A Ffestiniog Experiment: part 2 Merddin Emrys gets a makeover

[David B]

A few years ago, I booked a driver experience day on the Ffestiniog Railway. I’d asked if it was possible for Blanche to be available, as I’ve never forgotten my first trip up the line as a teenager in the early 80s. We’d been on the Tal-y-llyn, the Fairbourne and the Vale of Rheidol, and they’d all been enjoyable, but a bit dull. Then my brother and I turned up at Porthmadog and found Blanche simmering at the head of 8 carriages. From the moment the whistle blew and I heard that staccato Hunslet exhaust beat rapidly accelerating us across The Cob, I was hooked. When we turned left at Boston Lodge and started hammering up the hill with a sense of urgency that the other lines had all lacked, I knew that the FR was special.

So I was unexpectedly disappointed when the FR rang me to say that Blanche was unavailable, but I could have Earl of Merioneth for my driver experience day instead. What a fool I was - the experience of driving EoM up the gentle climb to Tan-y-bwlch and then through the Aberglaslyn Pass and up the savage 1 in 40 to Rhyd Ddu was amazing. I had to make a live steam model of it. So in this thread I’ll set out how I used the scale drawings in this excellent book:



plus sheets of 2mm mild steel and 1mm brass, as well as live steam components from Roundhouse Engineering, to make this:



Via this:

 

[mickoo]

I didn't realise this was live steam, that's an added bonus

It's something I've considered as a fringe anorak but not yet got the skill set or tools to accomplish it.

 

[AJC]

That looks rather special, David. The unique styling of the Earl is something I’ve never quite learned to live with but has character and presence: there aren’t many steam locos with such a ‘70s aesthetic. I’ll be intrigued to see how the mechanics translated into the small scale.
Adam

 

[Scale7JB]

I didn't realise this was live steam, that's an added bonus

It's something I've considered as a fringe anorak but not yet got the skill set or tools to accomplish it.

I had realised it was Live Steam, but not that the OP had built it

Fantastic!

JB.

 

[David B]

Thank you for all the Likes and comments . It’s only fair to point out there are several areas where my EoM deviates from the prototype, aside from the fact that it’s 19 times smaller and it’s operational in the 2020s and not sitting dismantled in a shed . So here are the main differences:

- the loco is fuelled by butane, and not coal or oil
- it has two separate boilers, rather than one
- there is no continuous firebox in the cab (yet) - I designed the model before Roundhouse Engineering produced their David Lloyd George, which has a much more elegant solution to the internal pipework and controls. I’ve tried fitting a firebox overlay, but it chokes the burners by restricting the airflow, so that’s still a work in progress. Fortunately the Earl has small side openings to the cab, and the driver and fireman help to create the necessary illusion. More to do there though.

In operation it resembles the real thing by riding very smoothly, pulling everything I’ve managed to hang on the drawbar (it barely notices 14 bogies weighing 30kgs) and it steams very freely. In answer to some of the questions on the other thread, it’s just over half a metre long, it weighs 7.5kgs and operates at between 20 and 40psi.

So (to quote a suitably Welsh bard), to begin at the beginning. I sourced most of the live steam components from Roundhouse Engineering and needed to work out how to make them fit. I’m no engineer, so I went back to my old 7mm days when I used to scratch build diesels and made lots of templates from styrene, card and paper. Here are the work worn final templates for the running board, the boiler wrappers and the cab upper body:



I made many errors along the way - for example, this was my first attempt at bending the cab upper body, where I managed to misread my own template and put the first bends in completely the wrong place…….



D’oh! It still sits on the workbench as a reminder that this is Bodgeton Lodge Works.

David

 

[Scale7JB]

Piqued my interest, more please..

JB.

 

[Chris Veitch]

I’m no engineer

Well, you managed to disguise that very well. Having been burnt and bruised by the original on a few occasions, I'm also keen to know more.

And is that really a page torn from Fairlie Locomotives of North Wales?

 

[Scale7JB]

Just a thought, would the real EoM count as the first ever ‘new-build’ loco?

JB.

 

[David B]

Well, you managed to disguise that very well. Having been burnt and bruised by the original on a few occasions, I'm also keen to know more.

And is that really a page torn from Fairlie Locomotives of North Wales?

Good spot Chris - even I wouldn’t rip a page out of that book! It’s a photocopy enlarged to scale (and now looking very tatty!).

 

[Dog Star]

I asked and you have provided, thank you.

regards, Graham

 

[David B]

I’ve just realised that including the photo of the drawings was probably testing the laws of copyright, so I’ve removed that photo and referred to the book itself instead (thanks to Chris for making me think of it).

