TM 55-203
steel brush to remove all traces of oxidation, then the
frames resulting from wood warping may cause leakage.
areas should be coated with red lead or some other rust
In this event, such members will be replaced and the
inhibitor, and painted.
doors refitted.
c. Locking Devices. The hardware of refrigerator
9-20. Waterproofing
car doors includes the hinges, cranks, locking bars, and
levers. These members generally are constructed of
The greatest single problem in the maintenance of
malleable iron, affixed with bolts passing completely
refrigerator car superstructures is the prevention of
through the door and anchored with a nut on the outside.
water seepage into the inner sections of the car, walls,
These locking and hinge devices become inoperative
ends, and floors. This seepage will In time corrode the
due to rust, wear, deformation or breakage, and
metallic members of the structure and decay the
looseness. If one of the devices cannot be repaired or
wooden portions. To correct this action waterproofing is
firmly affixed, it should be replaced with a new one, and
required Various remedies include the use of
the portion of the car body or door to which it is affixed
compounds and the application of plastic sheets.
be repaired to afford a satisfactory support or anchor
Impregnating all lumber used with a creosote mixture
point. Airtight closures are not possible if these devices
makes the material highly resistant to moisture. When
malfunction.
repairs are made to the car body, all joints should be
sealed with waterproofing materials.
The area
immediately behind the ice bunkers or brine tanks is a
9-19. Roofs
critical area and requires greater care because of its
proximity to condensate water and brine solutions
a. General. There are several types of roof used
contained in these tanks or0 emanating from them. In
on refrigerator cars: board, plastic, inside or outside
the case of box bunkers, in which the walls are formed
metal, and all-steel. It is important that car roofs be kept
by the ends and sides of the car, waterproof construction
leakproof to prevent decay and corrosion of the car
and repair are essential.
structure and/or damage to the loading. Roofs and all
parts such as roof boards, plastic coverings, metal roof
9-21. Overflow Pipes
sheets, purlins, carllnes, ridge poles, etc., should be
inspected periodically and any leaks or damage
Overflow pipes are used in conjunction with brine tanks
repaired. Neglect of damaged supporting members may
and are provided to drain off excessive moisture As the
result in the development of stresses that open seams
ice melts, the brine solution rises in the-tank until the
and joints, thereby causing leaks in the roof.
level of the overflow pipe is reached. At this point,
excess solution is drained into a tank and retained to be
b. Repairs. Outer or inner roofs which leak
discharged later, or when no damage to the tracks and
should be repaired or the leaky member replaced. In
roadbed will ensue. Overflow pipes become clogged
the case of plastic covering, the leaky portion should be
with sludge and incrustations. This must be removed
recovered This may be applied directly over the old
during routine maintenance and the pipes thoroughly
roofing. Where cars have inside sheet metal roofs, care
cleaned, since a stoppage of the overflow pipes will
will be taken to insure that 'nails used to secure the
result in overflow of the brine tanks and flooding of the
outer boards do not extend into the car interior and
car.
The overflow pipe valve will be periodically
puncture the metal lining. This type of repair generally
cleaned also and maintained In good working order.
can be effected without removing the entire roof;
however, It may be necessary to remove some roof
9-22. Bunkers
boards or parts of the running board. If car lines,
purllns, ridge poles, or planks must be replaced, it
usually will be necessary to remove the entire portion of
a. General. In some refrigerator cars, the
roof. In some types of construction, car lines are so
retaining wall or box bunker bulkhead is used to form
installed that removal is impossible without disassembly
one end of the ice bunker. In these cars the bulkheads
of the roof. If only one car line must be replaced, it can
are arranged as collapsible members that may be swung
be removed piecemeal and a new one installed in two
upward, or to one side, and fastened out of the way This
sections, to be spliced after installation Purlins, if
is done when commodities which do not require
defective, can be replaced by removal of the roof, or a
refrigeration are transported, so the space normally
section of it. Steel roofs deteriorate through rust and
occupied by
corrosive action. Rusty areas should be cleaned with a
9-9
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