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

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

#101

Post by HPsquared »

jedberg wrote: post #11

My dad worked on the Space Shuttle main engine program in the 80s. One of the things they built was the turbopump [0], which generated 23,000HP (and could drain your average home swimming pool in one minute). Seeing the test firings of the pump was pretty amazing, draining one "swimming pool" and filling another in a minute. [0] https://en.wikipedia.org/wiki/RS-25#Turbopumps

That's always blown my mind about rocket engines. If the FUEL PUMP has that much power, the overall machine energy flow must be insane. Especially in such a small package.

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

#102

Post by bombcar »

foxglacier wrote: post #79
FridayoLeary wrote: post #56

Earlier quoted context omitted.

torque is the more important figure. Which is why 13l truck engines output only about 600hp.

I never understood why people care about torque from an engine when it's going to be connected to a gearbox that can convert the torque to whatever you want anyway. So why is torque a more important spec than power for an engine?

It's usually because there's an implicit "everything else the same" - and so if you build a car engine entirely focusing on peak horsepower you might end up with a dog because the curve isn't well suited to the rest of the design, whereas if you build it for maximum low-end torque you get a kick in the pants (and then strip all the gears or snap an axle).

Especially since people often consider "horsepower" to be things like turbos, etc that have their own spool-up requirements and result in inability to launch well.

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

#103

Post by bombcar »

jauntywundrkind wrote: post #25

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.…

You don't bust this out until the building is already at risk anyway, so the amount of water is considered "the better option".

(Which is why almost ANY fire is a total structure loss unless you can contain it nearly instantly, because the water used to fight it destroys nearly everything. Only if the building is large, concrete, or the damage limited is it worth repairing; most fire-damaged houses get pulled down as it's cheaper overall.)

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

#104

Post by bombcar »

FridayoLeary wrote: post #54

>and flow over 10,000 gallons per minute at low pressures if the situation called for it. When the pressure was ramped up to to 350psi, it could move 8,800 GPM. That sounds counterintuitive . What about higher pressure will slow water down? The price of the system was huge. It's a theme that as we move to better and more efficient systems they become more boring. Most of the magic of driving is lost in electric vehic…

There's also a huge amount of efficiency tooling added "later" - early planes were simple - and they could still be if we wanted to not have efficient operation.

I remember a cold-war army manual on how to operate captured Soviet equipment; much of it was "long description on what all these dials and parts are for the howitzer - to use, ignore all that shit and fire it, see what you hit, and adjust and try again."

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

#105

Post by enopod_ »

giobox wrote: post #3

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

Two of the three crankshafts rotate in the same direction, whereas the third one moves the other way around!

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

#106

Post by Cthulhu_ »

hakoda wrote: post #6
mtmail wrote: post #4

How do you extinguish an oil-well fire? Enter the "Big Wind" with two jet engines on a tank chassis. "The water is moving at a maximum rate of 220 gallons of water a second," https://www.caranddriver.com/features/a15138374/stilling-the...

You could also nuke it; https://en.wikipedia.org/wiki/Urtabulak_gas_field

And since we're in this thread, you can also pump out the fuel from the sides: https://en.wikipedia.org/wiki/Darvaza_gas_crater

Of course, you probably want to put out a leak a bit faster than after 55 years.

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

#107

Post by dredmorbius »

stinkbeetle wrote: post #66
jedberg wrote: post #11

My dad worked on the Space Shuttle main engine program in the 80s. One of the things they built was the turbopump [0], which generated 23,000HP (and could drain your average home swimming pool in one minute). Seeing the test firings of the pump was pretty amazing, draining one "swimming pool" and filling another in a minute. [0] https://en.wikipedia.org/wiki/RS-25#Turbopumps

The numbers on rocket engines are just ridiculous. The turbine on the F1 engines on the Saturn V's first stage generate about 40MW just to pump the fuel and oxygen. 5 of them on the rocket is 200MW which is a respectablly sized power plant, or about 1/2 of a Nimitz aircraft carrier (which is able to push a floating city through the water at nearly 40mph).

The comparisons which stick in my head are that the Saturn V's first-stage fuel pumps were roughly equal in power to a naval destroyer's engines, and the five F1 engines delivered as much energy as France's entire electrical grid (presumably contemporaneously). This from books read as I was a wee lad.

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

#108

Post by ggm »

dboreham wrote: post #94
ggm wrote: post #7

Earlier quoted context omitted.

The type 55 "deltic" locomotives, named after army regiments used to do the east coast Edinburgh-London train run, there were 22 of them in service and one in the science museum London. They had the first 100mph rating for diesel passenger service. The engine had a unique characteristic whine or whistle. As an avid train spotter at Waverley station in edinburgh I loved hearing it, saw every one and was in the cab of…

> avid train spotter at Waverley station in edinburgh We probably met. I was there every day traveling to and from school but did casual trainspotting on the side. Oblivious someone would one day write a book with that title..

If you're the guy who flung a football pie at my head from a train window, I remember that pie crust.

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

#109

Post by dredmorbius »

giobox wrote: post #3

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

There are numerous "atypical" piston engine layouts, though I cannot recall precisely where I'd seen a reference, probably on YouTube ~10 years ago.

The basics are a single piston, dual (often opposed at an angle or flat-head design as on older BMW motorcycles), in-line (usually 4-cylinder), or V (as in V-6, V-8, V-12, etc.)

Then there are radial engines used in piston-driven aircraft. These virtually always have an odd cylinder count, to prevent locking (there's always an unbalanced force in the direction of intended rotation, or so one hopes).

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

There are various rotary engines, with the Wankel design best known. Very high power-to-weight ratios as a result of having three combustion chambers per rotor, but a relative short lifecycle due to wear, and some compromises in efficiency. "Flying car" company Moller International, out of Davis, CA (and apparently inactive since 2015) had at its core a Wankel-based powerplant, with four pairs of counter-rotating engines powering four ducted fans. It sounds like all the angry hornets in operation.

https://en.wikipedia.org/wiki/Moller_M400_Skycar>

Wikipedia lists some other unusual designs as well: https://en.wikipedia.org/wiki/Reciprocating_engine#Miscellan...>.

I believe that the axial engine may have been featured in that video mentioned in 'graph 1:

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

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

#110

Post by anjel »

garbagewoman wrote: post #50
potato3732842 wrote: post #48

Earlier quoted context omitted.

Think about all the processes they just didn't have to do back then.

just less massive amounts of waste, fraud and corruption

Thanks private equity! https://markorton.substack.com/p/fire-engines-monopolies-and...
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