What Welding Rail Repair is This?

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What Welding Rail Repair is This?

  • Thermite welds were great sport for college boys when I was in school.  I never participated but saw the end results.  The bad boys would "liberate" some powdered magnesium and powdered aluminum from the chemistry lab.  Then during the night they would pour a mix of the two elements into the space where a manhole cover mates with the base.  With a spark the mix is ignited and poof the lid is welded on.  For some reason the city fathers frowned on this sport.

  • There was a "sport" practiced by some college students with thermite welding while I was in college.  I never participated in the execution of this game but saw the final results.  The boys would "liberate" some powered magnesium and powered aluminum from the chemistry lab.  The elements would be mixed and in the middle of the night be poured into the space between the cover and base of a manhole.  A spark to the mix and poof:  the cover is welded to the base.  For some reason the city fathers frowned on this game.

  • Excuse the double posting.  For some reason when I tried to post I got an error message.

  • tree68

    Given that they're welding the rail, versus replacing sheared bolts in a joint, the hydraulics are certainly more predictable than the technique I saw CSX using a while back - lighting a fire on both sides of the rail on both sides of the joint to expand it so the joint closes back up...

    While I'm as quick to take jabs at CSX as the next guy I would suspect that the fire was to heat the rail to the average temperature for that climate so it wouldn't expand/contract and break the weld whenever the seasons changed.

     

  • Even in welded rail territory bolted up rail joints still exist - Insulated Joints for signal purposes if there are no others.  What you witnessed was a crew repairing a pull-a-part where the bolt sheared from the shrinking nature of rail at temperatures below it's 'normalized temperature' at which it was laid. 

    Using cotton 'rope' to heat 100 feet or so of rail on either side of the joint will cause the rail to expand back together so the joint can be re-bolted thus completing the repair.

    Sometimes for emergency broken rail repair, joint bars will be applied and a speed restriction will be issued over the point.  No ever trackman responding to a broken rail is a equipped Thermite welder.  Depending on the characteristics of the break using joint bars may not be a option and a complete segment of rail must be welded in place....needless to say when it is necessary to weld in a segment of rail it will take longer to complete the repair.  A Thermite weld takes approximately 2 hours of track time for the welder - setup - the welding process itself - the clean up and finishing grinding of the weld contour and then getting off the track.

    tree68

    Given that they're welding the rail, versus replacing sheared bolts in a joint, the hydraulics are certainly more predictable than the technique I saw CSX using a while back - lighting a fire on both sides of the rail on both sides of the joint to expand it so the joint closes back up...

    I've never seen rail welded as such first hand, but I've seen some smaller thermite-type welding done to bond grounds to towers, etc.  Pretty impressive.

    Never too old to have a happy childhood!

  • The pull-apart could also have been caused by / resulted from either a weld breaking, or the rail itself, due to contraction from cold temperature.  Even when fully anchored, a few hundred feet will spring or retract back.  Heat the rail up a little bit and vibrate it (hammer on the tie plates) to encourage the rails to close up the gap, and either make the weld or apply the temporary joint bars and drill bolt holes for same, pending the permanent repair.

    It's not cotton rope, by the way (though it does look like it) - that would burn up too quickly.  It's a woven fiberglass rope, soaked in kerosene or diesel fuel, laid out, and ignited with a fusee (flare) or cutting torch - see under "Rail Bender* Accessories" about 1/3 of the way down this webpage: http://www.westernsafety.com/aldon2010/aldon2010pg9.html and "close to home", this from North Baltimore, Ohio: http://nbnewsxpress.com/viewnews.php?newsid=2379&id=1   

    Smelly and messy, but effective, and warm, too, on those frigid bitter cold days . . .  Coffee  Headphones 

    (*Absolutely no relation to the "Bender" = "Bending Unit 22" robot character from the "Futureama" animated TV show - see: http://en.wikipedia.org/wiki/Bender_(Futurama - although after reading that description of his capabilities . . . Whistling  Smile, Wink & Grin  )

    - Paul North. 

    "This Fascinating Railroad Business" (title of 1943 book by Robert Selph Henry of the AAR)
  • mudchicken

    Watch'em do it in the middle of a 5000 ft tunnel. Except for the acrid smoke & fumes, pretty neat.Cool

    Oh, that DOES sound like fun.  I've often described the process as a miniature, man-made volcano.  In a tunnel would almost make it like being in the volcano.

     

    Chuck
    Allen, TX

  • Paul of Covington

        I remember watching this process on streetcar track about 20 years ago.    The blinding, bright light from the process was almost painful to watch from about 30 feet away.

    Pittsburgh Railways (and I imagine other streetcar lines) simply tossed a bare wire over the trolley wire and, presto!, an electric arc welder.  I remember seeing this done several times in downtown Pittsburgh, always at night to minimize interference with automobile traffic.

    Chuck
    Allen, TX