards
Jos Koopmans

James. Plenty of examples of early welding in mfg in heavy industry. But it was still in it's infancy, it was not the norm in construction in the day. If it were the cat's pajama's, then the riveting used in construction would of died off much faster than it did. While electric welding is older than WW2, it was often not of real good quality, compared to todays standards. Despite that it often worked. Again if this were not true then why did riveting stay around for so long? There were successful products that were welded early on, but my statement about electric welding not coming into it's own until the WW2 era was meant as a standard for repair or construction that grew into main stream. I appreciate the welding history lesson though.

Obviously there were a number of types of welding and some of the work was very good. From a lot of the small mining and lumber company locomotives I have seen, the welding and repairs were by todays standards, "not real pretty". In the same breath the "not so pretty" repairs often kept the locomotive operational for another 10-30 years. This is one of the reasons I find old repairs to locomotives so interesting. You can gasp at the cobbled appearance all you want, but those ugly repairs often worked! A true testament to the ingenuity of some of the mechanics that kept the wheels turning. They often had no choice but to try and make do with what ever materials and equipment they had to work with. Next time I am down south I will grab a couple of pictures to use as examples and put in a different thread.

The way we approach boiler and frame repair today is a different universe to the back shop of a small lumber company or a company who planned on replacing the locomotive in the near future say in the 1940-1950 era. Often the running repairs made to these same locomotives on tourist lines or museums in the 1960s though the next 30 years were not all that much different. We all did what we had to do to keep things running. Now people would have incontinence to even suggest to do what worked then. When two worlds collide kind of thing.

Thanks for the photo Jim, keep them coming, you started a great thread. Regards, John.

Actually, several of our recent repairs at Lock-N-Stitch have been furnace brazed rather than welding with a ferrous filler.

Here is a cracked center plate from Peninsular Railway interurban 52 after they repaired it.

Al Stangenberger
WRM

Al, very nice brazing repair on that center plate. Thanks for the picture

Brazing is technically not welding (lower temperatures involved), the base metal is not melted.

Brazing cracks on the exterior of cast iron is very feasible. Doing it in a furnace makes the temperatures more even and the stresses are lower.

In that center plate the loads are mostly compressive; car body pressing on center plate pressing on truck bolster. There might be a little tension when the car body shifts sideways and pulls the truck bolster with it. But with 4 bolts at any given time at least two of them are being pushed against (compressive stress)

The filler metal used in brazing is usually not as strong (20-40 kpsi) as steel (40-100+ kpsi). The filler material used in welding can be as strong or stronger than the base metal being welded.

Welding (where the cast iron is actually melted) on cast iron (especially cracks inside, not on the perimeter) is very difficult.

Brazing cracks in an engine frame is probably (my opinion) not strong enough.

Brazing a doubling plate (in parallel with the frame, over the cracks) might (repeat might) be strong enough, but some careful analysis would be needed.

Cheers, Kevin.

In the early 1960's my great uncle showed me in the Decatur Wabash shop their 300 amp welder that was bought in 1930 at depression era prices. This welder was used to weld broken frame parts on Wabash locomotives and freight cars in the backshop. I met one of the boilermakers who originally used the welder and he said they had sent him to the Hobart Institute of Technology in 1930 to learn heavy repair welding. hocarsand trains. James

Here’s the whole series of photos. Refer to the drawing in my original post for locations. The 4-digit numbers are the main portion of the photo file numbers; all have a (dash)_3 suffix.

6311 & 6313: weld #1. It has a crack in the weld, extending below the weld on the inside of the frame, fireman's side.  The crack starts on top, and extends through the oily spot. This is immediately behind the cylinder saddle. Note the "filler" that has been welded into the "V" part of the frame.  This filler is not present on the engineer's side. Photo taken looking up from the service pit, looking at the inside of the frame. The weld is hard to see; it starts just under the top of the tape measure, and extends left about 3", it comes down about 6".

6315: Also Weld #1. View from outside of the weld in 6313, looking down across the #1 driver. The weld extends onto the cylinder saddle. Crack, not visible in the photo, extends across the top of the weld, then down the inside of the frame as shown in 6313.

6304 & 6305:  Weld #2, engineer's side, at the most forward bolt hole for the front axle binder. Looks like there might be a crack showing just above the binder. Photo taken looking up from the service pit, looking at the inside of the frame.

6317:  Weld #3, fireman's side, just forward of saddle. Photo taken from outside, looking between front of cylinder and pilot wheel.

6319:  Welds #3 and #4, engineer's side, just forward of saddle. Photo taken from outside, looking between front of cylinder and pilot wheel.

Total of 7 pics. Here's another 3.

Here's the last

Thanks for the additional photo's. Actually those repairs look pretty good compared to ones I am thinking of. Way better actually. Let others chime in on this.

My welding on frame experience was more restoration of the jaws and wear points rather than repairing of broken sections. But thoroughly enjoy the subject matter.

Regards, John.

Thanks for the pictures. It looks as a proper welding job. However, if all of them show cracks, the probable cause is welding without preheating. Moreover this way of "weaving" vertical (?)welding induces a lot of very local heat and the result was probably never X-rayed. As for picture 6313, it confirms my fears that such a partial closure of the hole causes shrinkage problems probably contributing to the crack next to it.
If it were my frame, I would remove the welds ( I don't know the english name) by electroflame cutting with air. All welds horizontal by rotating the frame and use two welders to get a symmetrical shrinking weld.
Of course I bow to superior knowledge!
Kind regards
Jos Koopmans

I trust that those areas that look like hellacious HAZ are just 'overlap' from the wire wheel or whatever was used to clean and brighten the weld beads.

If this were mine, I'd have someone do a good NDT (perhaps X-ray) examination of these welds. You might even get the service wholly or partially donated -- this sort of thing is excellent PR. That will give you a good idea of what might be required here.

If you want to check some of the procedures used in contemporary welding at the time this work was done, search on 'autogenous welding'. There is also mention of the process and its details in some of the magazine and journal articles, and some of the 'locomotive up-to-date' types of textbook.

If the welds have to be cut out, I can't help but wonder if there is such a thing as a portable waterjet cutting apparatus -- there's been enough heat thrown into that frame already, I think, to make plasma cutting a less-preferred approach. I would agree with Jos on downhand welding if it is convenient to rotate the frame, BUT I can't help but wonder about the likelihood of warpage or even additional cracking when the frame is rotated out of plane with one or more welds cut out, with this many welds and so many proven cracks.

I'd also add that the frame be preheated properly for each weld, that perhaps one of the submerged-arc processes (with flux) be used rather than using gas blanketing, and that some kind of positive jigging be provided to keep the frame correctly aligned during the entire process (preheat, weld, aftertreatment).

Or, perhaps replace the frame or retire this locomotive in favor of one that is not suffering so many effects of historic damage and repairs that did not restore the frame to its design spec robustness.

I'm not convinced that it will be practically possible to make the kind of high tech and controlled repairs that are theoretically possible in the field on the frame as it sits in place and get any better results in terms of life expectancy before more cracking takes place.

Of course, it's up to you to decide whether or not you want to take that gamble with your resources. Are there potentially better options available to you?

dave

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