[HN Gopher] The Mack Super Pumper was a locomotive engined fire ...
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       The Mack Super Pumper was a locomotive engined fire fighter (2018)
        
       Author : mstngl
       Score  : 172 points
       Date   : 2025-11-03 20:37 UTC (1 days ago)
        
 (HTM) web link (bangshift.com)
 (TXT) w3m dump (bangshift.com)
        
       | MisterTea wrote:
       | Ah, the Mack Super pumper. Shame Mack started to struggle in the
       | 60s until the 80s and got out of the fire truck business. They
       | had some very interesting designs in terms of cab design and
       | components. I always loved the F model cab-over which were
       | produced until the early 80s which is what the CF fire truck was
       | built on.
        
       | giobox wrote:
       | 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
        
         | ggm wrote:
         | 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 two thanks to
         | long suffering kind engine drivers.
         | 
         | There was a mini deltic too. I'm not sure it went beyond a
         | testbed loco.
        
           | jacquesm wrote:
           | Those are amazing engines. It's a pity that in the future
           | we'll just be using magnets and coils, there something about
           | these designs that moves me in a way that nothing electrical
           | ever will. And I'm a great fan of renewable energy, and
           | realize that the pollution that has been created (and is
           | still being created) is absolutely unsustainable.
        
             | jcgrillo wrote:
             | There are people working on internal combustion engines
             | with a very similar design currently, for many applications
             | (military, trucking, etc) diesel or diesel electric is the
             | only realistic option for the foreseeable future:
             | https://achatespower.com/
        
           | lmm wrote:
           | A series of 10 "baby deltics" were built and ran for some
           | years, although they weren't particularly successful on the
           | whole.
        
             | ggm wrote:
             | They were basically out of service by the time I was out of
             | short trousers. I made special trips south to see the
             | "warship" class 43 hydromatic transmission in Western
             | Region out of Old Oak Common in London, the type 44 "peak"
             | series and the diminutive type 3 diesel shunter at
             | Birkenhead. The baby deltics were probably parked in a yard
             | waiting scrapping.
             | 
             | I have dim memories of being held up over a bridge to watch
             | steam trains pass, but by the time I was obsessively
             | writing down numbers they were special trains like "Sir
             | Nigel Gresley" and "the Flying Scotsman"
             | 
             | I left britain before the east coast electrification. I do
             | still see my favourite type 8 Diesel shunter, the most
             | ubiquitous kind in Britain, when I pass by.
             | 
             | If you want sheer power, It's a Deltic every time. That
             | high pitched whine, it's unmistakable.
        
           | dboreham wrote:
           | > 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..
        
             | ggm wrote:
             | If you're the guy who flung a football pie at my head from
             | a train window, I remember that pie crust.
        
           | ErroneousBosh wrote:
           | About 12 years ago they used to use 55022 as a shunter at
           | Springburn yard, because it was "road legal" and could couple
           | up to older carriages that were being taken in for
           | refurbishment. Nice cushy retirement job, easy shifts and a
           | well-appointed engine shed to park up it at night ;-)
           | 
           | I used to hear it all the time, working in a nearby
           | industrial site. I'd maybe just take five minutes to sit
           | outside and drink my coffee, listening to that weird
           | shimmering howl.
           | 
           | There are no good recordings of it on Youtube and I suspect
           | like a lot of things you have to experience it for yourself.
        
         | whycome wrote:
         | > The Napier Deltic engine is a British opposed-piston
         | valveless, supercharged uniflow scavenged, two-stroke diesel
         | engine
         | 
         | Any tech that includes the word "scavenged" must be cool and
         | efficient
        
           | mikkupikku wrote:
           | Scavenging here means getting the exhaust from the previous
           | cycle out of the cylinder and replacing it with fresh air.
           | Technically all internal combustion engines do it one way or
           | another, but usually you hear the word in relation to two
           | stroke engines. Two strokes don't have discrete "suck" and
           | "blow" steps so those need to be done at the same time. With
           | two stroke diesels, that was done using blowers to basically
           | force out the exhaust by blowing in fresh air.
           | 
           | Generally speaking at least, two stroke diesel engines
           | weren't super efficient, but did offer great power output
           | relative to their size.
        
         | mrlonglong wrote:
         | They're unique. Originally designed to power fast torpedo boats
         | during WW2, three of these powerful and compact engines would
         | churn out plenty of power for the boat up to 50 kt.
         | 
         | https://everythingaboutboats.org/napier-deltic/
        
           | mrlonglong wrote:
           | They're still in use by our UK navy. Nine minesweepers still
           | on active duty.
        
             | mrlonglong wrote:
             | I just realised they re-engined them with cat engines in
             | 2008. Pity.
        
         | noir_lord wrote:
         | Napier was on the cutting edge of certain kinds of IC engines
         | for a long time.
         | 
         | https://en.wikipedia.org/wiki/Napier_Sabre (1938).
         | 
         | Powered the absolute _monster_ that was the Tempest (up to the
         | Mk 2 - they did have reliability issues they never quite solved
         | but 3000+HP out of an engine that weighs barely more than a
         | tonne dry will do that)
         | 
         | https://en.wikipedia.org/wiki/Hawker_Tempest
         | 
         | Was happy to see the name re-used for our upcoming fighter.
         | 
         | We also called the Eurofighter the Typhoon and the (WW2)
         | Typhoon (also a Sabre engine) was the predecessor of the
         | Tempest - it started as a re-wing of the Typhoon but enough
         | changes where made to give it a new name.
         | 
         | Just a devastating superprop in its day.
        
