Unit tank trains on the BNSF at Kansas City typically have a hopper car or box car between the
power & tank cars. Is this a buffer to keep the crew away from the commodity ? Or is the hopper
filled with cat litter to use in the event of a leak ? If they want a buffer, wouldn’t a flat car provide
more distance ? Thanks
It’s a buffer to keep the crew away from the hazmat cars which may or may not make a difference in the event of a derailment.
First, John: WELCOME Here! [#welcome]
As Georgia Railroader says. Buffer Cars are used to provide a margin of safety, and I think it is a required placement between crews and trains with hazardous materials.
One think I’ve noticed out in this area ( South Central Kansas) that strings of tank cars seem to be broken into blocks and generally is is at least one hopper car (or several) that are used to break up what would have been a solid unit train of tankers.
It happens too often to be a random placement, although I am not sure if there is a specific company rule or not. It might be a sort of ad hoc safety measure done by the crews making up the trains, to protect the train, and crews in case of a derailment(?).
Many of the tanker trains running through this area are hauling ethanol, so hopper cars of grain would possibly have the same origin, and destination as the ethanol tank cars.
Maybe some one who works for BNSF can respond to that.
Depending on the comodity, one or five cover (buffer) cars are required.
The unit train with the buffer cars spaced through out is set up as either a classified block of cars to be broken up into smaller trains headed towards industries, or a block set up to be delivered to several yards, cover (buffer) included.
UP hazmat rules, standard on most GCOR roads.
When 5 buffer cars are required, it is when train length permits. If you don’t have 5 available, you use what you do have and must have at least one.
A loaded ethanol train requires the use of 5 buffer cars, if available. If the train is made up of one (for example) covered hopper and 80 loaded tank cars, it meets the requirement because only one car is available to be used as a buffer in the train. You don’t have to scrounge around the yard to find 4 other available cars.
If that loaded ethanol train originated with one covered hopper and 40 cars and then was to pick up another covered hopper and 40 loaded ethanol cars at another location, both covered hoppers would have to be between the engines and first ethanol load. You couldn’t pick up in a manner that would result in a consist of; engine, buffer, 40 loads, buffer, 40 loads.
The restriction isn’t so much about keeping the bad stuff away from the crew, but away from the engine(s), a possible ignition source, especially if things go really wrong. If you have a DP on the rear, it also requires 5 buffers, subject to the train length proviso. If you read the restrictions, there are prohibitions against direct placement of haz-mat next to cars that may have an ignition source or load that could puncture a tank car. Also different classes of haz-mat may need to be separated, too.
Jeff
Sam, is this a moving train you see, with the scattered buffer cars or one standing in a siding or a yard?
Restriction #2 calls for an equal number of buffer cars between the hazmet cars and a caboose, as between the hazmet cars and the engines (working or not).
Ed:
Most of my observations around here are moving trains. Very seldom do they seem to stop around this area. The will occasionally be held, but not for very long, as they seem to be running a higher priority train past the stopped units.
From the Junction(s) at Mulvane south towards Wellington, it is practically all double tracked, and signaled for bi-directional running on each main. Double track is on the El Dorado sub (#1 ) The Ark City sub through Mulvane is single tracked from Wichita down towards Winfield.
Ed, back to your point. The ‘Grain Worms’ pretty much seem to be regular shuttles through here (appearing roughly, the same time frames during the week) and generally made up of solid BNSF company cylindrical-style cars.)
Some of the trains that would meet a description as a ‘Unit Tank Trains’. Almost in some cases resemble a mixed merchandise type of mix. Blocks of tankers, blocks of grain hoppers ( mixed car designs and blocks of boxcars, most of there blocks are at least 4-5 cars) . Which as mentioned by Jeff would account for their positioning (?).
It is an interesting area to railfan, lots of traffic and a variety as well. Last evening, there was a TOFC/COFC stopped north of town, and another train of mixed hopper and tanks at Mulvane. The train north of town was unusual in that I counted at least 11 units on the headend. Generally, only three or four units are used. Just my observations but often see mixed consists on that afternoon train. COFC cars with Hunt/Schneider cans and then TOFC Flats and some stacks or auto carriers on the rear.
Without being there and watching in person, it sounds like a train that gathered up a bunch of cuts of cars from a few ethanol plants.
I know the one plant we have here on the PTRA always sets a boxcar, either empty or full of bagged and dried “mash” on the head end as a cover cars, so just wondering if that might explain the staggered boxes in your train.
The same old beat up boxcars seems to cycle back to them every couple of days on the inbound empties.
And as Jeff pointed out, often road trains are mad p of blocks of cars moving to different yards along the way, so you would expect to see all the boxcars in one group, covered hoppers in a block, tanks in another, and most of the “loose” cars, singles headed to a hump or switch yard for classification in there as a “block” too.
When we build up an outbound, that’s pretty much how we do it, and because shippers often order large blocks of the same type car, like Shell ordering 50 empty tanks, and Jacco, which ships bagged grains overseas always ordering boxcars.
When we pull the plants, and return to our yard with the cars, the boxes will be placed in the BNSF outbound track as a solid block, simply because that’s how they came out of the plant.
So, when BN leaves out, their train is composed of several blocks of cars destined for yards along their route, some blocks only go across town to New South Yard, some head out to Kansas, Idaho, you get the point, a train that is blocked out will pull into a yard, drop off the block of cars for that yard, pick up any forwarding blocks for farther down the line, so forth and so on.
