# Chemical tank cars



## vette-kid (May 2, 2020)

Teach me something about transporting chemicals over railways! Are there certain types of tank cars for various chemicals? Would fuel be transported in a different type of car than a coolant chemical (for commercial refrigerated warehouses), or other caustic chemicals? Or are they all the same type of car just labeled differently. Further, how about things like milk? 

Sorry, I'm pretty uneducated with this type of thing. Tried searching with Google but all u got was a bunch of irrelevant links or links to buy model train cars. 

Sent from my SM-G781U using Tapatalk


----------



## OilValleyRy (Oct 3, 2021)

Where to begin with this…. As a general rule, the heavier the commodity, the shorter the car is. There are exceptions to that rule, usually due to clearance (spatial clearance) restrictions. However older era cars are all short too, but look a bit more primitive in design.

There are many different types of cars, some the differences are hidden inside. 
Corn syrup is shipped in funnel-flow tank cars, which have a noticeable slant design into their body. 
Some commodities require special linings so the cargo does not attack the metal, or to isolate any contaminants. That can be deduced by commodity labeling. 
Some cars have heating coils hidden behind the car body exterior, so that the commodity can be heated and make unloading faster and easier. Tar would be a good example of this. 
There are general purpose cars too, which carry a variety of things obviously.
Placards will indicate, if the car is loaded, what kind of hazardous material is loaded and how dangerous it is (i.e. acidic, explosion, flammable, corrosive gas, etc).

Milk, I believe, is shipped in mechanical reefer (aka refrigerated) cars in order to keep them cool. Although powdered milk might be shipped in covered hoppers? Decades ago there were dedicated milk cars, which look like a butter dish to my eyes, or a deformed tank on a flat car.

Coolant transport would depend on the coolant. I.e. Freon is a poisonous gas shipped in large tank cars designed for gaseous loads, Transmission fluid is a liquid but might not meet the threshold of hazardous material. It may. I’m unsure. A Ford transmission plant used to get it in common general purpose looking cars.

Fuels: Again, this depends on the fuel type. Everyone thinks of gasoline right off. There is also diesel, heavy diesel (for ships), jet fuel, kerosene, heating oil, which are all liquids. Then there is butane, propane, and other gaseous fuels and feedstocks/catalysts (fuels in a different sense), which ship in longer larger cars. 
Gasoline, diesel, etc are shipped in the same kind of car, even the same car after it is cleaned out after unloading. So diesel one trip, then cleaned, and loaded with kerosene, is fine. 
Caustic Soda on the other hand, is specially lined and transports only caustic soda. Cars such as this are always labeled near the car end opposite of the reporting marks. E.g. Hot Asphalt, Hydrogen Peroxide, etc.
Some times cars have colored banding painted on, like a big yellow center area of the body, or a stripe(s) at one end.

It’d be easier to figure out exactly which commodities you are looking at, like what kind of coolant specifically, and then determine if it is hazardous, a liquid or a gas, etc. Tank cars are more diverse than 1950s locomotives, while keeping the differences very subtle.


----------



## GNfan (Jun 3, 2016)

vette-kid said:


> Would fuel be transported in a different type of car than a coolant chemical (for commercial refrigerated warehouses),


The most common refrigerant for cold storage facilities is ammonia, which is a gas at room temperature and atmospheric pressure. It would be transported in compressed gas tankers similar to propane. But those are closed systems once they're filled. They may lose a little here and there, but ammonia is so noxious even minor leaks can trigger evacuations.


----------



## vette-kid (May 2, 2020)

Specific to my layout, I'm looking at refrigerant, diesel, propane and human consumables (milk). I'll also need regular freight box cards, maybe livestock. But for liquid/ gas I think that's it. Possibly random chemical tanks would fit in too. 

But for a bigger picture, I've become rather fascinated with our freight transportation system in general. So all the above is welcome and fascinating information. 

Sent from my SM-G781U using Tapatalk


----------



## cv_acr (Oct 28, 2011)

vette-kid said:


> Teach me something about transporting chemicals over railways! Are there certain types of tank cars for various chemicals? Would fuel be transported in a different type of car than a coolant chemical (for commercial refrigerated warehouses), or other caustic chemicals?


