(warning this may be a picture rich ramble)
It returned to service initially in black but was repainted in fully lined maroon in time for the 2005 Vintage Weekend.
Over the last ten years its worked every season and has done over 90,000 miles. In that time I have driven it for quite a few of those miles. 3000 in the last four years.
This season I have driven Merddin for 840 miles and its still the best of the three Double Fairlies.
All good things come to an end (or should I say a pause as I will explain).
Locomotive boilers receive an annual inspection that involves pressure testing and visual inspection with a variety of mirrors on stick, endoscopes and ultrasonic testers whilst cold and then a further in steam inspection. This is all done non-invasively so whilst we remove inspection covers and other fittings we don’t take the structure of the boiler to bits.
This has limits as you can’t see all its little internal bits so it is decreed that every ten years it has to be taken apart for a much closer visual inspection of its internal bits.
In the last week I have driven Merddin Emrys for four days out of a five day visit (well only 3 really but you’ll have to wait for a following post for that to be explained) and yesterday, Sunday 13th September I drove it for my last two trips of this boiler ticket and put it back in the shed with just one day left to run.
Its quite hard not to be sad at it going out of traffic as its a favourite of the loco crews and the best performer right to the end of its ticket. At the moment we run a service that uses two of the three double engines each day and as if just to highlight the vulnerability of just having two to choose from the Earl of Merioneth failed on Saturday morning. Not in a long term way but enough to put it out of action for the weekend.
As I have been typing this blurb the photo below appeared on the Ffestiniog Railway Society Facebook page of Merddin Emrys arriving back in Porthmadog with its last train.
Right enough of the sloppy nonsense – lets get on and mend it!
Often on many railways the end of a ten year ticket will see the engine join the back of the overhaul queue and not be seen in steam again for many years. Not in this case. The overhaul starts tomorrow! Ten years ago the boiler had major works done to it and actually went off site to the premises of Israel Newton in Bradford.
The problem with the boiler then was cracking of the throat plates as you can see in this picture where the cracks have been ground out for welding. They had been ground out and welded at least two time previously but the cracks recurred. Actually after this shot they weren’t welded and as the cracks were spreading and a full repair was authorised.
Firstly, it was important to understand why the cracks were occurring and investigations showed that these boilers lacked sufficient longitudinal stays higher up in the boiler whilst being quite rigid lower down. Heating and cooling was causing the boiler to flex and the areas where the cracks started, right on the shoulders didn’t have enough give to allow the movement and so cracked and would keep doing so until the staying issue was addressed.
First thing to address was the staying. New longitudinal stays were added running from the smoke box tube plate at one end to the one at the other end. Handily I have some photos taken when it had one of its domes off (don’t ask, that’s another story) that shows them.
In this photo the longitudinal stay is labelled E and there is another out of shot to the right. Also added were firebox longitudinal stays in the raised top firebox, labelled A. [the other bits are B – compensation ring, C girder stays on the top of the inner firebox. D, the inner firebox]
With the cause of the cracking dealt with the next job was to fix the cracks themselves. The material having been ground and welded several times was deemed to need replacing. This is no mean feat as, to use Airfix kit terminology, the throat plates are parts 1A and 1B.
Newtons actually made two complete throat plates as that was easier than trying to makes sections of them. These were then cut to give the sections of plate to be let in to the old ones. In this one here, which is the drivers side top end, same as in the `cracked’ view its been bolted into place before being welded to the adjacent bits of throat plate and then riveted to the barrel and firebox wrapper.
All four corners were done with differing size patches and also some section of the bottom of the barrels at each smoke box end were built up and re-riveted. One of the pluses to this amount of work is that with big holes in the boiler you can have a good look inside and the rest of it was in good order.
When the boiler was returned to Wales it was craned back into the cradle and there was very nearly a whoopsie when we forgot to allow for being round the 180′ curve in Minffordd yard and we nearly had a right hand drive Double Fairlie.
Once in the cradle, which you can see here isn’t that substantial, the loco was returned to Boston Lodge to be put back together.
It doesn’t have to come quite this far apart for this 10 year exam and overhaul but it will be not far of this state in the next few days. The plus of all this access to the inside and doing all the major work ten years ago means we are reasonably confident that there aren’t any major issue looming (although you can never be certain with boilers)
The plan is to have it back in traffic for next season and the overhaul will be starting right away. All the long lead time items are in stock at Boston Lodge including the rolled stainless steel and end plates for the new smoke boxes and the tubes (they even ordered enough for both ends this time – don’t ask) are on a rack in the erecting shop. There is a hope that the cladding will be back on the re-tubed boiler for Christmas which would be excellent but it depends what else crops up. If the other two behave themselves then the fitters won’t get distracted but they have a habit of attention seeking if ignored. The body work will be going on for a repaint then.
The power bogies will be getting an overhaul over the winter and this may actually take the longest but it is just routine stuff. Merddin Emrys should be back for 2016’s High Summer service.
Victorian Weekend 2015
October 9th – 11th 2015 Details Here
It is going to seem odd this year not having Merddin for the Victorian Weekend this year but it will still be well worth a visit. It seems to grow in support each year with more people coming in period dress and more and more of Porthmadog joining in with period dress and decorating shops.
Last years event can be viewed in this video