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GS&WR Class 400

From Alfawiki
Great Southern & Western Railway
Company typeRailway company
IndustryRail transport
Founded1844
FateMerged into Great Southern Railways in 1925
Headquarters
Dublin
,
Ireland


  1. REDIRECT Template:Use Hiberno-English

Template:Infobox locomotive The GS&WR 400 class, also known as CIE class B2/B2a, comprised a fleet of ten 4-6-0 steam locomotives commissioned by the Great Southern & Western Railway (GS&WR) during the period from 1916 to 1923. These engines were designed specifically for express passenger service on the main line connecting Dublin and Cork. Although initially plagued by reliability issues, modifications carried out between 1927 and 1937 on the seven remaining locomotives—primarily converting from four cylinders to two—resulted in satisfactory operational performance. The final units were retired from service by 1961.[1][2]

Background

Edward A. Watson, originally from Clones, County Monaghan, joined GS&WR in 1911 as Works Manager at Inchicore. Prior to this, he had gained experience with the Pennsylvania Railroad and later with the Great Western Railway (GWR) in Great Britain, where he was valued for his knowledge of American engineering practices. In 1913, Watson was promoted to the role of Locomotive Superintendent, succeeding Richard Maunsell, who had departed for the South Eastern & Chatham Railway.[3] The GS&WR's principal route linked the two major cities of Southern Ireland—Dublin and Cork—with the Up and Down Mail trains representing the company's premier services.[4] By 1916, these flagship services were operated by Robert Coey’s 4-4-0 GS&WR Class 321 locomotives alongside the more powerful prototype No. 341 Sir William Goulding, introduced under Maunsell’s tenure.[4] Although No. 341 delivered commendable performance, concerns arose within the civil engineering department regarding its axle load.[5] Consequently, Watson aimed to develop an enhanced design for Cork line operations that would reduce reliance on double-heading, lower axle loads, and mitigate hammer-blow effects on the track.[5][6]

Prototype

Given Watson’s background at GWR’s Swindon Works, it is pertinent to compare his prototype No. 400 with the GWR Star class, especially since he had access to Star class drawings provided by GWR.[3] Both locomotives featured four cylinders with inner cylinders placed forward to drive the leading axle; however, several design elements diverged from GWR standards.[6] The location of the inner cylinders necessitated frame cutouts to accommodate rear bogie wheels, resulting in structural weaknesses. While Star class frames were constructed with 1+1⁄8 inches (29 mm) thick plating, those on No. 400 measured slightly thinner at 1+1⁄16 inches (27 mm), coupled with less substantial bolstering, which contributed to increased frame flexing and frequent steam pipe failures on No. 400.[6] The firebox dimensions resembled those of the GS&WR Class 368 rather than following GWR conventions, and boiler pressure was set at 175 pounds per square inch (1,210 kPa), a record level for Inchicore but lower than the 225 pounds per square inch (1,550 kPa) used on GWR Stars.[6] Additionally, Clements and McMahon noted that the piston valves employed a short lap of 1+1⁄4 inches (32 mm), compared to the GWR’s typical 1.63 minutes (98 s), reflecting chief designer Joynt’s preference but potentially detracting from performance.[6] Overall, No. 400 suffered from disappointing reliability combined with excessive coal and water usage.[7] Notably, No. 400 and its sister engines were unique as Ireland's only four-cylinder locomotives.Template:Fix/category[citation needed]

Main Production Runs

Following interruptions caused by shortages during World War I and complications arising from civil unrest, no additional locomotives were manufactured until 1921. At Inchicore, three enhanced units were constructed to address the shortcomings of No. 400. These featured reinforced frames, a redesigned steam pipe arrangement, modifications to the superheater, and the installation of Detroit three-feed lubricators. Consequently, the maximum axle load increased from Template:Long ton to Template:Long ton. The cab design was also revised during this production phase.[8]

Subsequently, two more sets of three locomotives each were produced by Armstrong Whitworth between 1922 and 1923. These batches incorporated further refinements and came equipped with larger tenders holding 4,500 imp gal (20,000 L; 5,400 US gal) of water. Notably, the second batch was delivered with saturated boilers operating at higher pressure; however, these units underperformed in service and required conversion to superheated boilers.[7]

Despite these enhancements, the class remained plagued by reliability issues.[7] Nevertheless, Oswald Nock acknowledged their speed capabilities, stating that "no one could say that the Watson 4-6-0s were other than fast," and praised their ability to function effectively even when fueled with inferior coal.[9]

