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The Mack Super Pumper was a locomotive engined fire fighter (2018)

(bangshift.com)
148 points mstngl | 1 comments | 03 Nov 25 20:37 UTC | HN request time: 0.201s | source
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jauntywundrkind ◴[03 Nov 25 22:15 UTC] No.45805094[source]▶
This thing feels like a mortal danger to the (up to 8x!) iron pipes / hydrants it's pulling from, that it'd want to just chew up the very pipes themselves! Or to the building it's hurling 37 tons of water a minute at! I don't understand how a connector hose wouldn't collapse, how it maintains any cross-section rather than being sucked into collapse.

Also wondering: what replaced this!

(Ed: great reply from Mindcrime. Also, the new Ferrara Super Pumper shows a very impressive ribbed(?) 8-inch "hard suction" hose! There's a whole wikipedia section for these drafting/vacuum hoses: https://en.wikipedia.org/wiki/Suction_hose)

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1. amluto ◴[03 Nov 25 22:28 UTC] No.45805215[source]▶
I imagine the hydrants were operated at positive pressure. Water mains are generally somewhere between 40 and maybe 120 psi gauge. You don’t gain a whole lot by sucking on them - at most you get to -14 psi, and you do not want to boil the water (aka cause cavitation) in your pump.