by Martin A Barker

THERE  are  a  considerable  number  of  builders  of  small  locomotives  of  all scales  and  gauges who  are completely at a loss when the term ‘quartering’ is mentioned. Basically, it is the setting of the wheels of a two or four cylinder locomotive to ensure that the crankpins on one side are at 90° to those on  the other, in order to ensure self-starting.  If both crankpins on each axle were synchronized, then not only would you get a lumpy running locomotive but, sooner or later with a steam locomotive,  you  would  stop  with  both  pistons  at  the  same  end  of  the cylinder, and then the problems become obvious!

I am not going to describe methods of setting wheels on each axle at 90°, suffice to say these are many and various, ranging from counting the spokes and  setting  by  eye  (not  recommended  for  obvious  reasons),  to  fearsome arrangements of steel plates, bits of bed angle or setting by dial test indicators on the lathe. In point of fact, it doesn’t matter if the wheels are at 89° or 91°, as long as all wheels are set at the same angle.

In the early days of locomotive construction,  it  was  the  difficulty  of  ensuring  that  all  wheels  were  set accurately  which  was  one  of  the  reasons  that  single  driving  wheeled  types were preferred for fast passenger train working.

It follows that one side of a locomotive is therefore ‘set’ so that it operates in advance of the other, and it is that side which is said to ‘lead’. The side in question  is  determined  by  choosing  a  fixed  point  on  one  locomotive  frame plus its corresponding point on the other side  and observing which crankpin passes the chosen point first after a complete wheel revolution - the right or left crankpin. The right or left side of a locomotive is determined by standing in the cab and looking forward.

Having determined how to find which side of a locomotive actually leads, it  now  remains  to  determine  which  full-sized  locomotives  had  right  or  left hand  lead,  and  this  is  done  by  listing  the  favoured  settings  of  the  various companies.  Unfortunately,  I  cannot  give  much  help  regarding  locomotives foreign to British shores or the Scottish companies, and it should be borne in mind that each of the ‘Big Four’ companies absorbed locomotives from their constituents  which  did  not  necessarily  see  eye-to-eye  regarding  wheel quartering. However, all the Big Four companies favoured right hand lead for

their standard designs, as did British Railways for theirs, but here is a list of

various designs pre-1923:

LNER constituents

Great Central   Right hand  lead.

Great Eastern  Right hand  lead.

Great Northern     Right hand  lead.

Great North of Scotland  Right hand  lead.

Hull & Barnsley Left  hand  lead.

Lancashire, Derbyshire & East Coast Left  hand  lead.

North British  Information welcomed !

North Eastern    Right hand  lead.

LMS Constituents

Caledonian Information welcomed !

Furness Left  hand lead.

Glasgow & South Western  Right hand lead.

Highland Right hand lead.

Lancashire & Yorkshire   Right hand lead.

London & North Western  Left  hand lead.

Midland Right hand lead.

North London  Information welcomed !

North Staffordshire  Information welcomed !

GWR and constituents

The constituent companies, particularly the Welsh Valley lines, would normally patronize the locomotive building companies for their engines, and as  we  will  see,  they  tended  to  have  their  own  ideas  as  to  wheel  quartering.

Few,  if  any,  companies  patronized  only  one  builder,  and  some  bought  odd engines second hand, so it was quite possible to find both right and left hand lead  locomotives  on  the  same  railway.  However,  any  information  would  be welcomed.

Great Western

    Standard Gauge engines   Right hand lead.

    Broad Gauge engines unknown.

Southern constituents

London, Brighton & South Coast Right hand lead.

London, Chatham & Dover  Left  hand lead.

London & South Western   Right hand lead.

South Eastern  Information welcomed !

South Eastern & Chatham

Joint  Management Committee Left hand lead on Wainwright engines. Maunsell engines not known.

However, the LSWR derived types, the N15, King Arthurs, and S15s, had right hand lead as did the Schools and Lord Nelsons.

Private locomotive builders.

Andrew Barclay and Kitson & Co., if left to themselves, favoured left hand lead. Peckett & Co. and Fletcher, Jennings both used right hand lead as their norm.  The Talyllyn Railway has two Fletcher, Jennings locomotives and two of Barclay origin: assuming that Barclay retained left hand lead on its narrow gauge engines, then the TR has engines with both right and left  lead on its metals!  It’s  years  since  I  saw  the  TR  engines,  so  I  can’t  for  the  life  of  me remember which side leads on its Henry Hughes and Kerr, Stewart engines.

Also, I have not noted which side was favoured by Beyer, Peacock; Manning Wardle; Hudswell, Clarke; Yorkshire Engine; Stephenson & Co.; Hawthorn, Leslie;  North  British  Loco,  and  constituents  to name but  a  few,  although  I can state that Black, Hawthorn used right hand lead.


There  are,  of  course,  qualifications  to  the  above.  It  would  seem  that  the GWR  may  well  have  reset  left  leading  locomotives  from  their  absorbed companies  if  they  came  in  for 

heavy  rebuilding  (new  taper  boilers, GWR pattern  side-tanks  and  bunkers,  etc.). There  were  also  oddities:  one  of  the preserved  LBSCR  Terrier  tanks  (Boxhill  if  I  remember  correctly), acquired left hand lead wheels as a result of a visit to Ashford Works, which belonged to  the South Eastern & Chatham.   I understand that  they had to make  a  new  crank  axle,  which  they  duly  did  to  their  standards,  but  then found  they  had  to  reset  the  wheels  to  suit,  so  of  all  William  Stroudley’s engines, it is unique in having its boots on the wrong  feet, so to speak.

