I have noticed that some locomotives, especially those used in logging operations, have duplex pumps mounted either on the locomotive or tender. Are these pumps being used as feedwater pumps? I would imagine that a duplex pump mounted on a tender may be used for filling the tender tank. I'm also rather curious as to how that would work. How would the suction hose and pump be primed in this instance?

So I'm just generally curious as to what people's experience has been working with duplex pumps on locomotives, and if they are worthwhile to use as either a backup feedwater pump or as a way of filling the tender tank.

Rick,

On logging locomotives the duplex pumps were usually for fire fighting. They drew water from the locomotive tank.

John

Someone fill in the details, but I think the main issues are

1) an injector can move a much larger volume of water in time than a pump, in a much smaller space, with fewer parts to maintain.

2) the injector heats the water.

3) however, the steam consumption per gallon of water pumped is better, lower, for the pump than the injector. The pump is more "efficient" in the quantity of fuel burned to pump xx gallons of water. So on marine and stationary installations, where weight and space are available, the pump is preferred for its economy.

What prompted my inquiry was seeing a duplex pump on a traction engine yesterday, plumbed in to pump water into the boiler. It did not have any feedwater heating ability whatsoever, so I can't imagine that it would have worked very well.

I had not considered the firefighting use prior to now.

I think many were used to function as a mobile pump for different services along the line, but a fire pump is usually an obvious answer. Two that I have worked with were used to pump oil into the tender for fuel, and I'm sure situations arose where moving material from one tank to another, in close proximity to the track, would have been easily done with a pump.

When I was in Guatemala back in the early '90s, the cantankerous steam pump on the deck of the tender tank (which was mostly operated with a hammer) was used to pump water from the aux tender into the locomotive tender. I would imagine the pump would be used to pump water into the tender tank from a pond or stream as well.

R.C. Whitehead

Rick,
Many traction engines had single or duplex pumps as original equipment and they also had feedwater heaters. Over the years many of the pumps and many of the heaters fell victim to the hard water syndrome when not properly drained. I've seen a fair number of engines whose heaters had been removed and straight piping employed. Not having the heater is a great thermal loss as well as tough on the boiler but since they no longer have to work for their supper, the situation is seen as "OK" by at least some. mld

As John T said they are primarily for fire fighting, and I've used one for this purpose myself once! These pumps were quite commonly used in logging shows for a variety of tasks. On most logging locomotives here in BC you would have seen several lengths of fire hose coiled up somewhere convenient, sometimes wrapped around the sand dome. Another use I've seen is to pump water from the locomotive's water tank into a spray bar mounted on the foot boards to water down the track in times of high fire risk, this would also be used to spray down trestles. It was also common to see these pumps mounted on tank car running boards for either moving water or fuel oil using steam from a locomotive. I've also seen loco's set up to draw water from a convenient river or lake using either a duplex pump or a steam syphon.

Pat Hosford

There will be a duplex pump and a hose reel going onto the tender deck of the Saginaw Timber No. 2 at Mid-Continent. Better to be ready for any eventuality.