         | hydrogen7800 wrote:
         | 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
        
           | jabl wrote:
           | Napier Nomad is one of my favorite engine designs. More info
           | at https://oldmachinepress.com/2019/08/05/napier-nomad-
           | compound...
        
           | mikkupikku wrote:
           | 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.
        
           | shawn_w wrote:
           | Speaking of turbines and fire apparatus, back in the 60's a
           | few jet turbine powered engines and one ladder truck were
           | made: https://www.aeroflap.com.br/en/when-fire-trucks-used-
           | boeing-...
        
           | dredmorbius wrote:
           | Gas turbines aren't generally noted for their _efficiency_ ,
           | but rather:
           | 
           | - Power-to-weight ratios. Critical in aerospace applications.
           | 
           | - Long duty cycles. Everything spins, reducing wear-and-tear
           | relative to reciprocating designs. Maintenance on piston
           | engined aircraft during WWII was a major logistical concern.
           | 
           | - Raw speed. Supersonic flight requires high rotary speeds,
           | and the few propeller-driven aircraft which achieved this had
           | ... issues. Ground crews _and pilots_ suffered health effects
           | _from the noise alone_ , and notoriously often flat refused
           | to work with the XF-84H "Thunderscreech": <https://en.wikiped
           | ia.org/wiki/Republic_XF-84H_Thunderscreech...>. At near-
           | supersonic speeds and above, propeller blade tips themselves
           | break the sound barrier, losing aerodynamic flow over the
           | blades, making quite a racket, and greatly reducing
           | efficiency.
           | 
           | Propeller-driven planes _remain_ more efficient than jets in
           | many instances, though last I checked US military forces rely
           | on turboprops over reciprocating engines in virtually all
           | instances, possibly excepting some civilian-based (e.g.,
           | Cessna  / Piper, etc.) trainer or observer variants.
        
         | enopod_ wrote:
         | Two of the three crankshafts rotate in the same direction,
         | whereas the third one moves the other way around!
        
         | dredmorbius wrote:
         | 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>
        
         | WarcrimeActual wrote:
         | It amazes me what we manage to figure out on the mechanical
         | side of things. Just look at motorcycle engines. Screaming
         | along at upwards of 20k RPM and just taking it in stride and
         | moving people down the road at what might as well be supersonic
         | speed.
        
       | mtmail wrote:
       | 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...
        
         | hakoda wrote:
         | You could also nuke it;
         | https://en.wikipedia.org/wiki/Urtabulak_gas_field
        
           | Cthulhu_ wrote:
           | 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.
        
         | dewey wrote:
         | Tangentially related and recommended. Werner Herzog's film that
         | also features longer sections on the fire fighting efforts on
         | the oil fields.
         | 
         | https://en.wikipedia.org/wiki/Lessons_of_Darkness
        
           | nchmy wrote:
           | Someone just recommended this to me the other day!
           | 
           | I must also recommend the recently-deceased legend Sebastiao
           | Salgado's photos from Kuwait oil fires.
           | 
           | https://publicdelivery.org/sebastiao-salgado-kuwait/
        
             | slybot wrote:
             | https://m.imdb.com/title/tt3674140/
             | 
             | I watched this movie on cinema a decade ago. Highly
             | recommended.
        
               | nchmy wrote:
               | It is, indeed, a tremendous documentary. He's one of my
               | greatest inspirations.
        
           | echelon_musk wrote:
           | For lighter viewing there is Sorcerer (1977) [0] with Roy
           | Scheider.
           | 
           | [0] https://en.wikipedia.org/wiki/Sorcerer_(film)
        
             | dreamcompiler wrote:
             | Great Tangerine Dream soundtrack too.
        
               | PaulDavisThe1st wrote:
               | firefighter and tangerine dream fan, eh? we should cross
               | paths ...
        
               | dreamcompiler wrote:
               | Pretty sure I'm just down the road from you too.
        
               | PaulDavisThe1st wrote:
               | north-central NM ?
        
             | mikkupikku wrote:
             | Not sure I'd call that lighter viewing, but it's a truly
             | excellent movie.
        
           | mtmail wrote:
           | Video is hosted on archive.org
           | https://archive.org/details/lessons-of-darkness-1992
        
       | tonetegeatinst wrote:
       | I have a question for folks who handle pumps regularly. Almost
       | all pumps are made for water, or sewage. How do you identify if a
       | pump is rated to handle liquid metal or hot fluids (heated
       | chemicals, or contents under extreme pressure)
       | 
       | I have never heard of a standard class of pumps for this....other
       | than basically finding a manufacturer who specialized in these
       | sort of pumps.
        
         | korse wrote:
         | You're thinking of temperature and viscosity parameters.
         | 
         | Read the data sheets and look for those terms, or look for
         | manufacturers of pumps that maximize both.
        
