Confined Space Sumner Tunnel Exercise Fire Fighter 1
Objective To provide effective radio communications while operating in the Sumner Tunnel. We will discuss the: - Existing tunnel radio system - Coverage Areas - Alternate communication resources - Radio Signal Propagation 2
Tunnel Radio System All traffic tunnels in the city of Boston are equipped with radio systems providing coverage on channels BFD 1 and BFD4, These systems are: - Always on - Simulcast with above ground system for seamless coverage 3
Coverage Area A radiating cable (antenna) runs the length of tunnel. The cable is located above the row of lights just below the ceiling. The antenna is susceptible to fire or physical damage. 4
Coverage Area Plenums above and below the roadway run the length of the tunnel. The tunnel radio systems DO NOT provide coverage in these areas. Members should not enter the plenum spaces without a communications plan. 5
Alternate All radio systems can fail. Fire fighters must be able to quickly recognize that a failure has occurred and develop an alternate plan for communications. Some options are: - Simplex radio channel - Tactical Repeater - Post Radio / Mobile radio - Futurecom Mobile Repeater (DVRS) 6
Alternate Simplex Radio Channel The Motorola XTS5000 portable radio carried by all Boston fire fighters is capable of providing reliable communications on a simplex channel from the midpoint of the Sumner tunnel to either portal. Caveats: Fully Charged Battery Antenna securely attached Radio held away from the body so the antenna can see the portal 7
Alternate Simplex Radio Channel A simplex radio channel can be used to establish communications between members operating at the midpoint of the tunnel and a member positioned at a portal. The member positioned at the portal must relay all messages from the simplex channel to the repeated channel (fireground) 8
Alternate Tactical Repeater The Taccom is equipped with a portable tactical repeater capable of automatically relaying messages between a simplex and a repeated channel. 9
Alternate Futurecom Mobile Repeater (DVRS) District Chief vehicles and the TACCOM are equipped with a digital vehicle repeater system. These systems patch a simplex channel to a repeat channel. To place a DVRS in service: - Locate vehicle as far into the tunnel that will allow reliable comms to Fire Alarm. - Set mobile radio to Zone L and position 3 (channel BFD3) - All members in the tunnel must operate on Zone L, Position 15 (channel BFD16) 10
Radio Signal Propagation UHF radio signals require line of sight between the transmitting and receiving antennas. Radio signals can see 15 degrees beyond the visible horizon. Radio signals are weakened when transmitted from a firecoat pocket. Concrete and metal will block radio signals. 11
Obstacles & Solutions A simplex channel providing reliable comms may fail if a large vehicle moves between the 2 radios. Options: Switch to a mobile radio to overcome the signal loss Utilize a Post Radio Station a member at the opposite portal to relay messages. 12