TM 55-3810-229-14/N
TM 55-3810-229-14/NAVFAC P-941
Table 7-1. Bill of Materials for Blocking and Tiedown of MT-250 and MT-300 Cranes on CONUS General Purpose Flatcars
Approximate
Item
Description
Quantity
Lumber
Douglas fir, or comparable, straight-grain, free from material defects; Fed Spec MIL
L-751:
2- x 4-inch
90 lin ft
2- x 6-inch
30 lin ft
6- x 8-inch
18 lin ft
Nails
Common, steel; flathead; bright or cement-coated; table XI-b, Fed Spec FF-N-105:
12d
52
20d
120
40d
60
Wire rope
6 x 19, IWRC; improved plow steel; preformed, regular-lay; table X, Fed Spec RR-W-
410: 5/8-inch
225 ft
Clamps
Wire rope, U-bolt clips, saddled, single-grip, steel, Crosby heavy-duty or equal; MIL-
STD 16842:
5/8-inch
86
3/4-inch
24
Thimbles
Standard, open-type: 5/8-inch
30
Cushioningmaterial
Waterproof paper, burlap, or other suitable material
as required
Table 7-2. Application of Materials for Blocking and Tiedown of MT-250 and MT-300 Cranes on CONUS General Purpose
Item No. Required
Application
A
Brake wheel clearance. Minimum clearance required is 6 inches above, in back of, and on both sides of,
and 4 inches underneath wheel (fig 7-1).
B
12
Chock blocks (fig 7-3, detail 1). Locate the 45 portion of block against the front of the front set and
against the rear of the rear set of front wheels. Also, locate the 45 portion of block against the front of
the front set and against the rear of the rear dual wheels. Nail the heel of the block to the car floor with
three 40d nails, and toenail the portion of block under the tire to the car floor with two 40d nails.
C
1 ea per item D
Suitable material, such as waterproof paper or burlap. Locate the bottom portion under item D.
And where wire
The top portion should extend 2 inches above item D (fig 7-3, detail 2).
rope contacts
carrier frame
D
4
Side blocks. Each to consist of one of 2- x 6- x 90-inch lumber and three pieces of 2- x 4- x 90-inch
lumber. Nail the 2- x 6- x 90-inch piece against the side of a 2- x 4- x 90-inch piece with thirteen 12d nails.
Place the 2- x 6- x 90-inch piece against the tires with item C in place, and nail to the car floor through the
2- x 4- x 90-inch piece with ten 20d nails. Nail the other two 2- x 4- x 90-inch pieces to the one below in
like manner.
E
8
Wire rope, /8-inch. Attach through the vehicle tiedown provision and in a complete loop through the
appropriate stake pocket on the same side of the car at a maximum angle of 45 (fig 7-3, detail 3). The
wire rope ends should overlap a minimum of 24 inches.
F
4
Wire rope, 5/s-inch. Attach through the vehicle tiedown provision and in a complete loop through the
appropriate stake pocket on the opposite side of the car at a maximum angle of 45. Do not use the same
stake pocket as for item E, but use the next stake pocket, away from the vehicle (fig 7-3, detail 3). The
wire rope ends should overlap a minimum of 24 inches.
G
48
Clamps, S/s-inch. Secure the ends of each wire rope at the overlapped area with four clamps, spacing the
clamps 3I/2 inches apart, with a minimum of 6 inches from the ends of the rope. Place one 3/4-inch clamp
(item I) at each tiedown provision and stake pocket (fig 7-3, detail 3) to secure thimble and wire rope
together.
H
26
Thimbles, open-type, %-inch. Place one at the bottom of each stake pocket and one at each vehicle
tiedown point where the wire rope passes through (fig 7-3, detail 3).
I
24
Clamps, 3/4-inch. Use to secure thimble to wire rope.
J
1
Wire rope, 5/8-inch. Wrap over the top of the boom and through the stake pocket on each side. The wire
rope ends should overlap a minimum of 24 inches.
7-7
