Fairlie locomotive
A Fairlie locomotive is a type of articulated steam locomotive that has the driving wheels on bogies. It was invented by Robert Francis Fairlie. The locomotive may be double-ended or single ended. Most double-ended Fairlies had wheel arrangements of or. All were tank locomotives.
While Fairlie locomotives are now used only on heritage railways, the majority of diesel and electric locomotives in the world follow the basic form of the Fairlie — two power trucks with all axles driven. Many also follow the Fairlie's double-ended concept, capable of being driven equally well in both directions.
Development of the design
In 1864, the Scottish engineer Robert Francis Fairlie published a pamphlet detailing his plans for a new type of articulated locomotive. He had become convinced that the conventional pattern of locomotive could be improved on, and that his proposed design would have higher tractive effort as all the locomotive's weight was on the driving wheels, was able to traverse sharper curves than a non-articulated locomotive of the same length, would be better at producing steam from its double boilers and would not need turntables because it could be driven in either direction. He received a patent for this design in May 1864.Fairlie's design was a double-ended steam locomotive that carried all its fuel and water on the locomotive and had every axle driven. It had a double-ended boiler, with one firebox in the centre and a smokebox at each end.
Predecessors
Fairlie was not the first engineer to design and build a double-engine. In 1850, the Belgian company John Cockerill & Co built a double-boiler locomotive called Seraing which featured two independently articulated driving bogies. It had several differences from Fairlie's design, notably the buffers were fixed to the carrying frame, not the bogies, and the bogies were attached to the frame using four carrying pins, which restricted the degree of articulation. Seraing was a failure and Robert Fairlie was likely unaware of it when he produced his design in the 1860s. In the early 1860s, Archibald Sturrock, the locomotive superintendent of the Great Northern Railway, experimented with powered bogies under the tenders of GNR steam locomotives. While these were not ultimately successful, Fairlie was influenced by Sturrock's work, and by the use of back-to-back locomotives on the Bhor Ghat incline on the Great Indian Peninsula Railway starting in 1856.Firebox
The first locomotive was The Progress, built in 1865 by James Cross and Company for the Neath and Brecon Railway. However, having the draught from both halves of the boiler through one firebox was unsuccessful. There was a tendency for most of the hot gases from the fire to go through one half of the boiler, so the other half made little contribution to steam-raising and was inefficient. The first, Festiniog Railway Little Wonder, had separate fireboxes with a water jacket between them and proved far more successful.Controls
The locomotive driver worked on one side of the locomotive, and the fireman on the other; the fireboxes separated them. The regulators for both power bogies were located above the centre of the fireboxes, with the steam brake valve at one end.Power bogies
Underneath, the locomotive was supported on two swivelling powered bogies, 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. Couplers and buffers were mounted on the bogies, not on the locomotive frame, so that they swivelled with the curvature of the track.Steam supply
Steam was delivered to the cylinders via flexible tubing. Initially, this was a coiled copper tube but this would fracture after a period of use. Later locomotives had rigid connecting tubes with the necessary flexibility provided by metal ball-and-socket joints similar to those used in laboratory glassware.Fuel and water
Fuel and water were carried on the locomotive, in side tanks beside each boiler for the water, and bunkers for the fuel above them.Examples in use
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 around the world.Locomotives were built for many British colonies, for the Russian Empire, and even one example for the United States.
In 1879, the first government railway line in Western Australia from Geraldton to Northampton utilised two double Fairlies as its third and fourth items of motive power, respectively, but without much success. The only really successful uses of the Fairlie locomotive, other than on the Ffestiniog Railway, were in Mexico, New Zealand, and Russia.
Wales
In 1869, Robert Fairlie's company built a locomotive named Little Wonder for the Ffestiniog Railway, a narrow-gauge slate railway in North Wales. The Ffestiniog was the first gauge railway to use locomotives. 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 Festiniog Railway Company a perpetual licence to use his locomotive patent without restriction, in return for using the line and the success of its Fairlie locomotives in his publicity. During its original operation, the Ffestiniog owned a total of five Fairlie locomotives, one of which is on display in the UK National Collection. Since the reopening of the railway in preservation, their Boston Lodge workshops have built three new Double Fairlies, the most recent being James Spooner II, which entered service in 2023 to replace Earl of Merioneth.United States
The locomotive sold in the US was ordered for the newly built Denver and Rio Grande Railroad in 1872, and was named "Mountaineer". It was the only Double Fairlie to operate on an American narrow-gauge railway. This was a smaller locomotive with four-wheel bogies, giving it a 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. At least one double Fairlie No. 164 Janus was built by the Mason Machine Works in Taunton, Massachusetts and worked on the Lehigh Valley Railroad.Canada
Five narrow-gauge Fairlie Patent locomotives were built by the Avonside Engine Company, Bristol in the early 1870s for use by Canadian railways.The Toronto and Nipissing Railway used a single gauge Fairlie from 1871 until the line was converted to in 1883.
The Toronto, Grey and Bruce Railway of Ontario also used one gauge Fairlie locomotive, delivered in 1872.
In Cape Breton Island, three gauge Fairlie Patent locomotives built by Bristol's Avonside Company were used to haul coal between Sydney and Reserve Mines from 1872 until 1902. Herb MacDonald's book "Cape Breton Railways: An Illustrated History" states that "a railway industry journal published early in 1903 stated that 'the old double-end locomotives... have recently been taken apart at the Reserve, and will be disposed of as old junk. The machinists who took them apart say it was the hardest job they ever tackled, as the engines were very strongly built and the parts mostly forge-made'."
Mexico
In Mexico, the Ferrocarril Mexicano used Fairlies on a mountainous stretch of line between Mexico City and Veracruz, where 49 enormous Fairlies weighing about 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 are notably high compared to relatively modern locomotives.Rolt wrote:
"...it 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. Boca del Monte, Mexico 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... 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 steamlocomotive.com
| Class | Road numbers | Date | Builder | T.E. | Weight ) | 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 | - | ||
| R-1 | 171-180 | 1902 | North British | - | ||
| R-2 | 181-182 | 1907 | North British | - | ||
| R-3 | 183-185 | 1911 | Vulcan Foundry | - |
Key:
- Date = building date of first locomotive in batch. Delivery may have been spread over several years
- n/k = not known
- T.E. = tractive effort
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.