Hazardous Materials Operations

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RAIL TANK CARS
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Categories of Rail Tank Cars

• Four categories of rail tank cars
• Pressure
• Non-pressure
• Cryogenic liquid
• Miscellaneous
• (not covered in this lesson)

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• Pressure Tank Cars

Dome houses both valves controls
A end
B end
Trucks
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Pressure Tank Cars

• Usually transport flammable non-flammable
  compressed gases Poison A gases
• Additionally, they can carry

• acrolein, inhibited
• pyrophoric liquids
• bromine
• motor fuel anti-knock compounds

• ethylene oxide
• hydrofluoric acid
• sodium metal

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Pressure Tank Cars

• Capacities range from 4,000 gallons to 34,000
  gallons

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Pressure Tank Cars

• PRESSURES
• range from 100 to 600 pounds per square inch
• vary according to the commodity being
  transported

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Pressure Tank Car Construction

• welded steel
• thickness will range from 1/2 inch to almost 1
  full inch
• insulated cars have 4 inches of insulation
  material wrapped around the tank
• an outer shell of sheet metal forms a tank within
  a tank

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Pressure Tank Car Construction

• Two types of thermal protection used
• 1) Jacketed thermal protection which is mineral
  wool or various manmade ceramic fiber blankets
  held in place by a metal jacket or...

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Pressure Tank Car Construction
2) Sprayed on thermal protection is a rough
textured coating sprayed onto the outer surface
of the tank, or jacket on some jacketed cars,
that insulates and protects by expanding when
exposed to fire
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Pressure Tank Car Construction

• All flammable gas tank cars MUST be built to the
  specifications for jacketed or thermally
  protected cars, and...

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Pressure Tank Car Construction

• 1) must have top and bottom shelf couplers

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Pressure Tank Car Construction

• 2) must have additional head shields

internal shield
external, retro-fit shield
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Pressure Tank Car Construction

• LOADING VALVES
• Pressure tank cars are loaded off-loaded from
  the top
• The valves gauging devices are housed in a
  dome cover (about 24 inches high 36 inches in
  diameter) with a lid at the top in the center
  of the tank car

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Pressure Tank Car Construction

• The dome cover protects conceals all valves

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Pressure Tank Car Construction

• A ladder leads to a personnel walkway and platform

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• Non-Pressurized Rail Tank Cars
• (General Service Tank Cars)

Top operating mechanism for bottom valve
Safety relief valve
Bottom valves
Combination fitting
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Non-Pressurized Rail Tank Cars (General Service
Tank Cars)
Transport a variety of liquids, solids,
poisonous liquids such as
flammable liquids combustible liquids toxic
substances corrosive liquids oxidizing
substances organic peroxides

• vegetable juices
• tomato paste
• molasses
• fruit juices
• vegetable oils
• solids, in hot molten state

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Non-Pressurized Rail Tank Cars

• CAPACITIES
• range from 4,000 gallons to over 45,000 gallons
• PRESSURES
• vary from 35 p.s.i. to 100 p.s.i., depending on
  the commodity being transported

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Non-Pressurized Rail Tank Cars

• CONSTRUCTION
• most are 1/4 inch thick welded steel and some
  are welded aluminum
• insulated cars have 4 inches of insulation
  material wrapped around the tank
• an outer shell of sheet metal forms a tank within
  a tank

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Non-Pressurized Rail Tank Cars

• CONSTRUCTION
• cylindrical in shape have a slightly rounded
  end
• LOADING VALVES
• usually loaded from the top off-loaded from the
  bottom
• located operated from the top and bottom of the
  tank

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Non-Pressurized Rail Tank Cars
Most often off-loaded using bottom outlet valves
with the valve controls on the top of the tank
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Non-Pressurized Rail Tank Cars
Can also be off-loaded using bottom outlet valves
with the valve controls located on the bottom of
the tank
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Non-Pressurized Rail Tank Cars
Can also be off-loaded using a top unloading
valve arrangement with the connections housed in
a dome cover
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Non-Pressurized Rail Tank Cars
Can be splash-loaded using the manway
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Non-Pressurized Rail Tank Cars
Non-pressure tank cars can be pressure on-loaded
using the bottom outlet valves
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Non-Pressurized Rail Tank Cars

• The valves gauging devices may be housed within
  an expansion dome (with the valves visibly
  protruding)

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Non-Pressurized Rail Tank Cars

• The valves gauging devices may be housed within
  a protective dome

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Non-Pressurized Rail Tank Cars

• Valve gauging controls may be mounted
  directly onto the top of the tank car, in the
  center of the car, without a dome of any kind
• In all cases a ladder to the top is provided
  that leads to a personnel walkway

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Cryogenic Tank Cars
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Cryogenic Rail Tank Cars

• Transport gases in a refrigerated
• liquid state, including liquefied

argon ethylene oxygen
hydrogen helium nitrogen
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Cryogenic Rail Tank Cars

• CAPACITIES
• Range from 4,000 gallons to over 30,000 gallons
• PRESSURES
• Will usually be very low, from 25 p.s.i. or
  lower, depending on the commodity being
  transported

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Cryogenic Rail Tank Cars

• CONSTRUCTION
• The inner tank is usually welded steel some
  are welded aluminum or a copper/bronze alloy
• The outer tank shell is usually 1/4 inch steel

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Cryogenic Rail Tank Cars

• CONSTRUCTION
• space between the two tanks is filled with an
  insulation such as cork or Perlite
• vacuum is created in this 4- to 6-inch space

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Cryogenic Rail Tank Cars

• CONSTRUCTION
• The combination of insulation vacuum is
  designed to protect the commodity for up to 30
  days with little product loss
• However, shipments are time-sensitive

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Cryogenic Rail Tank Cars

• LOADING VALVES
• Cryogenic tank cars are off-loaded from the
  rear compartment, or the side compartment,
  depending on how the tank car is designed
• The valves are located within this compartment

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Cryogenic Rail Tank Cars

• LOADING VALVES
• no dome cover or expansion chamber
• no valves or valve controls protrude from the
  car top