TM 9-1220-238-14
CHAPTER 2
OPERATING INSTRUCTIONS
Section I. CONTROL AND INDICATORS
dicators, and components provided for the proper
2-1. General
operation of the board plotting M18 (fig. 1-1).
This section describes, locates, illustrates, and furnishes
the using personnel with sufficient information pertaining
2-2 Controls and Indicators
to the various controls, in
Refer to table 2-1.
Table 2-1. Controls and Indicators
Control or Indicator
Function
Reference
Bracket assembly
Used when board plotting
is to be operated by one man.
Bracket assembly
Used when board plotting
is to be operated by two men.
Bracket assembly
To install scale assembly in
position for a one (1) man operation.
Bracket assembly
To install scale assembly in
position for a two (2) man operation.
Plotting disk
Permits plotting disk to be rotated to aline
its markings with the scale assembly
of the board plotting.
Vernier scale
Is graduated into 20 equal spaces and
numbered every second graduation from 1 to 10
making possible azimuth adjustments of table accurate to mil.
Section II. OPERATION UNDER USUAL CONDITIONS
a. Place the chest and board plotting M18 from its
2-3. General
stowed position or location. (fig. 1-2)
This section contains instructions for the proper care
of the material, preparation for use, and operation of the
Caution
board plotting, M18 (fig. 1-1) and plotting board chest
Because of its weight and bulk it is
conditions. For operation under unusual conditions refer
necessary for two men to lift and
to Section III.
position the board plotting in order
to avoid injury to personnel or
2-4. Care in Handling
damage to equipment.
a. Board plotting M18 will not stand rough handling
or abuse. Inaccuracy or breakage will result from
b. Turn wing keys (fig. 1-2) on each of the twelve
mistreatment.
Any instrument that is functioning
latches 1/2 turn counter clockwise to on latch cover Lift
inaccurately or contains damaged parts must be brought
off cover (fig. 1-2), turn the cover over so that the
to the attention of organizational maintenance personnel
inside is up, and place the cover on the ground.
for disposition. Repairs other than those expressly
c. Release six stow straps (fig. 1-2) attached to
authorized will not be performed by the operator.
the leg cradle assemblies mounted on the platform
b. Keep board plotting, M18 with chest clean and
assembly.
dry as possible. If the board plotting and/or chest is wet
d. Using the built-in support assembly handles
wire dry using a clean lint free cloth and allow to dry
located on each side of the vernier bracket assembly,
thoroughly.
c. When not in use keep the instrument inside the
assembly with both hands under the semi-circular
chest so that it is protected from dirt, dust, moisture,
segment.
chipping, scratching, and destruction.
e. Lift the support assembly off the posts of the
platform and the leg from the cradles and carry the
2-5. Preparation for Use
support and leg to the desired location (fig. 1-2). The
second man then inserts the leg into leg assembly
2-1
