Divided drive (locomotive)
Encyclopedia
A divided drive locomotive is a steam locomotive
that divides the driving force on its wheels by using different cylinders to power different pairs of driving wheel
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 to accommodate a larger firebox.
in the 1870s on a number of rigid-wheelbase compound locomotives, and then during the 1880s, on Mallet
articulated locomotive
s. 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. Similarly, Alfred de Glehn
introduced a successful divided drive 2-(2-2)-0
compound based on Webb's ideas, and, less successfully, by Dugald Drummond
of the London and South Western Railway
with his simple expansion T7
and E10 Classes of 4-2-2-0
. 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. This enabled an extra-long firebox
.
Divided drive could also be used on simple expansion locomotives with coupled driving wheel
s.
The NER Class X
(LNER Class T1) 4-8-0T shunting engines
designed by Wilson Worsdell
for the North Eastern Railway
had three cylinders with divided drive.. Similarly Richard Maunsell
of the Southern Railway (Great Britain)
designed the SR Lord Nelson class
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 of the London and North Eastern Railway
(LNER) used divided drive on his B17 class
4-6-0
for hauling passenger services on the severely weight restricted Great Eastern Main Line
. Gresley's successors Edward Thompson
and Arthur Peppercorn
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 concept was further developed in the early 1930s in the United States by the Baldwin Locomotive Works
, with their duplex locomotive
s which divided the drive between two sets of outside cylinders.
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...
that divides the driving force on its wheels by using different cylinders to power different pairs of driving wheel
Driving wheel
On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons...
s in order to give better weight distribution and reduce "hammer blow
Hammer blow
Hammer blow, in rail terminology, refers to the vertical forces transferred to the track by the driving wheels of a steam locomotive and some diesel locomotives. The largest proportion of this is due to the unbalanced reciprocating motion, although the piston thrusts also contribute a portion to it...
" which can be damaging to the track, or else to enable the wider spacing of the driving wheels to accommodate a larger firebox.
Origins
The system of dividing drive was originally developed by Anatole MalletAnatole Mallet
Jules T. Anatole Mallet was a Swiss mechanical engineer, who was the inventor of the first successful compound system for a railway steam locomotive, patented in 1874....
in the 1870s on a number of rigid-wheelbase compound locomotives, and then during the 1880s, on Mallet
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. Mallet's ideas inspired Francis Webb
Francis Webb (engineer)
Francis William Webb was a British engineer responsible for the design and manufacture of locomotives for the London and North Western Railway .- Biography :...
in Britain who introduced 2-(2-2)-0
2-(2-2)-0
Under the Whyte notation for the classification of steam locomotives, 2--0 represents the wheel arrangement of two leading wheels on one axle, four powered but uncoupled driving wheels on two axles, and no trailing wheels.-Usage:...
, 2-(2-2)-2
2-(2-2)-2
Under the Whyte notation for the classification of steam locomotives, 2--2 represents the wheel arrangement of two leading wheels on one axle, four powered but uncoupled driving wheels on two axles, and two trailing wheels on one axle.-Usage:...
, 2-2-2-2T, 2-2-(4-0)
2-2-(4-0)
Under the Whyte notation for the classification of steam locomotives, 2-2- represents the wheel arrangement of two leading wheels on one axle, two driving wheels powered from the inside cylinders, four coupled driving wheels powered from the outisde cylinders but no trailing wheels.-Usage:This...
T divided drive locomotives between 1882 and 1903. Similarly, Alfred de Glehn
Alfred de Glehn
Alfred George de Glehn was a notable English-born French designer of steam locomotives, and an engineer at the Société Alsacienne de Constructions Mécaniques . His steam engines of the 1890s combined elegance, high speed and efficiency...
introduced a successful divided drive 2-(2-2)-0
2-(2-2)-0
Under the Whyte notation for the classification of steam locomotives, 2--0 represents the wheel arrangement of two leading wheels on one axle, four powered but uncoupled driving wheels on two axles, and no trailing wheels.-Usage:...
compound based on Webb's ideas, and, less successfully, by Dugald Drummond
Dugald Drummond
Dugald Drummond 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...
of the London and South Western Railway
London and South Western Railway
The London and South Western Railway was a railway company in England from 1838 to 1922. Its network extended from London to Plymouth via Salisbury and Exeter, with branches to Ilfracombe and Padstow and via Southampton to Bournemouth and Weymouth. It also had many routes connecting towns in...
with his simple expansion T7
LSWR T7 class
The LSWR Class T7 4-2-2-0 was a prototype express steam locomotive design by Dugald Drummond for the London and South Western Railway introduced in 1897.-Background:Number 720 was a prototype locomotive built in 1897...
and E10 Classes of 4-2-2-0
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...
