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).
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.
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.
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.
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.
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.
> 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.
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.
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)
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.
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.
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 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.
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.
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/
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, and the diminutive type 3 diesel shunter at Birkenhead. The baby deltics were probably parked in a yard waiting scrapping.
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)
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.
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.
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.
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.
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.
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.
(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.
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.
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.
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.
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.
> 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?
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.
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.
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.
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.
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.
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.
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?
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.
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)
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.
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.
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.
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.
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.
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.
>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.
> 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.
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.
Wow. Those things could Dip Toontown off the face of the earth.
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.
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.
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.
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.
> 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.
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.
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.
H-h-how did you learn this?
The hard way.
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)
"No worries Chief, that'll buff out!"
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.
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).
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
The article uses various measures, so here's a quick table:
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
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.
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.
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/
A series of 10 "baby deltics" were built and ran for some years, although they weren't particularly successful on the whole.
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, and the diminutive type 3 diesel shunter at Birkenhead. The baby deltics were probably parked in a yard waiting scrapping.
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.
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
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.
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-...
Napier Nomad is one of my favorite engine designs. More info at https://oldmachinepress.com/2019/08/05/napier-nomad-compound...
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/
They're still in use by our UK navy. Nine minesweepers still on active duty.
I just realised they re-engined them with cat engines in 2008. Pity.
> 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
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.
Something the article doesn’t mention is why this was phased out. Was it replaced with something similar?
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...
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.
(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.
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...
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.
Some interesting history here: https://www.firerescue1.com/firefighting-history/articles/th...
Better building fire suppression systems. Not to mention improvements to flame retardant materials.
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!
Think about all the processes they just didn't have to do back then.
just less massive amounts of waste, fraud and corruption
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.
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.
Simply posting here to introduce people to the Snozzle. https://youtu.be/_DNyAKcEe6A
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...
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
For lighter viewing there is Sorcerer (1977) [0] with Roy Scheider.
[0] https://en.wikipedia.org/wiki/Sorcerer_(film)
Great Tangerine Dream soundtrack too.
firefighter and tangerine dream fan, eh? we should cross paths ...
Pretty sure I'm just down the road from you too.
Not sure I'd call that lighter viewing, but it's a truly excellent movie.
Video is hosted on archive.org https://archive.org/details/lessons-of-darkness-1992
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/
https://m.imdb.com/title/tt3674140/
I watched this movie on cinema a decade ago. Highly recommended.
It is, indeed, a tremendous documentary. He's one of my greatest inspirations.
You could also nuke it; https://en.wikipedia.org/wiki/Urtabulak_gas_field
The 'Curious Droid' video on this engine is fascinating. If I were more helpful, I'd leave a link to it
the station: https://maps.app.goo.gl/Tc2Hs8kdwbFcbaxC6
> 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?
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.
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.
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.
It could draw from 8 hydrants. So average of 900 feet in that case.
Which still seems like a lot, but not so incredible.
Hello hath no fury like a lithium ion battery fire.
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.
In case someone is interested in the engine powering this thing, a good writeup at https://oldmachinepress.com/2019/09/05/napier-deltic-opposed...
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.
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.
Those are pretty extreme applications that require extremely specific pumps. You are very firmly in the "call for pricing" territory
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.
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.
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?
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.
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)
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...
> 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.
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.
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.
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.
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
>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.
> 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.