New Boiler Ordered

A New Boiler has been ordered from Bartlett Engineering of Sageston, near Tenby in Pembrokeshire. [this may seem obvious but their works isn't open to the public - please contact me if you want more info]

The old boiler has been supplied as a pattern for the basic layout, location of pipe connections and the physical shape. This will be used to create a design for a virtually identical boiler to the old one but with the design updated to meet current boiler rules and to take advantage of modern manufacturing techniques.

The overriding design consideration will be that the boiler must fit back in the engine and as the old boiler was a very free steaming boiler no major changes are planned. Things that will differ are: - [this might also provide some clues for the boiler weight game]

Boiler Timetable

June 2003	Feb2004	March 2004	April 2004	May 2004	June 2004	Late Summer 2004	2nd half 2004	Early 2005
Boiler Ordered	Shell design submitted	Flanged Plates and Barrel Ordered	Flanging delivered	Detail Design submitted	Design approval received. Construction gets underway	Construction completed Boiler delivered to Boston Lodge	Fit boiler to engine and re-erect loco. New smokebox to make. Minimal mechanical work	Commission loco Repaint Return to service

Simple Boiler Explanations - Part 1 - The outside bits

Lesson one in elementary boiler design starts with the exterior components. These are also the first bits we will see of the new boiler as it comes together. All the bits here are made from certified quality boiler plate.

On the old boiler the joins shown as welded are overlapping plates and riveted joints. In addition the old barrel is made up of three rings so there are seams around the circumference of the old barrel as well as longitudinal seams.

On the new boiler the barrel is 810mm diameter and was rolled from flat plate. The seam was then submerged arc welded and 100% NDT [non destructive test] using radiography. When done the weld is hard to tell from the base material. Our Barrel was made by Plate Rollers Ltd.  The photo to the right shows sub arc welding being done.

The throatplate and backhead  are pressed from flat sheet over a former having been got red hot so the material becomes very plastic and formable. These parts have been pressed for us by Roger Pridham. Hopefully there will soon be some pictures of this being done.

These parts and the outer wrapper of the firebox will all be welded together with either full penetration welding [done all from one side] or welded for both sides.

The front tubeplate has been flanged by Gordon Newton as he had the right size flanging blocks already available. This will be riveted in place as its one of the components that will wear out during the life of the boiler and replaced.

The Kit Starts to Come Together click on the pictures for a bigger image

This is what a boiler kit looks like. Here are all the main external components as delivered. In the background is the barrel, furthest from the camera is the throatplate, middle is the backhead and nearest is the front tubeplate.

This second view gives you a view up the rolled and seam welded barrel. Can you spot the join? in the foreground the front tubeplate can be seen. When its complete it will be mostly full of holes!

In this pair of pictures you can see the plates flanged by Pridham's for the firebox and in the shot to the right you can see the old boiler as well. The left hand flanged plate will form the face of the old boiler you can see with the firehole door cut in it. the other plate forms the front of the firebox and the barrel connects to the pressed in it.  

pictures - courtesy of and copyright to Bartlett Engineering

The Inspection Game

Simply put, what our boiler insurers say is what goes! It is a bit more structured than that though.

The Festiniog Railway uses Royal Sun Alliance for all their pressure vessel insurance, that includes the loco boilers, diesel air tanks and the cafe tea machines! RSA have their own inspectors who do the on the ground inspections and design approval engineers at HQ. In the case of a new boiler the outline plan is that we discuss the intention to build a new boiler with them and at one level its "we'll build another one like the old one as it hasn't gone bang in 40 years" and at another level its a discussion of the details of the BS & ISO codes it will be built to. We also discuss whether it will be done to comply with the Euro Pressure Equipment Directive [PED] see below

From here we work on the design and whilst the plan is to largely copy Blanche's old boiler there are things that need to be different because of modern rules and things its sensible to do different due to new methods. The biggest example of this with the new boiler is to retain flanged plates but weld them together rather than rivet them, but then again we are riveting some bits in where welding was an option. The front tubeplate and the foundation ring will be riveted.

From this point we prepared our detail drawing and also engaged in further dialogue such that when we presented the drawings there were no surprises. Part way through the process we sent preliminary drawings in and got outline approval for the outer shell. This allowed us to order the materials with the longest lead time. Now we have submitted the detail drawings and have received approval subject to two very minor changes, so minor we don't have to resubmit the drawings, just build to the changes and show them in the as built drawings.

So now with approval is it all over? No, its just moved to the construction phase. Now we can build the boiler but the construction has to be inspected at stage by the RSA inspector and it has to have the agreed amount of non destructive testing of welds as it goes together. All the material has to be of certified quality and Bartletts will keep this on file available for inspection. Ultimately the boiler will have am hydraulic test and a steam test all witnessed by the inspector.

