TM 55-2210-224-12
2-29. MULTIPLE-UNIT OPERATION (cont)
(3) Certain alarm and protective devices, and auxiliary controls such as sanding, are connected through the
jumper, but the power plants and heavy duty circuits of the coupled units remain entirely independent of
each other.
b. Coupling.
CAUTION
The 80-ton locomotive can only be hooked up in multiple-unit operation with
another same model 80-ton locomotive.
(1) Couple locomotives mechanically in the usual manner. Refer to paragraph 2-18.
(2) Connect trainline hoses as follows:
Brake Pipe
to Brake Pipe
M. R. Equalizing Pipe
to M. R. Equalizing Pipe
Actuating Pipe
to Actuating Pipe
Independent Application and to Independent Application and
Release Pipe
Release Pipe
(3) Open cutout cocks at the ends of air lines on both units.
CAUTION
To protect multiple-unit control jumper from damage, position it up and out of the
way of the drawbar.
(4) Connect multiple-unit control jumper (1) to both units. Push each plug all the way into its receptacle and
lock in place.
c. Starting.
NOTE
Check that the PMCS has been performed on both units.
(1) Determine which locomotive is to be the trailing unit and, if
not already started, start in accordance with paragraphs 2-
10 and 2-11.
(2) Set controls on trailing unit as follows:
(a) Cutoff pilot valve (2) to OUT.
(b) Double-ported cutout cock (3) to CLOSED position.
2-40
