On trains with blocks of tank cars, it's common practice to place a spacer boxcar or hopper between the first car and the loco, to protect the engine crews. But what if some of the tank cars contain caustic or corrosive loads instead of "oil" or ethanol? Some of my model tank cars are stenciled for hydrochloric acid, or potassium hydroxide, or liquid sulfur. Do railroads attempt to isolate these cars from those containing petroleum products and ethanol, or are tank cars typically run in a single block no matter their contents?
Thanks.
I do not recall all of the fine print I have read concerning placement of various commodities in trains, but there are certain ones that are NOT to be placed next to certain others.
Good oxidizers should not be placed next to easily oxidized substances. One day when I was working in the physical chemistry lab I heard a "boom" down the the hall, and thought that the boys in the organic lab had found a new process or had let an accepted process get out of hand. However, the stockroom boy had been combining various chemicals in a glass jar, had turned away to get something else, and when he turned back, he caught the jar, in pieces, in his arms and chest.A few years later, he told me that every now and then another piece of glass would work its way out.
It is known what most of the commodities shipped by rail can do, and every effort is made to keep undesirable events from taking place.
Johnny
Deggesty has it right. I'm not sure if I saw it in an employee TT or the Rules for Conducting Transportation but I have seen charts concerning the placement of placarded loads of all sorts.
I have seen the charts in ETT's. The railroads are doing everything possible to avoid interactions between incompatibles.
Incidentally, when I was concerned with the shipping of hazardous materials (going on at least 12 years ago), anhydrous ammonia was simply a compressed gas in the USA--but an inhalation hazard in Canada.
In general the answer to the original question is NO. If you read the CFR or ETT placement charts you will see the phrase 'placarded loaded tank cars' that as a group must be separated from certain other types of cars. What that means is that placarded loaded tank cars of all hazard classes can be freely intermingled, with the exception of loaded cars of any type placarded 'Poison Gas'. This is as of 1984 SP ETT.
I do not know how the Feds dealt with Poison Inhilation Hazard materials. Some of them are the old Poison Gas, some are not.
I used to live this stuff as a Bureau of Explosives inspector and member and later Superintendent of SP's Hazardous Material Control group.
I work in the Great White North so have no idea how the U.S. regs work, only that they are somewhat different from ours.
In Canada dangerous goods being transported by rail are classified into four groups: A,B,C or D. They are all subject to general restrictions, which include not being placed next to an engine, caboose or other occupied car (unless all cars in the train contain dangerous goods, that is why unit oil trains do not have to have a buffer car in Canada), next to a load prone to shift, next to a car with a operating heating/cooling system, etc.
Cars containing Group A chemicals may only be marshalled next to cars containing other Group A chemicals. Group A chemicals are all extremely flammable or explosive.
Cars containing Group B chemicals may only be marshalled next to cars containing the same chemical. All the Group B substances are listed in our operating manual, and it is a very short list.
Both these first two groups are uncommon, and I have actually never encountered them at work.
Group C must not be marshalled next to Groups A or B, and only the general restrictions apply to Group D.
All dangerous goods may be freely marshalled next to cars that do not contain dangerous goods and are not subject to any of the general restrictions.
There is no limit on how many dangerous cars may be in a train, and I have seen trains of over 100 cars composed almost entirely of liquefied propane and/or anhydrous ammonia, both of which are far more dangerous than the unit oil trains the public is so scared of.
Greetings from Alberta
-an Articulate Malcontent
I hear you on those 2 goods. The most dangerous thing out there is cholrine gas followed by LP gas then Anhydrous Ammounia. My drivers would rather haul a load of explosives than anyone of those 3 items. Yet people think explosives are worse. The same weight of cholrine gas will kill more people over a larger area than the same weight of explosives would.
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Deggesty Incidentally, when I was concerned with the shipping of hazardous materials (going on at least 12 years ago), anhydrous ammonia was simply a compressed gas in the USA--but an inhalation hazard in Canada.
I used to repair Blue Print machines which develop the image with Anhydrous ammonia. It is not something I would want released into the air in my community or work place. It was bad enough when you opened the developing tray of the machine, releasing very small amounts.
Dave
Lackawanna Route of the Phoebe Snow
Phoebe VetI used to repair Blue Print machines which develop the image with Anhydrous ammonia. It is not something I would want released into the air in my community or work place. It was bad enough when you opened the developing tray of the machine, releasing very small amounts.
When I first got involved with weather balloons, USAF still had some hydrogen generators which broke down anhydrous ammonia to create hydrogen for the weather balloons. If we had to bleed off the ammonia, we just stuck the hose in a bucket of water and, voila!, ammonia for cleaning! We usually just dumped the bucket in the driveway.
We won't get into the fact that the retort (the anhydrous ammonia cracked at around 1200 degrees, as I recall) was packed in asbestos, which we handled from bags dry, mixed it with water, and packed it with our bare hands... Those were the days!
I worked in a facility that made microfiche via a diazo process. It used ammonia as well.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
tree68 Phoebe Vet I used to repair Blue Print machines which develop the image with Anhydrous ammonia. It is not something I would want released into the air in my community or work place. It was bad enough when you opened the developing tray of the machine, releasing very small amounts. When I first got involved with weather balloons, USAF still had some hydrogen generators which broke down anhydrous ammonia to create hydrogen for the weather balloons. If we had to bleed off the ammonia, we just stuck the hose in a bucket of water and, voila!, ammonia for cleaning! We usually just dumped the bucket in the driveway. We won't get into the fact that the retort (the anhydrous ammonia cracked at around 1200 degrees, as I recall) was packed in asbestos, which we handled from bags dry, mixed it with water, and packed it with our bare hands... Those were the days! I worked in a facility that made microfiche via a diazo process. It used ammonia as well.
Phoebe Vet I used to repair Blue Print machines which develop the image with Anhydrous ammonia. It is not something I would want released into the air in my community or work place. It was bad enough when you opened the developing tray of the machine, releasing very small amounts.
I worked with the first XEROX process back in the middle '50s while in a PRR engineering office, where we took an exposure on an energized plate with a bellows camera, then rocked toner over it. We then transferred the image to a multilith master and fused it with either heat ( a small pizza oven) or an etheleyne gas. It took about 15 minutes to make a copy. This was before Xerox came out with their first automatic copier (914) in 1959. And as you said, the blue print machines used ammonia for developer. Room had some good exhaust fans fortunatly. Today, your home printer can copy and print in color. As I get older I wonder what our grandkids have to look forward to. Remember when we used to laugh at Dick Tracy and his wrist phone. The only thing I can say with confidence is impossible is my getting pregnant.
Electroliner 1935The only thing I can say with confidence is impossible is my getting pregnant.
I'm sure someone is working on it...
The first copier I worked with required single sheets be fed (no copying a book or part of an oversize document) and used heat to make the image on thermal paper.
As you note, one wonders what's next for imaging - although more and more businesses are going strictly electronic. Almost all of the EMS agencies around here now use electronic documentation, including gathering signatures. The only paper usually involved with a patient is the sheet we get from the hospital outlining info we need from them.
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