Single Fairlie

Fairlie locomotive

A Fairlie is a type of articulated steam locomotive that has the driving wheels on bogies. The locomotive may be double-ended (a double Fairlie) or single ended (a single Fairlie). Fairlies are most associated with the Ffestiniog Railway in Wales.

While the Fairlie locomotive has all but disappeared, the vast majority of diesel and electric locomotives in the world today follow a form not too dissimilar from Fairlies — two power trucks with all axles driven, and many also follow Fairlie's idea of being double-ended, capable of being driven equally well in both directions.

Development of the design

The Fairlie was invented and patented by the Scottish engineer Robert F. Fairlie in 1864. He had become convinced that the conventional pattern of locomotive was seriously deficient; they wasted weight on unpowered wheels (the maximum tractive effort a locomotive can exert is a function of the weight on its driving wheels) and on a tender that did nothing but carry fuel and water without contributing to the locomotive's adhesive weight. Furthermore, the standard locomotive had a front and back, and was not intended for prolonged driving in reverse, thus requiring a turntable or wye at every terminus.

Fairlie's answer was a double-ended steam locomotive, carrying all its fuel and water aboard the locomotive and with every axle driven. The double-ended part was accomplished by having two boilers on the locomotive, joined back-to-back at the firebox ends, with the smokeboxes at the ends of the locomotive (looking fairly conventional, until you realise the locomotive is two-faced, Janus-like). In Fairlie's original design the boilers shared a common firebox, but with separate water spaces; it was found that this did not work as well as expected, and on later locomotives the fireboxes were partitioned into two.

The locomotive driver (US: engineer) worked on one side of the locomotive, and the fireman on the other; the joined fireboxes separated them. There were, of course, controls at both ends of the central cab to allow the locomotive to be driven equally well in both directions.

Underneath, the locomotive was supported on two swivelling powered bogies (US: trucks), with all wheels driven; smaller locomotives had four-wheel bogies, while larger had six-wheel. The cylinders on each power bogie pointed outward, towards the locomotive ends. Steam was delivered to the cylinders via flexible tubing. Couplers and buffers (where fitted) were sometimes mounted on the bogies, not on the locomotive frame, so that they swivelled with the curvature of the track.

Fuel and water were carried on the locomotive, in the form of side tanks beside each boiler for the water, and bunkers for the fuel above them.

Examples in use

Early Fairlie locomotives were rather unsuccessful, examples being built for the Neath and Brecon Railway and for the Queensland Railways in Australia being notably unsuccessful, in the latter case resulting in locomotives being returned to the builder.


In 1869 Fairlie's company built a locomotive, named Little Wonder (Fairlie was not an individual given to modesty) for the Ffestiniog Railway, a slate hauler in north Wales, and this one proved to be an outstanding success. Particularly important for a narrow gauge line as small as the Ffestiniog, with a gauge of , was the fact that the Fairlie design meant that the fireboxes and ashpans were not restricted by frame or track width, but only by the overall loading gauge. Little Wonder was such a success that Fairlie gave the Ffestiniog Railway Company a perpetual license to use the Fairlie patent without restriction in return for using the line and the success of its Fairlie locomotives in his publicity. The Ffestiniog went on to own a total of six Fairlie locomotives.

Various countries

Armed with the success of Little Wonder on the Ffestiniog, Fairlie staged a series of very successful demonstrations on the Ffestiniog line in February 1870 to high-powered delegations from the many parts of the world. This sold his invention (and the concept of the narrow gauge railway on which it was based) around the world.

Locomotives were built for many British colonies, for Imperial Russia, and even one example for the United States. In 1879 the first government railway line in Western Australia from Geraldton to Northampton utilised a Fairlie for one of its first items of rolling stock.

The locomotive sold in the US was ordered for the newly built Denver and Rio Grande Railroad in 1872, and was a smaller locomotive with four-wheel bogies, giving it an 0-4-0+0-4-0 configuration. The railroad's experience with the locomotive was typical, and an indication of the fact that, though Fairlie had eliminated several problems of the conventional locomotive, he had introduced new ones of his own.

The only really successful uses of the Fairlie locomotive, other than on the Ffestiniog Railway, were in Mexico and New Zealand.


