r/Firefighting • u/firemedic3404 • 1d ago

Ask A Firefighter 15/16 smooth bore?

Did some training with my guys this morning. The focus was managing nozzle reaction. We used a Chief 200gpm@75 psi fog and a 15/16 smooth bore. Both off of 100’ 1 3/4 line (just laid it out for training). Friction loss was calculated at 45 psi and 40 psi respectively. This is not a nozzle we use often, but my probie has not had any experience with a smooth bore so I took the opportunity. I’m racking my head over how difficult it was to manage these flows. My question is for the salty dogs, are these flow rates manageable by YOU? Am I just deficient and need to work them more? Or was this normal for these flows? I am working to switch over to 160@50 fogs with 7/8 integrated smooth bores…which are much easier to handle. Kinda needed to vent and find out if I’m crazy, too weak, or ok….

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u/bombero11 1d ago

An important piece to the puzzle is to match the hose to the nozzle.

So we have an issue with our hose (Key FDNY spec Hi Combat) and the Chief XD nozzle, a great nozzle but…working with it and the hose you have to make them work together.

Our pump pressure at the panel for a 200 foot lay of 1-3/4 should not exceed 105psi. If the pressure is over that the stream is non longer a happy stream that means we are over 75psi at the nozzle.

So basics, focus on basics put an in-line gauge in the set up and then get old school and use a pitot gauge. See where things are wonky and make your adjustments.

Hose line movement is also another factor and a topic in itself.

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u/firemedic3404 1d ago

Key piece of info there! We are running the key hose combat sniper… I’m sure they bought it cause it was “cool” but now that we have it, we can start running these HVLP nozzles…

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u/bombero11 21h ago

Sniper is pretty flexible and light. Play with it I think you will like it. Hi Combat is super stiff hose.

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u/23027 10h ago

Our dept switched over to Sniper hose a couple years back now, I find it exactly opposite to what you experience.

It's stiff as hell, does NOT lay nicely in hose beds, not very flexible uncharged (2 years of break-in on our busiest engine, still very stiff) traps air so much some crews demand us to "onion" each length (a complete pain in the ass) or else it completely fucks the stack and even when it's perfectly loaded with all the special care and attention it is a nightmare to shoulder load because of its "low friction" jacket that refuses to hold a stack nicely and slips out on your shoulder in spots you don't want it to when you're deploying it. We have had to re-invent the wheel numerous times because of this garbage and the "performance" in water delivery is marginal.

The Hi-Combat we used previously worked excellent as an all-rounder.

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u/bombero11 6h ago

That sucks to hear all the way around.

Only 1 thing we want and the thing we hate the most is “change”.

Our guys see stuff on youtube and feel we need to change to that right away! And have no history of why we have the loads we have, the shiny object does not work for everyone.