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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: 0.197s | source
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giobox ◴[03 Nov 25 21:23 UTC] No.45804622[source]▶
That "deltic" engine just for the water pumping is incredible, I'd never seen that cylinder layout before.

> https://en.wikipedia.org/wiki/Napier_Deltic

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hydrogen7800 ◴[03 Nov 25 22:14 UTC] No.45805088[source]▶
Piston engines got pretty wild before turbines eventually took over the world. The most efficient ones were more efficient than today's turbines in terms of BSFC[0]. One of the most interesting to me was the Napier Nomad[1], which used turbo- and super-charging. However, the turbo had secondary fuel injection and effectively ran as a turbine to drive the compressor.

[0]https://en.wikipedia.org/wiki/Brake-specific_fuel_consumptio... [1]https://en.wikipedia.org/wiki/Napier_Nomad

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1. mikkupikku ◴[03 Nov 25 23:50 UTC] No.45805913[source]▶
Those exhaust driven turbines didn't just drive the compressor like is typical with turbochargers, but was also mechanically linked to the crank shaft so the turbine contributed to the overall power output of the engine directly, not just by forcing more air into the cylinders. That's what made them "turbo-compound."

The youtube channel "Greg's Airplanes and Automobiles" has a nice video about turbo compound engines.