JAMES SPOONER
Building an all-new double Fairlie
Steam locomotives wear out, and few locomotives operating on preserved railways today have any large proportion of original material in their makeup – facts that won’t surprise anyone. The larger and heavier components usually stand the test of time, but much of what we see – and almost all of the wearing parts – will have been replaced at some stage in a locomotive’s career. Express engines in particular would do long journeys almost every day for a couple of years before being pulled into the works, where a thorough overhaul would be undertaken and boilers swapped for newly built or repaired replacements. Even within a few years of its construction, a locomotive might therefore have a new boiler and a different set of fittings. Boiler cladding wouldn’t last beyond the first few overhauls, and smokeboxes were very much disposable items. Thanks to strict standardisation, the GWR transferred parts from one locomotive to another, and it is therefore not really surprising that the engine thought to be No. 4983 Albert Hall turned out to be No. 4965 Rood Ashton Hall upon more detailed inspection (SR215, March 1998). The regime of taking a locomotive apart every ten years for mechanical overhaul and a major boiler repair, familiar to preserved railway operators, is not typical of what happened in times gone by.
BOGIE ISSUES
In its intensive use of steam locomotives, the day-to-day operation of the Ffestiniog & Welsh Highland Railways tends to reflect the methods of steam locomotive usage on main line railways prior to 1968 much more than most preserved lines. Although the FF&WHR has a relatively large number of locomotives in its fleet, the core train services rely on half a dozen larger locomotives, all of which are required in traffic for 200 days in each year. ‘NGG16’ Garratt No. 87, for example, has clocked up 100,000 service miles in just nine years. Modifications and improvements to allow such high mileages have been applied throughout the fleet. For instance, the double Fairlies used on FR core services have been subject to various modifications over the years to improve reliability, and some of the power bogies have been in service under every Fairlie the railway owns. A few years ago a new design of monobloc cylinder and steam chest casting was created for these locomotives, incorporating piston valves in place of the original slide valves. Tested on the single Fairlie Taliesin, this has been a success and the same cylinder block was therefore incorporated in a new pair of power bogies for David Lloyd George in 2014. The new cylinder blocks use the original valve gear and as such can easily be retrofitted to other power units as the original cylinders wear out. The new power bogies for David Lloyd George marked a milestone for the FR in that they displaced from service the last two bogies that had been in use with the old pre-preservation company. The original bogies have been withdrawn and placed in store as historic artefacts. In 2017 the first new Fairlie power bogies built in the preservation era, originally made in 1986 for Merddin Emrys, were given a comprehensive overhaul. In essence these units had run from new to having worn-out tyres in 30 years. Now back in tip-top condition, they were latterly paired with the 1979-built Fairlie Earl of Merioneth, which is currently in the last year of its tenyear boiler certificate. This combination has worked very well indeed, having prevented an ageing boiler from being overstressed delivering steam to tired power units. These ‘good’ units will form the basis of a new locomotive: James Spooner. More on that shortly…
RE-EVOLVING
With seven power bogies in good condition after a programme of renewals, attention has turned to other parts of our Fairlies. In simple terms the superstructure of a Fairlie consists of four key parts – a simple cradle frame that carries the boiler and holds
everything together, the boiler itself (including smokeboxes and associated parts), the water tanks, and the cab (see page 40). Looking at water tanks, a spare set was built for eventual use on Earl of Merioneth in the early years of this century. These tanks were never fitted because when the railway returned to coal firing, Earl of Merioneth was the test bed. Its existing tanks, made of poor-quality plate in the 1970s, were quite worn, but rather than replace them, they were given patch repairs and modified while the best arrangements for coal firing were determined. The square tanks on Earl of Merioneth have soldiered on, but are increasingly frail and leaking water. Turning to boilers, both Earl of Merioneth and Merddin Emrys are fitted with boilers built by Hunslet in 1969/70. The then recently arrived Hunslet ‘Ladies’, Linda and Blanche, were giving good service and this led to the idea that two ‘Lady’ boilers joined back to back might form a good basis for a double Fairlie boiler. This was quite different from the original design of boiler for the Fairlies. At first this seemed to be a successful move, and the new boiler shape changed the look of the locomotives. But as time went on it also became apparent that the new design had flaws. Cracked throatplates became a real problem on occasion, requiring complete dismantling of the locomotives and heavy repairs. Although modifications have since mitigated that problem, the railway will not persist with the same design for future boilers. When it was built in 1992, David Lloyd George was fitted with an all-welded boiler, which was much closer in shape to the originals and designed to work at a higher pressure. This has proved successful in service although, again, a few modifications have been required. The lessons learned have led to the creation of a new design of boiler, largely of welded construction, but with riveted foundation rings.