         | estimator7292 wrote:
         | Those are pretty extreme applications that require extremely
         | specific pumps. You are very firmly in the "call for pricing"
         | territory
        
         | mindcrime wrote:
         | That's a bit outside my wheelhouse, but in regards to
         | firefighting specifically there is another such distinction
         | that comes up, and that is in regards to pumps that are
         | designed to regularly pump seawater, versus pumps that
         | primarily pump freshwater. The difference is mainly in the
         | materials used for building the pump, and relate to the
         | corrosive effects of seawater. You _can_ pump seawater with a
         | "normal" fire pump, but if you do it's imperative to flush the
         | pump (and other hose and appliances) thoroughly with freshwater
         | as soon as possible to avoid damage. The seawater rated pumps,
         | on the other hand, can handle seawater all the time. As you can
         | probably guess, the primary application of seawater rated pumps
         | is for fireboats or onboard firefighting on other sorts of
         | ships.
        
       | jedberg wrote:
       | 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
        
         | interroboink wrote:
         | To say nothing of the launchpad sound suppression water
         | system[1] that dumps 7,300 gal/sec (about 2-3 seconds for one
         | swimming pool)!
         | 
         | Though that's just gravity-fed, of course. Still pretty cool
         | though, I think (:
         | 
         | [1] https://en.wikipedia.org/wiki/Sound_suppression_system
        
           | jauntywundrkind wrote:
           | The article uses various measures, so here's a quick table:
           | Baikonur Cosmodrome: 4,800 gal/s (peak)       Space Shuttle
           | Launch Complex 39: 7,317 gal/s (net)       Wallops: 4,000
           | gal/s (?)       SLS: 18,333 gal/s (peak)            Mack
           | Super Pumper (this article): 146 gal/s (net)
           | Replacement new Super Pumper 1: 87.5 gal/s (net)
        
         | stinkbeetle wrote:
         | 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).
        
           | dredmorbius wrote:
           | 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.
        
         | HPsquared wrote:
         | 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.
        
       | citizenkeen wrote:
       | Something the article doesn't mention is why this was phased out.
       | Was it replaced with something similar?
        
         | plasticsoprano wrote:
         | Better building fire suppression systems. Not to mention
         | improvements to flame retardant materials.
        
         | mindcrime wrote:
         | FDNY reintroduced the "Super Pumper" concept in a somewhat
         | different form a few years ago.
         | 
         | See:
         | 
         | https://www.firefighternation.com/lifestyle/new-fdny-super-p...
        
         | dublinben wrote:
         | Some interesting history here:
         | https://www.firerescue1.com/firefighting-history/articles/th...
        
         | michaelt wrote:
         | The article says the "super pumper" could supply 8,800 gallons
         | per minute, and it came with three "satellite trucks [...] not
         | burdened with a pump of their own"
         | 
         | Your basic modern fire pump unit can pump 2,200 gallons per
         | minute (if you can find a water source that'll give you that
         | much) and it'd typically have a crew of 4-5 firefighters on
         | board.
         | 
         | So you'd probably replace it with 4 regular fire trucks? Then
         | you've got just as much pump capacity, plus you've got the
         | flexibility to send the trucks to different places.
        
           | mindcrime wrote:
           | _(if you can find a water source that 'll give you that
           | much)_
           | 
           | Note that, for what it's worth, fire pumps are generally
           | rated for their capacity when drafting from a static water
           | supply (think, pond, lake, river, etc). Basically all modern
           | fire pumps can easily exceed their rated capacity by a pretty
           | good margin when pumping from a pressurized source, but then
           | you're back to your point of "do you have a source that can
           | supply that?" Still, there are ways. In my firefighting days
           | we had some hydrants in our district (the ones on the big 30"
           | main that ran right down the middle of the county in
           | particular) that could individually supply 2000gpm. And
           | nothing says you are restricted to using one hydrant! There
           | are also all sorts of complex water supply evolutions one can
           | run, involving relay pumping with multiple engines, drafting
           | _and_ using hydrants, etc.
        
             | michaelt wrote:
             | In the UK a large-scale fire will often be attended by far
             | more fire engines than the local water network can supply.
             | 
             | At the major Grenfell Tower fire, the water network could
             | only supply ~4,320 litres per minute (1141 us gallons per
             | minute) [1] despite firefighters asking the water suppliers
             | to maximise the water supply.
             | 
             | And that fire was attended by _seventy_ fire engines and
             | _two hundred and fifty_ firefighters, as they needed pretty
             | much all the breathing apparatus in the city. So they had
             | substantially more pump capacity than they had water
             | available.
             | 
             | [1] https://www.insidehousing.co.uk/news/lfb-did-not-
             | follow-even...
        
               | mindcrime wrote:
               | Oh it happens in the US as well. I know of at least one
               | relatively large metro area fire department here in NC
               | that has a few sections of the city with known water
               | supply issues - to the point that structure fires in
               | those areas get dispatched with automatic mutual aid for
               | tankers from surrounding rural departments.
        
       | andrewstuart wrote:
       | There was a fire station we used to walk past when my little boy
       | was about 2 years old. Often the fire trucks were out the front
       | being cleaned. The fire fighters always let him sit in the cabin.
       | Heaven for 2 year olds obsessed with trucks.
        
       | xnx wrote:
       | 2400 hp sounds like a lot, but a Model X Plaid is 1020 hp. I
       | assume it couldn't output 1020 hp for as long though.
        
