Stow Nighthawk Dedicated Light Tower LT-12D - Manual (Page 33)

LT-12 SERIES LIGHT TOWER — OPERATION MANUAL — REV. #1 (08/15/08) — PAGE 33
LT-12 SERIES LIGHT TOWER — MAINTENANCE
Check Cable Wear
The wire rope (cable) that raises and extends the mast is a very
important part of the light tower. There is one cable/hand winch
system, located on the tounge of the trailer, that raises and
extends the light tower mast. There is a second cable/hand winch
system located on the mast that serves to raise and lower the two
extendable sections of the mast.
Servicing the Mast Extension Cable System:
To replace the cable in the mast extension cable system, use the
following steps (Reference Figure 21):
1. Lower the mast to the horizontal resting position.
2. Inspect the cable clamps, pulleys, and other components for
worn or damaged parts. If either of the cables on the mast
needs to be replaced, they should both be replaced at the
same time.
3. Disassemble the mast by disconnecting the cables form the
mast and sliding the sections apart. The lower cable can be
disconnected from the winch.
Figure 21 Mast Extension Cable System
CENTER
MAST
PULLEY
ROUTE TO
HAND WINCH
LOWER
MAST
PULLEY
UPPER
MAST
CENTER
MAST
LOWER
MAST
LOWER
MAST
SHACKLE
Wire rope (cable) will fail if it is worn, frayed, misused, crushed,
kinked or damaged in any way. ALWAYS check the cables and
pulleys for any abnormalities before use.
DO NOT use it if there is even the slightest cause for
concern and replace any damaged cables or pulleys
immediately.
DANGER - Light Tower Cable System Safety
WARNING - Mast Service Safety
4. There are two pulleys in the mast raise/lower cable system.
They should be removed, and replaced if worn or damaged,
as they can cause premature cable failure if they are in poor
condition.
5. Reassemble the mast extension cable system by connecting
the cable to the bottom of the upper mast and sliding the
upper mast into the opening of the center mast. Connect the
second cable to the bottom of the center mast and slide the
center mast into the opening of the lower mast, observing
proper lifting techniques.
6. Route the upper mast cable through the center mast pulley
and connect the free end of the cable to the lower mast ankle
shackle. Route the center mast cable through the lower mast
pulley and connect the free end of the cable to the hand
winch at the bottom of the lower mast.
7. Raise, extend, retract and lower the mast several times to
verify correct operation.
Servicing the Mast Raise/Lower Cable System:
To replace any components in the mast raise/lower cable
system, use the following steps (Reference Figure 20):
1. Lower the mast to the horizontal resting position.
2. Inspect the cable clamps, pulleys, and other components for
worn or damaged parts.
3. Disconnect the cable from the ball socket pin and remove
from the mast pulley and cable sheave. Detatch the cable
from the hand winch as necessary.
4. Replace the pulley and the cable as needed.
5. Re-thread the cable through the pulley and reattach the cable
to the ball socket pin.
6. Raise and lower the mast several times to verify correct
operation.
Figure 20. Mast Raise/Lower Cable System
The mast sections are heavy and awkward to handle. Use
proper lifting devices and procedures when servicing the mast
and its components.