The project So Far
Steam Tunneltug Hasty

 

Boiler Feed, Water and Vacuum Pumps

All pumps were bought on eBay and have been chosen for their performance at low speed, robust design and ease of maintenance. The fact that they all have quite a lot of moving parts also adds to the interest and their aesthetic value.

The Boiler Feed Pump

 

This is a 3 piston pressure washer pump by speck. It was made around 1980 and has an output of 12.6L at 1460 rpm. I chose this pump because it is small and very well engineered. All of the wear parts are either available as off the shelf standard parts or are simple to reproduce on a small lathe and milling machine.

 

As you can see I have fitted a by-pass valve which is set at 175psi. This is because I intend to have a maintenance  isolation valve between it and the boiler. There is also recirculation pipe that can be adjusted to either regulate or stop the flow to the boiler if needed.

 

I have decided that, as I am using black iron fittings and pipe, a filter should be installed on the pump inlet. This doesn't need to be anything fancy and so I will use a 1/2" bsp "Y" strainer. This has the knock on requirement for an isolation valve before the filter to stop the contents of the hot well pouring out when the "Y" strainer is opened up for cleaning.

The Vacuum Pump

 

I believe this to be an American made orchard sprayer pump but this is open to debate as there are no makers marks or any other means of identifying it's origins. It has 3 pistons all with a bore and stroke of 2" and at 60 rpm it quickly reaches 25"hg but more importantly it holds that vacuume for about 10 minutes before it starts to drop. The red sprocket on the side is just so that it can be turned by hand for test purposes, when installed it will be driven by chain from the crank through a short line shaft to the large grey sprocket that can be seen at the bottom

The Water Pump

 

I guess that most people would recognise this as the increasingly rare Lister H4 pump. This picture was taken before it's overhaul which should be finished in Sept 07.

 

Besides a good clean up and painting in Hammerite Satin Dark Grey (Which ICI have now discontinued) to match the rest of the machinery this pump will benefit from new PB bushes all on the axles and connecting rods, new small spur gears to drive the crank wheels, all new rubber valves and a reground piston (possibly)

 

The overhaul will be quite straight forward and due to the basic design, all of the most likely wear parts can be simply remade if they do need replacing in the future.

This pump weighs approximately 125kg which will help with the excessive ballast that will be needed on the boat to get the 31" diameter prop under the water.

 

26/08/07, The overhaul is progressing well apart from the new small spur gears are very tight and making a lot of noise. As far as I can tell due to the new teeth running on the old worn teeth of the larger crank gears. The uneveness of the wear on the large crank gears caused by the varying load of the crank position is shockingly evident.

 

As a small note, I worked the gears out to be 10DP but if anybody has any other knowledge about this, please contact me.

 

Video of the first test run of overhauled pump

 

 

 

 

The Pumps