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.

"I'm Still Here"

After some considerable time without any blog posts, I'm hoping to do some catching up.

My original intention was to record the restoration activities of Joyce so that I would be able to refer back later - it's easier and quicker than actually dismantling an assembly to recall what I did years before. For me, it has been useful on many occasions; I hope it has been helpful to others too.

Of course, the restoration finished in earnest in 2016 when Joyce began pulling passengers. I didn't want to just show pictures of Joyce in action as many others have done that better than me (it's difficult to take good photos from the driver's cab!).

Joyce has been pretty reliable for a steam locomotive but she's kept me on my toes to achieve that. Having J R Goold Steam Ltd close-by has been a godsend for rapid repairs and I am very grateful for their amazing support in times of need.

There have, however, been a few little problemettes...

Here was an unwelcome sight one Sunday morning in May 2021 while getting ready for passenger train duties.

Tell-tale Jet of steam

This was a pin-hole in the main steam pipe feeding Joyce's rear engine. Needless to say, she didn't run that day.

Pin-Hole

I contacted my Goold support team and a new pipe was made then lagged and fitted by me in about 8 days.

New Pipe

The new pipe fitted perfectly. Godsend is the right word.

Ready to go again

How are the new fire-bars performing?

I'm glad someone asked me that. Perhaps a video clip will help... 

I hope you enjoy this.

I guess the answer is... Grate!

Not So Grate!

Most of the Sentinel 7109 articles I've written in this 'blog over the last 8 or so years have been fairly upbeat although I did get frustrated with gland packing not so long ago.

However, not all goes as well as I'd like and I've had a new downer to deal with. I've shown the photo below a number of times to illustrate the how the fire-grate began.

The Fire-Grate as new prior to first steaming in 2016

With an eye on environmental issues, at the beginning of 2019, at Midsomer Norton, we began using a cleaner Welsh coal. All seemed fine for some months and I did the usual half-yearly boiler and fire-box washout in August. However, shortly before the start of the four Santa Specials in December, the centre section of the fire-grate decided to disappear spectacularly as shown below.

Fire-Grate after cleaning at the start of December 2019
(After the first of four Santa Specials)

(This was the reason a diesel shunter was used as banker for the Santa Specials).

Obviously this was not great news and the timing was particularly inconvenient.

I've had to dig deep to figure out how this could have been caused to prevent it happening in the future. I think there are basically two causes, both to do with the coal.

The Welsh coal is clean; it produces very few 'volatiles' (the nice-smelling but smoky stuff) and burns hot. It also tends to disintegrate through agitation and during combustion. In either case, it forms a lot of 'dust' which sits around underneath the coal nuggets. Our nuggets were large, some about the size of three fists.

The dust tends to form into clinker and block the grate in places. Air then has to be concentrated through the remaining unblocked areas and causes hot spots which melt the fire-bars, a bit like a blow-torch. As the year progressed, the coal in our storage bunker became more dust than nuggets and so the amount of grate blockage increased as the year went on and finally precipitated the damage.

Anyway, in summary, that is my interpretation of what happened. All we have to do now is to prevent further damage and replace the fire-bars.

Traditionally, fire-bars have been made from grey cast iron. However, I've had advice that a 20-30% alloy of Chromium and iron is much longer-lasting than plain old grey cast iron.

I've taken this advice and, to be ready for the first 2020 steaming on March 22nd, I rapidly placed an order for a pattern to cast the new fire-bars from Chromium Cast Iron (the pattern has to be specific for the material as the metal would not cool to the right size otherwise). I had to purchase a minimum quantity of 30 fire-bars (which should keep us going for a while!).

The bars arrived just ahead of the delivery date and I am grateful to the staff at Cerdic Foundries Ltd for their help in a time of difficulty.

Quite a car load!

I've not tried a funding appeal before but this is one occasion when I think it is the right thing to do.

Including VAT, the pattern will be £2,400 in round figures - I have bought this.

Including VAT, each of the 30 fire-bars is £120 in round figures.

Please consider donating a fire-bar for Joyce. Donations can be made via PayPal or cheque (preferred as PayPal takes a percentage) by clicking here. I would be more than happy to entertain donors with a cab ride on your next visit.

Go on, you can do it! Thank you in anticipation.

Hooked

As Sentinel 7109 progresses through its new working life, I run into many little irritating operational problems that can be solved quite easily. Filling the water tank is one.

We use a 6-wheeled tanker wagon as reservoir. It's simple to fill the tanker slowly from a domestic supply tap when there is plenty of time. For rapid watering during operations, we use an impeller pump at the tanker to pump along sections of flaccid hose linked by claw couplings to Joyce's tank.

The trouble with a flaccid hose is that it's flaccid. It flaps around merrily in the top of Joyce's tank while filling and is partially blocked by the weight of the tank lid sitting on the hose to prevent it from jet-propelling itself out.

I made a more resilient hose extension to overcome the problem.

Not-so-flaccid hose extension

It neatly hooks over the tank filler rim and doesn't get squashed by the lid.

Simple but effective

Hopefully, we also won't get quite so wet when the tank overflows (which never happens, of course!).