A divided drive locomotive is a

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the loco ...

that divides the driving force on its wheels by using different

cylinders A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an in ...

to power different pairs of

driving wheel On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons (or turbine, in the case of a steam turbine locomotive). On a conventional, non-articulated locomotive, the driving wheels are all coupled ...

s in order to give better weight distribution and reduce " hammer blow" which can be damaging to the track, or else to enable the wider spacing of the

driving wheels On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons (or turbine, in the case of a steam turbine locomotive). On a conventional, non-articulated locomotive, the driving wheels are all coupled to ...

to accommodate a larger firebox.

Origins

Anatole Mallet

The system of dividing drive was originally developed by Anatole Mallet in the 1870s on a number of rigid-wheelbase

compound locomotives A compound locomotive is a steam locomotive which is powered by a compound engine, a type of steam engine where steam is expanded in two or more stages. The locomotive was only one application of compounding. Two and three stages were used in shi ...

, and then during the 1880s, on

Mallet A mallet is a tool used for imparting force on another object, often made of rubber or sometimes wood, that is smaller than a maul or beetle, and usually has a relatively large head. The term is descriptive of the overall size and propor ...

articulated locomotives.

Francis Webb

Mallet's ideas inspired Francis Webb in Britain who introduced 2-(2-2)-0, 2-(2-2)-2, 2-2-2-2T, 2-2-(4-0)T divided drive locomotives between 1882 and 1903.

Alfred de Glehn

Alfred de Glehn introduced a successful divided drive 2-(2-2)-0 compound based on Webb's ideas,.

Use in the UK

Dugald Drummond Dugald Drummond (1 January 1840 – 8 November 1912) was a Scottish steam locomotive engineer. He had a career with the North British Railway, LB&SCR, Caledonian Railway and London and South Western Railway. He was the older brother of the eng ...

of the

London and South Western Railway The London and South Western Railway (LSWR, sometimes written L&SWR) was a railway company in England from 1838 to 1922. Originating as the London and Southampton Railway, its network extended to Dorchester and Weymouth, to Salisbury, Exeter ...

used divided drive (not very successfully) in his simple expansion T7 and E10 Classes of

4-2-2-0 Under the Whyte notation for the classification of steam locomotives, 4-2-2-0 represents the wheel arrangement of four leading wheels on two axles, four powered but uncoupled driving wheels on two axles, and no trailing wheels. The arrangement bec ...

. In the latter two instances the divided drive was adopted to allow the driving wheels to be spaced more widely than normal without the need for long

coupling rods A coupling rod or side rod connects the driving wheels of a locomotive. Steam locomotives in particular usually have them, but some diesel and electric locomotives, especially older ones and shunters, also have them. The coupling rods transfer ...

. This enabled an extra-long

firebox Firebox may refer to: * Firebox (steam engine), the area where the fuel is burned in a steam engine * Firebox (architecture), the part of a fireplace where fuel is combusted *Firebox Records, a Finnish 8101705801record label * Firebox.com, an elect ...

. Divided drive could also be used on simple expansion locomotives with coupled

s. The

NER Class X The NER Class X (LNER Class T1) was a class of 4-8-0T tank locomotive designed by Wilson Worsdell for the North Eastern Railway. They were intended for use as powerful shunting engines to arrange and move coal wagons for loading into ships. In ...

(LNER Class T1) 4-8-0T shunting engines designed by

Wilson Worsdell Wilson Worsdell (7 September 1850 – 14 April 1920) was an English locomotive engineer who was locomotive superintendent of the North Eastern Railway from 1890 to 1910. He was the younger brother of T.W. Worsdell. Wilson was born at Monks C ...

for the North Eastern Railway had three cylinders with divided drive. Similarly

Richard Maunsell Richard Edward Lloyd Maunsell (pronounced "Mansell") (26 May 1868 – 7 March 1944) held the post of chief mechanical engineer (CME) of the South Eastern and Chatham Railway from 1913 until the 1923 Grouping and then the post of CME of the ...

of the

Southern Railway (Great Britain) The Southern Railway (SR), sometimes shortened to 'Southern', was a British railway company established in the 1923 Grouping. It linked London with the Channel ports, South West England, South coast resorts and Kent. The railway was forme ...

designed the

SR Lord Nelson class The SR class LN or ''Lord Nelson'' class is a type of 4-cylinder 4-6-0 steam locomotive designed for the Southern Railway by Richard Maunsell in 1926. They were intended for Continental boat trains between London (Victoria) and Dover harbour ...

with divided drive between the front coupled axle for the inside cylinders and the middle coupled axle for the outside cylinders 'to give better weight distribution and reduced hammer blow'.

Sir Nigel Gresley Sir Herbert Nigel Gresley (19 June 1876 – 5 April 1941) was a British railway engineer. He was one of Britain's most famous steam locomotive engineers, who rose to become Chief Mechanical Engineer (CME) of the London and North Eastern Rail ...

of the

London and North Eastern Railway The London and North Eastern Railway (LNER) was the second largest (after LMS) of the " Big Four" railway companies created by the Railways Act 1921 in Britain. It operated from 1 January 1923 until nationalisation on 1 January 1948. At th ...

(LNER) used divided drive on his B17 class

4-6-0 A 4-6-0 steam locomotive, under the Whyte notation for the classification of steam locomotives by wheel arrangement, has four leading wheels on two axles in a leading bogie and six powered and coupled driving wheels on three axles with the ...

for hauling passenger services on the severely weight restricted

Great Eastern Main Line The Great Eastern Main Line (GEML, sometimes referred to as the East Anglia Main Line) is a major railway line on the British railway system which connects Liverpool Street station in central London with destinations in east London and the ...

. Gresley's successors Edward Thompson and

Arthur Peppercorn Arthur Henry Peppercorn, (29 January 1889 – 3 March 1951) was an English railway engineer, and was the last Chief Mechanical Engineer (CME) of the London and North Eastern Railway. Career Arthur Peppercorn was born in Leominster in 18 ...

both adopted divided drive on their larger designs as a consequence of their wish to overcome the maintenance problems associated with the

Gresley conjugated valve gear The Gresley conjugated valve gear is a valve gear for steam locomotives designed by Sir Nigel Gresley, chief mechanical engineer of the LNER, assisted by Harold Holcroft. It enables a three-cylinder locomotive to operate with only the two sets ...

Use in the United States

The concept was further developed in the early 1930s in the United States by the

Baldwin Locomotive Works The Baldwin Locomotive Works (BLW) was an American manufacturer of railroad locomotives from 1825 to 1951. Originally located in Philadelphia, it moved to nearby Eddystone, Pennsylvania, in the early 20th century. The company was for decades ...

, with their duplex locomotives, which divided the drive between two sets of outside cylinders.

References

Sources

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