What is PED?

The uncharitable view would be that it is Euro Bullshit. It is the Pressure Equipment Directive and unlike a good old British standard it doesn't tell you what you can and can't do it invites you to propose what you want to do, get someone to audit it and say its Ok, you can then do it and be checked you did it like you said you would. It's a bit of a pig when it comes to heritage locomotive boilers as it was written to stop the Italians flooding the market with compressors with cheapo sub standard air receivers that would last past the first inspection. They were all made in Italy because the government there was subsidizing the industry.

What does it mean to Blanche? Well we have had to do a bit of procedure writing for the idea of a welded boiler with riveted bits as its not currently part of PED but the approval process to PED is such that it can run alongside the construction and, by and large, if you have done all the proper design work and, more importantly for PED, the reams of paperwork our boiler design will be approved under PED and we will be allowed to stick a CE mark on it. In practical terms it will be no different to a boiler that was made well but not PED approved.

Its a lot of paperwork but it is the way of the world so we have done it. Others have gone down the road of repairing a boiler beyond sensible repairs because a repair isn't required to be subject to PED.

Here's how to do flanging

First things first, all these images are thumb nailed and will enlarge if clicked. These pictures were taken by Pridhams and are used with their permission for which I am grateful. What we are doing here is called flanging and we are basically forming flat boiler plate in to the shapes we need to build a boiler. Pridhams have done two of the three flanged plates needed. These are the Throatplate and the backhead. The outer edge of these are the same. The throatplate differs in that it has a hole flanged through it to meet with the boiler barrel. The first thing you need is one of these, a large hydraulic press, I am assured that this one bearing one of our drivers names is a co-incidence.

The press is going to use a lot of force to press a flat plate through a former and around a die so it take the shape we want. In the second picture the flat plate can be seen sandwiched between to large blocks of steel and supported by the press. Note that the upper large block has curved edges of the shape we want. this is the male part of the flanging set. The large chunk of steel at the bottom supported on legs and looking like a door frame is the female part of the set. Note that the lower edge of the hole is the final size needed and that the area leading to it is tapered so that the shape is formed progressively as the plate is pushed through.

The plate is too thick to be formed cold. To try would need to much force and leave the risk of cracks forming in the plate. Lots of heat is applied using oxy propane torches to heat the metal to a bright cherry red state. At this stage the metal becomes plastic and will form easily. Heat is continuously applied to keep the plate at the right temperature. Get the temperature wrong and there is a risk of cracking now or in the future. apparently Pridhams are the second largest user of propane in Devon!

Once the plate is at the right temperature the forming can begin as the press pushes the plate down into the female die whilst constantly applying heat. Despite the metal being very plastic at this stage this still needs a lot of force, hence the big press.

At this stage it gets quiet dramatic as the female die is coated in graphite grease to ease the passage of the plate through the die. As it passes though a holocaust erupts as the oily element of the grease burns off leaving it coated in graphite.

When its all cooled down a bit it looks like this and the press can be undone from around the plate. Then they can be packed for transport. The second plate done was still hot and smoking when it was put on the pallet for delivery.

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pictures - courtesy of and copyright to Pridhams. If you want to show them to others please send them a link to this page rather than copying the pictures

LATEST BOILER NEWS

Well actually its a week old now. These pictures were sent at the end of week 3 of July and it has moved on since these were taken. Its now the other way up having had the firebox cut to length. The holes for the dome and turret have been cut and the boiler has moved from this bay, the fabrication shop, into the next bay, the boiler shop. All the facilities are impressive, each bay has a high capacity electric crane and you can see some of the tooling in the background.

There will be some more pictures soon.

Meanwhile here are some of the components pictures I took when we had a site visit to discuss some details and view progress on the 11th July. That was some weekend, with a Merddin project meeting on Saturday at Boston Lodge and a site visit near Tenby on the Sunday. I can now tell you that driving York, Boston Lodge, Tenby, York in a weekend gives you a numb bum and is 746 miles!

We saw some other stuff whilst we were there.

Superheater Elements: The elements are about shot so we are looking at having new ones made.

Superheater Header: This is also in need of refurbishment.

Picture Frame: This is is a frame that fastens the panplate to the boiler. We have been discussing these fixings for the new boiler.

Pocket Casting: Machining the recess in a brass is a real pain so we were pleases to see these with a pocket cast in. Our patterns  for Merddin are now with the same pattern maker & foundry.

