d. Thermal detectors. Twenty-seven thermal detectors are installed on the LSV. Fifteen of these are 1350 sensors
and 12 are 2000 sensors. The thermal detectors use an air chamber, a flexible metal diaphragm, and a calibrated vent.
Normal fluctuations in temperatures cause expansion and contraction of the air in the chamber and the vent "breaths."
With a rapid increase in temperature, as in a fire, the air expands faster than it can be vented. This creates a pressure
which distends the diaphragm and closes electrical contacts. If the heat is removed, the air in the chamber contracts,
relieving the pressure and restoring the electrical contacts to the normally open circuit position. Six of the installed units
contain internal incandescent lamps to allow visual identification of an operated detector.
e. Manual fire stations. Sixteen manual fire stations are installed on the LSV. These manually operated "pull-
down" lever units allow the reporting of a fire from various locations on the vessel. The action of the lever closes a
normally open contact.
f. Remote alarm lamps. Seven remote alarm lamps are installed on the LSV. These lamps are used where the
detector is out of sight or the space monitored may be normally unmanned. The lamps are electrically connected to a
detector. When the detector senses a fire and activates an alarm at the control panel, the remote lamp identifies the
detector unit which initiated the alarm.
g. Sensor distribution. The following list describes the units installed on the LSV, by zone and location.
Zone 1 Bridge Deck
Ladder way to Bridge with lamp port side of
Thermal Detector 1350
Manual Fire Station
Port side, Bridge area