         | FridayoLeary wrote:
         | torque is the more important figure. Which is why 13l truck
         | engines output only about 600hp.
        
           | foxglacier wrote:
           | 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?
        
             | bombcar wrote:
             | 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.
        
             | devilbunny wrote:
             | An F1 gearbox can convert your torque to HP, but the
             | gearing may or may not survive very long. If, like marine
             | or rail applications, you need a fairly constant output
             | power that isn't brutal on the spinning bits of metal, you
             | will optimize for high torque at relatively low RPM.
        
             | maxerickson wrote:
             | They are related by the shaft speed anyway.
             | 
             | The reason that a lot of applications consider torque is
             | that's more efficient to operate near the required shaft
             | speed than it is to run faster and gear down. You fight
             | more inertia in the engine at higher speed, and you add
             | rotating mass with your gearbox.
        
           | uncorkthe wrote:
           | I had an old coworker who had a fox body Mustang. He liked to
           | say "Horsepower doesn't win [drag] races, torque does."
           | 
           | One day we were out servicing a conveyor drive with a 5hp
           | motor attached to a gear reducer. I pointed out the spec
           | plate on the reducer, it claimed an output of more than a
           | thousand foot-pounds of torque.
           | 
           | "So this thing should be able to beat your Mustang in a race,
           | eh?"
           | 
           | Horsepower is just torque * RPM.
        
         | trogdor wrote:
         | The Plaid can only output its maximum power at 100% state-of-
         | charge (or close to it).
         | 
         | As state-of-charge decreases, so does the overall battery pack
         | voltage. Since the motors can only pull some peak number of
         | amps, doing so at lower pack voltage will always deliver less
         | total power.
         | 
         | I own a Model S Plaid and I used to pay close attention to the
         | OBD-II data, out of curiosity.
        
       | jauntywundrkind wrote:
       | 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)
        
         | amluto wrote:
         | 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.
        
         | mindcrime wrote:
         | _This thing feels like a mortal danger to the (up to 8x!) iron
         | pipes / hydrants it's pulling from,_
         | 
         | When pumping a fire engine supplied by a hydrant (or any other
         | pressurized source, as opposed to drafting from a static water
         | source like a pond or lake) there's an idea of "residual
         | pressure" which is monitored by a gauge on the pump panel. The
         | engineer is responsible for making sure the residual pressure
         | doesn't drop below the level where damage would occur to the
         | water system, supply hose, or the pump itself. It's been a few
         | years, but I think most departments spec somewhere around 20psi
         | as the minimum residual pressure they allow.
         | 
         |  _Also wondering: what replaced this!_
         | 
         | The Super Pumper[1], of course! :-)
         | 
         | The new one isn't quite as extreme, not tractor drawn and no
         | separate engine. This is more of a traditional fire engine
         | style platform, but the specs are still pretty impressive.
         | 
         | [1]: https://www.firefighternation.com/lifestyle/new-fdny-
         | super-p...
        
         | topspin wrote:
         | > Also wondering: what replaced this!
         | 
         | A collection of smaller pumps and monitors, which is likely a
         | better scheme, in terms of flexibility and fault tolerance.
         | While a remarkable design, the single pump with long hoses to
         | multiple hydrants, then radiating to multiple monitors, is a
         | system that takes great coordination and precious time to
         | deploy and rework in action.
         | 
         | The Napier Deltic engine is the party piece in all this. It is
         | an ambitious and yet successful design, intended to push the
         | limit of power-to-weight in a diesel engine. I investigated the
         | state of current diesel locomotive engines in comparison to the
         | Deltic and it remains, _to this day_ , the highest power-to-
         | weight diesel engine in use for locomotives. (There are half a
         | dozen still running in the UK today in limited service.) I've
         | personally visited the Bay City museum to see this engine.
         | 
         | These engines require forced induction; they cannot run
         | naturally aspirated. In its various naval, rail and other
         | applications there were many different induction designs
         | applied to the Deltic: turbos, superchargers and combinations
         | of both. Today, we have _electric_ forced induction, enabled by
         | the high performance electric motors that have emerged
         | elsewhere in transport applications. One thinks of what diesel
         | wonders might be created by combining the Deltic design with
         | electric forced induction.
        
           | jabl wrote:
           | I believe most contemporary marine two stroke diesels use
           | electrical blowers for scavenging at low speeds. At higher
           | speed the turbocharger spins up and takes over, and the
           | electric blowers are shut down.
        
         | bombcar wrote:
         | 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.)
        
       | kazinator wrote:
       | That https://en.wikipedia.org/wiki/Napier_Deltic is pretty
       | interesting.
       | 
       | You would initially think that the ignition events would be
       | evenly spaced, but that's not the case. For every delta triplet,
       | the ignitions come rapidly one after another, close together in
       | the cycle.
       | 
       | In that second animation on the page, showing the firing order
       | among 6 delta piston assemblies, if you keep your eyes fixated on
       | any of the six columns, you can see the three firing events.
       | Always C, B, A order.
        
       | jabl wrote:
       | In case someone is interested in the engine powering this thing,
       | a good writeup at https://oldmachinepress.com/2019/09/05/napier-
       | deltic-opposed...
        