Yes.

Tank cars are probably one of the most varied car types out there.

While there are "general service" designs, often tanks will be dedicated to a single commodity. Even if the car is appropriate to many different commodities, they're not that easily switched between different loads, as the car would need to be entirely cleaned at a maintenance facility to remove all traces of the original load or the product could be contaminated.

Broadly speaking, there are several distinct types of tank cars, described below, and also within each type the sizes of the car will vary considerably depending on the density of the designed load, as it may take much less volume of a particular commodity to hit ~100 tons than another.

Non-insulated, regular tank cars for liquid service.

Insulated tank cars for liquid service. Likely also having internal (steam) heating coils, to which a steam line can be hooked up to heat the contents of the car if the load needs to be hot to flow.

Most general-service cars of the above types will have top loading fittings, presure relief vents, and a simple bolted manway cover for loading and/or maintenance access. Bottom fittings for unloading (and steam line hookup if applicable).

Next are acid/corrosive liquids cars. These tend to be smaller due to the liquid density, but also have different top fittings, and no bottom fittings (some exceptions may apply) or pressure relief valves. Product is generally unloaded by pumping out through the top (the unloading fitting has a pipe on the inside of the car to pump out the bottom).

Lastly the the products that are not liquids at all, but compressed or liquified gases. These again have no bottom outlets, and no pressure relief valves. Top fittings are obviously also different again, and usually contained in a protective cover.

Different reactive products may also require special tank linings (acid cars are lined with glass or rubber). You won't see that externally but it is critical for the applicability of the car to the load.


----------



## cv_acr (Oct 28, 2011)

vette-kid said:


> Specific to my layout, I'm looking at refrigerant, diesel, propane and human consumables (milk). I'll also need regular freight box cards, maybe livestock. But for liquid/ gas I think that's it. Possibly random chemical tanks would fit in too.


While I'm not sure that milk is actually currently shipped in railway tank cars, if it was, it'd definitely be in an insulated type tank car with a food grade lining. Diesel fuel in similar cars, but not necessarily requiring special lining. Obviously you can't see the interior linings, but the tanks, while similar, would be dedicated to the particular product. General service cars in the 20,000-30,000 gallon range.

Refrigerant and propane are both liquified/compressed gases so they can't use the same car. Ammonia and propane are shipped in the largest gas tank cars (33,000 gallons). Other types of refrigerant gas in smaller sizes of cars depending on the specific density of the product.


----------



## gunrunnerjohn (Nov 10, 2010)

I think milk cars went out of service many years ago, probably 40-50 years.


----------



## Old_Hobo (Feb 20, 2014)

This milk car was built starting in 1936….










This is also a milk tank car….internal tanks…..


----------



## MichaelE (Mar 7, 2018)

When I worked at an asphalt tank farm in the late 80's- early 90's, we would receive asphalt maybe one a week via tank car. Most of it was unloaded from river barges, but the railroad would drop off a tank car once a week or so.

These were average sized tank cars, always black, with a single dome and access hatch on the top. We had to temp check the asphalt before unloading and it hovered around 435°F before unloading. 

I don't know if the car was heated and we never had to fool with any heating elements or steam lines if it was. I do know it was a double wall insulated tank, and was painted black to help absorb any sunlight to help keep the outer tank warm. They were actually pretty damn hot, but not hot enough to burn you when climbing up to open the hatch before unloading the car. Very uncomfortable in summer with full protective gear on.

A hose with a locking connector was attached to a spigot under the car and when we set up the correct routing to a tank on the farm, we'd open the valve under the car and start the tank pump to the tank where it was to be stored.

Sometimes we would blend straight out of the car too as this would save a step later on. Once the blend amount was reached, we would stop the flow from the tank car, close the tank valve(s), and stop the pumps. Then reroute the remaining asphalt to a storage tank for later blending.


----------



## vette-kid (May 2, 2020)

Old_Hobo said:


> This milk car was built starting in 1936….
> 
> View attachment 569967
> 
> ...


That top one is just cool lookin!

Sent from my SM-G781U using Tapatalk


----------



## vette-kid (May 2, 2020)

Great info, thanks everyone

Sent from my SM-G781U using Tapatalk


----------