In Mexico the Ferrocarril Mexicano (FCM) used Fairlies on a mountainous stretch of line between Mexico City and Veracruz, where 49 enormous 0-6-0+0-6-0 Fairlies weighing about 125 tons apiece were imported from England. The largest and most powerful locomotives built there up to then, they were used until the line was electrified in the 1920s. The tractive effort figures (see table below) are impressive compared to a relatively modern locomotive, e.g. the BR Standard Class 9F.

Rolt wrote:

" was the Mexican Railway that became Fairlie's most devoted adherent. Three twelve-wheeled Avonside Fairlies were built for this Company in 1871 to work traffic on the steeply graded section of the main line between Cordoba and the . Bocca del Montre summit in the Orizaba mountains, a distance of . So successful were they that they were the forerunners of no less than fifty Fairlies supplied to Mexico by Avonside and other British builders over a period of forty years."

Durrant took a more sceptical view:

"The largest Fairlies built were...102 ton examples for the Mexicano Railway...Despite their impressive proportions, these engines were devoid of superheaters or modern valve arrangements and were soon replaced by electrification."

This table shows brief details of the locomotives. Detailed specifications can be found at

Class Road numbers Date Builder T.E. (lb.) Weight (lb.) Notes
n/k n/k 1871 Avonside n/k n/k 3 locomotives
n/k n/k n/k n/k n/k n/k 19 locomotives
R-1 159-170 1889 Neilson 39,893 216,994 -
R-1 171-180 1902 North British 37,614 222,656 -
R-2 181-182 1907 North British 46,059 269,024 -
R-3 183-185 1911 Vulcan Foundry 59,133 309,120 -


  • Date = building date of first locomotive in batch. Delivery may have been spread over several years
  • n/k = not known
  • T.E. = tractive effort

Durrant shows a photograph (credited to English Electric) of FCM number 184, built by Vulcan Foundry (VF) in 1911. This is of typically British appearance apart from the sanding dome which, curiously, is provided at one end only. This photograph of FCM number 183 shows a locomotive of distinctly American appearance. If it is one of the VF engines, it has certainly been heavily re-built.

The VF engines were almost certainly built as oil-fired. The photograph in Durrant's book looks like a works photograph showing the engine in new condition and there are rectangular tanks on top of the boilers, which was the usual arrangement on oil-fired Fairlies. Heat from the boilers kept the oil warm and prevented it from becoming too viscous in cold weather.

New Zealand

In New Zealand the R class and S class single Fairlies and the B class and E class double Fairlies were ordered in the 1870s for use on the narrow gauge (3' 6") system built under Julius Vogel's 1870 "Great Public Works" programme to open up the country.

Problems with the design

Fuel and water

Most critical was the absence of a tender, meaning that the capacity for fuel and water was very small. A locomotive is already a crowded place, and Fairlie's design gave even less room to place its supplies than a normal tank locomotive, which at least has a space behind the driver's cab to fill. Moreover, the central position of the cab meant that it was hard to add a tender later. As was later the case with Bulleid's Leader class locomotives, limited fuel supplies would not have been a problem if fuel oil had been used instead of coal. Some of the large Fairlies for Mexico (see above) were oil-fired and oil-firing has, in recent times, been used on the Festiniog Railway (see below).

Steam pipes

Also problematic were the flexible steam pipes to and from the cylinders of each swivelling engine; they were prone to leakage and wasting of power. These problems were clearly solved to a significant extent. It is recorded that difficulties encountered in 1909 with the design and construction of steam-tight flexible steam connections for the Garratt locomotive were solved by Beyer-Peacock's designers after studying a description of the spherical steam joints used on a Fairlie locomotive built for the Ffestiniog Railway followed by a visit to the FR to observe these locomotives at work.

Power bogies

A further problem lay in the power bogies; there was a good reason for unpowered wheels on a steam locomotive, in that they served a function of stabilising the locomotive, reducing its tendency to wander or 'hunt' when rolling on straight track, and leading the locomotive into curves and thereby reducing derailments. Early Fairlies had a tendency to be rough-riding, rough on the track they rode, and more prone to derailment than they should have been. This was certainly in part true of Little Wonder, which was worn out and replaced by the FR after less than twenty years intensive use. It has been said that it literally shook itself to pieces on the rough track. To a large extent the problem was not the use of power bogies but faults in their design and especially the absence of weights on the trailing ends of the bogies to counter-balance the cylinders. . Subsequent FR engines were much easier on the track. All FR Fairlies have had a reputation for a smooth footplate ride when compared with the original George England built 0-4-0 engines.


