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01 December 2011

Hose Stretch Estimates....A look at My Home

I've often been told I have too much free time on my hands, I tend to think its more like I find ways to fit in my quirky little experiments between other daily happenings.  In this case, after my son is in bed asleep, I have begin to map out the hose stretch scenarios for my home.

Using a 100ft commercial tape measure reel (available at home depot) I have come up with some real world numbers.  To my slight surprise, the size of my modest little dwelling unit shows a little deviation from typical hose estimate formulas.


The testing device
I live in two story, attached, wood frame townhome with a peaked truss roof and a full unfinished basement.  The approximate dimensions are 16 wide x 30 deep.

If you use the hose stretch formula of (length + width), a fire in the basement would require two lengths, as there is a stair case to descend to get to the basement.

Running the tape from the far corner of the basement up to the front door. 
My result, 50 feet almost exactly from the far basement corner to the front door threshold.  I was a little surprised.  The hose stretch from the front bumper of my truck to the far basement corner was 100 feet.  The tape was taught on the corners, so there might be a few additional feet to account for the more gradual bows of the hose at corners.  My summary for this stretch is that three lengths would be very adequate for a fire in my basement if the rig pulled past my unit, leaving room for the truck.

The next stretch, to the top (second) floor, front bedroom.  As my tired little boy sleeps quietly, I am stealthily laying out my tape measure to determine how much hose is needed to fight a fire in his bedroom.  The L + W formula says it should take two lengths, as the fire is on the top floor and we must account of the stairwell.  The result.  40 feet to the front door threshold from the far corner of his bedroom.  This run was from the front door, up the stairs and around the newel post at the top of the stair landing.  By dropping the line over the railing, it saved 5 feet of hose, making the required hose from the front door to his room only 35 feet.


Running the line over the railing saves 5 feet of hose

Any fire in my home will easily be handled with three lengths of hose, assuming the rig is within 50 feet of the edge of my parking space (in front of my home).  The bottom line here is to know your buildings.  Is the formula wrong, not at all.  Its simply an estimation formula.

Here are a few points not to be forgotten with regard to hose stretching.
  • Stretch for the fire and look ahead.  If you have fire in the basement, there will likely be fire above.  The first line should be stretched with enough hose to reposition it to adjacent areas or levels where likely fire extension may be found, especially if you know there will be a delay in additional lines being placed.
  • The "backup line" should be stretched to assist the attack line and in most cases should be THE SAME diameter, as its typically unnecessary to stretch a 2 1/2 into an average sized private dwelling.  It should be estimated to reach the location of the attack line and have enough hose to advance to any areas of likely exposure (adjacent rooms, floor above etc).
  • Remember to plan for setback, and include any obstacles you may need to lay the line around
  • Stretching too short can be devastating, and result in a nozzle team that is pinned in a hallway with fire advancing on them.
  • If you run short, running hose over top of cars in the parking lot, over railings, fences, etc will shorten a stretch and avoid potentially having to shut the line down and extend it until the fire has been knocked down.  Always try these options first before retreating to shut down and extend.  Engine or truck company drivers can cut down fences and other obstacles to make a stretch shorter in dire circumstances.
  • Stretching too much hose can be devastating when numerous kinks prevent full flow to the nozzle.  A nozzleman with poor pressure can try to "pump" the bale, causing purposeful water hammer spikes that might push some kinks out.
In summary, get to know your district.  Get a measuring wheel or tape and after making some estimates, check them to see if they are close.  Use the routine and nuisance runs as training opportunities to plan your hose stretches.
Stay Safe.

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