Merddin at Duffws c1880
|Built By||Boston Lodge|
|Designed By||GP Spooner|
|1961||Return to service|
|April 1973||Converted to oil|
|2005||return to service|
|Length||32 ft 6ins|
Merddin Emrys is a Double Fairlie locomotive, the third such locomotive built for the Festiniog Railway, the suitability of the type having been proven in tests using Little Wonder. Merddin was built in the Festiniog Railway Company's own workshops at Boston Lodge in 1879 to the design of Percy Spooner and has spent its entire working life on the Festiniog Railway. When the railway closed in 1946 Merddin was the only double engine still available for service, Livingston Thompson having been withdrawn for repairs.
Merddin was returned to service in 1961 and converted to oil burning in 1973. In 2007, as part of the FR's fuel diversification process, the locomotive reverted to coal firing again.
A picture gallery of this locomotive is available.
This was the first locomotive to be built by the Festiniog Railway Company in its own workshops at Boston Lodge; the Works had been extended by the building of an Erecting Shop specifically to enable the work to be done and some of the costs were set against the account for Merddin. Built to the design of G. P. Spooner and incorporating Fairlie's Patent articulation, leading to the type being commonly known as as a double engine or Double Fairlie, Merddin was the third such locomotive to operate on the Festiniog Railway and, like all the others it had an 0-4-4-0 wheel arrangement. The FR had proved the suitability of the Fairle type for its particular circumstances during internationally observed trials in 1870. The success of those trials led to Fairlie articulated locomotives being adopted in several other countries and, as a token of appreciation, Robert Fairlie had granted the FR free use of his patent.
The decision to proceed with construction was taken in 1877, with the frame plates supplied by the Farnley Iron Co of Leeds. The frame plates were flattened, planed and set out by Adamsons of Hyde in Cheshire, who also supplied the boiler. It left Boston Lodge on 21 July 1879 as number 10, having cost £2,235 7s 8d. It had two half-cabs, with the gap in the roof between able to be filled in to make the now familiar FR double engine cab profile.
In February 1881, the splashers (which were only fitted to Merddin) were put on. Also at this time the experimental thermic syphon was removed from the firebox. In January 1882 Salter safety valves were fitted and petticoat pipes were fitted inside the smokeboxes.In August 1882 the cab side sheets were shortened and a canvas cover in two parts was provided for the gap between the two halves of the cab. It had a major overhaul in 1885 with the boiler being retubed and new centres for the bogies. In 1886 the square sandboxes provided when the locomotive was built were replaced with the cast cylindrical pattern eventualy fitted to all FR locomotives. The 4 brass handrails on the sides of the smokeboxes were also fitted and two Wilsons Patent lubricators put on. In 1888 the fire doors on the drivers side were removed and all the tube ferrules were replaced in stages that autumn. In January 1889 the reversing rod broke through the effect of heavy strain from want of proper lubricant. Vacuum brakes were fitted in October 1892 - the first FR locomotive to be fitted. Through the early 90s, much work was done to patch the firebox and keep the tubes expanded, finally, in 1896, the engine was rebuilt and fitted with a new mild steel boiler from the Vulcan Foundry, Newton-le-Willows, with Everetts red metal tubes. Two new smokeboxes were fitted with the brass handrails in the pattern seen today. The work took from January to August to complete. In March 1899 a trial fitting of two piston rings instead of 3 was tried - this was subsequently successful and applied to other engines. In 1901 the balance pipe between the tanks was enlarged for quick filling. From 1904 onwards firebox and boiler repairs become more often, but the tubes were never recorded as being replaced.The boiler lasted until 1915 when Merddin had to be taken out of service. It was not until October 1919 that the tender of £1905 was accepted from the Vulcan Foundry on condition that the new boiler was delivered in 6 months. The new boiler was delivered in December 1920! The engine re-entered service in 1921 with the bogies from Livingston Thompson. After a surprisingly short time Merddin was taken out of service again in 1930 because of the state of the boiler. It was 1934 before heavy repairs were carried out. A new boiler was needed but as an alternative, major work on the existing boiler and firebox was carried out by the Avonside Engine Co in Bristol.
Merddin was the only double engine in service when the railway closed and had been run into the ground as a result. Because closure came so abruptly, literally overnight, the loco had been put into the shed with water in the boiler and tanks and coal in the bunkers, ready for its next turn of duty. The unfortunate results were inevitable and Merddin was rendered completely unfit for use during the eight years when the railway was closed.
 Post preservation
 1959-1961 overhaul
The work required for a return to service, post-preservation, was significant, unlike the funds available to finance it. New smokeboxes, chimneys and tanks were donated by John Summers & Sons Ltd in 1959 and boiler work was carried out on site by Vulcan Foundry staff. The locomotive returned to service in an unfinished state in April 1961. In July 1962, further boiler problems put it out of commission for the remainder of the year and new stays were fitted before a return to service in 1963, but problems with the superannuated 1920 boiler meant it was out of service once more from 1967.
 Hunslet boiler (1970) and conversion to oil (1973)
A new, superheated, boiler from the Hunslet Engine Company, Leeds, was fitted in 1970. The rebuilt locomotive was longer, larger and more angular than before, a cause of concern to many traditionalists. It was converted to oil burning in 1973, at which time it was found to be carrying the wheels from James Spooner.
 1984-1988 rebuild
By 1984 a major overhaul was required. Improvements to the railway's loading gauge and a growing recognition of the value of the railway's heritage, coupled with a generous sponsorship scheme permitted a complete redesign of the superstructure to produce a locomotive that more closely resembled the 'traditional' Fairlie appearance. The rebuilt locomotive re-entered service at the end of 1987.
 1996-2005 rebuild
Another major rebuild project was started in 1996, and although little physical work was done initially, by 2005 this was completed. This included the fabrication of new water tanks.
During Winter 2006/07 Merddin Emrys was converted to burn coal, and returned to service on Friday 7th April 2007. Steaming was not as good as Earl of Merioneth and so in January 2009 Merddin was the subject of performance testing. A number of different blast pipe arrangements were made for the testing by a group working with Paul Molineux-Berry. The optimum arrangements will be then used on the other locomotives.
In November 2009 Merddin Emrys and Taliesin took part in a photocharter on the WHR. This was the first time a double engine had been on the WHR in 86 years (picture below).
 Major facts and figures
Principal stated dimensions in 1923:
- Heating surface: 887 sq.ft.
- Grate area: 12.4 sq.ft.
- Cylinders (4): 9" x 14"
- Nominal wheel diameter: 2' 8"
- Boiler pressure: 160 psi
- Tractive effort (85% BP): 6,059 lb
- Total wheelbase: 20 ft
- Driving bogie wheelbase: 4' 8"
- Weight: 24 tons
- Water capacity: 667 gallons.
- Boyd, James I.C. (1975 / 2002). The Festiniog Railway 1800 - 1974; Vol. 1 - History and Route. Blandford: The Oakwood Press. ISBN 0-8536-1167-X. OCLC 2074549.
- Boyd, James I.C. (1975 / 2002). The Festiniog Railway 1800 - 1974; Vol. 2 Locomotive and Rolling Stock and Quarry Feeders. Blandford: The Oakwood Press. ISBN 085361-168-8.