Engineering Update

No.563 is now with our Friends at the Flour Mill. In late June the 563 project manager and Locomotive superintendent visited to be updated on progress and understand what the next steps need to be. 

No.563 appears to be in quite remarkable mechanical condition. The chassis appears to be a freshly overhauled locomotive from Eastleigh.

The slide valves appear to be brand new and the motion looks like it has only just been put up after overhaul. There are machining scraping marks on the white metal bearings that show that the bearings have only just been used as you would normally expect these marks to be worn away with persistent use.

At this stage the locomotive remains on its wheels and we have decided to keep it this way for the time being. The reason being is that we can see what is going on. We will have the wheels and axles ultrasonically tested to check for cracks but taking it off its wheels at this stage wont tell us much. Axle box work is fairly standard work in preservation now and the Flour Mill can quote accurately for this work in advance. We have therefore decided to use the strip down budget to focus on something far more important.

The boiler has the ability to make this project easy or hard. When the cladding was removed, all involved were astonished by its exterior condition. The barrel is externally corrosion free and the firebox outer wrapper is in the same condition. When the tubes were removed, the story continued. The internal initial exam has shown that the barrel is also clean.

So it begs the question why is the outside and barrel so good but the inner firebox is so bad? Is this boiler hiding something that we can’t see?

The boiler inspector agrees with us that the inner firebox requires replacement. We had talked about doing extensive non destructive testing of the boiler to establish its condition. However, the whole team is now in agreement that because the inner firebox is life expired, the best way to examine the boiler is to remove the inner box. 
The boiler inspector can then see everything left. There will be nowhere for any cracks to hide and we will be able to extensively measure thicknesses.
The Flour Mill have advised us that under the authority of the boiler inspector, they will remove the inner firebox as a complete unit from the foundation ring.  Work is planned to be complete on the removal by the end of the summer. It will take a bit longer than planned due to staff leave. We are not aware that this has been done that often in preservation so its a bit of a learning curve, but doing this will allow us to preserve the inner box.
We want to do this because the firebox shows extensive patching that was undertaken to keep the engine in service in its later years. As a historical artifact, it is interesting and we intend to place it on display on the Swanage Railway in future. The work will be undertaken in such a way that should the boiler inspector find anything terminal with the outer shell, we could reinstate the original firebox and place the locomotive on display. Obviously we are hoping this wont be the case, but its careful extraction will give us the option to do so should the SRT wish. Doing things this way will give us one of the most accurate boiler overhaul quotes yet assembled. 
Remember you can still donate to the SRT for the T3 project via the Swanage Railway Trust website.