Buffer/Spacer cars

[Ntrainz1]

What are the requirements for buffer/spacer cars used in hazmat unit trains? Loaded or mt? Any specific types (I see box cars and airslide covered hoppers). Are they required for both loaded and empty trains?

How much protection would a crew get?

I am seeing more of these unit trains in SJ (ethanol, crude oil).

Thanks.

Bob.

[Robbman]

Depends on the roads operating rules... and on the hazmat being carried

Generally though, for requirements, one ahead/behind any motive power (this is why you'll see trains with one on the rear... to protect any pusher)

No specific type, but you tend to see lesser used cars being used

Crew protection... honestly... little to none.

I

[nkalanaga]

It also depends on the hazmat.  Crude oil and ethanol rank fairly low on the danger scale.   According to my big 1977 hazmat manual, ethanol (Ethyl Alcohol back then) is "Flammable", while crude oil can be either "Flammable" or "Combustible", depending on the flashpoint.  "Flammable" is below 100F, "Combustible" is 100F to 200F, at least in that manual.

For operators, another thing to consider is that there are many different types of hazmat, and some can't be next to each other.  They're not all obvious, either.  For instance, a car of radioactive material cannot be placed next to a car of undeveloped film, and there are more radioactive materials shipped than one might imagine.  They're not all the high level waste that makes the news...

From a 1977 Bureau of Explosives manual for railroaders:

Any car placarded "Explosives-A", including TOFC/COFC, and any placarded tankcar other than "Combustible", cannot be closer than the 6th car from the engine or caboose.  I remember my father saying there had to be 5 cars between a tankcar and the engine on the BN, so he was probably talking about this rule, in the 60s and early 70s.

The next entry on the chart says "no closer than second car", in other words, at least one idler, if the train is too short for 5 spacer cars on each side.

A loaded flatcar, without fixed ends, and any open top car where the lading extends above the ends, cannot be placed next to "Explosives-A", "Poison Gas", or a placarded tankcar other than "Combustible".

There seem to be no location restrictions on "Combustible".

An engine or caboose cannot be next to a placarded "EMPTY" tankcar except combustible.

Explosives, poison gas, and radioactive cannot be put next to ANY loaded placarded car, except another car with the same placard, or combustible.  They can be put next to empty placarded tankcars.

Any car with an open flame or internal combustion engine, including reefers and rider cars with stoves or IC engines, cannot be next to explosives, poison gas, or any loaded placard tankcar except combustible.

Wet storage batteries cannot be shipped in reefers or plug door cars unless they are vented.  They can be shipped in open top cars, as long as they have solid floors.  No wet storage batteries in hoppers!

Put a few placards on your cars and you can really complicate the crews' lives.
 

[RockGp40]

Robbman is spot on. We had another lesson learned on my short line recently that has everything to do with what nkalanaga posted. A reefer cannot be used as a spacer when couple up to LP gas cars (1075, flammable). There has to be another car between the engine and the reefer. Apparently, it has to do with the fuel cell/combustion engine for the reefer unit.

Combustibles can be pulled next to the locomotive. Its not preferred though and crews generally will put a spacer car in front of it.

I have used many car types as a spacer, including boxcars, non placarded tanks, covered hoppers, centerbeams, flats, gons, and even an empty depressed flat too.

[nkalanaga]

For the steam-era modelers, an iced reefer can be used as a spacer, if it doesn't have a lit heater in it.  As RockGp40 said, it's the fire/engine that causes the problem, so all mechanical reefers are ruled out.   If you turn the engine off, it may be usable, as then it becomes an insulated boxcar.  But I wouldn't swear to that, and there's no guarantee that an overzealous car inspector wouldn't turn it back on, thinking it was turned off by accident!