TM 55-2200-001-12
Change 3
Section No. 1--General Rules (Rev.-9-1984)
(d)
When gondola car is used for an idler, the width of overhang, as shown in Tables 1 and 2, must be reduced by
an amount equal to the difference between 12 ft. and the minimum inside width of gondola car, as per following
example:
60'-0"
Length of load. (Table No. 1).
46'-0"
Length of car used. (Table No. 1).
8'-9"
Assumed width of idler car used.
12'-0"
Arbitrary figure for all loads. Rule 8, Sec. (d).
12'-0"-8'-9"-3'-3" Amount of reduction, Rule 8, Sec. (d).
7'-0"
Allowable width of load. (Table No. 1) Flat car as idler.
7'-0"-3'-3"-3'-9" Allowable width of load. Rule 8, Sec. (d). Gondola car as idler.
Rule 9. Bearing Pieces, Sliding Pieces, Separators, Clamping Pieces, Braces, Cleats, Wedges,
Blocks, Guide Rails.
(a)
Such items of lumber must be in accordance with General Rule 3. Substitute, if desired, suitable metal sections
of equal strength. When metal items are specified, substitutions cannot be made. For bearing pieces, sliding pieces,
separators and cleats, the width of the pieces must not be less than the height.
(b)
Bearing Pieces-The width of base must not be less than its height. The length must not be less than the width of
car, that is the distance between the inside face of the stake pockets. For General Rule loads, bearing pieces must be
secured. If the load is prepared under a specific figure that does not require securement, it will not be necessary to
secure bearing pieces. Bearing pieces 5 in. high or less must be in one piece. Bearing pieces over 5 in. high may be
laminated to increase height, providing no laminations are less than 2 in. thick and all pieces are full width and length of
bearing piece and adequately secured together. When bearing piece is 6 in. x 8 in. or larger and additional bearing
piece height is required, longitudinal risers of 2 in. x 6 in. minimum size and projecting 18 in. beyond each side of
bearing piece may be added, providing height of risers does not exceed width. Risers must be located at points of load
concentration, using 5 risers for bearing pieces less than 12 in. x 12 in. and 3 risers for bearing pieces over 12 in. x 12
in. Risers must be secured to car floor, underneath of and at right angles to bearing pieces. (The foregoing provisions
for lamination and build-up of bearing pieces do not apply to Forest Products Loading, Section No. 5.) Bearing pieces
under loads requiring the use of more than one car must be secured so as to prevent displacement. For loads requiring
the use of more than one car and pivoted bolsters, see General Rule 17.
(c)
1. Bearing pieces, separators and guide rails must be of uniform thickness and width for their entire length,
unless otherwise provided for under a specific figure.
2.
Bearing pieces and separators, where specified under Forest Products Loading, Section No. 5 must not be
built up or laminated unless the method of lamination has been tested and approved by the AAR. The bearing pieces
and separators must be stamped on both ends with the letters AAR and the fabricators identifying mark. The following
fabricators have had their product tested and approved:
Name of Fabricator
Identification Mark
Strickler-Taylor Lumber Co.
AAR-STL
(d)
Sliding Pieces - Length must be equal to width of car and width of base not less than its height. Placing them
directly over bolsters is preferred but they may be placed between bolsters. To provide specified clearance of flexible
material, they may be located not more than 18 in. from center of bolsters toward end of car. When sliding piece is 6 in.
x 8 in. or larger and additional sliding piece height is required, longitudinal risers of 2 in. x 6 in. minimum size and
projecting eighteen (18) inches beyond each side of sliding piece may be added, providing height of risers does not
exceed width. Risers must be located at points of load concentration using five (5) risers for sliding pieces less than 12
in. x 12 in. and three (3) risers for sliding pieces over 12 in. x 12 in. Risers must be secured to car floor, underneath of
and at right angles to sliding pieces. Risers are to be toe-nailed to car floor with 20-D nails, spaced about 12 inches apart
on both sides. Sliding pieces must be secured through risers and car floor with 34 In. bolts, length to suit, countersunk to
clear top of sliding, piece.
(e)
Steel sliding plates, 1/4 in. x 6 in., length equal to width of car. Must be secured with two 3/4 in. dia.
Countersunk head bolts, etc., heads to be flush with or below top of plate. They must be grease(] so as to provide free
movement of load to destination..
(f)
When rods, etc., used to secure loads, not covered in detailed figures, are passed through car floor, a 4 in. x 4
in. x 18 in. hardwood cleat, or 1/2 in. x 4 in. x 18 in. steel plate must be placed lengthwise of car under floor. When
rods, etc., pass through stake pocket, a 1/2 in. x 4 in. x 10 in. steel plate must be placed lengthwise of car under stake
pocket.
(g)
When sloping wedges are used for end blocking against vertical surfaces, the flat side of wedge should be
placed on floor.
D-18
