The Diary of the Building of a 5" gauge Stirling Single

    

Steam Test 2025
28 August 2025
It is a requirement of MMES that ones locomotive has a Boiler Steam test, repeated every 4 years, part of which is a repeated  Hydraulic Test. This is a hydraulic test, this time with all of the fittings on essentially this is carried out when the loco is ready to go, but with safety valves plugged. On my loco the plug for the safety value has  a 1/4” x 40 male thread is required to attach to the test pump. The boiler is pumped up to 1.5x working pressure, assuming it reads to a high enough pressure, ideally with the pressure gauge still attached, with my boiler the pressure required to be held for a period of time is 80 x 1.5 = 120 psi.
Once the hydrostatic test has been passed a steam accumulation test is undertaken to ensure the safety valves lift at the correct pressure, at the RED lin on the pressure gauge, that injector(s) and water pump(s) can maintain the minimum level of water in the boiler..

I arranged a boiler test on my Stirling single locomotive for the 27th of August 2025, I would normally have tried to test out things to find any obvious leaks, but it was suggested I just take the loco along to the club and the boiler tester will do what he can.

The time and date arrived and the test commenced with checking the pressure gauge to comply with the necessary red line at the working pressure, the test was passed successfully.

However, the hydraulic test did not go well and no pressure could be raised on the test pressure gauge due to leaks, particularly on the regulator and more in the smoke box and also down the rear of the boiler
So I now have the loco back home and preparing to find where the leak is come from and take photographs and then cure the leak problems
The first thing I will do is to remove the cab so that I have easy access to all of the fittings on the rear of the boiler.
29th August 2025

With the opening into the smoke box being very crowded I decided to locate my Endoscope and check out how it works. I originally bought this back in 2019 when I was having problems with leaks the first time round.
I found it in my shack and checked it out and we pleased that I could locate a operating manual on the web so that was printed out and will be kept in the Loco Toolbox.
I was pleased to learn that the unit has an internal battery which needs to be charged before use and my iPhone already had the App loaded. All checked out well and I was able to set the resolution to 1920 x 1080px.


30th August 2025

From earlier in the build I had to make up an adaptor to allow the nuts to just fit in the 5BA socket and the adapter to fully tighten. So that job for today is to locate this adaptor to save me having to make another one !!



To remove the cab of the loco, four 5BA nuts had to be removed from the decorative handrails and two brass bolts from the rear of the cab floor The cab could then be lifted clear

The pressure gauge which had been removed for testing, was then refitted.
To remove the cab of the loco, 4  5BA nuts had to be removed from the decorative handrails
These are located just below the window and just behind the pipe n right hand side.


The cab nuts in the left hand side just to left of water gauge top fitting and just to left of lower fitting.


The bolt is to the rear of the right hand side and similarly on left hand side of the cab. The bolts are threaded into the floor.


Two brass bolts from the rear of the cab The cab could then be lifted clear

The pressure gauge which had been removed for testing, was then refitted.


31st August 2025

My new supply of V-tech high temp silicone gasket maker I am ready to tomorrow open up the smoke box end of the regulator as shown in the photo.
You can see how sooty it look so all of that will need to be cleaned up before removal and then refitting.


1st September 2025

This shot show the blanker cleaned up a bit


Now with the retaining bolts removed


This shows the reverse side of the blanker complete wit "O" ring which needs all to be very much cleaned up.


This shows the regulator in the open position with the exit hole fully uncovered
Regulator closed but I think it is not fully closed but I will try to get a better photo tomorrow.
Even with the chimney removed I still could not get a good view of the regulator position !!!
2nd September 2025

Looking again at the valve which this photo shows and putting the cover back in place it was found that when the regulator lever was moved to the closed position that it knocked on the cover plate.

New gasket material and "o" rings have been ordered so that a ticker gasket can be made to bring the cover fractionally away from the header unit.

I think I may make up a new blanker with out the "O" ring  and then it must be well clear of the valve which is closing.
3rd September 2025

The supplies of cleaner gasket paper and "O" rings arrived.
 So for tomorrow I can start on a good clean up inside the smoke box and make up a new blanking plug and of course take photos !!!.
4th September 2025

A start made on the cleaning up of the base of the chimney and inside the smoke box and now allowing evaporation of the cleaner to escape.
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