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British Railway Steam Locomotive

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Note: To Obtain Consistency in the Steam System, Shed Codes used are those Registered at Nationalisation on 1st January 1948
2nd Grouping Number
1st Grouping Numbersr 2032
2nd Pre Grouping Number
1st Pre Grouping Numberlbsc 32
Works/Lot Number
Class CodeI4
DesignerMarsh DE
BuilderBrighton Works (SR/British Railways)
1948 Shed
Last Shed75A Brighton
Disposal detailsEastleigh Works (B.R.)
DisposalCut Up
Disposal Date30/09/1940
NotesLast of class

Class Information

The LB&SCR I2 class was a class of 4-4-2 steam tank locomotives designed by Douglas Earle Marsh for suburban passenger service on the London, Brighton and South Coast Railway. The huge success of Marsh's I3 class where the I1 and I2 classes had been so disappointing led to an attempt to recreate the trick with the I4 class of the same design, basically a superheated I2, in 1908.

In 1907, following the failure of his I1 class, Douglas Earle Marsh sought to remedy some of the faults with a new design of 4-4-2T with a longer wheelbase, larger boiler and detailed changes to the front end. In the original order, five of the locomotives would incorporate a superheated boiler, to be supplied by the North British Locomotive Company, and the remainder traditional saturated steam boilers from Brighton Works. In the event, the superheated boilers were delayed in construction and so all ten I2 locomotives had traditional boilers. When the superheated boilers eventually arrived they were used for five further locomotives of the same design, but which were classified I4.

Just five locomotives were built which were almost identical to the I2 class but with superheating, the cylinders' diameter increased from 17 ins to 20 ins and the boiler pressure reduced to 160 lb. Sadly it was soon proved that the superheating alone was not the key to the success with the I3 tanks and the I4 engines were a big disappointment. In fact, in his book on the LB&SCR, Hamilton Ellis goes so far as to describe them as being 'shocking'.

Unfortunately the modifications in these designs did not address the fundamental problems with the I1 class, which was a firebox that was far too small. As a result the two classes had relatively short lives working lightly loaded secondary services, and the Stroudley D1 class, and Billinton D1 class, which they had been designed to replace, continued working.

The Southern Railway inherited these beasts and didn't know what best to do with them. There was a proposal to rebuild them along the lines of the I1x rebuilds of the I1 class, but in the end opted to scrap them. All bar one had gone by 1937, with the survivor, No. 34, hanging on until 1940. It is surprising that the creator of the H1 and H2 classes (albeit basically a copy of the Great Northern Atlantics) and of the I3 class made such a poor job of his other designs.

It is somewhat ironic to note that whilst Marsh was still building dismal 4-4-2Ts at Brighton, based on his experiences with the GNR, the GNR was busy introducing successful 0-6-2T locomotives that were, in turn, based very much on the 1902 E5 class of Marsh's predecessor, Billinton.

LB&SCR numbers were 31-35. The Southern Railway, which acquired the locomotives in 1923, initially numbered them B31-35 and later 2031-2035.

The I4 class were withdrawn between 1936 and 1940.

The first loco withdrawn was 2031 in January 1936.
The last loco withdrawn was 2034 in May 1940 from Brighton shed.
None are preserved.

Technical Details

Designer : Douglas Earle Marsh
Introduced : 1907
Builder : Brighton Works
Build date : 1907-1908
Total produced : 5
Configuration : 4-4-2T
Gauge : 4 ft 8 in (1,435 mm)
Leading wheel diameter : 3 ft 6 in (1.067 m)
Driver wheel diameter : 5 ft 6 in (1.676 m)
Trailing wheel diameter : 4 ft 0 in (1.219 m)
Locomotive weight : 70.25 tons (71.38 t) I4
Fuel type : Coal
Water capacity : 2,238 imp gallons (10,170 l; 2,688 US gal)
Boiler pressure : 170 psi (1.2 MPa)
Cylinders : Two (inside)
Cylinder size : 17 in x 26 in (445 mm 660 mm)
Tractive effort : 16,400 lbs (79.13 kN)
Retired : 1933-1940

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