Table 7-7. Application of Materials for Blocking and Tiedown of Trailer Support Unit on CONUS General-Purpose Flatcars (Figs 7-7 and 7-8).

TM 55-5811-900-14

Table 7-7. Application of Materials for Blocking and Tiedown of Trailer Support Unit on CONUS

General-Purpose Flatcars (Figs 7-7 and 7-8).

Item

No. Reqd.

Application

Brake wheel clearance. Minimum clearance required is 6 inches above, in back of, and on

both sides of the wheel and 4 inches underneath the wheel (fig 7-7).

Lunette support. Consists of fifteen 2 x 4 x 15-inch pieces of lumber. First, position the lunette

in its proper place, then nail it to the flatcar bed. Nail the remaining pieces to the first

piece.

Chocks. Consists of six 2 x 8 x 7-1/2 -inch pieces of lumber, cut as shown in figure 7-9. Nail

together and place one piece tightly before each front wheel and behind each rear wheel.

End blocks. Each consist of two 2 x 4-inch x 9-inch pieces of lumber. Place one piece tightly

against the base of item B and nail it in place. Nail the second piece to the first.

Side blocks. Each consists of two 2 x 4-inch X 6-foot pieces of lumber. Place one piece tightly

against the outside of the wheels and nail it in place. Nail the second piece to the first.

Wire rope -inch, 6 x 19, IWRC. With each cable (about 25 ft), form a complete loop

between the tiedown shackle and stake pocket (sketch 1, fig 7-3).

Clamps, -inch, four each. Place clamps on each cable loop at the overlap area, and space

3 inches apart, with a minimum of 6 inches from the ends of the cable. Place another

clip under each stake pocket and shackle to secure the cable and thimble together (sketch

Thimbles, open-type, -inch. Place one thimble at the bottom of each stake pocket and

shackle (sketch 1, fig 7-3).

Wire rope, -inch, 6 x 19 IWRC. With each cable (about 10 ft), form a complete loop

between the tiedown shackle and stake pocket (sketch 1, fig 7-3).

Middle chock blocks. Each consists of six 2 x 8 x 41-inch, cut as shown in detail 2, figure 7-9.

Nail two pieces together with three 16d nails. Then nail the next piece to these two

pieces with three 16d nails. Repeat with other pieces. Then place the blocks between

the front and, rear wheels as shown in figure 7-7.

7-13