Loading Semitrailers on Special-Purpose Flatcars

TM 55-2330-200-15-1

providing that the kingpin height is between 47

7-6. Loading Semitrailers on Special-Purpose

inches minimum and 52 inches maximum.

Flatcars

d. Figures 7-4 and 7-5 show typical loads of

a. Semitrailers can be shipped more efficiently on

semitrailers on a flatcar with retractable hitches.

specialized railroad freight equipment such as the

CAUTION

TTX-type flatcars with retractable hitches (fig 7-3).

Insure that retractable hitch is securely

Whenever possible, shippers should request this

locked in UP position. Securement of the

type of flatcar when shipping semitrailers.

trailer on the retractable hitch will be in

b. Loading may be accomplished in the same

a c c o r d a n c e with the car owner's in-

manner as outlined in paragraph 7-5a above.

structions. Check to insure that trailer

c. This method of loading is applicable to other

kingpin is locked in place on the hitch.

types of semitrailers weighing up to 40,000 pounds

Table 7-1. Bill of Materials for Blocking and Tiedown of Typical 12-Ton

Semitrailer on CONUS General-Purpose Flatcars (Fig 7-1 and 7-2 )

Approximate

Item

Description

quantity

Douglas-fir, or comparable lumber, straight-grain, free from material defects;

Lumber

Fed Spec MM-L-751H:

2- x 4-in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

68 ft

2- x 6-in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36 ft

4- x 4-in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45 ft

6- x 8-in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8 ft

Nails

Common, steel; flathead, bright or cement-coated; para 3.6.11.2, Fed Spec FF-

N-105B:

12d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Wire

No. 8 gage, black, annealed; Fed Spec

200 ft

QQ-W-461G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Wire rope

Type I, general-purpose; class 2, 6x19, improved plow steel, wire strand core

or IWRC; Fed Spec RR-W-410C:

-in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

100 ft

Clamps

Wire rope, U-bolt clips, saddled, single grip, forged steel, Crosby heavy-duty,

or equal; Fed Spec FF-C-450D:

-in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

Thimbles

Standard, open-type: -in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cushioning

Waterproof paper, or suitable material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

as required

material

Table 7-2. Application of Materials for Blocking and Tiedown of Typical 12-Ton

Semitrailer on CONUS General-Purpose Flatcars (Fig 7-1 and 7-2)

Item

No. required

Application

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).

Chock blocks (detail 1, fig 7-2). Locate 45 portion of block against outside front of front

wheels and against outside rear of rear wheels. Nail heel of block to car floor with three 40d

nails, and toenail that portion of the block under tire to car floor with two 40d nails before

iteme C and D are applied.

1 ea per

Suitable material such as waterproof paper or burlap. Locate bottom portion under item D.

item D

The top portion should extend 2 in. above item D (detail 2, fig 7-2).

Side blocking, each to consist of one piece of 2- x 6- x 72-in. lumber and three pieces of 2- x 4-

x 72-in. lumber (detail 2, fig 7-2). Nail one edge of the 2- x 6- x 72-in. piece to the bottom 2-

x 4- x 72-in. piece with eight 12d nails. Then place against tire with item C in place, and nail

to car floor through the 2- x 4- x 36-in. piece, with eight 20d nails. Nail the other two 2- x 4-

x 72-in. pieces to the one below in like manner.

For items E through O, following below, refer to forward bracing detail (detail 3, fig 7(2).

Lumber, 2- x 6- x 92-in. Nail to car floor with one 30d nail every 8 inches in vincinity under

trailer kingpin. See fig 7-1 for exact location.

7-4