       | mindcrime wrote:
       | And while we're talking about highly specialized firefighting
       | apparatus... while I don't think Chicago FD ever ran anything
       | quite like the FDNY Mack Super Pumper, they are well known for
       | their use of a piece of apparatus known as a "turret wagon".
       | Basically, it's a big-ass truck with a huge deluge gun (aka
       | "monitor" or "turret") mounted on the back, and with a big intake
       | manifold for receiving multiple supply lines. You could think of
       | a "turret wagon" as being conceptually akin to the "Satellite"
       | units that were part of the FDNY Super Pumper System.
       | 
       | Anyway, one of the best known Chicago Turret Wagons was "Big
       | John" (aka 6-7-3).
       | 
       | https://chicagoareafire.com/blog/2013/04/chicago-fd-turret-w...
       | 
       | https://chicagoareafire.com/blog/2013/04/chicago-fd-turret-w...
       | 
       | Not sure if CFD still maintain any Turret Wagons in contemporary
       | times or not, but variations on the concept are still found,
       | particularly in industrial fire departments that protect high
       | hazard sites like oil refineries, certain chemical plants, etc.
        
         | bitwize wrote:
         | Wow. Those things could Dip Toontown off the face of the earth.
        
         | bombcar wrote:
         | It's interesting to think about - because Big John obviously
         | takes some time to connect/setup but then can (apparently)
         | deliver 10,000 gallons per minute as long as there's water in
         | the pipes.
         | 
         | Whereas a modern tanker truck can do 1,000 GPM for 2 or 3
         | minutes, but can do it immediately upon arriving onsite.
         | 
         | https://www.piercemfg.com/fire-trucks/tankers/bx-tanker
         | 
         | It's also relative to how fire-fighting has changed over time,
         | modern buildings that are big enough to NEED the Big John are
         | also much more fire-resistant (concrete instead of wood, etc).
        
       | 7402 wrote:
       | Anyone else struck by this bit?
       | 
       |  _Mack was awarded the contract to build the truck in 1964 and by
       | the end of the year, the unit was nearly ready to hit the streets
       | of NYC._
       | 
       | Seems amazingly fast by current standards. Those were the days!
        
         | potato3732842 wrote:
         | Think about all the processes they just didn't have to do back
         | then.
        
           | garbagewoman wrote:
           | just less massive amounts of waste, fraud and corruption
        
             | anjel wrote:
             | Thanks private equity!
             | https://markorton.substack.com/p/fire-engines-monopolies-
             | and...
        
               | dmix wrote:
               | There was a senate investigation in Sept 2025 and it
               | sounds a good case for an antitrust investigation:
               | 
               | https://www.hsgac.senate.gov/wp-
               | content/uploads/Musharbash-T...
               | 
               | Whenever there's market centralization the first question
               | is why aren't upstarts taking over the market if there's
               | such a backlog and high costs. Briefly reading into this,
               | there's a large barrier to entry for fire engines in
               | terms of extensive certification, local/state
               | regulations, and the large emergency operations buying
               | them need safe supply lines so they won't risk betting on
               | newbies. You also won't easily find foreign suppliers to
               | help fill the void (euro companies will focus on euro
               | certifications). Plus you'd need to make deals with other
               | mega-corp truck manufacturers and other specialized
               | equipment.
               | 
               | Combine that with 2008 financial crisis + flood of cheap
               | capital, it was easy pickings for
               | financialization/consolidation.
        
       | jcgrillo wrote:
       | Indirectly related, for anyone interested in the topic, Pirault
       | and Flint's Opposed Piston Engines[1] is a nice survey.
       | Unfortunately it seems to be commanding a shocking price these
       | days though.
       | 
       | [1] https://www.amazon.com/-/he/Martin-Flint/dp/0768018005
        
       | joemi wrote:
       | > During a fire in the Bronx, firemen laid 7,000ft of hose to get
       | to a suitable water supply and the truck pumped as though it was
       | dipping its feet into the ocean.
       | 
       | "7000 ft" sounds wrong to me. That's over a mile of hose. Feels
       | like that's unnecessarily long. I'd love to learn more about
       | this. Anyone know when or what fire this was?
        
         | maxerickson wrote:
         | It could draw from 8 hydrants. So average of 900 feet in that
         | case.
         | 
         | Which still seems like a lot, but not so incredible.
        
           | permonst wrote:
           | It's not uncommon to see an individual fire engine in the US
           | with 800-1000 feet of supply hose. I don't know if that's a
           | common configuration in a dense city like NYC, but it's
           | certainly a reasonable amount per engine.
        
         | dleary wrote:
         | The article mentions that the main pumping unit could draw
         | water from 8 hydrants at once. So 7000 ft of total hose to get
         | to 8 hydrants sounds like it makes sense.
         | 
         | I wonder if maybe it can't even use hydrants that are too near
         | each other in the plumbing graph.
        