I thought I would take a stab at the original question in this thread, “If they want a buffer, wouldn’t a flat car provide more distance ?”
In a bad wreck sometimes the cars accordion. If a flat car was the buffer, I could see a tank car rolling over it. A hopper would seem to give more crumple zone isolation.
Mike,
Not trying to be a smart alec, but we don’t really have a choice, it’s not like we have a yard where we keep a selection of buffer cars we can pick or choose from…
You go with what’s on hand, if it’s a boxcar, great, and non-placarded tankcars work, flats, coil car, any non-placarded car other than shiftable loads.
In the instance of the ethanol plant here, they either bought or leased a bunch of old boxcars themselves…if they hadn’t, we would have to find cover cars to take out there and pull the plant, and make sure the cover car was one that would normally go to the same destination on the same outbound train as the ethanol cars or, if the ethanol cars were made part of a bigger train, make sure they were placed at least 5 cars deep behind cover cars, (buffer cars)in the consist…
Buffer or cover cars provide or serve two purposes,
One, they keep flammable loads away from a possible ignition source, the locomotive, and two, they provide a cushion or buffer in case of a collision.
In the latter instance, they are there simply to give the placarded cars something else besides the locomotive to run into.
The GCOR says you can get by with only one, if that’s all that’s available at the time, but you must run at restricted speed until you reach a yard, terminal or siding where you can pick up more buffer cars, unless the train is a unit train, (all the same cars all carrying the same commodity, and all originating at the same terminal or yard) until you reach the required 5 buffer cars.
Look closely at the placement in train chart and you can see some placarded cars can run with no cover or buffers if empty or residue, some combustibles only requires one car cover.
The reality of course is that, if you have say, 20 or 30 loaded gasoline or LPG cars 5 back from your locomotive, and have a collision at track speed that punctures the cars, you stand a good chance of becoming a Post Toastie anyway, but the rule about placement is there
Ed you hit the Nail on the head. Here is what Explosive teams are called Suicide Jockeys or the Stick and Spoon or the Sponge Brigade why if that load goes BOOM the way they sometimes have to pick you up is with the Stick and the Spoon or with a Sponge. LPG and a few other things we haul are JUST AS BAD if not worse. Heck try this Combo it was Placarded Non Flammable Gas the Dry Ice that was ON THE LOAD that was boiling off the load. Then Flammable Corrosive on top of it. It had to be kept BELOW 20 Degrees or the Crap would Spontaniously COMBUST on its OWN. Load was 45K lbs at the Begining when I left the plant. Get to the other end and I was at 10K lbs and I only had 8K lbs of Product on. Moved that stuff 1500 Miles in less than 48 hours solo since I was the ONLY ONE in the area with the required Endorsements. They normally make it on site but they needed more at the place needed so I got the call. Man it was a PITA to move. Lets just say the DOT left me alone with that one.
edblysard, thanks for your reply, it was educational. That ethanol plant could have gotten a deal on 48’ well cars for buffers, probably for next to scrap prices. I should mention that the Midland in my sign-on name does not refer to Midland, TX, but to the midwest region, which the author R.J.Cook referred to as the Midlands. I could never discern if my local shortline paid much attention to placement of placarded tank cars. Maybe they were empty, or maybe I should remember my hazmet training which says never to believe that a placard is always right.
Ed wrote:
We did see a long ethanol train holding at Alpha IL. I thought it was unusual that there was no buffer car. I guess your post explains it.
Loaded cars are preferred for buffer cars in unit trains. Empties do get used at times, but an empty buffer car(s) in a loaded unit train will trigger a train placement warning on our paperwork.
Jeff
Loaded cars are preferred for buffer cars in unit trains. Empties do get used at times, but an empty buffer car(s) in a loaded unit train will trigger a train placement warning on our paperwork.
Jeff
The chart that ED posted states tank cars loaded with a flammable liquid, or its residue, require at least one buffer car. Chances are the train you saw had a tank car as a buffer.
As Eric points out, all that is needed is a non-placarded car, so it could easily be a tankcar for cover.
Another thread in this forum links to an EB BNSF Ethanol train. I watched the video (all 9 minutes) and it showed a single hopper car buffer after the engines and before the trailing DPU. I noticed what looked like white diamond placards, whereas, I expected red for ethanol.
The information contained in the following link may be of interest as it explaines the nomenclature and reading of various kinds of Hazard Class Placards.
From the following link:
http://www.mcor-nmra.org/publications/articles/reading%20hazardous%20materials%20placards.pdf
The following information is located on Page 5 of the linked PDF:
“…Tank cars are required to be placarded when they are loaded with hazardous materials. When tank cars are emptied, they are required to continue to be placarded until they are washed out, or cleaned out such that all traces of the hazardous materials are removed. “Empty” tank cars with some product still left in them are known as “residue” tank cars. “Residue” tank cars may have as much as 3% of their original contents still in them, but be listed on the train list as “empty”. So when you are watching tank cars going past you at a railroad crossing, you may not know if the car is full, half full or almost empty because they will all be “placarded” the same. This is where a check of the compression of the springs on the trucks may help, or being able to read the train list if you can talk to the train crew. At one time, placards could just be turned around in their holders, because on the backside was the same placard markings, but it read” residue’ but those markings are now gone…"
Hope the above in