2-6-6-0
Encyclopedia
In Whyte notation
for the classification of steam locomotive
s by wheel arrangement
, a 2-6-6-0 is a locomotive with one pair of unpowered leading wheel
s, followed by two sets of three pairs of powered driving wheel
s, and no trailing wheel
s. The system was principally used on Mallet-type
articulated locomotive
s.
in South Africa
by the
American Locomotive Company
(Alco) which later became SAR Class MA. It was successful and a further five were ordered from Alco (SAR Class MB). A third order for ten was built by the North British Locomotive Company
in 1912 (SAR Class MC), followed by twelve more superheated
locomotives by North British in 1914 (SAR Class MC-1).
Ten locomotives of a new Mallet design by D.A. Hendrie (SAR Class MJ) were built by Maffei in Munich
but only two were delivered by the outbreak of War in 1914. Eight were therefore built by the North British Locomotive Co. in 1917. The original eight missing locomotives from Maffei were delivered in 1921. North British also constructed five further 2-6-6-2 Mallets (SAR Class MH) in 1915.
. Towards the end of their life these locomotives were used by the Denver and Rio Grande Western Railroad
after the acquisition of the Denver & Salt Lake. These locomotives were used first over the Rollins Pass
and later Moffat Tunnel
route of the Denver & Salt Lake. They were all scrapped between 1948-1952 by the D&RGW.
. It was built at the Petone Workshops in Wellington and designed for use on the world famous Rimutaka Incline and received the number 66 making it E 66. It spent its entire life in the Wellington region hauling trains up and down the Rimutaka Incline until it was transferred to banking duties on the Wellington-Johnsonville section but it was not designed for that work. In 1917 E 66 was withdrawn from service and scrapped. Sadly it didn't survive long enough for preservation.
Whyte notation
The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte and came into use in the early twentieth century encouraged by an editorial in American Engineer and Railroad Journal...
for the classification of steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
s by wheel arrangement
Wheel arrangement
In rail transport, a wheel arrangement is a system of classifying the way in which wheels are distributed beneath a locomotive.. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and connections, with the adopted notations varying by country...
, a 2-6-6-0 is a locomotive with one pair of unpowered leading wheel
Leading wheel
The leading wheel or leading axle of a steam locomotive is an unpowered wheel or axle located in front of the driving wheels. The axle or axles of the leading wheels are normally located in a truck...
s, followed by two sets of three pairs of powered driving wheel
Driving wheel
On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons...
s, and no trailing wheel
Trailing wheel
On a steam locomotive, a trailing wheel or trailing axle is generally an unpowered wheel or axle located behind the driving wheels. The axle of the trailing wheels was usually located on a trailing truck...
s. The system was principally used on Mallet-type
Mallet locomotive
The Mallet Locomotive is a type of articulated locomotive, invented by a Swiss engineer named Anatole Mallet ....
articulated locomotive
Articulated locomotive
Articulated locomotive usually means a steam locomotive with one or more engine units which can move independent of the main frame. This is done to allow a longer locomotive to negotiate tighter curves...
s.
Equivalent classifications
Other equivalent classifications are:- UIC classificationUIC classificationThe UIC classification of locomotive axle arrangements describes the wheel arrangement of locomotives, multiple units and trams. It is set out in the International Union of Railways "Leaflet 650 - Standard designation of axle arrangement on locomotives and multiple-unit sets". It is used in much...
: 1CC (also known as German classification and Italian classification) - French classification: 130+030
- Turkish classificationTurkish classificationIn the Turkish classification system for railway locomotives, the number of powered axles are followed by the total number of axles. It is identical to the Swiss system except that the latter places a slash between the two numbers.Thus0-6-0 becomes 33...
: 34+33 - Swiss classification: 3/4+3/3
South Africa
This wheel arrangement was first used on a single Mallet locomotive built for the Natal Government RailwayRail transport in South Africa
Rail transport in South Africa is the most important element of the country's transport infrastructure. All major cities are connected by rail, and South Africa's railway system is the most highly developed in Africa...
in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
by the
American Locomotive Company
American Locomotive Company
The American Locomotive Company, often shortened to ALCO or Alco , was a builder of railroad locomotives in the United States.-Early history:...
(Alco) which later became SAR Class MA. It was successful and a further five were ordered from Alco (SAR Class MB). A third order for ten was built by the North British Locomotive Company
North British Locomotive Company
The North British Locomotive Company was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp Stewart and Company , Neilson, Reid and Company and Dübs and Company , creating the largest locomotive manufacturing company in Europe.Its main factories were...
in 1912 (SAR Class MC), followed by twelve more superheated
Superheater
A superheater is a device used to convert saturated steam or wet steam into dry steam used for power generation or processes. There are three types of superheaters namely: radiant, convection, and separately fired...
locomotives by North British in 1914 (SAR Class MC-1).
Ten locomotives of a new Mallet design by D.A. Hendrie (SAR Class MJ) were built by Maffei in Munich
Munich
Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...
but only two were delivered by the outbreak of War in 1914. Eight were therefore built by the North British Locomotive Co. in 1917. The original eight missing locomotives from Maffei were delivered in 1921. North British also constructed five further 2-6-6-2 Mallets (SAR Class MH) in 1915.
USA
The only American railroad to purchase these locomotives was the Denver, Northwestern and Pacific Railway, which later became the Denver and Salt Railroad, then Denver and Salt Lake RailwayDenver and Salt Lake Railway
The Denver, Northwestern and Pacific Railway was a U.S. railroad company incorporated on July 18, 1902, by David H. Moffat, Walter S. Cheesman, William Gray Evans, Charles J. Hughes, Jr., George E. Ross-Lewin, S.M. Perry and Frank P. Gibson...
. Towards the end of their life these locomotives were used by the Denver and Rio Grande Western Railroad
Denver and Rio Grande Western Railroad
The Denver & Rio Grande Western Railroad , often shortened to Rio Grande or D&RGW, formerly the Denver & Rio Grande Railroad, is a defunct U.S. railroad company. The railroad started as a narrow gauge line running south from Denver, Colorado in 1870; however, served mainly as a transcontinental...
after the acquisition of the Denver & Salt Lake. These locomotives were used first over the Rollins Pass
Rollins Pass
Rollins Pass is a high mountain pass in the Rocky Mountains of north-central Colorado in the United States. The pass is located on the continental divide at the crest of the Front Range southwest of Boulder, at the boundary of Grand and Boulder counties.-Description:Rollins Pass Rollins Pass (el....
and later Moffat Tunnel
Moffat Tunnel
The Moffat Tunnel is a railroad and water tunnel that cuts through the Continental Divide in north-central Colorado. Named after Colorado railroad pioneer David Moffat, the tunnel's first railroad traffic passed through in February 1928....
route of the Denver & Salt Lake. They were all scrapped between 1948-1952 by the D&RGW.
New Zealand
The NZR E class of 1906 comprised the only 2-6-6-0 tank locomotive ever built and used by the New Zealand Railways DepartmentNew Zealand Railways Department
The New Zealand Railways Department, NZR or NZGR and often known as the "Railways", was a government department charged with owning and maintaining New Zealand's railway infrastructure and operating the railway system. The Department was created in 1880 and was reformed in 1981 into the New...
. It was built at the Petone Workshops in Wellington and designed for use on the world famous Rimutaka Incline and received the number 66 making it E 66. It spent its entire life in the Wellington region hauling trains up and down the Rimutaka Incline until it was transferred to banking duties on the Wellington-Johnsonville section but it was not designed for that work. In 1917 E 66 was withdrawn from service and scrapped. Sadly it didn't survive long enough for preservation.