OUT OF FASHION
Deciding whether to repair or replace a boiler is never easy. The extent of any repair work only becomes fully apparent when the boiler has been stripped and that work in itself takes time and effort. With a relatively new boiler, one can usually be confident that only minor repairs will be required. However, with older boilers the amount of time spent on refurbishment has to be considered against the costs of starting afresh with new metal. The FR currently faces just such a situation with double Fairlie boilers, where two of the fleet have 50-year-old boilers with original fireboxes and the newest boiler is now 25 years old (and considered to be mid-life). There are three options. We could press on with the old boilers, repairing them as required. Alternatively
THE AMOUNT OF TIME SPENT ON REFURBISHMENT HAS TO BE CONSIDERED AGAINST THE COSTS OF STARTING AFRESH WITH NEW METAL
a pair of new boilers could be ordered. The third option is a halfway house solution – repairing the best existing boiler and replacing the worst one. The first option increases the exposure of the business to older equipment. The risk is difficult to quantify, of course, but experience tells us that nothing lasts forever. The second option exposes the company to the risks associated with a new design. Again, previous experience shows that new designs need to be evaluated in service, no matter how thoroughly the design team have done their job. The third option has the greatest appeal to the FR company board, spreading the risk across both approaches and keeping our options open as far as possible. Merddin Emrys’ 1970s boiler is considered to be in the best condition of the two, and this has been repaired to give a further ten years’ service. Earl of Merioneth’s 1970 boiler, thought to need new inner fireboxes, or at least very heavy repair, is to be kept in dry storage while a new boiler is built and tried for the new locomotive. Assuming the new design works as well as anticipated, it is expected that a second boiler will be ordered in five or six years’ time. All of the above has fed into the decision-making process about the new Fairlie. Knowing that a new boiler and tanks were both desirable, and apparently the most cost-effective way forward, further decisions were needed. What should happen to the old tanks, and what shape should the replacement tanks be? Keeping the old boiler as a strategic reserve is a simple decision. A decision to build replacement, more traditionally shaped tanks was made back in 2003; material had been ordered and some work done on tacking the pieces together. However, those tanks have corroded heavily while in storage, were also designed for an oil-fired locomotive, and would need much modification. It would be simpler to build from clean metal, and thus the question of shape re-emerges. We chose to follow the traditional
Fairlie outline as it is part of our ‘house style’ and one of our defining features. Yet some of our supporters who have worked with Earl of Merioneth for a long time wish to keep the spirit of 1979 alive. This locomotive was, after all, the first new-build locomotive of the preservation age and deserves its place in the history books. The solution was actually quite simple. By building a new cradle frame (the relatively simple frame that carries the boiler and connects the superstructure to the bogies) it is possible to leave Earl of Merioneth intact as a complete unit, with the bogies and some small parts swapped out for use on the new James Spooner: a homage to the 1872 original, due for completion in 2020. The power units on which it initially ran when it was launched in 1979 were withdrawn and stored some time ago. The locomotive can therefore be reunited with these units to leave a complete engine – albeit one on which every part is heavily worn. Nonetheless, it leaves options for the future and allows us to work with clean metal on the new locomotives.
‘SPOONER’, AND SOONER
Now 21st-century technology comes into play, as does an opportunity for volunteers to support the railway in a way nobody could have imagined even a decade ago. Computer design is, of course, commonplace in the industry now. But for the Ffestiniog Railway, where in our daily work we still often refer to copies of paper drawings from the 1890s, it comes as quite a revelation. Details can be displayed with just a few key presses, and sections and aspects of the engine can be quickly viewed – and at any angle. What a change this is compared with the hours spent looking at drawings while trying to build a three-dimensional image in one’s mind! The images on the left show the proposed shape of the locomotive as it currently stands, some 80-90% of the way through the design process. It is not a straightforward replica of the original James Spooner, as that locomotive, which was the second double Fairlie built for the FR, had a number of features that were later improved upon (a longer wheelbase for the power bogies, for instance). We want to create a design that clearly echoes the features of the locomotive from a hundred years ago, but which is capable of coping effectively with modern train operation. Our Fairlies have become longer over the years, as the power bogie frames were extended to accommodate an on-board steam brake. They have also become taller as loading gauge improvements permitted. The width of the engines has not changed, however, and careful work has to be done to keep the proportions right. As can be seen in the diagrams, stovepipe chimneys are planned, with short tanks and the early square-type sandboxes. A semi-open style of cab is also under consideration, albeit with sliding roof panels for the winter months. Looking forward to the next steps we are now approaching the exciting stages of the project, where metal starts to arrive with us. At present we have all the boiler components. External contractors are welding up sub-assemblies, and early in the New Year these assemblies should start to be joined together at Boston Lodge. The cradle frame will follow as the boiler nears completion. This reasonably simple fabrication will hold the boiler and allow it to be placed on bogies, thus aiding movement around the works. Initially these will be accommodation bogies from old African wagons, but in due course the power units themselves will take their place. A pivotal moment will be when we press the button to order all the cut plates for the tanks. These will take up a lot of space, so we have to allocate time to assemble them immediately after they arrive. As this happens the real outline of the locomotive will become apparent. The cab will follow but then, as with all locomotives, visible progress tends to slow as the long job of building the front end and spark arrestors takes place, along with piping-up and finishing jobs. We have at least two years of hard work ahead of us, but the end result will be a core fleet locomotive in A1 condition.