Western Railroad Discussion > Pull Aparts

Last Friday noon I went down to the Amtrak station to see #6 that was 6+ hours late. While waiting for # 6 I watched a UP section crew. At first I couldn't figure out what they were doing. Then they started a fire along one rail. A CNW roadmaster once told me this was how they fixed pull aparts. Get some old rags and other combustibles, soak 'em in oil, lay 'em next to the rail, start 'em on fire, and eventually the heat will cause the rail to expand and then you can bolt the rail back together. I have a couple of questions about this. First, it really didn't seem to be pull apart weather. It was maybe 40 degrees at that time and the overnight low was maybe mid-20s. When I think of pull aparts I think of temps in the single digits, and most likely sub-zero temps. I mean we're talking c-o-l-d. Second, maybe the technique is old, but they stuff they were burning looked like black rope or hose, and they poured some stuff out of blue containers to stoke the fire. What do they burn these days to heat the rail? Thanks.

They use the technique you described to fix broken rails as well as pull aparts. Pull aparts are more common in jointed rail territory as, for those who don't know what they are, the bolts will break and the joint actually separates from the other rail, creating a gap. In cold weather, and yes, the temperatures you described can cause pull aparts and broken rails, once a separation in the rail occurs, the rail will actually shrink due to the coldness of the metal in the rail. This is the same as the rail expanding when its heated. To heat the rail in the field, they use a product called Fire-Snake (http://www.fire-snake.com/) to heat the rail. And, I would assume that if they were pouring some type of fuel on the Fire-Snake, then that would be kerosene which is conducive with it being in a blue container (gas cans are red, diesel cans are yellow and kerosene cans are blue but the people filling them don't always use the proper can for the selected fuel). This will then heat the rail and expand it so the joint bars' bolt holes line up in a pull apart or the rail meets properly for a field weld.

Pull-aparts and broken rails are especially prone to occur whenever there's a sharp drop in ambient temperature, because that causes the metal to shrink rapidly. It doesn't even have to go below freezing for this effect to occur. Opposite applies to rapid warm-ups, when the sun kink hazard develops.

We used to get a few on my railroad when the first hard cold snap occurred. However, once the long cold winter set in we didn't get anymore.

Here's one we found flagging a few years back just east of Gardner, KS after about a 50 degree drop in a 12 hr period. This one was over 4". The signal maintainer got permission from the Chief to walk us over it with a 7500' stack train at 5 mph or less.

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snap

You sure you want to walk a train over that?

upengr21 Wrote:
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> Looks like a broken rail.I thought pull apart was
> at a joint when bolts break.

The picture is of a broken rail. But this thread devolved from its original subject into the discussion of both pull aparts and broken rails.

WAF Wrote:
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> You sure you want to walk a train over that?

Have put trains over a pull aparts in the Nevada wastelands that were over 8 inches apart.
All you need is a temperature drop from 50 degrees at 4:oopm to -5Deg at 7:30 pm.
We also found some pull aparts that trains had traversed that were over 14 inches apart. The train crew in the caboose reported a bad tough spot.
There wasn't just one wide pull a part but dozens.
The good old winter time.

Well you could sit there and get disciplined for delaying the train I guess. I've seen pictures (and I'm sure I'm not the only one on here) of broken rails that have been run over by coal loads running 50 MPH without derailing.

Pump

WAF Wrote:
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> You sure you want to walk a train over that?

I was working a yard job one night when a train set out about 50 cars. We pulled those same 50 cars out immediately after they left to switch them. When we pulled most of the track out, my helper stopped the move, hopped off for a minute (I could see his lantern moving about), jumped back on and pulled the rest of the way out. When he went by me, he chucked off a 10" piece of rail off of the car that had just been shoved over and pulled back across. Not one car derailed.

Got a pull a part here or maybe just broken angle bars. I've seen the angle bars intact, but all the bolts broken out and the holes no longer lined up. I've heard those called stripped joints too.

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WAF Wrote:
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> You sure you want to walk a train over that?

I would hazard to guess that as long as the length of the gap does not exceed the chord distance of the wheel before it hits the ground and moves wrong-ways, and the two sections of the tracks stay aligned (good ties and tie-plates being important), then all you have is a big bump when you go over. For example, suppose you have a 40" main wheel on your truck, and assuming at least 9" for the height of the rail, then the gap could conceivably be 32 inches before the flange hit the ground, and the drop that you would feel would only be about 8" (or less, as the momentum of the train would keep you more level until you hit the next rail).

Not that I would like to experience it, mind you, as Houston streets are bad enough. . .

Roger

WAF Wrote:
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> You sure you want to walk a train over that?

Watch the documentary, War Trains. Amazing what it can take to derail a train

Different railroads, different rules and different priorities, but if I got called out on that break, no way I'd walk a train over it without at least putting a pair of joint bars across the break. And I found at least two pull aparts just today. Of course, car thermometer in car said 29 deg when I left the hotel this morning.

Greg

Greg Ramsey
Las Vegas, NV

ddg Wrote:
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> Here's one we found flagging a few years back just
> east of Gardner, KS after about a 50 degree drop
> in a 12 hr period. This one was over 4". The
> signal maintainer got permission from the Chief to
> walk us over it with a 7500' stack train at 5 mph
> or less.


That must have sounded like a Bomb going off when that broke!!!

I was stuck on Amtrak 5 near Beowawe, Nevada, one February for five hours because of a five inch break. (It occurred before dawn and it took that long to get MOW to the area and fix the break.) Although the first truck of the locomotive went over the break before the train stopped, and although MOW had to walk the locomotive back over the break to be able to make the repair, no one suggested walking the entire train over the break and letting us go on our way. I suspect that, even if that might have been possible for a freight train, it was completely out of the question when passengers were involved.

I expect it did. A steel tensile test specimen, typically a quarter of an inch in diameter, sounds like a pistol shot when it breaks.

"Walking" the train over a break or pull-apart--I presume if the "Chief" gives permission, it's on his head if things go awry. And yes, it's amazing what a crew can move along a railroad with faults like this if A) they go slooooooowly, and B) the track is straight. I would also presume that if the already bad situation got worse, they'd cut the train and wait for help. Brings to mind the "snap track" technique used in the early day of Orange Empire Ry. Museum to get cars from the end of the Santa Fe track in Perris to the museum main line.

The break in the photo threw up a red signal for the train ahead. As we approached the red signal, they told us "we thought we saw something about a car length west of the signal". We've all seen broken rail in the winter time in the headlight, it usually looks like a white chalk line across the rail from the cab. You look for that, and as soon as you see it, you slide the window back and listen for the thump sound as the wheels roll over it. We expected the usual 1/2"-1" break which we normally just continue to roll over at restricted speed with no problems. When I saw this one, I knew it was quite large, on an outside curve rail, and went ahead and stopped with it under the third unit. A signal maintainer was in the area, and he looked at. He told us he had some training and was authorized to walk us over it up to 4" but this one was over that by just a little. That's when he called the Cheif, and told him to go ahead and watch us over it.