Purpose and Scope

TM 55-2410-234-14

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Technical Manual

HEADQUARTERS

DEPARTMENT OF THE ARMY

No. 55-2410-234-14

Washington, DC, 10 August 1984

TRANSPORTABILITY GUIDANCE

TRANSPORT OF CATERPILLAR, MODEL D8K-8S-8 TRACTOR,

WITH RIPPER OR WINCH ON M870, 40-TON, LOWBED SEMITRAILER

USING THE M920 TRUCK TRACTOR

Paragraph

Page

Purpose and Scope ............................................................................................................................. 1

Description

..................................................................................................................................... 2

Sectionalization................................................................................................................................... 3

Item Characteristics and Related Data ................................................................................................ 4

Preparation and Loading ..................................................................................................................... 5

Dimensions:

1. Purpose and Scope

Length ..........................321.0 in. (5.10 m)

This manual provides transportability guidance for

Width ............................156.0 in. (3.96 m)

movement, by highway mode only, of the Army D8K-8S-

Height ...........................134.3 in. (3.41 m)

8 tractor on the M870 trailer. The text prescribes

Reduced height.............106.0 in. (2.69 m)

procedures and materials for the loading and tiedown of

Weight (operational) ..... 86,422 lb (37 201 kg)

the D8K tractor.

Shipping Data:

2. Description

Operational:

The model D8K-8S-8 is a full tracked, low-speed,

Volume .........................3891.9 ft (110.2 m

drawbar pull tractor. It is powered by a four-stroke

Area..............................347.8 ft2 (32.3 m2)

cycle, six-cylinder, diesel engine, Model D342. The

Reduced:

planetary-type power shift is 21 inches (530 mm) in

Volume .........................1458.6 ft (41.3 m )

diameter and has high-torque-capacity oil clutches. A

Area..............................165 ft (15.3 m )

special valve permits unrestricted speed and direction

5. Preparation and Loading

changes under full load.

Hydraulically actuated,

multiple-disc oil clutches require no adjustments. The

a. Materials.

tractor is capable of performing all types of construction

(1) Four chain assemblies. Each assembly

work including ripping, ditching and dozing.

consists of two, 120-inch-long, 1/z-inch-diameter chains

3. Sectionalization

with hooks on each end (breaking strength, 45,000

a. The overall height can be reduced from 134.25

pounds). (This type of chain is shown in the February

inches (3.41 m) to 106 inches (2.69 m) by removing the

1983 General Catalog of The Crosby Group Inc., PO

exhaust stack and rollover protection system (ROPS).

Box 3128, Tulsa, Oklahoma 74101; or, in the catalog of

McMaster-Carr Supply Company, PO Box 4355,

b. With the D8K tractor on the M870 trailer, the

Chicago, Illinois 60683).

total height from the ground to the top of the ROPS is

177.25 inches and from the top of the ROPS to the

(2) Four load binders. Each binder is 1/2-

bottom of the trailer main frame is 164 inches. This

inch in diameter (breaking strength, 45,000 pounds).

height exceeds the vertical clearance of many bridges.

b. Procedures.

Preplanned and selective routing is required.

(1) Extend the outriggers and use extra

4. Item Characteristics and Related Data

timbers to raise the outrigger floor level with the trailer

Data are based on item in unloaded condition plus fuel.

floor.

(2) With the M870 trailer gooseneck

National Stock Number ....2410-00-574-7598

extended flat, drive the D8K tractor onto the M870 trailer

Line Item Number ............W88699

as shown in figure 1. Park and brake the D8K tractor

near the trailer's rear axles to keep the heavy load off

the front of the trailer and trucktractor winch cable.

Raise the M870 trailer gooseneck to the travel position

and connect the semitrailer to the M920 truck tractor as

shown in figure 2. Check contact between the outrigger

plank