The Mack Super Pumper was a locomotive engined fire fighter (2018)(bangshift.com)
bangshift.com
The Mack Super Pumper was a locomotive engined fire fighter (2018)
https://bangshift.com/bangshiftxl/mack-super-pumper-system-locomotive-engine-powered-pumper-extinguish-hell-often/
126 comments
Wow. Those things could Dip Toontown off the face of the earth.
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).
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).
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.
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.
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.
> 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.
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.
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.
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.
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.
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.
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.
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!
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!
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)
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.
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...
https://www.firerescue1.com/firefighter-safety/photo-video-l...
This kind of incident is embarrassing to any fire service, but I'll always sacrifice apparatus if it saves people. I'll be the butt of jokes for the rest of my career, but it's still a win.
>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.
Great! Now I'll have to see this quote over an image of a sweaty firefighter on LinkedIn every 3 weeks for eternity.
https://i.imgur.com/zCjoWIZ.jpeg
I feel gross.
I feel gross.
> 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.
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
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.
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
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
Seeing the test firings of the pump was pretty amazing, draining one "swimming pool" and filling another in a minute.
[0] https://en.wikipedia.org/wiki/RS-25#Turbopumps
The numbers on rocket engines are just ridiculous. The turbine on the F1 engines on the Saturn V's first stage generate about 40MW just to pump the fuel and oxygen. 5 of them on the rocket is 200MW which is a respectablly sized power plant, or about 1/2 of a Nimitz aircraft carrier (which is able to push a floating city through the water at nearly 40mph).
The comparisons which stick in my head are that the Saturn V's first-stage fuel pumps were roughly equal in power to a naval destroyer's engines, and the five F1 engines delivered as much energy as France's entire electrical grid (presumably contemporaneously). This from books read as I was a wee lad.
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
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:
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)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.
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
> https://en.wikipedia.org/wiki/Napier_Deltic
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.
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.
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.
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/
[deleted]
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.
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.
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, 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.
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.
> 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..
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..
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
[0]https://en.wikipedia.org/wiki/Brake-specific_fuel_consumptio... [1]https://en.wikipedia.org/wiki/Napier_Nomad
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.wikipedia.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.
- 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.wikipedia.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.
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.
The youtube channel "Greg's Airplanes and Automobiles" has a nice video about turbo compound engines.
Napier Nomad is one of my favorite engine designs. More info at https://oldmachinepress.com/2019/08/05/napier-nomad-compound...
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-...
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/
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.
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>
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>
> 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
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.
Generally speaking at least, two stroke diesel engines weren't super efficient, but did offer great power output relative to their size.
Two of the three crankshafts rotate in the same direction, whereas the third one moves the other way around!
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.
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)
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)
> 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.
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.
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...
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...
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.)
(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.)
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.
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!
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
Thanks private equity!
https://markorton.substack.com/p/fire-engines-monopolies-and...
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.
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.
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.
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...
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.
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.
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...
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.
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.
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.
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.
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.
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.
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
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)
[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.
north-central NM ?
yep
Santa Fe County, eastern region, here.
Sent you some email. Might have gone to spam.
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/
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.
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
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.
Of course, you probably want to put out a leak a bit faster than after 55 years.
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
[1] https://www.amazon.com/-/he/Martin-Flint/dp/0768018005
> 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?
"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.
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.
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.
Which still seems like a lot, but not so incredible.
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.
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.
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.
Those are pretty extreme applications that require extremely specific pumps. You are very firmly in the "call for pricing" territory
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.
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.
Read the data sheets and look for those terms, or look for manufacturers of pumps that maximize both.
In case someone is interested in the engine powering this thing, a good writeup at https://oldmachinepress.com/2019/09/05/napier-deltic-opposed...
[deleted]
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.
There are still a bunch of class 55s operational so if you're sufficiently motivated you can go hear one first hand.
Simply posting here to introduce people to the Snozzle. https://youtu.be/_DNyAKcEe6A
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.
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.
The 'Curious Droid' video on this engine is fascinating. If I were more helpful, I'd leave a link to it
This site is not a charity.
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.
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.
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.
torque is the more important figure. Which is why 13l truck engines output only about 600hp.
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.
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.
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?
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.
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.
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.
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.
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.
[deleted]
>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?
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?
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.
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.
> 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.
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.
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."
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."
the station: https://maps.app.goo.gl/Tc2Hs8kdwbFcbaxC6
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.