When do we stretch back up Line? Who mans/staffs back up line? What if fire is getting knocked down; do we still stretch it? What size and type? Where should the back line go?
County Fire Tactics
The Firefighters Source for Rural to Urban Fire Tactics
Back up lines should always be stretched when there is a doubt the fire can be extinguished with the first line or the firstline is more than a room or two in deepth inside the structure.
They should not be charged until a positive water source or a significant amount of tank water is available.
As to where the back up line should go there is only a couple of hard rules on this. One being if the backup line has advanced past the firstline, you are not the backup. The other being if the backup did not advance the same path as the firstline you are probably opposing.
Ok so there is three, back up lines should not be on anything other than a straight stream if a adjustible pattern nozzle is in play. Trying to retreat back through a fog pattern rates pretty high on the stuff that sucks meter.
When you are the back line you have to know who and how manner crews are operating inside the structure that you are to protect. i.e. You have a Engine (attackline crew) advancing away from you and a Truck (Search crew) on the second floor. You need to position to cover both crews. You have to maintain a position to stop the fire from traveling up the stairs trapping the crew on the upper floor.
Our department SOG is for the 2nd due engine to secure water supply and stretch the back-up line. Stretch through the same entry point as the primary line and a minimum of the same diameter line. As far as the vent point ignition goes, well the officer on the primary attack line should be watching for it “lighting off” while making the push. Snakes in the smoke? Open up and push it back as you advance.