Clara City, MN derailment

[Jr64]

There was a major derailment on the BNSF mainline through Clara City, MN this morning at 4AM.  A cloud of hydrocloric acid was released from one of the cars.

Reports were that a couple rail cars came to rest against the Hwy 7 bridge supports so the bridge remains closed until cars are removed and the bridge inspected.  Some details are posted here:

http://kstp.com/article/stories/S239659.shtml?cat=1

I thought some of you may be interested in this.

[Jr64]

 

Here is a photo gallery from the West Central Tribune 

http://www.wctrib.com/photography/includes/gallery.cfm?id=141

 

[zardoz]

That is one weird-looking derailment!  (those Tribune photos were great)

How did all of those tank cars tip over so neatly?  It almost looks like a string-line type of derailment, but I've never heard of that happening on straight track!

And by the bridge in the distance (near the walk path) you can see some cars nearly perpendicular to the tracks with all the cars in front of them, beside them, and behind them all correctly situated, and the derailed car laying across the other tracks with the cars on THAT track in front of and behind still on the rails.

And how did those tank cars near the bottom of the picture get across the rails, when the rest of the tank cars were lying on their side on the opposite side of the tracks?

Weird!

[Anonymous]

This the way I heard it described on the news:

Two trains were passing, and the last car of one train derailed and struck the other train causing it to derail. 

If this is correct, I assume that, since the head end of one train is derailed, it struck the last tank car of the tank train, which apparently fowled the path of the other train.  But the way all those tanks went over together is mighty strange.  There must have been a wave generated in the intial impact where the falling tanks could just keep toppling the next ones right down the line. 

[edblysard]

Try this...

Assume the train on the right is shoving into the siding...the empty center beam and two tanks derail, with the gray tank riding up and over the train on the left, tipping that car on its side...if that train were moving, the slack would be out and all the knuckles would be in a bind...one goes over at the impact point, the rest just tip like dominoes.

Remember, tanks don't have a lot of play in the drawbar.

 

Because the train on the right is shoving, when the air busts, the set starts at the break, running back towards the motors...because there is what, about  half a cars worth of slack there....when it gets to the motors, which are still pushing, the train buckles and the locomotive jack knife.

Or they could have been dragging towards us, and the same the sudden brake set snatches an empty hopper off the tracks behind the motors, and the locomotives follow, although I like the first theory better, makes more sense to me.

 

Nothing in the story or photos suggest the impact point is the locomotives, and from the photos, I don't see any impact damage to either one...if they smacked a tank hard enough to rupture it, the BN motor would have the nose pretty much mangled.

[CShaveRR]

Also remember that most tank cars are required to have shelf couplers, if not Type F (tight-lock) couplers.  There's no way for the cars to come apart, absent the opening of a knuckle.

[edblysard]

Never occured to me, but Carl is right...if they were all hazmat tanks, they would have shelf couplers, all locked together...tip one and and the rest follow....beats having one telescope into the one ahead of it....

 

[Anonymous]

I think it is hopeless to find an explanation in any of the news coverage.  About all I can conclude is that it involved two trains that somehow fouled each other.  Maybe someone close to the scene can get a more detailed explanation and post it here.  The most detailed news statement comes from the above article, which says this:

 

"The derailment happened about 4 a.m. when a southbound BNSF Railway train pulled onto a siding and 61 cars derailed. That "fouled" an adjacent northbound mainline track and caused 22 more cars to jump the tracks said company spokesman Steve Forsberg."

 

Another article said this:

 

"The train struck another train that was parked at about 4 a.m.,..."

 

Just a guess, but I would say the tank train is on the siding.  It looks like it may have 61 cars on the ground.  I don't see where the "22 more cars" are unless some of them were more tank cars on the tank train that derailed after the impact.  Whatever the fouling of the two trains was, it does not sound like that is what tipped over all the tank cars.  From the description, it sounds like the tank cars tipped before the fouling. 

[Anonymous]

Here is the official explanation of how this strange derailment happened, extracted from the linked article:

 

"The accident started at 3:30 a.m. Monday when a slow-moving train, going about 3 to 4 mph on a siding, derailed for some unknown reason. The cars were connected close together with tight couplings, which created a chain reaction involving 58 cars.

The last car on the side rail was struck by a second train, which was traveling about 35 mph on the main line. Two locomotives and 10 cars on the main line derailed, including the tanker carrying the hydrochloric acid.

The wheel sets of many of the cars stayed on the tracks and crews were able to put the tankers back on the wheels quite quickly, Forsberg said."

 

http://www.wctrib.com/articles/index.cfm?id=26406&section=news