London, Brighton & South Coast 4-4-2 Locomotives in Great_Britain

Class H1 (Locobase 9082)

Data from Fowler, Illustrated Locomotive Dictionary (1906) and "Atlantic Passenger Locomotive, L B & SC Ry", The Locomotive Magazine, Vol XII (15 January 1906), p. 5. J N Maskelyne, "The Express Locomotives of the London, Brighton and South Coast", Locomotive News and Railway Notes, Volume I [1], No. 5 (10 May 1919), p. 40. Works numbers were 4351-4355 in 1905.

Designed by Douglas Earle Marsh in what would be a warm-up for the celebrated H2s (Locobase 2293) and described by Glover (1967) as derivatives of Ivatt's Great Northern Atlantics. Certainly the big boiler deserved a bit more firebox area than is shown in the specs. Still and all, these were impressive engines with a relatively wide grate, individual splashers on the drivers and outside bearings on the trailing axle.

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Class H2 (Locobase 2293)

Data from "New 4-4-2 Express Locomotives, LB & SC Ry", Locomotive Magazine, Volume XVII (15 November 1911), p. 238. See also Ahrons (1927) and J N Maskelyne, "The Express Locomotives of the London, Brighton and South Coast", Locomotive News and Railway Notes, Volume I [1], No. 4 (25 April 1919), p. 40.

While it may be true that D E Marsh's 1905 Atlantics were direct derivatives of Ivatt's Great Northern, as Glover (1967) says, these 1911 engines are impressively larger. Indeed, the 1911 LM report compares them to the H1s and notes that adding the Schmidt superheater allowed the use of larger 21" cylinders and 10" (254 mm) piston valves. Valve travel seems a bit short at 4 5/8" (117 mm). Bearing grates of 31 sq ft and superheaters, these engines lacked only the 200+ psi boiler pressure to allow comparison with most powerful Atlantics of the day in Britain.

(OS Nock, Southern Steam (1968) shows a slightly lower value for firebox heating surface of 134.5 sq ft.)

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Class I1 (Locobase 10600)

Data from "Railway Notes- London, Brighton & South Coast Ry," The Locomotive Magazine, Vol XIII (15 January 1907), p. 1.

The Southern E-group's website -- [], last accessed 30 May 2006 -- has harsh things to say about three of the classes of 4-4-2T tank engines designed by D E (Douglas Earle) Marsh. With the exception of the I3 class, "

... his Atlantic tanks were pretty much a poor bunch." The first ten, which were delivered between September 1906 and June 1907 were numbered 595-604. The second batch, which used the wheels and motion from Stroudley D1 & D2 0-4-2s, was delivered in June-December 1907. The adoption of the D1 layout shortened the driving wheelbase to 7 ft 7 ins (2.31 m).

The SEmG writer declares "All twenty engines steamed very badly which is far from ideal in a loco built for heavy suburban traffic!" (exclamation in the original).

It was only when they were rebuilt in 1923-1932 by Maunsell using boilers from the B4 or superheated boilers from the I3 4-4-2Ts that the class amounted to anything. See Locobase 4205 for the I3.

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Class I3 (Locobase 3131)

[] tells the story of how Marsh was persuaded by Chief Draughtsman B K Field to fit a superheated boiler to the very-recently-launched I3 class (Locobase 4205). The first of these, Number 22, appeared in March 1908.

It was a defining moment for superheating advocates in England, according to the SEMG:

"Trials with N'22 showed it to be economical on both coal consumption and maintenance and a powerful performer on the heaviest of trains."

After each of the saturated and superheated variants had been produced, they were subjected to detailed comparisons. According to SEMG, "[w] hen compared with saturated I3s, H1s and B4s the superheated I3s consumed 30lb of coal per mile as against the 36, 40 and 42lb of the others. Furthermore, they were capable of operating the heaviest of LB&SCR expresses over all routes without problem and could work the 84 miles from Clapham Junction to Fratton in 1 hr 40 mins non-stop [51 mph average], despite having just 2,110 gallons water capacity."

The following example typifies the advantage of superheat, according to SEMG: "A superheated I3 could leave Brighton with a piled high bunker containing some 3+ tons of coal and take the above-mentioned train to Rugby and back without need for water en route or recoaling at Rugby, a performance of about 27 lb per mile (7.61 kg/km), assuming no coal remaining when returned to Brighton."

The contest was over and the remainder of the class was delivered (October 1910-March 1913). The seven saturated-steam locomotives were superheated by Maunsell in the mid-1920s. Used widely in the Southern network, the class endured until the early 1950s.

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Class I3 (Locobase 4205)

See also Steamindex's file on L B & SCR locomotives designed by Douglas Earle Marsh at [].

The Southern E-group's website -- [], last accessed 30 May 2006 -- has harsh things to say about three of the classes of 4-4-2T tank engines designed by D E Marsh. With the exception of the I3 class, "... his Atlantic tanks were pretty much a poor bunch."

The I3s differed from the poor performers in having a bigger boiler (taken from Billinton's B4 4-4-0 (Locobase 2260) and much taller drivers. 21 was delivered with 19" diameter cylinders, but the others all appeared with the larger-diameter cylinders shown in the specs.

Steamindex quotes Philip Evetts as considering the I3s superior in their design to Churward's County-class tanks, with which Evetts was familiar from his days at Swindon.

Beginning in 1908, much of the class was delivered with superheaters at the urging of the LB & SC's Chief Draughtsman B K Field; for the dramatic results, see Locobase 3131. The seven locomotives in this class were superheated beginning in September 1919 (21); the other six were superheated between October 1923 (28) and May 1927 (29).

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Class I4 (Locobase 2313)

Data from Ahrons (1927).

DE Marsh seems to have been unafraid of superheating and in this inside-cylinder tank engine design allowed an impressive amount of space for the flues.

The Southern E-group's website -- [], last accessed 30 May 2006 -- which speaks critically of the I1s as they were delivered (Locobase 4205), says that the D E Marsh-designed I2s delivered a year later were also "lack-lustre". All ten were delivered between December 1907 and August 1908. Unlike the I1s, this class was never updated or modified and all but two had been scrapped by 1939. Those two - origina 13 & 19 - were first used as improvised air-raid shelters, then transferred to the Longmoor Military Railway as 2400-2401 (72400-72401 as of 1944).

What Ahrons seems to have covered in his tables was the superheated variant of the I2, designated I4 - he credits them with 21" cylinders. About this quintet the SEmG account is even more severe, quoting C Hamilton Ellis's description of their performance: "Shocking!" LIke the I2s, later engineers made no effort to modify the locomotives and they had all been scrapped by 1940.