British Rail 18100

British Rail 18100
British Rail 18100
	British Railways
Power class	BR Type 5
First run	1952
Last run	1954
Retired	December 1957
Disposition	Rebuilt to 25 kV electric locomotive E1000 (E2001 from 1959)

British Rail 18100 was a prototype main line

Paddington station

, London.

Overview

It was of

wheel arrangement and its gas turbine

was rated at 3,000 horsepower (2,200 kW). It had a maximum speed of 90 mph (140 km/h) and weighed 129.5 long tons (131.6 t; 145.0 short tons). It was painted in BR black livery, with a silver stripe around the middle of the body and silver numbers.

Technical details

The gas turbine was of a type which would now be called a turboshaft engine but it differed from modern free-turbine turboshaft engines in having only one turbine to drive both the compressor and the output shaft. It was based on aircraft practice and had six horizontal combustion chambers (spaced radially around the turbine shaft) and no heat exchanger.

The emphasis was on power, rather than economy, and the fuel consumption was high. It was designed to use

reduction gearing

:

three
main generators
one auxiliary generator for battery charging
one exciter for the main generators

Each main generator powered two traction motors. Unlike No. 18000, there was no auxiliary diesel engine and the turbine was started by battery power, using the main generators as starter motors.

Comparison of 18000 and 18100

The following table gives a comparison between 18000 and 18100. There are some anomalies and these are described in the notes.

Value	18000	18100	Notes
Weight (tons)	115	129	-
Turbine horsepower	10,300	9,000	(1)
Power absorbed by compressor	7,800	6,000	(1)
Output horsepower	2,500	3,000	(1)
Number of traction motors	4	6	-
Total traction motor horsepower	2,500	2,450	(2)
Starting tractive effort ( lbf )	31,500	60,000

Notes:

In 18000, output horsepower is 24% of total horsepower and in 18100, output horsepower is 33% of total horsepower. This suggests that 18100 had the higher thermal efficiency but, in practice, 18000 had the higher thermal efficiency. The horsepower figures should, therefore, be regarded with some scepticism.
Where electric transmission is used, the horsepower of the traction motors is usually 81% (i.e. 90% x 90%) that of the prime mover. The figure for 18100 is therefore about right but the figure for 18000 looks anomalous.

Conversion

In early 1958 it was withdrawn from operation and was stored at

25 kV AC electric locomotive. As an electric locomotive, it was numbered E1000 (E2001 from 1959) and was given the TOPS classification of class 80.^[1]