I apologize if this topic has been dissected before on this forum (a “community” search yielded no useful information). Where did the requirement/use of a boxcar placed between locomotives and tank cars originate? I have seen it several times on BNSF tank car unit trains, and most recently on the cover of the June 2013 issue of Trains magazine. When there are helper diesels pushing on the rear, there is a boxcar separating them from the tank cars as well. I’ve read that tank cars are rather stoutly made.
This is a requirement of the Hazardous Materials Regulations of the Department of Transportation. Part 174 is railroad operating requirements. Used to be I could quote section and paragraph, but I have been away from it for a while.
Requirement is for a nonplacarded car, often called a “buffer car”. Can be any car type.
Restriction applies only to placarded loaded tank cars. NO.
If “a few” then they need to be at least 5 cars away from locomotives.
YES
N/A
Zardoz,
LNG fuel tenders will require an Exemption. Carriers would apply, justify and hope. Since BN tested LNG tenders years ago I suspect an exemption was issued at the time. I do not know if that exemption is still in effect.
Not all hazardous materials that are loaded into tank cars and require a placard have train placement restrictions. For those that don’t have restrictions, they can be next to an engine and be used as a buffer car for those that do have restrictions.
For those tanks that handle hazardous material loads that require placement restrictions, the following applies between those cars and engines. (Cars are placarded whether loaded or empty.) Residue empty tank cars require one buffer car. Loaded tank cars require 5 cars when train length permits. When train length doesn’t permit 5, use as many as possible, with at least one required.
That provision about train length permitting is why you might see a loaded ethanol train with only one or two buffer cars between the engine consist and train.
An FRA guy giving an NMRA clinic a few years back reminded us that a nominally “empty” tank car likely retains just enough residue of the load to make for quite an effective explosion under the “right” circumstances. I remember reading about the potential force contained in a cup of gasoline for example.
Can I add to the question list? Would I correctly assume that to be a buffer car the car has to have some sort of bulk of its own, in other words, a flat car would not be an acceptable buffer car? Or is pure distance all they are looking for?
This weekend while out at the BNSF Eola yard we saw one of the (these days) many crude oil trains (this one westbound and empty) roll by…it just so happened that one of the more friendly BNSF Eola yard employees was speaking with us and we asked him abou the “buffer” cars (this train had one…a hopper…behind the power but not one at the rear end) and he essentially told us they have a big pile of sand at the east end of the West Yard used to fill such “buffer” cars with ballast and he went on to offer his opinion that at 60 mph if “you go into the ditch you had better kiss your a-s goodbye as buffer car or not, it’s all over”. I think he’s likely right about that.
The DOT rules say a car, no specification as to car type. Carrier rules or special instructions are probably more specific. I suspect they specify some minimum weight to keep them on the rail under high buff force conditions.
As to “empty” tank cars that carry inhalation hazard gases, there is no such thing as an empty car, just as there is no such thing as an empty gas cylinder; there is always residue. When I was returning “empty” cylinders, I made certain that the driver of the truck had proper placards on his rig. And, since I had no isea as to how much residue there was, if it was necessary to report the release of a particular gas into the atmosphere, I always indicated that there was a reportable quantity present. I do not doubt that there would be a reportable quantity left in a car that had carried chlorine.
There has been some previous discussions around here dealing with ISSUES OF HOW’S AND WHY’S OF car placement within trains. Buffer cars, apparently, are a necessary item when building trains, but also serve to become part of switching moves enroute, and at origins and destinations; particularly ,as to their impact on excessive switching moves to pt a train together, or delivered at intemediate stops. THe prime motivation is to protect the on-board crews.
This letter explaines the rule making process, and the Official recomendations [from PHMSA ] for an accident at New Brighton.Pa, in October of 2006. IT was an NS train (68QB119)
As a point of possible interest to some around here: (admittedly, it may be “getting out in the weeds” on this issue), but certainly shows ha many agencies (and ideas) are
Per my FD hazmat training - unless such a tank has been thoroughly cleaned (I think there was an article in Trains some time back about such facilities) it must be placarded. Since they aren’t going to be cleaning an entire train worth of cars each go-round, if you see placarded cars, you’ll have to know where they’re going to know if the cars are full or “empty.”
Short of having the documentation for the car in hand, about the only way to know if it’s full or “empty” would be to observe things like the springs.
In general, as a firefighter I’m going to be somewhat happier to find out that a wrecked tank (RR or highway) is “empty” instead of full - if only because it means I’ve got just that much less of the material to deal with.
BNSF has a rule that empty cars should not be placed at the head-end of a train(minimum of 45 tons/car). They ‘load’ the covered hopper used as a ‘buffer’ to bring the weight from about 30 tons up to 45 tons. I have not seen any DPU mid-train or on the rear of ethanol trains locally(DM&E). I suspect they are too short to require DPU. I have heard that BNSF does not normally run DPU on the oil trains as they are usually going down grade(EB) and have no drawbar requirements.
Buffer cars are required with even 2 or 3 unit consists(even though the trailing units are not ‘occupied’). Based on that, they may be required on the end of a train that has a DPU pusher - Interesting question!
I want a car that weighs a lot more than 45 tons between me and a 10,000 ton crude oil train. Our buffers (pebbles on the manifest) are fully loaded to 70 tons. A buffer is required on the rear end if DPU is used as well.( We are looking into doing just that) . In Canada buffers are not needed on unit trains.
The one car buffer works ONLY for unit trains, if the yardmaster wants to add a few cars he’s going to have to add them on the head end and he better have 4 of them.
Because you need to load the car for weight. You can’t handle an empty car on the head end unless you want to derail the thing. A long car or one with long drawbars is not desirable either (no auto racks).