. 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. This enabled an extra-long firebox
Firebox
In a steam engine, the firebox is the area where the fuel is burned, producing heat to boil the water in the boiler. Most are somewhat box-shaped, hence the name.-Railway locomotive firebox :...
.
Divided drive could also be used on simple expansion locomotives with coupled driving wheel
Driving wheel
On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons...
s.
The NER Class X
NER Class X
The NER Class X 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 total 15 were built, 10 by the NER between 1909 and 1910, and a...
(LNER Class T1) 4-8-0T shunting engines
Switcher
A switcher or shunter is a small railroad locomotive intended not for moving trains over long distances but rather for assembling trains ready for a road locomotive to take over, disassembling a train that has been...
designed by Wilson Worsdell
Wilson Worsdell
Wilson Worsdell was a British locomotive engineer who was locomotive superintendent of the North Eastern Railway from 1890 to 1910. He was the younger brother of T.W. Worsdell.-Family:...
for the North Eastern Railway
North Eastern Railway (UK)
The North Eastern Railway , was an English railway company. It was incorporated in 1854, when four existing companies were combined, and was absorbed into the London and North Eastern Railway at the Grouping in 1923...
had three cylinders with divided drive.. Similarly Richard Maunsell
Richard Maunsell
Richard Edward Lloyd Maunsell held the post of Chief Mechanical Engineer of the South Eastern and Chatham Railway from 1913 until the 1923 Grouping and then the post of CME of the Southern Railway in England until 1937....
of the Southern Railway (Great Britain)
Southern Railway (Great Britain)
The Southern Railway 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...
designed the SR Lord Nelson class
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 and Dover harbour, but were also later used for express passenger work to the South-West...
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
Hammer blow
Hammer blow, in rail terminology, refers to the vertical forces transferred to the track by the driving wheels of a steam locomotive and some diesel locomotives. The largest proportion of this is due to the unbalanced reciprocating motion, although the piston thrusts also contribute a portion to it...
'.
Sir Nigel Gresley of the London and North Eastern Railway
London and North Eastern Railway
The London and North Eastern Railway was the second-largest of the "Big Four" railway companies created by the Railways Act 1921 in Britain...
(LNER) used divided drive on his B17 class
LNER Class B17
The London and North Eastern Railway Class B17, also known as "Sandringham" or "Footballer" class was a class of 4-6-0 steam locomotive designed by Sir Nigel Gresley for hauling passenger services on the Great Eastern Main Line...
4-6-0
4-6-0
Under the Whyte notation for the classification of steam locomotives, 4-6-0 represents the wheel arrangement of four leading wheels on two axles in a leading truck, six powered and coupled driving wheels on three axles, and no trailing wheels. This wheel arrangement became the second-most popular...
for hauling passenger services on the severely weight restricted Great Eastern Main Line
Great Eastern Main Line
The Great Eastern Main Line is a 212 Kilometre major railway line of the British railway system, which connects Liverpool Street in the City of London with destinations in east London and the East of England, including Chelmsford, Colchester, Ipswich, Norwich and several coastal resorts such as...
. Gresley's successors Edward Thompson
Edward Thompson (engineer)
Edward Thompson was Chief Mechanical Engineer of the London and North Eastern Railway between 1941 and 1946.- Biography :Edward Thompson was the son of an assistant master at Marlborough College. He was educated at Marlborough before taking the Mechanical Science Tripos at Pembroke College,...
and Arthur Peppercorn
Arthur Peppercorn
Arthur Henry Peppercorn, OBE was the last Chief Mechanical Engineer of the London and North Eastern Railway.- Career :...
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
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...
.
The concept was further developed in the early 1930s in the United States by the Baldwin Locomotive Works
Baldwin Locomotive Works
The Baldwin Locomotive Works was an American builder of railroad locomotives. It was located in Philadelphia, Pennsylvania, originally, and later in nearby Eddystone, Pennsylvania. Although the company was very successful as a producer of steam locomotives, its transition to the production of...
, with their duplex locomotive
Duplex locomotive
A duplex locomotive is a steam locomotive that divides the driving force on its wheels by using two pairs of cylinders rigidly mounted to a single locomotive frame; it is not an articulated locomotive...
s which divided the drive between two sets of outside cylinders.