johnsmachines

machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment. I read every comment and respond to most.

Tag: Fowler R3

Scale Traction Engine – installing a steam powered boiler injector.

My 3″ Fowler R3 Traction Engine boiler can be filled with a hand pump from the tender tank, by a crankshaft powered pump from the tender tank, or by a battery powered electric pump from the driver’s trailer.   The full size original R3 (see previous post for photos) has a steam powered injector, which uses boiler steam to suck up water from the tender tank using a venturi effect, then using black magic passing the steam+ water through some cones, increases the pressure which forces the mixture back into the  boiler.

Here is a link to a YouTube site which sort of explains how the black magic works.

And this is the steam injector on the full size R3 Fowler.

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And this is the injector which I bought for the 3″ scale Fowler.

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It is a vertical injector, with connections for 1/4″ (6.35mm) pipes.  But I did not use it because it protruded too far underneath the tender.  So I have used an identically sized horizontal injector, which is shown below, during installation.  The full size original also appears to be horizontal.   The black fitting connected is the water inlet valve.  The control handle will extend above the rim of the cockpit.

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The red thing is the winch, and its driving disk.  Winch engaging pins have never been completed, another job for later.  The rear wheel has been removed.  The injector pipework passes between the winch drum and the hornplate, with just enough clearance.  Running the pipe around the brake axle seemed like a good idea at the time, but I am not so sure now.  When painted black it will not look so odd.   The water connection with the tender tank is yet to be made, as is the steam supply connection.  A few more hours.

The Boiler Inspector.

Today I loaded the Fowler 3R traction engine onto its trailer and drove to Werribee, to have an official inspection of the boiler.

This is not a legal requirement, because I can operate my traction engine  whenever I please on my own property.  But all model engineering Clubs and Societies require a current certificate before they will permit steam engines to be operated at their meetings.

The maker of my traction engine had the boiler inspected and passed about 18 months ago, but that certificate has now expired.  So it needed re-certification.

The original test pumped water into the boiler at double the maximum operating pressure to test the boiler for leaks and distortion.  The boiler is actually designed to withstand pressures of EIGHT times maximum operating pressure, so the safety factor is reassuring.

But, boiler explosions are horrific, so the caution is understandable.

My boiler is made of copper, thus avoiding the problem of steel boilers which gradually becomed thinned by rust.   And my boiler seams were joined by silver soldering, which, if expertly done is as strong as the parent metal.  As a matter of interest, the maker of my boiler told me that he had used $AUD1000 of silver solder in the construction of the boiler!

The test today involved pumping water into the boiler at 25% above maximum operating pressure, and holding it there for 20 minutes, checking the boiler for leaks and distortion.  It passed that test without problem.

The next test was for the functioning of the safety valves.  I had cleaned them and replaced the balls and polished the seats, and I had seen them blowing off when the pressure was above 100psi, so I was fairly confident that the certification was “in the bag”.

So the fire was lit, and after some coaxing because I had stupidly forgotten to bring the chimney blower,  the  steam pressure was raised to 100psi.  The safety valves started venting off.  But, the test is fairly demanding.  The fire was roaring, the steam blower was turned on full, and the pressure continued to rise.  It rose to 120psi which fails the test because the safety valves should have released enough steam to keep the boiler pressure at 100 psi or 110psi maximum..  Some adjustments to the safety valves did not fix the problem.

Some machining will be required to fix the valves, but after consideration I have ordered brand new safety valves and the test will be re-done when the new ones are fitted.

The boiler inspector was quite particular and proper, and very helpful.  I am grateful that this safety issue was detected, and I totally agree that it has to be fixed.  Thinking back to my problem of about 1 month ago, when I “dropped the fire”, (see “Holes in Swiss Cheese) I now believe that the problem was partly caused by the inadequate safety valves.

Add one more hole to the Swiss Cheese theory of disasters.

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The inadequate safety valves.

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FOWLER R3 TRACTION ENGINE

Start of the parade of tractors at the Geelong Show.   Graeme and John driving the Fowler R3.   Video by Stuart.

 

Fowler R3 at The Geelong Show

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I took my Fowler R3 3″ scale traction to the Geelong Show, and here it is on display.

The R3 is a bit of an uncommon traction engine, so I was rather surprised, delighted and awed to find a full size R3 on display also.  Of course I met with the owner and spent a lot of time talking to him and examining the real McCoy Fowler R3.  Apart from the size difference, the similarities were striking.  Even the colour scheme was similar.  And the full size machine was a heavy haulage model whereas mine is a road locomotive.

I found the numbers were interesting

weight     250kg/18tonnes

length 1.5m/ 6m

towable load 250kg/60 tonnes

cylinders 2/2

boiler pressure 100psi (copper)/180psi (riveted iron)

year of build 2016/1911

 

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Me, getting a driving lesson from the owner, Graeme Brown

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The firebox door, throttle, looking forward

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Winch

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Forward/reverse lever

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Water pump, crankshaft driven

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crankshaft with its cluster of big ends and valve rod eccentrics.

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Con rod big end hardware

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Fire box door and water level sight glass

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Fowler R3 heavy haulage engine.  spent most of its working life in and around Ballarat, Victoria, Australia

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Rear wheel hub and winch

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This could be a photo of my engine, but it is not

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Lubricant and tool storage area.  Actually the front suspension and steering drum.  I imagine that the springs are to protect the  gear teeth.

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Not sure that the brass cylinder cover is kosher.

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The wheels hardly dented the grass during the grand parade.

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The engine mechanicals, oiler, whistle, and hose support.

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Boiler inspection hatch, and water intake.

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Belly tank, steering gear

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The engine could be used as a cathedral reliquary

And a series of non-edited videos, to recapture some magic moments.