           | mindcrime wrote:
           | _I wonder if maybe it can 't even use hydrants that are too
           | near each other in the plumbing graph._
           | 
           | There's a lot of variables in that equation. For example, say
           | you have a "dead end" main that ends somewhere near the fire.
           | If you connect to the last hydrant on the main and start
           | flowing water, there's a good chance you won't get a lot of
           | _additional_ water by connecting to the next hydrant up the
           | street. But if you connect to a hydrant that 's on a main
           | that is part of a loop, there's a better chance you'll be
           | able to get more water by doing that.
           | 
           | And without getting into too much detail that would be boring
           | to non-firefighters (probably)... there's actually two big
           | variables for a given hydrant: the maximum _volume_ of water
           | it can supply (in GPM) and the _pressure_ available at the
           | hydrant. And those two things are related. Anyway, net-net,
           | you can have a hydrant that is capable of - in principle -
           | flowing, let 's say 2000 GPM. But the pressure at the hydrant
           | is only, say, 40 psi. That means you only have 20 psi
           | (approximately) available[1] to overcome the friction loss in
           | the supply hose between the hydrant and the engine. And that
           | friction loss in turn is a function of the hose size and the
           | flow rate.
           | 
           | Anyway, that results in a situation where you might have a
           | hydrant that _could_ supply you 2000GPM, but if your fire is,
           | say, 1500 feet away, you might effectively only be able to
           | take advantage of maybe 500GPM of that.
           | 
           | And that in turn leads into stuff like using a "four way" or
           | "hydrant assist" valve, or having a relay engine sitting
           | right on the hydrant (to minimize friction loss between the
           | hydrant and the engine) and then using its pump to boost the
           | pressure going to the attack engine. By using multiple
           | engines like that, you can get closer to achieving that
           | hypothetical 2000GPM (or whatever) flow.
           | 
           | It gets pretty complicated, but fortunately fires in urban
           | areas where the municipal water system is the limiting factor
           | seem to be relatively uncommon (but not unheard of!) in this
           | day and age.
           | 
           | [1]: because you don't want to pull the residual pressure
           | down too low or it can damage the water system, supply hose
           | or your pump.
        
         | dreamcompiler wrote:
         | If they were all in a single line it probably wouldn't have
         | worked -- series hydrodynamic hose impedance adds just like
         | series resistance in a circuit and the pressure at the end
         | would have been too low to be useful. But if it was 7000 feet
         | arranged in several shorter parallel lines it's possible.
        
       | linsomniac wrote:
       | SysAdmin related: I was once talking to a fire chief and I asked
       | about how much water the fire engines carried. He said that they
       | carry about enough to put out the typical house fire. The first
       | engine on scene immediately jumps to fighting the fire. The
       | second engine on scene hooks the first engine up to the water
       | supply before going on to fight the fire.
       | 
       | I've often thought about that when there's a work crisis: If I'm
       | the second on the scene, what can I do to support those fighting
       | the fire right now, before jumping in.
        
         | dreamcompiler wrote:
         | Our engine holds 1200 gallons. It goes in first* and starts
         | putting the wet stuff on the red stuff.
         | 
         | As the engine drives in it drops a 3" hose along its path. Next
         | is our big tender with 3000 gallons. It stops at the street and
         | connects to the dropped hose to pump more water up to the
         | engine.
         | 
         | The tender also has a drop tank -- think about a portable kids'
         | wading pool but much larger and deeper. Shuttle tenders refill
         | the drop tank while our big tender draws from it to continue
         | supplying the engine.
         | 
         | We don't have fire hydrants, so this is the dance we have to
         | do.
         | 
         | * It's very important to park the engine close to the fire _but
         | not too close_. Ask me how I learned this.
        
           | jonstewart wrote:
           | H-h-how did you learn this?
        
             | dreamcompiler wrote:
             | The hard way.
        
               | mindcrime wrote:
               | "No worries Chief, that'll buff out!"
        
               | dreamcompiler wrote:
               | Exactly. Back when I was a newbie we melted all the
               | lights on the engine as well as on my own truck since I
               | was first on scene POV (Personally Owned Vehicle). And of
               | course we charred some hose but that's common. Then CHAOS
               | happened (Chief Has Arrived On Scene) and he quickly
               | moved both trucks farther away from the fire, saving the
               | county (and me!) the cost of a new truck.
        
               | mindcrime wrote:
               | It's incredibly unfortunate when those things happen, but
               | it comes with the territory sometimes. Case in point:
               | 
               | https://www.firerescue1.com/firefighter-safety/photo-
               | video-l...
        
               | tharkun__ wrote:
               | Details!
               | 
               | Also, please set up something like this or give me a link
               | to a North American fire department that has such high
               | production value videos:
               | https://www.youtube.com/@BrandweerLunteren
               | 
               | I just love that the guy literally bikes to the fire
               | station in like a minute and he's not even the first guy
               | to arrive or just barely. And the others following in the
               | van are like a couple minutes out at most. Where I am,
               | the volunteers at the fire department have to be there
               | within 15 minutes plus the time it takes to get to the
               | actual fire.
               | 
               | (no worries I understand that the Netherlands is a much
               | different country with regards to fire hydrant
               | infrastructure and closeness to the station from the US /
               | NA, at least/especially the rural US/Canada. I just want
               | such awesome videos from other places around the globe
               | really)
        
           | mulmen wrote:
           | > It's very important to park the engine close to the fire
           | but not too close. Ask me how I learned this.
           | 
           | I was a farm hand as a summer job to cover beer and books in
           | my college years. We harvested wheat which carries a high
           | fire risk. Most farms kept a tractor with a large plow hooked
           | up so it could quickly encircle and contain any fires.
           | 
           | Pulling a 40' wide plow is _hard_. Tractors can do it because
           | they have huge engines that suck in huge amounts of oxygen.
           | 
           | Just like fires.
           | 
           | If you get a tractor too close to a fire it starves for
           | oxygen and stalls out. The plow becomes an anchor. There's
           | just enough time to bail out before the tires catch fire.
           | After a few minutes the whole thing is a pile of ash and
           | melted steel.
        
