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

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

#91

Post by permonst »

FridayoLeary wrote: post #54

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

> 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.

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

#92

Post by permonst »

maxerickson wrote: post #49
joemi wrote: post #47

> 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?

It could draw from 8 hydrants. So average of 900 feet in that case. 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.

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

#93

Post by dboreham »

mberning wrote: post #81

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.

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

#94

Post by dboreham »

ggm wrote: post #7
giobox wrote: post #3

That "deltic" engine just for the water pumping is incredible, I'd never seen that cylinder layout before. > https://en.wikipedia.org/wiki/Napier_Deltic

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

> avid train spotter at Waverley station in edinburgh

We probably met. I was there every day traveling to and from school but did casual trainspotting on the side. Oblivious someone would one day write a book with that title..

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

#95

Post by uncorkthe »

FridayoLeary wrote: post #56
xnx wrote: post #21

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 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.

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

#96

Post by dboreham »

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.

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

#98

Post by ErroneousBosh »

ggm wrote: post #7
giobox wrote: post #3

That "deltic" engine just for the water pumping is incredible, I'd never seen that cylinder layout before. > https://en.wikipedia.org/wiki/Napier_Deltic

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…

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.

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

#99

Post by bombcar »

mindcrime wrote: post #37

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.…

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).

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

#100

Post by bombcar »

dreamcompiler wrote: post #57
linsomniac wrote: post #53

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…

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…

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!

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