Everything you wanted to know, but were afraid to ask.


https://www.youtube.com/watch?v=Rdj5-6t6QI8

Fascinating. An article on exothermic rail welding in which the word 'Boutet' is never mentioned.

Or head-hardening, or bainite, or the need to test weld integrity with shock as well as increasing static pressure. Or flash-butt welding or jig assembly of CWR to reduce the number of field joints. Or the whole issue of rail anchors/anticreepers in transmitting expansion or contraction forces.

I admit it was amusing to hear them mix up 'negative tension' and 'positive tension', but that might confuse some poor bastard who doesn't understand how to adjust to achieve 'neutral temperature' prestress when not working at neutral temperature. I think he missed a sure bet by not demonstrating the 'fire snake' method of rail lengthening... that's precisely the kind of sensationalism that isn't clickbaiting.

Unlike some Youtubers, this one is receptive to comments regarding errors or omissions.

You might want to make some. I assume anybody (attempting) doing a deep dive into a highly technical subject is likely to make a few mistakes and would benefit from the comments of somebody with in depth technical knowledge.

Track structures and welding is decidedly outside my wheelhouse, so... (I am that poor *******, with the exception of having been born sufficiently long enough after my parents were wed to avoid the application of such a term).

This video popped up on my Youtube feed a few days ago but I didn't initially watch it since a lot of these types of videos are mostly entertainment or railfan videos without any worthwhile info. After seeing this post, I did watch it and it does have some interesting facts to it that may peak someone's interest to investigate more. I've never been directly involved in thermite welding rail myself but I did get to watch the process by a MoW crew a couple years ago. It's quite the fire show.

I have utterly no complaint about Veritasium's content or approach, and I can easily understand why a 'non-railfan' would make the Goldschmidt company the 'center of attention' in an explanation about application of the Goldschmidt reaction.

There's quite a bit to be said about adjusting the alloy composition of the weld in the 'powder metallurgy', and the precise meaning of the 'countdown' in pulling the mold, etc. -- what's missing so far is careful reporting on how the experienced crews do the welds. I was privileged in 1977 to hear from one of the Conrail (ex-PC) rail-welding crew leaders (he mentioned the failure rate then was about 4 welds in 100) -- I regret that I did not take advantage of the opportunity to learn.

The thing that kept biting at me was all that intercutting of HSR trains during a discussion of Boutet/Goldschmidt rail welding -- are those kits used for LGV maintenance? I'd think flash-butt welding or even laser keyhole welding would be needed for that application.

I presume the title of this thread is supposed to read "Continuously Welded Rail / Thermite", not "Rate". Autocomplete can be a terrible thing. A colleague says it's quicker than his spouse at completing his sentences for him....

There's a lot more to thermite rail welding than can be condensed into a half hour video, but this seems to be a decent introductory dive into the topic. Suffice it to say that welding rail is not a DIY project.


That's because the producers of the video were working with people from Orgothermit, a Boutet competitor. Incidentally, in North America, the Boutet rail welding product line is now being sold by Pandrol.

Here at Pennsylvania Trolley Museum, we thermite welded about 1,200 linear feet of relay-grade 128 pound girder groove rail as part of our East Campus project. This is track that's embedded in our Volunteer Boulevard and we didn't want to deal with the potential maintenance issues of that many bolted joints in pavement. Welding also provided 100% electrical continuity for traction power negative return. Our trackwork contractor subcontracted the rail welding work to a fellow named Ron Michaels, a one-man business based in northwestern Pennsylvania. While Ron personally prefers working with Orgothermit products, the rail welding kits for our job came from Pandrol (nee Railtech Boutet, located in St. Jerome, PQ) as they are the only vendor who currently has the tooling to make ceramic welding molds to fit the now-obsolete 128 pound girder rail. Ron was indifferent, as he routinely works with both brands. (He also does stick welding repairs to worn frogs and switch points.)

The results have been completely satisfactory. I expect the softer metal in the heat affected zones (HAZ) might someday develop batter and begin sounding like jointed rail, but that's likely two or three decades out, so it will be PTM's Next Generation who will be addressing it, not me. Incidentally, there are post-welding heat treatments now available to bring the hardness of the HAZ up to that of the parent metal and the weld metal, but the necessary equipment won't fit over the 6-inch wide head of the girder rail.

/s/ Larry
Lawrence G. Lovejoy, P.E.
Director of Engineering
Pennsylvania Trolley Museum, Inc.