             | dreamcompiler wrote:
             | Didn't know wheat harvest came with fire risk. I know about
             | the dangers of grain silos but I didn't know the harvest
             | itself was risky.
        
               | mulmen wrote:
               | Oh yeah. It's a constant threat.
               | 
               | The wheat is harvested "dry". The plant dies and dries
               | out. The drier the better. Moisture leads to mold in the
               | silos and clogs up the harvesters.
               | 
               | The wheat is harvested by "combines" which are literally
               | a combination harvester and thresher. Both machines are
               | extremely complex.
               | 
               | They're used at 110% capacity to beat the fall rains then
               | sit rotting for 9-10 months. Lots of seized bearings or
               | broken bits of machines sparking and starting fires.
               | 
               | The grain trucks I drove had their air conditioners
               | removed to discourage idling and the exhaust pipes dumped
               | directly in front of the rear tires to auto-snuff exhaust
               | fires.
        
           | jonah wrote:
           | Wow. We're probably more rural and can't fit such large
           | apparatus in many places we have to go. Out our type 1 engine
           | carries 1,000 gallons, and our type 3 (wildland) 500 gallons
           | and our tenders have 2,000.
           | 
           | 1,000 isn't going to put out a house fire unless it's really
           | small and not fully involved. The past two good structure
           | fires we had took 20,000 and 60,000 to gallons respectively.
        
             | dreamcompiler wrote:
             | Agreed. We could never put out a residential structure fire
             | with one truck's worth of water. That's why we ask for
             | mutual aid and an army of shuttling tenders shows up.
             | 
             | Our big tender never leaves the street; it's too big and
             | too heavy for residential driveways.
             | 
             | We do have a brush truck for tighter spots and for use as a
             | relay pump for extra long driveways.
        
           | bombcar wrote:
           | How did you learned this?
           | 
           | Rural properties I'm familiar with required a 3,000 gallon
           | water tank with fire-connection far enough from the main
           | structure as to be accessible.
           | 
           | But ask the fire department how they'd approach your house,
           | and put the hydrant on that road; it might NOT be the
           | road/driveway you normally come up!
        
         | WarcrimeActual wrote:
         | >I've often thought about that when there's a work crisis: If
         | I'm the second on the scene, what can I do to support those
         | fighting the fire right now, before jumping in.
         | 
         | Great! Now I'll have to see this quote over an image of a
         | sweaty firefighter on LinkedIn every 3 weeks for eternity.
        
         | WarcrimeActual wrote:
         | https://i.imgur.com/zCjoWIZ.jpeg
         | 
         | I feel gross.
        
         | BuildTheRobots wrote:
         | > I've often thought about that when there's a work crisis: If
         | I'm the second on the scene, what can I do to support those
         | fighting the fire right now, before jumping in.
         | 
         | A lot of it depends on the size and skill-set of your team and
         | the escalation routes available to you, but in general (and off
         | the top of my head):
         | 
         | - Get the first people on scene to give a summary of the
         | problem as they know it. Make sure everyone actually agrees on
         | what the problem is and what symptoms have been observed.
         | Understand what areas people are currently investigating and
         | make sure they aren't trampling over each other or actually
         | making the situation worse [1]
         | 
         | - Make sure the situation hasn't evolved whilst the first on
         | scene have been investigating the initial symptoms. It's easy
         | to get lost in the weeds digging into a handful of monitoring
         | alerts only to look up and realise there's now 300 and the
         | original problem is only a small part of what's going on.
         | 
         | - If there isn't one already and you're not better doing
         | something else, become incident commander. When done right it's
         | an extremely important and useful role.                 - Take
         | over external communication and protect the team from
         | distractions       - Start assessing escalation options       -
         | Take copious notes and keep a timeline        - Act as a shared
         | memory and keep people honest        - Have a less panicked,
         | wider (non minutia) view of the problem       - Start collating
         | and pulling up documentation/schematics so the people at the
         | coalface can quickly query it rather than getting distracted
         | searching for it.       - Be ready to jump, for when someone
         | inevitably asks "can someone check..." or "does anyone know"
         | - Keep track of the "shared truth" of the incident as it
         | evolves. What have we witnessed, what do we believe is the
         | cause, _why_ do we believe that? Have we invalidated anything,
         | do we need to reassess, are we sure logical lynchpins aren't
         | confirmation bias or dyslexia?       - Onboard new people and
         | hand over if appropriate.
         | 
         | Being at the coalface when it's on fire is a very different
         | view of the world to watching other people panic and singe
         | their fingers. It's also very easy to get lost in a chain of
         | technical problems [2] when it's mostly irrelevant to the wider
         | picture.
         | 
         | If you get a moment, it can also be a good time to assess how
         | useful your monitoring is during an actual event.
         | 
         | [1] "Hey, server x has flagged on monitoring and my ssh session
         | is hung waiting for a login prompt!" I've been round the houses
         | enough to know this is probably OOM and if I just wait, I'm
         | likely to finally get in. I also know that saying this in a
         | room of 20 technical people, means the server is now processing
         | 22 new ssh sessions and now no one is getting anywhere.
         | 
         | [2] The famous Malcolm in the Middle intro where Hal is tasked
         | with changing a lightbulb and ends up repairing the car. Except
         | in my example the bulb is actually fine and there's a power cut
         | we missed. https://www.youtube.com/watch?v=AbSehcT19u0
        