Locomotive Rebuilding

When Bazin succeeded Watson, he inherited ten flagship locomotives that were problematic, unreliable, and expensive to maintain.[7] It is believed Bazin sought guidance from Maunsell, who assigned his chief designer Harry Holcroft to assist him; Bazin may also have drawn on experience from his previous role at Doncaster Works. Utilizing the boiler from the 400 class, Bazin developed a two-cylinder 4-6-0 mixed traffic model designated No. 500. This design was immediately successful and proved suitable for Cork Mail services despite not being tailored specifically for express passenger duties. The introduction of the Class 372 Woolwich Mogul in 1925 further demonstrated advancements over the 400 series by offering greater power alongside improved operational efficiency and reliability.[10]

Following the formation of the amalgamated Great Southern Railways (GSR) in 1925, Inchicore and Bazin assumed expanded responsibilities. Initial efforts focused on consolidating existing rolling stock from merged companies, much of which had deteriorated due to prior civil unrest.[11] In 1927, Bazin undertook an extensive rebuild of No. 402 into a two-cylinder locomotive drawing upon lessons learned from No. 500 and Holcroft’s input.[12] Although costly—the rebuild retained only the boiler and firebox while completely renewing frames and wheels, lengthening the wheelbase, and fitting a cab similar to the 500 class—the result was a successful locomotive.[13]

Due to financial constraints exacerbated by the global economic depression beginning in 1929, decisions were made to retire Nos. 341, 400, 404[lower-alpha 1], and 408. Around the same time in 1930, Inchicore undertook extensive rebuilds on engines No. 401 and No. 406 similar to that of No. 402; however, these included the addition of Caprotti valve gear and were classified as B2a. This left six reliable locomotives available for primary Dublin–Cork routes from both the 400 and 500 classes: Nos. 401, 402, 406, 500, 501, and 502.[14]

In 1930 Walter H. Morton became Chief Mechanical Engineer, later advancing to General Manager in 1932 when W. E. Harty took over as CME. Under Harty’s leadership between 1934 and 1935, Armstrong Whitworth-built locomotives Nos. 403, 405, and 409[lower-alpha 1] underwent rebuilds that were more economical and less extensive than previous ones. These retained existing wheels but incorporated new 19+1⁄2 inches (500 mm) cylinders with a shorter 26 inches (660 mm) piston stroke. Since this adjustment did not increase the distance from the leading driving axle by 6 inches (150 mm), it allowed modification of existing frames instead of full replacements as seen with Nos. 401, 402, and 406 rebuilds.[15] The resulting locomotives delivered a tractive effort of approximately 19,100 lbf (84.96 kN), around 1,500 lbf (6.67 kN) less than earlier rebuilt versions.[16] No. 407 followed suit in a rebuild completed by 1938; altogether these reconstructions spanned eleven years.[17]

Post-rebuild modifications resulted in most locomotives featuring split footplates; no two appeared identical after their respective refurbishments.[1] For instance, No. 401 had a split footplate design while No. 402 retained a flush footplate configuration; similarly, No. 406’s footplate was flush up to its cylinders due to their elevated position relative to the footplate surface.Template:Fix/category[citation needed]

Post-rebuild service

Following their reconstruction, the 400 series demonstrated significantly enhanced reliability and cost efficiency, providing many additional years of dependable operation for both the GSR and CIÉ.[18]

Among the rebuilt locomotives, No. 402 is often cited by Clements and McMahon as the preferred model.[19][lower-alpha 2] Notably, No. 402 reportedly achieved an average velocity of 67.5 miles per hour (108.6 km/h) during a special non-stop journey covering 165.3 miles (266.0 km) from Cork to Dublin Kingsbridge in March 1934, hauling a modest consist of three bogie coaches totaling 95 tons gross.[20] The other B2a rebuilds, numbers 401 and 406, were fitted with Caprotti valve gear and might have been more fuel-efficient than No. 402,[19] although there is evidence suggesting that optimal driving methods for this configuration were not consistently applied.[21]

By the late 1930s, the weight of trains operating on Cork routes was increasing.[22] Consequently, the 400s frequently required one or two pilot engines to assist with the ascent departing Cork. To address this challenge, the GSR introduced three new 800 class Queen locomotives during 1939–40 to facilitate faster schedules for the Cork Mail train.[23] The 400 series could only substitute and sustain these timings if the load remained under 100 tons.Template:Fix/category[citation needed]

