TM 55-7440-240-14
Table 5-3. Bill of Materials
for Blocking and Tiedown of
Shelter, S491, and Power Unit, PU-732/M, on Highway Carrier
Approximate
Description
quantity
Item
Douglas-fir, or comparable, straight-grain, free from material defects; Fed Spec MM -L-
Lumber
751H:
6- x 8-inch
6 linear ft
22 linear ft
4- x 4-inch
linear ft
2- x 6-inch6
2- x 4-inch
52 linear ft
Common, steel, flathead, bright or cement-coated; Fed Spec FF-N -105B:
Nails
20d
24
30d
106
8
40d
43
60d
122 ft
6 x 19 IWRC, improved plow steel, performed, regular lay; Fed Spec RR-W-410C:
3/8-inch
Wire rope
Wire rope, U-bolt clips, saddled, single grip, steel, Crosby heavy-duty or equal; Fed Spec
Clamps
48
FFC-450D: 3/8-inch
16
Standard, open-type:
3/8-inch
.
Thimble
as required
Waterproof paper, burlap, or other suitable material
material
Table 5-4. Application of Materials
for Blocking and Tiedown of
Shelter, S491, and Power
Unit, PU-732/M, on
Highway Carrier
Application
Item
No. required
A
4
Chock block (detail 1, fig 5-3). Place 45 end against front and rear of each wheel as shown in
figure 5-4. Toenail
heel of
block (33 end near bottom edge) to trailer to
floor with one 20d
nail in each block. Drive two 40d nails into heel of each block, perpendicular to floor. Toenail
each side of each block to floor with two 30d nails.
B
as required
Cushioning material (detail 2, fig 5-3). Locate bottom portion under item C, and between tire
and item C so as to be 2 inches above item C.
c
2
Side block (detail 2, fig 5-3). Each to consist of one piece of 2- x 6- x 36-inch lumber and two
pieces of 2- x 4- x 36-inch lumber. Nail 2- x 6- x 36-inch piece to edge of lower 2- x 4-
x 36-inch piece with five 20d nails. Place 2- x 6- x 36-inch piece against cushioning material
and inboard side of tire and nail to floor through 2- x 4- x 36-inch piece with five 20d nails in
a staggered pattern. Nail upper 2- x 4- x 36-inch piece to lower piece with five 30d nails.
D
Support block. Consists of one piece of 4- x 4- x 18-inch lumber. Place on floor under lunette.
1
Nail to floor with three 60d nails.
E
Tiedowns (detail 3, fig 5-3). Each to consist of one piece 3/8-inch 6 x 19 IWRC wire rope, length
8
as required. Form a complete loop between tiedown provision and appropriate trailer stake
pocket at a maximum angle of 45 degrees. Wire rope ends should overlap approximately 24
inches.
F
Clamps (detail 3, fig 5-3). Place four on each item E at overlap area. Space clamps 3.-inches
48
apart with a minimum of 6 inches from ends of wire rope. Place one clamp on each thimble,
item G, to secure thimble to wire rope at trailer stake pockets and at equipment tiedown
provisions.
G
16
Thimbles (detail 3, fig 5-3). Locate one under wire rope at each place where wire rope passes
through equipment tiedown provisions and over edge of trailer stake pockets. Secure each
thimble to wire rope with one 3/8-inch clamp.