We did have bit of fun though. We needed a break on the drive home so called at the Evesham Vale Light Railway

Boiler Latest - September 2004

OK, lets try this as the first attempt at spin. The boiler is being delivered in July so today must be the 85th of July 2004 and we should get the boiler around the 117th! You're not going to fall for that are you? OK, lets try some truth, no one will ever believe that. Most of the boiler is now assembled and our boiler manufacturer has been tearing his hair out trying to get materials to build it with and at affordable prices. We have been faced with a number of problems Boiler Steel Prices have tripled in the time we have been building this boiler because the Chinese are buying all the steel they can get their hands on. On special shapes and sizes the price hike is even more, but that's not all. You can't get the sizes you want because the Chinese have bought it all. Specialist contractors are going out of business faster than you can give them work. Material/contractor availability requiring a design change and the delays in getting that approved. I won't go in to tremendous detail here but this is an abbreviated sage that has gone on over several weeks and has involved masses of phone calls and e-mails chasing me round the USA whilst on holiday:- First up the flues come from Germany via a company that swages the ends. Swaging company goes out of business and the UK supplier covers this up before admitting they can't source an alternative. We find another UK supplier and they promise the earth, don't deliver and quote a price that would blow an enormous hole in the budget. We find a UK contractor who can swage one way only. I can't remember which way but there solution is to do both swages [lets say they swage down] on separate bits of tube and then butt weld them together. Yes they would do ours, yes they would treat it as urgent and give a rapid turnaround. However joined flues is a design change. Contact insurers. Can't get hold of the man who can say yes. Eventually, switchboard get fed up with us and give us his mobile number. Man is not happy when we call his secret mobile number but agrees to the design change - probably to get rid of us. With design approved we call pipe supplier who said he had the stuff for immediate delivery - He lied! Chase round the rest of the country. Get a quote for £1600 @ 3 weeks delivery. We laugh - hysterically! Many phone calls later we get the pipe for £550 [ish] on 7 day delivery direct to swaging contractor. Call swaging man to tell him its on its way. He says he'll get right on it. On this occasion I believe them. Right so where does that leave us? Quite rightly the holes for in the tubeplates can't be drilled until we actually have the flues at the works to measure. As these have to be drilled we can't assemble the boiler. As we can't pit the inner box in for keeps we can't drill all the hole for the stays as these are drilled from the outer box right through the inner box. The boiler team are fast running out of stuff to do until the flues arrive. All the small parts for the final assembly have been made or are being finished off now. The smoke tubes sit there ready to go in. The regulator assembly has been overhauled and is ready to fit. The boiler has had its statutory welding inspection and it was done to a higher standard than required. A sample 10% of welds are to be tested according to code. We have tested 50% with Ultrasonic and the other 50% with die pen. All passed with no remedial work required. It all waits for the flues!!!

These first three views show the collected parts waiting for assembly on 22nd September 2004. Not much more can be done without the flues This group show the foundation ring being flame cut by the CNC profiler this morning 23rd September 2004 Having been cut out the foundation ring was dressed and made to fit on to the inner firebox. The inner box and and the foundation ring were then fitted into the outer firebox. This is only temporary but it made everyone feel good when it went in. These two shots show the front tubeplate having the holes for the tubes drilled in it. With not having the superheater flues this will have to be set up on the machine again to bore the holes  for them once we have them. This pair of photos show some more of the kit dry assembled.  The upper photo is looking in the firehole at the inner firebox and tubeplate. The lower picture shows the front tubeplate from inside the boiler. Note the doubler plate on the inside. This replaces palm stays on the old boiler. Note: In both pictures the boiler is upside down. Finally for now.......... We might let him out later   Thanks to the lads, Richard & K at Bartletts for the pictures

My final point on the boiler for the moment is to make a pre-emptive strike to say that we remain very happy with our boiler contractor and sympathise with them for the supply problems they have faced. They have kept us fully informed of the issues and the solution has been a joint one with both parties melting the phone lines. The work completed so far is of the highest quality [witness the 100% welding score] and we are already discussing other jobs they may do for us. When we eventually receive it we will have a high quality boiler.

What does this do for the FR loco situation?

Well you may well be aware that Linda has been withdrawn two years early for a re-tube following a failure. This is now top of the priority list and will delay bringing Blanche into Boston Lodge so the lack of a boiler will not be a problem for a bit longer yet. After Linda we have Merddin and Blanche to do. The powers that be have decided that whilst they want them both NOW [or sooner], that if there has to be a priority then Merddin will be done before Blanche. Blanche should still return to service next year but it may now be later in the season. It would be good to have it ready for high summer in time for the attrition that service causes - witness this year with engines dying like flies!

Latest Pictures - taken Christmas Eve

Compensation Ring

The curved sections of a boiler such as the barrel and the curved top of the firebox are strong because of the curvature. If you cut a whole in them you remove some of the natural If you cut a hole in it you remove some of the strength so you have to compensate for this hence the name Compensation Ring. It is a giant polo mint shaped piece of metal welded to the outside of the boiler to increase the thickness around the hole. Bigger the hole bigger the compensation ring.

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