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Permalink Reply by Andy Turnham on October 29, 2011 at 7:00pm

This is an old, old trick.  In the UK (that's where I'm from) this was found to be invaluable during WWII when water mains would be destroyed by bombing, a series of pumpers would be set up and move water for miles to where it was needed. 

Far more recently the British Government has invested huge sums of money in special, high volume, transportable pumps along with hose layers and other specialised equipment as part of their Disaster Preparedness plans (Google "New Dimensions program" and something should come up about it).

These pumps can move huge amounts of water, either to fight major fires or to reduce flooding.  They can be set up in relays or in groups depending on the need.

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Permalink Reply by Don Catenacci on October 30, 2011 at 11:45am

Ian,

 

Relay pumping has been around almost since the time of the first fire engines.  It is really a simple thing.  Place an engine at the source and pump to the next engine at a high enough pressure to maintain at least a 20 psi residual pressure.  That engine then pumps to the next and so on and so on.  San Francisco FD did a test relay operation several years ago where they moved water through a relay something like 20 miles if I remember right. 

 

There are some specialized companies on the west coast with special apparatus specifically designed to relay water over great distances ofr disasters like earthquakes.  I can't think of the name of the company right now but if it comes to me I will post it.

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Permalink Reply by ian wilcox on October 30, 2011 at 3:11pm

thanks for the input that is awsome

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Permalink Reply by 55 TRUCK on October 31, 2011 at 12:03am

Relay pumping is part of engineer class. It is an old and commonly usec
firefighting technique. I find it suprising that it seems new to anyone.

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Permalink Reply by Terry Canning on October 31, 2011 at 2:02pm

Relay pumping is certainly a long used practice to move water from a standing supply to a location where it is needed, but more recently (particularly in rural areas) has been supplanted by the water tanker shuttle.  In this process one pumper sets up at the water supply (to fill 1500-2500 gal.tankers) and one at the fire with a portable tank(s) to draft water to apply to the fire.  The number of tankers that shuttle between the two is dependent on the distance between the two locations, the volume of water required, and the capacity of tankers available.  In this fashion, if one truck breaks down the flow of water continues.  In the pumper relay, if one truck breaks down, the flow of water completely stops until it can be replaced in the relay.  We have many times moved over 1000gal/min in rural tanker shuttles.

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Permalink Reply by FETC on November 1, 2011 at 11:50am

Getting 1000 GPM uniterrupted RURAL tanker shuttle fire flow is impressive.  What was the distance between the water source and the fire and how many tankers did you use to flow that?

 

I teach an engineer class and there are a few factors that were not mentioned in the response.  These are factors that effect the "uninterrupted" part, for which include but not limited to capabilities of the source pumper's GPM, size and maintenance of the source dry hydrant, use of trucks suction, or two suctions? # of trucks that can be filled at the same time or wait, then you have each individual tankers piping in relation to each tankers fill time, and then we can talk about gravity and jet dump times, or even rear or both side dump capabilities, if you can't get it into the tank quickly (rear only dump) that extends the clock to get the tanker backed in verse pulling up next to it. Each tankers capacity, throw in a 1750 gallon taker in with 3-3000 gallon tankers, the little one is the weak link if they are all spaced out correctly. Then you have OTR over the road travel time, speeds, weather and traffic patterns.   If a tanker breaks down, or has to wait for traffic with narrow one passable lane road this directly reduces the GPM unless they attempt to flow the max and then run out.

 

Back to the thread, we train to lay dual 4" lines between the source and the fire for uninterrupted fire flow when the source is not too far.  Dependant upon GPM needed and distance this is a choice the IC needs to make, long before the fire ever happens. This is done via run cards. We also use 800' rule for an in-line relay pumper to be positioned to continue the flow. Either by breaking the line and jumping in at the beginning or the use of a Z-valve while water is flowing. Our area has reel trucks with 4000-5000 feet of 4" LDH. So if we have a good source, it is not unheard of to lay out a 1/2 mile of dual laid LDH.

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Permalink Reply by Andy Turnham on November 2, 2011 at 5:22pm

Back in the "bad old days" when British fire departments were often one-pump affairs and had no standardisation of equipment, they got around the problem of water relay and miss-fitting couplings by pumping into portable dams (Port-A-Tanks).  The first pumper would draft from the source and pump up the line to a dam, the next pumper would draft from the dam and pump it further up the line, and so on until the water was where it was needed.

Exactly the same method as used by the old hand pumpers!

Back then they never got into tanker shuttles very much, and very few Brigades had large tankers, if any tankers at all.  Even now the preference is to relay pump rather than shuttle.

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