Steam at the end of the Tunnel...

It's been a long time since Joyce's original superheater (SH) blew a hole in June 2022. Getting a new one up and running has not been easy but I'm now only a few odd jobs away from being ready to do a test firing.

Despite all the difficulties, I did eventually receive the SH but it arrived as a poorly assembled kit of parts.

I'm very grateful to my friends at the North Yorkshire Moors Railway (NYMR) for helping me with transport logistics.

On initial examination, it was obvious that the coils were not secured properly; they had shifted and were no longer properly supported.

These photos illustrate the point.

Centre of photo shows coil clamps (Upper is displaced)

Coil spacers poking out on one side correctly...

 

...But not on the other side

RH bottom clamp out of line and not supporting inner coil

I did of course make this known to RBS but was assured that it was fine when it left them and denied all responsibility.

Let's consider this:

1. It's a superheater required to operate in a very harsh environment whilst being continually shaken, rattled and rolled by the surrounding steam loco. If it cannot survive a ride in a van, it is not fit to be in a steam locomotive.

2. On collection from RBS, I was told by the NYMR driver that it had been unceremoniously dumped outside RBS leaving the driver no option but to borrow a fork lift truck from a neighbouring company to put it into his van. 

These photos were taken at NYMR on my collection visit.

My first view of the completed unit

Same location - the clamps were already displaced
Note the SH spreader plates tied on, not fitted

Welded locking bar

So why had this happened?

I removed the two welded locking bars and loosened the two supporting struts and did my best to pull things back into shape. However, I had limited facilities and could not make any impression on it.

I did however try taking off the top plate and substituting ½” spacers under the large nuts. The idea being that with the top plate out of the way, I would have better access to pull things into shape. But to no avail.

It was at this point that I realised why the coils had shifted. When I tried to tighten one of the clamping brackets with the ½” spacer present, I found that I could not tighten the clamp down on the coils because the nut had reached the end of the threads on the supporting strut.

As such, with the top plate in place, it would not be possible to clamp the coils securely.

In the next photo, the fixing rods are shown protruding through the brackets but there is insufficient thread to tighten the brackets and secure the coils.

Limited thread on the struts

My conclusion at this point was that, although the coils were actually pretty good, the unit as a whole was not fit for purpose - certainly not the ready-to-drop-straight-in item I had ordered.

So what next? 

When I had originally begun looking for someone to make the new SH, I started with JR Goold Steam Ltd whom I had worked with during Joyce's restoration. They were unable to do the tube bending, however, given completed coils, the job was now well within JR Goold's capabilities. They had also done the same work first time round during Joyce's restoration.

(Check out https://www.gooldsteam.com/sentinel_superheaters).

I was certainly not prepared to continue with RBS for obvious reasons. (https://sentinel7109.blogspot.com/2024/04/renewing-joyces-superheater-1.html).

Initially I discussed the problems with JRGS referring to a Sentinel boiler drawing similar to Joyce's and photos of the problem shown above.

These were my requirements:

1. Flatten the top plate so that the funnel bases will seal properly. There is a dip in the middle of the cross-piece at present.

2. Make the necessary spacers to hang the SH coils properly from the top plate.

3. Reassemble the tubing and top plate and tighten the coils in place.

I also provided some dimensions as to where the tube flanges would need to be should any adjustment be necessary.

A few weeks later all was complete and I asked Peter Hawkins, Joyce's boiler inspector since 2009, to examine it before accepting from JRGS. All was well and a preliminary certificate was issued covering the work and giving me the go-ahead to reassemble all into Joyce ready for a test steaming to check for anything untoward. A formal inspection run would follow as in previous annual inspections. (The test run is to make sure that all is well - Boiler inspectors still have to be paid even if they don't issue a certificate).

The final unit from JRGS

Clamps holding the coils correctly

New spacers supporting coils on one side...

...and on the other

Clamps in line and supporting the coils

The unit followed by the funnels was craned-in with help from local company R J King Ltd. Their driver, Paul, had craned in the entire boiler back in October 2011 and so it was almost a repeat performance for him.

Sky Hook?

And seated!

Watch this space.