LB&SCR D1 class

LB&SCR D1 Class

D1 class, 230 Brookhouse, as built

Type and origin Power type Steam Designer William Stroudley Builder Brighton works (90), Neilson & Co. (35) Build date 1873–1887 Total produced 125

Specifications Configuration: ​  • Whyte 0-4-2T  • UIC B1 Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Driver dia. 66 in (1.676 m) Trailing dia. 54 in (1.372 m) Wheelbase 15 ft 0 in (4.57 m) Adhesive weight 27 long tons (27.4 t; 30.2 short tons) Loco weight 38.15 long tons (38.76 t; 42.73 short tons) Fuel type Coal Fuel capacity 1.5 long tons (1.5 t; 1.7 short tons) Water cap 860 imperial gallons (3,900 l; 1,030 US gal) Firebox:  • Firegrate area 15 sq ft (1.4 m2) Boiler pressure 140 psi (9.7 bar; 0.97 MPa) 150 psi (10 bar; 1.0 MPa) (later) Heating surface 1,029 sq ft (95.6 m2) Cylinders Two, inside Cylinder size 17 in × 24 in (432 mm × 610 mm)

Performance figures Tractive effort 15,200 lbf (68 kN)

Career Operators LB&SCR Southern Railway British Railways Class D1 Power class BR: 0P First run 1873 Withdrawn 1903–51 Disposition All scrapped

The LB&SCR D1 class were powerful 0-4-2 suburban passenger tank locomotives, designed by William Stroudley of the London Brighton and South Coast Railway in 1873. They were originally known as "D-tanks" but later reclassified as class D1. Members of this very successful class survived in service until 1951.

The D1 class were Stroudley's second tank engine class, intended for heavier tasks than could be undertaken by his A1 class "Terriers" which had been introduced in 1872. They had larger 5' 6" coupled wheels and a 140 psi (970 kPa) boiler pressure. Between November 1873 and March 1887, 125 locomotives of the class were built, 90 of which at Brighton railway works and the remainder by Neilson & Co. After 1883, new locomotives were given boilers with 150 psi (1,000 kPa) pressure, and in 1892 following Stroudley's death, the boiler pressure for replacement boilers was raised to 160 psi (1,100 kPa).

For twenty years the class were the mainstay of the LB&SCR outer suburban services, until gradually replaced by R.J. Billinton's D3 class 0-4-4 tank engines in the mid-1890s. Thereafter they were used on a variety of secondary passenger, and occasionally freight services throughout the railway. The first locomotive was withdrawn in December 1903, but many of the locomotives were still in good condition and popular with the engine crews. Douglas Earle Marsh therefore sought to rebuild six examples in 1910 with a larger boiler and cylinders. In the event, only one locomotive, number 79A, was rebuilt. This locomotive was known as D1X class, but although it was more powerful than the originals, it was found to be unsteady at speed and so no further rebuilds were authorised. Of the other five new boilers, one was used to rebuild E1 class no. 89 in 1911, and the other four were put to stationary use at various places on the LBSCR system.