The driver is on one side of the firebox and the fireman on the other. As a result, the locomotive is left-hand drive going in one direction and right-hand drive in the other. This would not help with visibility of signals.


Fairlie's vision was limited by the limitations of the steam locomotive — its thirst for water and the unbalancing forces of its directly driving pistons.

Single Fairlie or Mason Bogie

A variation of the Fairlie that enjoyed some popularity, especially in the United States, was the single Fairlie, essentially half a double Fairlie, with one boiler, a cab at one end, and a single articulated power bogie combined with an unpowered bogie under the cab, maintaining the ability to negotiate sharp turns. This design abandoned the bidirectional nature of the double Fairlie but gained back the ability to have a large bunker and water tank behind the cab, and the possibility of using a trailing tender if necessary. The single conventional boiler made maintenance cheaper and did away with the crew's separation. A fair number were built, especially by Fairlie's licensee in the United States, William Mason, who built 146 or so Mason Bogies. In the UK, a single Fairlie 0-4-4T was used by the Swindon Marlborough and Andover Railway and three 0-6-4T by the North Wales Narrow Gauge Railways.

Péchot-Bourdon locomotive

The Péchot-Bourdon locomotive was the final development of the Fairlie type. The Péchot-Bourdon was developed by Captain Péchot of the French artillery to operate on gauge railways associated with field artillery and fortresses. The design was chosen with the belief that if one boiler or set of valve gear was damaged by enemy fire, the loco could continue to operate. The primary difference between a Fairlie and the Péchot-Bourdon is that the latter only had one steam dome. Only one design was constructed, an 0-4+4-0. About fifty examples were constructed in 1906, and a further 280 were constructed during World War I, some by the American Baldwin Locomotive Works. Two examples are preserved, one in Dresden, Germany, and one in Serbia.

Modified Fairlie

The Modified Fairlie was introduced by the North British Locomotive Company to South African Railways in 1924. It was similar in appearance to a Garratt but the boiler, fuel and water tanks were all mounted on a single frame which was pivoted on the power bogies. This arrangement differs from the Garratt in which the fuel and water tanks are mounted directly on the power bogies.

Fairlies today


The Ffestiniog Railway in Wales still uses Fairlie patent locomotives to this day; it has three double Fairlies and one single Fairlie in running condition. The most recent double Fairlie locomotives, Earl of Meirioneth and David Lloyd George, were built in 1979 and 1992 respectively in the Ffestiniog's own Boston Lodge works. The veteran Merddin Emrys of 1879 was the first engine to be built at Boston Lodge. The Ffestiniog also owned and operated Taliesin, a single Fairlie, from 1876 to 1927. It was scrapped in 1935 but a replica was built at Boston Lodge in 1999.

The Fairlies on the Ffestiniog Railway were designed to burn coal. Following trials in 1971, in common with most other Ffestiniog engines, they were modified to burn oil. In 2005, Earl of Merioneth was converted to coal having been built as an oil burner. The success of this conversion result in the oldest of the FR Fairlies - Merddin Emrys reverting to coal burning in 2007.

The oldest Fairlie still in operation is a Mason Bogie preserved at the Henry Ford Museum in Dearborn, Michigan. The 0-6-4 locomotive was built in 1873 and still hauls passengers on a tourist train during the summer season.


No other Fairlies operate today, though two are preserved in New Zealand's South Island: Josephine, a double Fairlie, at Dunedin, and R 28, a single Fairlie, at Reefton. A double Fairlie tramway type engine is also preserved in Eastern Germany, and one of the original Ffestiniog locomotives, Livingston Thompson of 1885, is in the National Railway Museum in York.



  1. Locomotive Engines, What they are and What they ought to be. by R.F. Fairlie, London, John King & Co., 693, Queen Street, E.C. 1864. (Reprinted and published 1969 by Festiniog Railway Company)
  2. Railways or No Railways - The Battle of the Gauges Renewed. by R.F. Fairlie, London, Effingham Wilson, Royal Exchange. 1872. (Reproduced c1982 by Railhead Publications, Ohio)
  3. The Fairlie Locomotive by Rowland A. S. Abbott, Devon, UK, David & Charles (Publishers) Ltd. 1970.

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