Next up, here is the first test of the Roundhouse Engineering live steam components on the 2mm mild steel running plate, which I laboriously chain-drilled, cut and filed to shape once I was happy with the styrene template above. Getting the ride height correct was tricky, because the flanges are perilously close to the bottom of the boiler when going round bends which make Tyler’s Curve look generous. The bogies, which are from Roundhouse’s Taliesin model and are lovely pieces of kit, are bolted to brass mounts with large diameter rubbing plates to provide the stability needed for this very top heavy beastie. That took a lot of experimentation. It’s a bit different from buying in the motor and gearbox for the kind of models I used to make in 7mm…..I am in awe of people who can manufacture their own live steam cylinders.





The smokebox is a Roundhouse casting which was the right diameter, but needed shortening. I’ve also sawn off the bottom of the casting and ground off the details on the face. The chimney is a thick-walled brass tube which I turned to a tapered profile.

 

[simond]

This is great.

I enjoyed 16mm for many years and started, but failed to complete, a Mountaineer, based on scaled down drawings from the 3.5” one published in ME when I was a kid. I moved back to 7mm some 22 years back, when we moved house and the garden railway was dismantled. I did have an R/C Prince, and a selection of battery locos, including a Wrightscale Baldwin, which was a lovely kit, and a decent selection of rolling stock built from Tenmille kits and scratch.

looking forward to seeing more!
Simon

 

[Dog Star]

David,

The photos of the frame and bogies show an impressive beast in the raw. Please continue with the story in a similar style, maybe with more on the construction details.

regards, Graham

 

[Giles]

I DO like this........!

 

[Steve Cook]

Great work David and clever use of the Roundhouse components to get what you wanted - enjoying seeing how you got to your finished model.

 

[LarryG]

FR, It's only 40 minutes away from here and is a railway I return to regularly having seen its remnants sixty odd years ago. Lovely build and a smart looking model. I say the this because the full size angular loco is hardly attractive.

 

[David B]

Do you know that feeling when you’re trying to get a motor and gearbox to fit invisibly in your latest model? Well it was just the same with this loco. The big challenge here was how to get the two boilers to fit back-to-back in the space. If you look at the photo in my previous post, you’ll see two chunks of metal sticking out from the back of the boiler. The lower one is the gas jet, which fits into the burner, which then fits into the central flue running through the boiler. The upper one is the regulator, which sits on the steam turret at the top rear of the boiler. Two standard Roundhouse boilers placed back-to-back are too far apart for EoM - I needed both steam turrets to fit inside the cab sheets in a way that still allowed the upper cab body to be removeable. Anyone who has a gas fired live steam loco will also know that the gas jets can occasionally get blocked by tiny particles of dirt, so they also need to be accessible and removable, ideally without dismantling the whole loco to do so. I suppose I could have ordered a couple of custom-made boilers, but I didn’t want to spend any more money having already bought two, so I was (as my son would say) pot-committed.

It was the work of seconds to rotate the horizontal position of the regulators on the steam turrets so that they could sit alongside each other at a slight angle from the centreline. This photo from later in the build shows both regulators in place alongside each other at an angle (they are the two brass cylinders inboard of the pressure gauges). For anyone who wants a sense of scale, you can just make out the chimney cover sitting on top of the cover between the side tanks (it’s the disk with a handle and too much solder which is just visible behind the nearer chimney cap) - this is made from a wheel taken from the outer axle of a Hornby 4mm scale Class 31 diesel, and yes, it does fit into the copper chimney cap):


The gas jets were much more trouble - I researched whether I could reduce the length of the burner mounting, but quickly realised that even if I could get the two gas jets to fit in line with each other, the only way I could remove one to deal with a blockage would be to dismantle half the locomotive in order to take off the smokebox so that I could pull the boiler forwards. Not a good solution when the smokebox mounting screws can only be accessed by dropping the bogie and removing all the steam pipes. So I explored whether I could mount the burners at a slight angle like the regulators. It took weeks of experimentation to find an angle which meant that the burners weren’t touching the walls of the flue and still had air all around them. I then had to make two mounting brackets from brass bar which would hold the burners firmly in position. Fortunately this worked and the boilers produce steam as freely as my other standard Roundhouse locos. All of the positioning was worked out (when the boilers were cold!) using styrene templates as above. So here are both boilers in position:

 

[David B]

Can I just say a quick Thank You to everyone for your kind comments and Likes. This has been a very quirky project and I didn’t think anyone would be interested. I love the fact that WT and its members are so much more broad minded and open minded than I’ve found elsewhere.

 

[Dog Star]

I am so glad that you have responded to the questions and requests from the WT members because otherwise we could not appreciate the trials and tribulations that you have faced in getting the model to steam. Thank you.

regards, Graham

 

[Scale7JB]

Very clever.

The question is of course, what did you use for a flexible main steam pipe ?

JB.