Why are the couplers on tank cars different from those of other cars? When did the change happen?
They are shelf couplers and have been part of a set of FRA / NTSB rules (along with end shielding and double lined tanks) that started in 1981 to cut down the number of tank cars punctured in derailments.
So I take it they are locking couplings? So they won’t come apart in a derailment. Thanks for the info.
They aren’t tightlock couplers (I don’t think they are any way). They just have a larger knuckle as the tendency in sudden stops is for one to ride up and disengage and them puncture the head of the tank. This was after some pretty severe tank car explosions. I think part of the directive was also to strengthen the head of the tank with a thicker shell on the end.
Any chance of this style coupler showing up on all rail cars?
Some tanks have tight lock and some have shelf couplers. I don’t know why the different types but I guess they serve the same purpus.
All tank cars have shelf couplers top and bottom, they can be tight lock as well but they must be shelf top and bottom so no other cars will ride under or over. Many other cars I have seen now have shelfs on the bottom only. I do not know the rules for other types of cars but I bet someone will. LOL!!!
Just a slight correction…all HazMat tanks built after 1981are required to have shelf couplers, some acid cars, hydrocyanitic acid cars for one, have to have locktights.
Food service (corn syurp, tallow and animal fat cars) and non hazmat tanks can still have E or F couplers.
Hazmat tankcars still in service built before 1981 are grandfathered in, they dont have to have shelf couplers installed unless the car was rebult or refurbished after 1981…and these are quickly going away as they have reached the end of their service life under FRA and AAR interchange rules.
Ed
I should have said cars built after 1981 for hazmat. I beleive many shippers retro fitted there cars to the new standard so that a hard coupling would no longer result in a damaged car.??? They may have been more inclinded to do so as most fleets were privatly owned and it makes economic sence to protect there investment. [2c]
it makes you feel alittle better, but still kind of a scary feeling to see “blast” shields on anhydrous amonia cars[:O]
These were brought in as a result of the derailment in Missisauga Ont. in 79 where they had to evacuate a quarter million people.
Shelf couplers are stronger than you might think. There are reported instances of one end of a tank car being supported by the coupler attached to an adjacent tank car while the train is in motion after the truck under that end came apart.
Did any tank cars have self or tight lock couplers before 1981?
I’ve seen this first hand , a disadvantage is you can literally drag a train of derailed cars for many miles… the air hoses will never part !!!
Randy
Without releasing some sensitive information, what is hydrocyanitic acid?
Liquid cyanide under pressure, gaseous cyanide at atmosphere…
Cyanide is an acid, used, beside the gas chamber, to recover precious metals…and in several industrial applications.
Introduce it to say, mine trailing as a liquid in a sealed container, then allow it to “bond” to the metals you want, vent the gas to a separate chamber, put it under pressure, allow the metals to precipitate down, then pump out the gas back to a pressure vessel, where it will become a liquid again.
The metals will remain in the second chamber, just wash and use!
Simplified version above, but with different pressures and applications, you can recover zinc, silver, gold, lots of other compounds and elements.
You can tell a Hydrocyanitic acid car very easily, it is white, with a red stripe down the side, red end bands, and a huge red sign on each side and the ends telling anyone who finds one leaking, or anyone involved in a accident with one, who to call, and what to do, (like NOT try to rerail or move the car!)
Ed
Never seen a car that looks like that. Sounds pretty deadly. I dont think I would want to work around or near the stuff.
The cars are pretty stout…and the stuff has a lot of other industrial uses, it is used to make a whole bunch of other chemicals.
Think about it, a LPG car, if you manage to bang a hole in it, will most likely explode…
A cyanide car won’t explode, and the stuff turns to gas at atmosphere, it is heaver than air, sinks and collects in low areas like ditches and such, and will dissipate.
Of course, if you’re unlucky enough to walk into a cloud of it…
They tell us it smells like almond extract, or fresh cut hay…like if you can smell it, you can survive it…
The guys that make the stuff down here tell us if you can smell it, it is way too late to worry about getting away…
Look up Hampshire Chemicals, they make and use a lot of it.
Ed
Hydrocyannic acid is one of the most deadly subsances around. I will kill you within seconds if it gets to you. It does smell like burnt almond. Accoding to my Emergency response book. If there is a leak of HCL(Hydrocyaniic acid0 a five mile area is evacuated around the site. That is the maximum evacuation limit. Not too many hazmat chemicals rate that large an evacuation zone.
Just a couple of corrections. ALL DOT specification cars are required to have shelf couplers as well as all other tank car specifications (AAR, TC (Transport Canada)) that carry hazardous materials.
Also, hydrocyanic tank cars did carry the paint scheme that was mentioned to aid in their easy and early detection. They are being repainted to a basic paint scheme now without the stripes to minimize the attention they draw, i.e. terrorist.
Finally, hydrocyanic acid (UN ID# 1613, 1614 or 1051 depending on the concentration and state of HCn), warrants an isolation distance of 200 to 500 feet in all directions and then 8/10 of a mile downwind evacuation at night for less than 20% HCn and 2.3 miles downwind at night for more than 20% HCn. (2004 Emergency Response Guidebook)
HCl is hydrogen chloride, commonly found dissolved in water to make hydrochloric acid.