Fairlie locomotive#Single Fairlie or Mason Bogie

A single Fairlie, in the United States also called Mason Fairlie or Mason Bogie, is an articulated steam locomotive with only a powered bogie and a trailer bogie. The motor bogie if it were a Double Fairlie; However, the boiler has a normal design, and also visually resembles a single Fairlie normal, but relatively long tank locomotive.

Pros and Cons

The advantage over the steifrahmigen design is that a ( thermally advantageous ) large firebox can be arranged with adequate capacity ashtray behind the dome wheels and still holds even on tracks with tight turns, the lateral overhang, especially at the rear end of the locomotive within limits. Compared with the Double Fairlie eliminates the disadvantage of complicated double boiler and related tightness in the cab. The house larger fuel and water supplies is not a problem.

The principal disadvantage of the single- Fairlie opposite the double Fairlie is that only part of the weight rests on the driving axles. In addition, has a single Fairlie no longer driving axles than a regular steam locomotive, nevertheless it requires portable steam lines with the associated sealing problems.

Dissemination

In the UK, Single Fairlie were rare. A standard gauge locomotive was built in 1878 for the Swindon Marlborough & Andover Railway - the first British locomotive with Walschaerts control - and three narrow gauge locomotives for the North Wales Narrow Gauge Railways Moel Tryfan and Snowdon Ranger (both 1875) and Gowrie (1908 ). Another narrow gauge locomotive named Taliesin (1876 ) had known for her Double Fairlie Ffestiniog Railway.

For the U.S., the locomotive manufacturer William Mason licensed the Letters Patent number 1210 by Robert Francis Fairlie. However, he built only one Double Fairlie and then only single Fairlie. One advantage of the Double Fairlie, usability in both directions, fell in the U.S. of little consequence, since there was usually plenty of room for turntables or track triangles. Mason built nearly 150 locomotives of this type; as axis sequences were found almost all conceivable combinations of two - and three-axle railcars and bogies with or without leading the barrel axis. Three series were powered bogies with four driving axles ( wheel arrangement ( 1'D ) 3 ').

To simplify the problem, prone to leaks portable steam connection, Mason changed the basic principle of Fairlie from, by leading the steam line through the Drehgestellager and not as before from the smoke chamber directly to the underlying slide boxes. However, this arrangement prevented the use of the average in the U.S. inside Stephenson valve, so that the first locomotive Masons with Walschaerts control in North America. A characteristic -to-find and only Mason Fairlies detail was the lack of space above the boiler mounted control shaft with a correspondingly long suspension of iron ( see pictures).

Whereabouts

Of the three machines of Moel Tryfan NWNGR which survived the longest; it was taken in 1937 for a repair from service and experienced in this state, the setting of the (old ) Ffestiniog Railway. In 1954, the vehicle was classified as no longer suitable for restoration and sold as scrap.

The first Taliesin was around a long time, from 1876 to 1931, and to the successful single Fairlies the 18 machines of the New Zealand class R can be counted, which were introduced in 1878 and partly were up in the 1940s in use. This Taliesin was rebuilt in 1999 by the Ffestiniog Railway, which was used as the only original part of the reversing lever. The motor bogie of the locomotive corresponds in its basic dimensions are the Double Fairlie train.

Apart from the Taliesin may exist worldwide, only two other single Fairlies: The Torch Lake, a Mason Fairlie in 1873, is received operational, and in New Zealand is a copy of the class R in a museum.