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ModelWorks Pride of Penrhyn Overtype Steam Lorry A Cart for my POP
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2nd January 2005:
With no boiler to keep me occupied over Christmas I had to find something
else to do between the unusual excesses.
The lengthways beams are 5/8" sq by 2 foot. The front cross beams are 1 1/4" x 1/2" supporting a 1/2" thick plate providing the fork pivot. In an attempt to
reduce weight and make it more aesthetically pleasing I have begun to
profile some of the sections. Monday: Today I profiled the front axle. The picture right, shows the front axle prior to profiling. The front axle was formed from 15" of 1" x 5/8". Pictured below is the finished result. It took a while but I was able to reduce its weight from 2.2 lb to 1 lb. The finish was not as good as I hoped but the milling practice will be useful for future projects.
Wednesday 19th January: Today I completed manufacture of the parts for my cart. It has taken a while but I would other been kicking my heels as there is still no sign of the boiler for the Burrell. As it has become the custom I have included a team photo of all the parts and unlike the POP and Burrell this is all my own work!
I have been musing on the water tank and have decided to go for a tank below the top board between the frames. I am hopeful that I will be able to find a way to use the POP's crank driven pump to suck water from it. My plan is to install a 3 way valve inside the main tank so I can switch the pump to take water from the cart. If this fails I will make a steam powered water lifter to transfer water between the tanks.
My original plan was to silver solder it but as soon as I brought the brazing torch near the brass plate began to distort. As there was no way I would be able to heat the whole tank to a uniform temperature I abandoned this approach and assembled the tank using slotless 8 BA brass screws. I then soft soldered the joints to make the whole thing water proof. I plan to fill the tank through a spout in the lid (see photo above). I will cut a hole in the cart's base board thought which the spout will protrude. As the tank is quite long I have include a baffle near the front in an attempt to stop water sploshing out through the spout. Today I etch primed the tank in readiness to give it a top coat tomorrow. I don't know whether my plan will work but I hope to be able to suck water straight from cart's tank, time will tell. The valve will have a body with three
ports at 120 degree intervals with a valve block in the centre that can be
rotated so as to connect any two ports. The only tricky step was machining the
working surfaces of the valve to ensure a perfect fit. Without
disturbing the setup I bored the valve body and machined the tapered valve
block . I milled the passage in the valve block prior to
machining it's taper. I was then able to use the machined valve body
as a gauge so that the valve ports aligned with the valve block's passage.
To enable me to see what was going on With the inlet clack cleaned, the pump began to work. Strangely it worked far better when drawing water from cart than drawing water from the main tank. I ran the pump for some time hoping that things would improve, they didn't. I have used clear tubing between the cart and the POP and I could see that the water was being forced partly backwards (small bubbles in the water). I also noticed that pump was not developing a lot of pressure so it is clear that until I fix the pump's inlet clack that there is no point steaming. I have had trouble in this area since day one so I will spend some time to see if I can get to the route of the problem.
My
attention has now switched to making the cart more presentable. My
plan is to make drop sides for both the cart and POP. This has been
made more challenging by my transport arrangements for the cart. There
is not enough space in my Rover 25 to accommodate the cart with the side
attached, so the sides will have to be completely removable. I have
built a The corner consists of several steel components silver soldered together with the aid of jigs to ensure alignment. I am now partway though series production of 8, hopefully, identical corners. I am in a rush as I would like to finish in time for a rally I am attending in three weeks time.
Thursday 14th July: The cart is finished! What started as a Christmas project has taken me six months to complete. Now that I have finished I am very pleased with the results. I have also added drop sides to the POP together with a cushion.
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I have been planning to build a cart for some time to carry additional water
together with coal and tools. I am surprised at how much water POP
uses and would like the cart to be able to carry several gallons. I
have not finally decided whether to carry the water in an under slung
tank below the base board or in a barrel on top. While an under
slung tang leaves the top "free" gravity can't then be employed to
transfer water to POP. 
So
far I have built the basic frame. I had planned to use box section
tube but when it came to it I opted for solid mild steel. The down side of
using solid is that it has made the fame very heavy. 
Friday
18th Feb: I have not been completely idle whilst waiting for the
Burrell's boiler. I have pressed on and made the under slung tank. The
tank is constructed from 0.7mm brass plate and is 16 1/2 inch long and will
hold over 2 gallons. 
Saturday
19th March 2005: 
...
Friday
25 March: I removed the side tank and made a new exit hole at the back of the
tank. I was hoping to support the valve on the pipes but it
immediately became apparent that this was not on as the valve is relatively
tight. I improved the situation by marking a simple bracket fixed
to the base of the tank.
to
the POP and connected the carts tank to the new port on the POP feed water
system.
I
did not want to steam POP so I connected up my compressor. I have a
spare connection on the steam manifold used for the original whistle.
and
to avoid getting the boiler wet I disconnected the pump's feed to the
boiler. As I feared, on starting POP, there was no sign of water
irrespective of which tank I selected. By disconnecting the pipe to
the pump I was able to demonstrate that there was nothing wrong with the
water supply to the pump so the problem was in the pump itself. 
Monday:
I removed the pump and retired to my workshop. I had consulted Martin
Evans book "Model Locomotive and Marine Boilers" to determine the
correct proportions for a clack valve. This suggested a ball lift of
1/32" To enable me to observe the inlets valve lift I removed the
bypass banjo from the side. Unexpectedly I could immediately the
source or the problem - when I reassembled the clack valve yesterday I
failed to get the ball bearing on the valve seat - it was pushed off to one
side - no wonder it didn't
work. With the ball bearing back in it correct place I checked the
lift and discovered it was only about 10 thou. Perhaps this is why it
clogs so easily. By introducing washers I was able to increase the
valve lift to 30 thou.
prototype
corner in which the corner post and sides are removable. 
Saturday 9th July:
Series production it was! I have made 54 separate hinge components
sufficient to fit drop sides to both the cart and POP. Each component consists
of two or more metal parts silver soldered together. It is fortunate
that I have retired as this has be a full time job for the last two weeks (briefly
interrupted by Burrell 