Primarily assigned to the Dublin-Cork mainline, these locomotives hauled express passenger services as well as heavy freight and seasonal beet trains. In 1950, with the extension of the Enterprise Express to Cork, these engines—alongside the 800s and possibly some from the 500 series—were tasked with managing these runs.Template:Fix/category[citation needed] The deployment of Metropolitan Vickers A class Diesel locomotives in 1955 displaced them from regular duties on principal express services.[24] While Nos. 401 and 402 remained operational as late as 1962, all units had been withdrawn and scrapped by 1964.Template:Fix/category[citation needed]

Fleet

Class 400 B2/B2a Fleet details[25]
No. Manufacturer Entry into Service Superheated 2-Cylinder Valve Gear Date Withdrawn Remarks
400 Inchicore Works 1916 1916 - Walschaerts 1929
401 Inchicore 1921 1921 1930 Caprotti 1961
402 Inchicore 1921 1921 1927 Walschaerts 1961
403 Armstrong Whitworth 1923 1923 1934 Walschaerts 1958
404 (409) Armstrong Whitworth 1923 1923 1935 Walschaerts 1958 Renumbered from 409 to avoid withdrawal
405 Armstrong Whitworth 1923 1923 1934 Walschaerts 1955
406 Inchicore 1921 1921 1930 Caprotti 1957
407 Armstrong Whitworth 1923 1925 1938 Walschaerts 1955
408 Armstrong Whitworth 1923 1924 - Walschaerts 1930
409 (404) Armstrong Whitworth 1923 1924 - Walschaerts 1930 Renumbered as 404 prior to withdrawal/scrapping


Livery

Locomotive No. 400 originally appeared in the standard GS&WR paint scheme of a muted or dark grey tone,[lower-alpha 3] accentuated with red and white lining.[27][lower-alpha 4] Visual evidence reveals metal number plates mounted on the cab sides alongside orange-painted numerals on the red front buffer beam.[29] This grey livery persisted until 1947, at which point the remaining engines were repainted green with black and white lining, aligning with several other passenger locomotive classes. The C.I.E. flying snail emblem was typically displayed on the tender, metal cabside numbers were removed,[30] and photographic records show that front buffer beam numbers were sometimes taken off and repositioned above the smokebox.[31][lower-alpha 5]

Model

A highly detailed O Gauge replica of engine 404 exists within the Fry model railway collection. This model was initially crafted by Bassett-Lowke for display at the 1924 British Empire Exhibition.[33]

  1. ↑ 1.0 1.1 Clements & McMahon (2008), pp. 235–244.
  2. ↑ Carse (2016).
  3. ↑ 3.0 3.1 Murray & McNeill (1976), p. 152.
  4. ↑ 4.0 4.1 Baker (1972), pp. 82–83.
  5. ↑ 5.0 5.1 Baker (1972), p. 83.
  6. ↑ 6.0 6.1 6.2 6.3 6.4 Clements & McMahon (2008), p. 236.
  7. ↑ 7.0 7.1 7.2 7.3 Clements & McMahon (2008), pp. 236–238.
  8. ↑ Clements & McMahon (2008), pp. 236–237.
  9. ↑ Nock (1982), pp. 189–190.
  10. ↑ Clements & McMahon (2008), pp. 234–235, 238–239, 245–246.
  11. ↑ Clements & McMahon (2008), pp. 129–130.
  12. ↑ Clements & McMahon (2008), pp. 238–239.
  13. ↑ Clements & McMahon (2008), pp. 238–241.
  14. ↑ Clements & McMahon (2008), pp. 229–243.
  15. ↑ Clements & McMahon (2008), pp. 240, 242–244.
  16. ↑ Nock (1982), p. 190.
  17. ↑ Clements & McMahon (2008), p. 239.
  18. ↑ Baker (1972), p. 85.
  19. ↑ 19.0 19.1 Clements & McMahon (2008), p. 241.
  20. ↑ Nock (1982), pp. 190–191.
  21. ↑ Nock (1982), pp. 194–195.
  22. ↑ Nock (1982), p. 196.
  23. ↑ Nock (1982), p. 271.
  24. ↑ Baker (1972), p. 90.
  25. ↑ Clements & McMahon (2008), pp. 235, 239.
  26. ↑ Baker (1972), p. 210.
  27. ↑ Baker (1972), pp. 83, 210.
  28. ↑ Clements & McMahon (2008), p. 235.
  29. ↑ Clements & McMahon (2008), pp. 239–244.
  30. ↑ Baker (1972), pp. 211–212.
  31. ↑ Clements & McMahon (2008), p. 243.
  32. ↑ Baker (1972), p. 212.
  33. ↑ Clements & McMahon (2008), p. 380.


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