LB&SCR I2 class facts for kids

LB&SCR I2 & I4 classes
Side-view builder's photo of LB&SCR I2 class 4-4-2T.
Power type	Steam
Designer	D.E. Marsh
Builder	Brighton Works
Build date	1907-1909
Total production	I2: 10; I4: 5
Configuration	4-4-2T
Gauge	4 ft 8 1⁄2 in (1,435 mm) standard gauge
Leading wheel diameter	3 ft 6 in (1.067 m)
Driver diameter	5 ft 6 in (1.676 m)
Trailing wheel diameter	4 ft 0 in (1.219 m)
Locomotive weight	68.5 long tons (69.6 t; 76.7 short tons) I2, 70.25 long tons (71.38 t; 78.68 short tons) I4
Fuel type	Coal
Water capacity	2,238 imp gal (10,170 L; 2,688 US gal)
Boiler pressure	170 psi (12 bar; 1.2 MPa)
Cylinders	Two, inside
Cylinder size	17.5 in × 26 in (444 mm × 660 mm)
Tractive effort	I2: 17,425 lbf (77.51 kN), I4: 17,790 lbf (79.13 kN)
Retired	1933-1940
Disposition	All scrapped

The LBSCR I2 class and I4 class were types of steam tank locomotives. They were designed by D. E. Marsh for carrying passengers on local train lines for the London, Brighton and South Coast Railway. The I4 class was very similar to the I2, but it had a special part called a superheater which made the steam hotter and more powerful.

I2 Class Locomotives

In 1907, a designer named Douglas Earle Marsh wanted to fix problems from an earlier train design, the I1 class. He created a new type of steam tank locomotive called the I2 class. These trains had a longer base between their wheels and a bigger boiler.

Originally, five of these new trains were meant to have a special superheater boiler. This type of boiler makes steam even hotter and more efficient. The other trains would use traditional boilers. However, the superheated boilers were delayed. So, all ten I2 locomotives were built with the traditional boilers.

I4 Class Locomotives

An I4 incorporating a superheated boiler

When the special superheated boilers finally arrived, they were used for five more trains. These trains were built with the same design as the I2 class. But because they had the superheated boilers, they were given a new name: the I4 class.

Unfortunately, neither the I2 nor the I4 class solved the main problem of the earlier I1 class. This problem was that the firebox (where the coal burns) was too small. Because of this, both the I2 and I4 classes did not last very long in service. They were mostly used for lighter jobs on smaller train lines. Older, more reliable trains like the Stroudley D1 class and Billinton E4 class continued to be used instead.

How They Were Numbered

The London, Brighton and South Coast Railway (LB&SCR) gave these trains numbers from 11 to 20 and 31 to 35.

When the Southern Railway took over in 1923, they renumbered them. First, they added a 'B' in front, making them B11-B20 and B31-B35. Later, they changed the numbers again to 2011-2020 and 2031-2035.

When They Were Retired

All the I2 class trains were taken out of service between 1933 and 1939. However, two of them, numbers 2013 and 2019, continued to work. They were used on the Longmoor Military Railway and stayed in service until at least 1947. On this military railway, they were first numbered 2400 and 2401. Later, these numbers were changed to 72400 and 72401.

The I4 class trains were retired between 1936 and 1940. Sadly, none of these I2 or I4 class locomotives were saved. They were all eventually scrapped.

Locomotive Summary