       | FridayoLeary wrote:
       | >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 vehicles, biplanes,
       | and the propellor planes of ww2 capture the imagination in a way
       | jets don't. The monstrously complicated cabins of old 747s are
       | fascinating in a way that modern far more capable planes are not.
       | Back then you had 2 pilots and a guy whose main job was stopping
       | the plane from falling out of the sky! Now it's a bunch of very
       | clever computers under the cockpit that does all of that. It's
       | worth noting that steam engine which was the driving element in
       | the Industrial Revolution and maybe the most important invention
       | in history was originally developed to pump water from mines.
       | Some of these distant ancestors of modern engines are on display
       | in London. James Watt might have predicted a pump like this, but
       | he probably never guessed it would be pulled by anything but a
       | team of horses!
       | 
       | Compare that to Sam Altmans wild prediction that agi will capture
       | "the light cone of all future profits in the entire universe",
       | maybe true, but it will never be as interesting as a steam
       | engine, where the collective ingenuity of a century of engineers
       | and metallugrists is on display in all it's glory.
        
         | foxglacier wrote:
         | > That sounds counterintuitive . What about higher pressure
         | will slow water down?
         | 
         | I suppose that means back-pressure. More back-pressure on a
         | pump means it can't provide such a high flow rate at the same
         | power output because power = flow rate * pressure.
        
         | permonst wrote:
         | > That sounds counterintuitive . What about higher pressure
         | will slow water down?
         | 
         | It sounds counterintuitive because it's not worded well.
         | Imagine a garden hose with no nozzle: The water doesn't go very
         | far, but you can fill a bucket with it pretty quickly. You can
         | also restrict the flow by putting your thumb over the end of
         | the hose. That increases the pressure and allows you to fill up
         | a bucket farther away, but it takes longer because you've
         | lowered the volume (GPM) of water flowing from the hose.
         | 
         | Firefighters use nozzle tips of different sizes to make trade
         | offs between pressure and volume.
        
         | bombcar wrote:
         | 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."
        
       | bolangi wrote:
       | Hello hath no fury like a lithium ion battery fire.
        
         | PaulDavisThe1st wrote:
         | Tell me more.
         | 
         | As a firefighter, the training I've had tells me that they're
         | generally no big deal. You spray water on them to keep the
         | overall temps down, and wait. Not a big deal. The main
         | difference is that they don't tend to go out quickly, so you
         | may be stuck nursing it as it burns itself out for a long time.
        
       | sklargh wrote:
       | Simply posting here to introduce people to the Snozzle.
       | https://youtu.be/_DNyAKcEe6A
        
       | anArbitraryOne wrote:
       | The 'Curious Droid' video on this engine is fascinating. If I
       | were more helpful, I'd leave a link to it
        
         | andrewstuart wrote:
         | This site is not a charity.
        
       | mberning wrote:
       | The Napier Deltic has a very distinctive sound. You can hear it
       | in locomotive form on youtube. If you are into that sort of thing
       | there are some really good videos on the Rolls Royce Crecy engine
       | as well.
        
         | dboreham wrote:
         | There are still a bunch of class 55s operational so if you're
         | sufficiently motivated you can go hear one first hand.
        
       | Kallikrates wrote:
       | the station: https://maps.app.goo.gl/Tc2Hs8kdwbFcbaxC6
        
       | dboreham wrote:
       | For the curious: most locomotive desiel engine designs have
       | marine origins. That's because ships transitioned to desiel power
       | (from steam) before trains did. At least in the UK. The general
       | design constraints are similar and so when folks began looking
       | into making diesel locomotives they generally selected existing
       | marine designs and adapted them. Often de-rating the maximum
       | power to improve reliability.
       | 
       | When the UK converted from steam to diesel it was easier to
       | switch the locomotives while leaving the coach stock as-is.
       | Modern trains aren't like this: they're "multiple units" with
       | more than one drive car. Anyway, a steam engine can generate much
       | more power than a 1950s diesel engine can, particularly factoring
       | in the UK loading gauge which restricts engine height. So in
       | order to make a diesel locomotive capable of taking over from A4
       | Pacific steam engines on the east coast main line, it was
       | necessary to design a locomotive that had two desiel engines,
       | with a high power to weight ratio. Hence the class 55 cited in
       | the article. The deltic engines were very complex and costly to
       | maintain but solved a problem arising from the transition away
       | from steam. In the 1970s they were in turn replaced by trains
       | with a DMU configuration (HST), featuring a permanently coupled
       | power/van car at each end, removing the need for a single very
       | high power locomotive.
        
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