TM 5-5420-280-23&P
0018 00
BRIDGE HALF REPLACEMENT (Contd)
REMOVAL
1. Remove two retaining pins (2) and disconnect launch boom support (3) from launch boom (1).
2. Start Launch Power Unit (LPU). Refer to TM 5-5420-280-10.
3. Depress control valves KY1 and KY18 until launch boom (1) lowers to 0-degree position. Use winch
emergency switch to lower winch wire rope hook (14). Shut off LPU. Refer to TM 5-5420-280-10.
4. Remove four screws (9), washers (8), and two stop blocks (7) from top of A-frame angle bracket (11).
NOTE
Mark location of limit switch prior to removal for installation.
5. Remove two locknuts (12), four washers (5), two screws (4), and limit switch (6) from bracket (13) on
A-frame (10). Discard locknuts (12).
6. Install four sling hooks (20) or straps on fastening rod brackets (16) and connect sling lifting eye (17)
or straps to a suitable lifting device.
WARNING
All nonessential personnel must stand clear during lifting
operations. Use taglines during removal. Failure to comply may
result in injury or death to personnel.
7. Disconnect winch wire rope hook (14) from lifting eye (15) on launch beam of top bridge half (18).
8. Lift top bridge half (18) off lower bridge half (19) and bridge pallet (21), place bridge half (18) on
dunage, and remove sling hooks (20) or straps from bridge half (18).
9. Install four sling hooks (20) or straps on tiedown strap brackets (16), lift lower bridge half (19) off
bridge pallet (21), place bridge half (19) on dunnage, and remove four sling hooks (20) or straps from
bridge half (19).
INSTALLATION
1. Install four sling hooks (20) or straps on tiedown strap brackets (16) and connect sling lifting eye (17)
or straps to a suitable lifting device.
WARNING
All nonessential personnel must stand clear during lifting
operations. Use tag lines during installation. Failure to comply may
result in injury or death to personnel.
2. Lift either bridge half (18) or (19) off dunnage and place bridge half (18) or (19) on bridge pallet (21)
with ramp end facing away from winch wire rope hook (14). This bridge half (18) or (19) will become
the lower bridge half (19).
3. If necessary, start LPU and depress KY1 and KY5 until pin wheel drive moves bridge and end of
launch beam contacts A-frame (10). If necessary, install anchoring straps and draw bridge quarters
together.
4. Remove four sling hooks (20) or straps from tiedown strap brackets (16) and connect on other bridge
half (18) tiedown strap brackets (16). This bridge half (18) will become top bridge half (18).
5. Lift top bridge half (18) and place on top of lower bridge half (19) and bridge pallet (21) with ramp
end facing winch wire rope hook (14). Pins on end of launch beam must fit into angle brackets (11) on
A-frame (10) as top bridge half (18) is lowered onto lower bridge half (19).
6. Install winch wire rope hook (14) on lifting eye (15) on launch beam of top bridge half (18).
CAUTION
Ensure limit switch is installed as marked during removal or
damage to equipment may result.
7. Install limit switch (6) on bracket (13) with two screws (4), four washers (5), and two new
locknuts (12).
0018 00-2