With three cylinder engines, ‘quartering’ is not actually done at quarters, but  is  nominally  at  120°,  although  that  only  applies  to  engines  with  all cylinders at the same angle of inclination. With the Gresley Pacifics and V2 2-6-2s, the driving crankpins and crank axle are actually set at 120°, 114° and 126° due to the difference in angles between inside and outside cylinders. This may  well  have  applied  to  other  Gresley  engines,  such  as  the  B17,  D49,  K3, K4,  02,  P1,  P2,  V1,  V3 (photo above),  V4  and  W1  classes.  H. Holcroft,  an  expert  in conjugated  valve  gears,  had  pointed  out  to  Gresley  that  all  three  cylinders need not be at the same angle provided that the difference was allowed for in setting  the  cranks, and this  cleared  the way for  the famous Gresley  ‘2  to  1’ gear, usually in front of the cylinder block, but behind on the B17 and D49 types. With cranks set at 120° three cylinder engines gave six exhaust beats per wheel revolution.

Most four cylinder engines had adjacent cranks (outside and inside), set at 180°  to  each  other  and  the  inside  cranks  at  90°,  so  the  back  stroke  of  one cylinder synchronized with the forward stroke  of another so  that  there were still four exhaust beats per revolution, and making it easy to operate one set of valves by means of rocking levers thus saving two sets of valve gear.  However, the Southern.s Lord Nelson 4-6-0s had four sets of Walschaerts. valve gear set  to  give  eight  exhaust  beats  per  revolution  -  the  so-called  135°  crank settings, although the outside right crank was set  at 90° to the outside left; the  inside  right  crank  was  at  90°  from  the  inside  left  but  at  45°  from  the outside left, which leaves the inside and outside right  cranks at 135°, with the left  side cranks similarly. LBSC and Holcroft between them devised a 2.5 inch  gauge  Pacific,  Tugboat  Annie,  which  had  four  cylinders  and  eight exhaust  beats  per  revolution.  The  valves  were  worked  by  an  ingenious conjugated  gear,  which  has  been  well  described  in  various  books  on locomotive building by LBSC and Martin Evans.

Of course, engines with crank axles do not necessarily have to have three or four  cylinders;  for  around  a  century  and  a  quarter  Britain’s  rail  traffic  was moved by locomotives with two inside cylinders only. In point of fact when the end of North Eastern Region steam came in September 1967, there were still  four  such  0-6-0s  on  the  books,  belonging  to  the  old  North  Eastern Railways P3 class (LNER J27).

Most inside cylinder engines had the driving cranks set at 180° to the side-rod crankpins on their respective sides, although Stroudley on the LBSCR set them in line. The webs on the crank axle themselves were normally oblong or oval  in  shape,  although  the  North  Eastern  from  T.W.Worsdell  in  the  late 1880s  used  circular  webs, ideal  for  those  who  prefer  to  turn  crank  axles between  centres  from  solid  bar,  and  H.A.Hoy  on  the  L&Y  from  1900 introduced  ‘waisted’  crank webs which resembled  a  figure  8,  but  these were ultimately  discarded  as  being  too  weak.  Sometimes,  crank  webs  of  oblong form were extended beyond the  axle opposite to  the crank itself  in  order to

produce  a  degree  of  balance:  a  feature  used  by  Dugald Drummond on  the LSWR.

One feature  that  I  have  never  seen  referred  to  in  print,  is  the  fact that many locomotives had inside crank throws which differed from that of the  wheel  crankpins  -  North  Eastern  passenger  locomotives  had  side  rod throws of 2 inches less than the driving crank throw, a feature which seems to have  been  applied  to  wheels  with  diameters  of  around  5  ft.  and  above. The NER  was  not  alone  in  this  practice,  although  different  engineers  used different amounts.  I do not know why this was done; was it to cut down on centrifugal  forces and the  resulting ‘hammer blow’ when running at  speed, or  a  form  of  gearing  up  or  down,  possibly  to  increase  torque  effect? 

One example of an outside cylinder type with different crank throws also exists, the  GNR  Ivatt  Atlantics,  which  had  the  driving  crankpins  turned  on  two different  centres  to accommodate the  different  throws.  I  expect  the LBSCR Marsh Atlantics to have had the same feature, due to their common origins, and  the  replica  Brighton  Atlantic  currently  being  built  on  the Bluebell  Railway may well  have  this  feature. 

Finally for builders of  Stephensons  Rocket  as  a  serious  working  locomotive,  I  feel  it  is worthwhile  pointing  out  that  its  crankpins  and  wheels  are  set  to  give  left-hand lead.

The foregoing information has been gathered from observations of preserved  locomotives,  supplemented  by  examination  of  various  works drawings  and  articles  in  Engineering  and  The  Engineer,  plus  conversations with retired locomotive men, many of whom are now sadly no longer with  us.   Where possible,  I  have  looked  at  several  examples  of  a company’s locomotives, but with the Furness for example, I only had No.3 to look at, so had to take a deep breath and cross my fingers and hope that timings didn’t alter.  As it is, I hope this has been of use to some-one, and any feedback to fill  in  the  missing  gaps would be welcome; also  the  definitive answer to the different crank throw conundrum!