LSWR O2 class

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LSWR/SR O2 ^[1]

Number W24 Calbourne and vintage ex-SECR carriage on the Isle of Wight Steam Railway (c) Ron Strutt.
Power type	Steam
Designer	William Adams
Builder	LSWR Nine Elms Works
Build date	1889-1895
Total production	60
Configuration	0-4-4
Gauge	4 ft 8½ in (1,435 mm)
Driver size	58 in (1.473 m)
Trailing wheel size	37 in (0.940 m)
Length	30 ft 8.5 in (9.36 m)
Locomotive weight	48.40 long tons (49.2 t)
Fuel type	Coal
Fuel capacity	1.50 long tons (1.5 t); later 3.25 long tons (3.3 t)
Water capacity	800 imp gal (3,600 l)
Boiler pressure	160 psi (1.10 MPa)
Cylinders	Two, inside
Cylinder size	17½×24 in (445×610 mm)
Tractive effort	17,235 lbf (76.67 kN)
Career	London and South Western Railway, Southern Railway, Southern Region of British Railways
Class	LSWR: O2 SR: O2 BR: 0P
Locale	Great Britain
Disposition	One preserved, remainder scrapped

The LSWR O2 Class is a class of 0-4-4T steam locomotive designed for the London and South Western Railway by William Adams. Sixty were constructed during the late nineteenth century.

[edit] Background

Adams was presented with the problem of a greatly increasing volume of commuter traffic experienced with the suburbanisation of London during the 1880s.^[2] This was exacerbated by the fact that there were few locomotive classes in the LSWR stable that could undertake commuter traffic at the desired level of efficiency.^[2] The LSWR therefore required a locomotive with attributes of power and compactness, with a small wheel size to gain acceleration on intensive timetables. Adams settled upon the 0-4-4T wheel arrangement to provide the basis of what was to become the O2 Class.^[2]

[edit] Construction history

The second of William Adam's 0-4-4 designs, the O2 Class was a development of his previous T1 class of 1888.^[1] The brief behind the design was to create a locomotive capable of mixed-traffic operations, a characteristic dictated by the relatively small wheel diameter and smaller cylinders, effectively to replace the obsolete Beattie Well Tank.^[3] As a result, a compact locomotive with high route availability was produced, a factor that would be taken into account during the later career of the class.^[3]

Production began in 1889, with the first 20 being constructed at the LSWR's Nine Elms works.^[1] The success of the locomotive ensured that a second batch of 30 locomotives was ordered the next year. A final batch of ten was constructed by 1895.^[1]

[edit] Livery and numbering

[edit] LSWR and Southern

Initially outshopped in early LSWR passenger Yellow Ochre/Brown livery with the initials 'LSW' on the water tank sides.^[2] This was eventually superseded by the later LSWR Passenger Sage Green livery, with black edging and black and white lining.^[3] Numbering was in gilt, as was the 'LSWR' lettering on the water tank side.^[3]

All the O2s allocated to the Isle of Wight were granted names that were relevant to the island. Only a solitary mainland locomotive ever carried a name in service, number 185 Alexandria for a short period in 1890.^[3]

Numbering was differentiated between those allocated to the Isle of Wight and the mainland, with those on the island numbered W14 to W36, and those on the mainland were numbered 177 to 236.^[3]

[edit] Post-1948 (nationalisation)

225 pictured in 1948.

The class was given the Power Classification of OP (Other Passenger), and initially carried the Southern livery with the addition of 'British Railways' on the water tank sides, though this was promptly changed to the BR Standard Mixed-Traffic Black livery with red and white lining.^[4]

The Isle of Wight's unique numbering system was retained on the BR examples on the island, along with the names. They were numbered W14 to W36.^[4]

The mainland complement were given numbers in the 30xxx series. These locomotives were numbered as thus: 30177 to 30236.^[4]

[edit] Operational details and preservation

The class was distributed throughout the LSWR system, being of particular use on restricted branch lines due to the relatively low weight and short wheelbase.^[3] However, they were made increasingly redundant by the larger, more powerful M7 Class designed by Dugald Drummond when they were introduced to LSWR metals in 1897.^[1]

The class is usually best associated with the Isle of Wight railway system, with the Isle of Wight Central Railway making enquires as to the possibility of purchasing some class members in the early twentieth century.^[1] This plan, however, fell through, and it was not until after Grouping in 1923, that the newly formed Southern Railway was forced to resolve the desperate locomotive power situation on the Isle of Wight.^[3]

The situation to resolve this problem presented itself when electrification of the LSWR's suburban meant intensification of timetables and a requirement for newer, more powerful designs, such as the M7s and T1s.^[3] As a result, several O2s became surplus to mainland requirements, allowing nine O2s to be sent over to the island, where they proved to be highly successful.^[2]

A further 14 were sent over, the final two being sent over in 1949, after Nationalisation, resulting in a total of 23 locomotives on the island.^[3] Due to tunnel restrictions at Ventnor, none of the final series of 10 with the higher cab roofs were sent to the island.^[1] Because of their compact nature, they proved ideal for island duties, although the problem of the lack of adequate coal bunker space hampered the class. This meant that from 1932, a much larger extended bunker was fitted to W19 (formerly 206), and this design subsequently became the standard for all the island locomotives.^[1]

The larger cabbed examples and other mainland O2 locomotives began to be withdrawn, with eight going in the 1930s, and four more in the 1940s.^[1] However, the rest lasted well into BR days, working various branch lines until closure began to take place in the late 1950s and early 1960s.^[4] As a result, the mainland O2s became redundant and the last to go was no.225 in 1962.^[4]

In terms of the Isle of Wight examples, they were gradually withdrawn with some of the class lasting until the end of steam on the island in 1966.^[4] One, W24 Calbourne survived to preservation on the Isle of Wight Steam Railway.^[1]

[edit] References

1. ^ ^{a b c d e f g h i j} Herring, Peter: Classic British Steam Locomotives (Abbeydale Press: London, 2000) Section "O2/M7 Classes" Pages 60-61 ISBN 1861470576
2. ^ ^{a b c d e} Burtt, F.: L. & S.W.R. locomotives: 1872-1923 (London: Ian Allan, 1949)
3. ^ ^{a b c d e f g h i j} Bradley, D.L.: LSWR Locomotives: The Adams Classes (Didcot: Wild Swan Publications, 1985)
4. ^ ^{a b c d e f} Longworth, Hugh: British Railway Steam Locomotives: 1948-1968 (Oxford Publishing Company: Oxford, 2005) ISBN 0860935930

[edit] See also

• List of Isle of Wight-based O2 Class locomotives

[edit] External links

• http://www.semgonline.com/steam/o2class_01.html