Fire Pump Power Requirements

[TurnipTruck]

To prevent the scrapping of this cool little firewater pump, I let the prior owner give it to me. I also let him give me the set of suction and discharge hoses and the foam cannon.


I don’t need it, but if I can make it functional much fun could be had with the new neighbors across the cove.
Now, how to power it? The Luxembourg firefighting Unimog (below) that the pump came from is good for like 80hp PTO, but 540rpm multiplied by a 4.5:1 gearbox (that I didn’t get) is 2430rpm! None of my Unimogs or tractors can do that kind of speed if I wanted to build a pto trailer.
I DO have a pair of single-cylinder air-cooled diesels or a 2cyl 17hp gas engine laying around unemployed if I want to try a self-powered skid. Maybe even a 33hp Perkins/Shibura, but it’s governed to 1800rpm.


BUT; there isn’t a trace of documentation or data plates anywhere on the pump. I did find a reference from 1963 that the earlier gasoline Unimogs used Ziegler pumps, which got me this contemporary equivalent:


OMG! TWO HUNDRED SIXTY EIGHT HORSEPOWER!?!!
I seriously doubt the Unimog had more than 125 hp to begin with, so my guesses/assumptions/interpretation/metric conversions may be in error someplace.
Personally, I am not a fire pump engineer nor have I operated anything larger than wheeled drychem extinguishers or 100# halon, so if anyone has any experience or guesses how much power I need to apply to this 100mm suction’d pump, lay it on me.

Moar pics?

 

[cvairwerks]

To make that pump useful, you would need close to 100hp for a drive motor. They are designed to be run while the truck is stationary and all engine power is directed to the PTO. Our trucks ran big Cummings or Detroit diesels and took about 1500 rpms to drive the PTO and provide about 1200 gpm water flow at almost 150 psig. Interlocks kept you from engaging drive while in PTO mode, but the one time someone did and had a failure, it wouldn't even move the truck, it bogged down so bad.

 

[no704]

VW type 4 2000cc.

 

[PCustoms]

Clearly you need to LS swap it

 

[TurnipTruck]

Clearly you need to LS swap it

Precisely my intent if I ever end up with spare engines.
Buuuuuut, if I build a skid with LS mounts, I could use it as a water brake and break in engines under load. Hmmm.

 

[36truck]

For many years the older fire pumps were gas trucks. Like you have said around 150 HP. is enough to power the pump. They do run 1500/1800 rpm. They could push 1000 gal. per minute @ 125/150 PSI. They could run at a lower RPM if you didn't need the high flow.

 

[NUTTSGT]

To make that pump useful, you would need close to 100hp for a drive motor. They are designed to be run while the truck is stationary and all engine power is directed to the PTO. Our trucks ran big Cummings or Detroit diesels and took about 1500 rpms to drive the PTO and provide about 1200 gpm water flow at almost 150 psig. Interlocks kept you from engaging drive while in PTO mode, but the one time someone did and had a failure, it wouldn't even move the truck, it bogged down so bad.

They do build some trucks that "Pump & Roll" but those are generally for a specific purpose. Doing a truck that can pump and roll without it being a skid unit (gas powered like Wildland or grass truck) is going to introduce a lot into the equation.

Not only are you going to be trying to power that pump but you're going to need to supply it with water.

The other thing to consider is your weather, you're in Alaska. It's either going to need to live indoors or winterized to prevent freezing and breaking stuff. . . even gauges freeze up.

 

[TurnipTruck]

This is interesting (to me anyway):

A beetle flat four powering a Ziegler pump;



And a two cylinder BMW bike engine on a fire pump

 

[Xti04]

This is interesting (to me anyway):

A beetle flat four powering a Ziegler pump;



And a two cylinder BMW bike engine on a fire pump

My buddies dad has a stack of unclaimed air head BMWs at his shop. I have been looking to pick one up and build a generator out of one. Good to see them use it for a fire pump

 

[cvairwerks]

My buddies dad has a stack of unclaimed air head BMWs at his shop. I have been looking to pick one up and build a generator out of one. Good to see them use it for a fire pump

Yeah, but Rosenbauer quit building those pumps in the 1960's....

 

[TurnipTruck]

I was just given this natgas 20kw generator powered by a 4cyl Ford because I was in the right place at the right time. I have no particular need for a fourth generator (especially one that needs 400kscf !), but if I find a PTO clutch housing to fit…hmmm. Fun and Games could be had.

 

[mike93lx]

I was just given this natgas 20kw generator powered by a 4cyl Ford because I was in the right place at the right time. I have no particular need for a fourth generator (especially one that needs 400kscf !), but if I find a PTO clutch housing to fit…hmmm. Fun and Games could be had.

Granted 20kw is the output from the generator, not engine, but that is the equivalent of <30hp. I doubt that engine has enough to power the pump. But maybe it's rated for much more at a higher rpm

 

[1redTA]

What size shaft is on the input to the pump? You could work backwards.

 

[TurnipTruck]

What size shaft is on the input to the pump? You could work backwards.

This drive flange is 100mm OD with a 76mm bolt circle. Does that sound familiar to anyone?
I have a 1-3/8” 6spline PTO drive flange from an old Deere that I can adapt, but the tractors all turn the wrong direction and likely don’t spin fast enough even at 1000rpm.

 

[driftpin]

We had a 750 GPM front-mounted fire pump w/a Ford V8 which could 'pump & roll' for grass fires, predominantly. It was the lowest GPM pumper in the dept. inventory. As I recall, Hale was the manufacturer of the fire pumps on our pumpers, most of which were 1000-1500 GPM. The 750 GPM pump & roll truck was the notable exception.