TM 5-5420-234-14&P
2-13. BRIDGE BAY LAUNCH.
CAUTION
Water depth for fording should not exceed 4 feet (1.2 m) or damage to equipment
could occur.
NOTE
During all bridge bay launching operations, the operator will drive and be
responsible for the operation of the LHS cab control box. The assistant acts
as a ground guide and will be responsible for assisting and directing the
operator. The operator, assistant, and boat crew will prepare bridge bay and
Transporter for launch. The operator is responsible for the completion of all
tasks.
In case of emergency while the remote control unit is in use, push the
emergency stop switch to shut down operation of the LHS.
a. Launch Methods. There are three recommended launch methods: controlled launch, free launch, and high-
bank launch. The launch method depends on terrain, water conditions, and tactical requirements. The free-
launch method requires the least amount of time and is normally used. Water and bank conditions best suited
for each type of launch are described below. For information on the operation of interior bay and ramp bay,
refer to TM 5-5420-209-12.
b. Launch Conditions. In addition to site survey conditions for normal Transporter operations (para 2-8), the
following specific conditions apply for bridge bay launching:
(1)
Controlled Launch (para 2-14). For a controlled launch, shore slope should be uniform, with a slope of
not more than 20 percent. Water velocity should not be greater than 5 feet (1.5 m) per second. In swift
water of about 6 feet (1.8 m) per second, a Y-shaped bridle is attached to the bridge bay. With a 20
percent slope, interior bay requires a water depth of at least 42 inches (1.0 m), with the top of back tire
hubcap at the water line (whole hubcap in the water). Ramp bay requires a water depth of at least 50
inches (1.2 m), with the top of back tire rim at the water line (whole rim in the water). In addition, one
travel latch on bridge bay must remain in the secured position when launching. The boat crew will install
a lanyard to release latch after the bridge bay is in the water, and will open the bridge bay.
(2)
than 20 percent. Water velocity should not be greater than 8 feet (2.44 m) per second. With a 20 percent
slope, interior bay requires a water depth of at least 42 inches (106.7 cm), with the top of back tire
hubcap at the water line (whole hubcap in the water). Ramp bay requires a water depth of at least 50
inches (127 cm), with the top of back tire rim at the water line (whole rim in the water).
(3)
of not more than 5 percent. On slopes greater than 5 percent, front end of launching Transporter must
be anchored using self-recovery winch of another Transporter or self-recovery winch of launching
Transporter. Bank height should be no greater than 28 feet (8.5 m) and near vertical for bridge bay to
clear the side while launching. There also must be room to operate Transporter perpendicular to the bank
while still maintaining room for a bridge bay to be set behind Transporter, parallel to the bank. Water
depth should be at least 30 inches (76.2 cm). If necessary, bridge bay can be launched in 17 inches (43.2
cm) of water. Water velocity should be less than 5 feet (1.5 m) per second. In swift water (6 feet [1.8 m]
per second), a Y-shaped bridle is attached to bridge bay.
