The Glasgow and South Western Railway 540 Class were 4-6-4T steam tank locomotives designed by Robert Whitelegg and built in 1922, shortly before the G&SWR was absorbed into the London, Midland and Scottish Railway (LMS). They were referred to in official G&SWR publicity as the Baltic Class, although they were also known more prosaically to enginemen as the 'Big Pugs'.[3]

Glasgow & South Western Railway 540 Class
Type and origin
Power typeSteam
DesignerRobert Whitelegg
BuilderNorth British Locomotive Company, Hyde Park Works, Glasgow
Serial number22886–22891
Build date1922
Total produced6
Specifications
Configuration:
 • Whyte4-6-4T
Gauge4 ft 8+12 in (1,435 mm)
Leading dia.3 ft 6 in (1.07 m)
Driver dia.6 ft 0 in (1.83 m)[1]
Trailing dia.3 ft 6 in (1.07 m)
Wheelbase39 ft 0 in (11.89 m) ​
 • Leading07 ft 0 in (2.13 m)
 • Drivers06 ft 7 in (2.01 m) +
06 ft 7 in (2.01 m)
 • Trailing07 ft 0 in (2.13 m)
Loco weight99 tons[1]
Boiler:
 • Diameter5 ft 6+316 in (1.681 m)
 • Tube plates14 ft 11 in (4.55 m)
Boiler pressure180 psi[1]
Heating surface1,730 sq ft (161 m2)
Superheater:
 • TypeRobinson, 21-element
 • Heating area255 sq ft (23.7 m2)
CylindersTwo, outside
Cylinder size22 in × 26 in (559 mm × 660 mm)[1]
Valve gearWalschaerts[2]
Valve typePiston valves
Performance figures
Tractive effort26,741 lbf (118.95 kN)[1]
Career
OperatorsG&SWR • LMS
ClassG&SWR: 540
Power classLMS: 5P
Numbers
  • G&SWR 540–545
  • LMS: 15400–15405
Withdrawn1935–1936
DispositionAll scrapped

Overview

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The G&SWR had historically favoured small tender locomotives for almost all duties other than light shunting, and prior to the delivery of the Baltics its only passenger tank engines were 14 small 0-4-4Ts built for suburban services. However, Robert Whitelegg had previously served as Locomotive Superintendent of the London, Tilbury and Southend Railway which made almost exclusive use of tank engines on its heavy commuter traffic, and he brought this experience with him when he joined the G&SWR as Chief Mechanical Engineer in 1919. During his time at the LT&SR Whitelegg had designed the first 4-6-4T locomotives to operate in Great Britain; the LT&SR 2100 Class. Some of the G&SWR's passenger traffic resembled the LT&SR express services, so Whitelegg again opted for a 4-6-4T.[3]

The new Baltics were built to a very high specification and were intended to represent the very best practice of their time, so they were very expensive to build. They were also easily the most powerful locomotives ever operated by the G&SWR, and the company made the most of their delivery for publicity purposes. In service the locomotives performed very well on express passenger trains between Glasgow St Enoch and the Ayrshire coast towns or Kilmarnock, however they were expensive to maintain.[4]

LMS ownership

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Within a few months of delivery the locomotives passed into the ownership of the newly formed London, Midland and Scottish Railway, and their green G&SWR livery was replaced by LMS crimson lake. By the end of the 1920s they were being repainted into lined black.

The LMS drive for standardisation saw large numbers of new Fowler 2P and 4P Compound 4-4-0s delivered to the former G&SWR section, and in time these displaced the Baltic tanks from the top passenger services. There was little other work suitable for such large tank engines, and in any event as a non-standard class of only 6 engines they were doomed to be withdrawn once their boilers became due for renewal. The whole class was therefore withdrawn and scrapped between 1935 and 1937.[5]

Numbering and locomotive histories

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Table of locomotives[5][6]
G&SWR no. LMS no. Builder's no. Delivered Withdrawn
540 15400 NBL 22886 Mar 1922 Jan 1935
541 15401 NBL 22887 Mar 1922 Apr 1935
542 15402 NBL 22888 Mar 1922 Apr 1935
543 15403 NBL 22889 Apr 1922 Dec 1935
544 15404 NBL 22890 Apr 1922 Sep 1936
545 15405 NBL 22891 Apr 1922 Aug 1936

References

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  1. ^ a b c d e Casserley & Johnston 1966, p. 161.
  2. ^ Smith 1976, p. 140.
  3. ^ a b Smith 1976, p. 179.
  4. ^ Essery & Jenkinson 1986, p. 137.
  5. ^ a b Smith 1976, p. 180.
  6. ^ Baxter 1984, p. 169–170.
  • Baxter, Bertram (1984). Baxter, David (ed.). British Locomotive Catalogue 1825–1923, Volume 4: Scottish and remaining English Companies in the LMS Group. Ashbourne, Derbyshire: Moorland Publishing Company. pp. 169–170.
  • Casserley, H.C.; Johnston, S.W. (1966). Locomotives at the Grouping 3: London Midland and Scottish. Ian Allan.
  • Essery, Bob; Jenkinson, David (1986). An Illustrated History of L.M.S. Locomotives, Volume Three: Absorbed Pre-Group Classes, Northern Division. OPC.
  • Smith, David L. (1976). Locomotives of the Glasgow & South Western Railway. David & Charles.