Northfleet Series Electric Tramway

One the earliest electric tramways was opened at Northfleet in Kent in the Spring of 1889, it pioneered a different method of electric transmission to earlier systems (although had been already tried in the United States). The Northfleet system was a series electric instead of parallel like other tramways. With a parallel electric system the electric current that passes through a motor (or any other electric device like a lamp) does not pass through any other [1]. With a series electric the whole current of the system passes through the devices using it. One advantage of this system was that a much smaller current could be applied as parallel systems needed larger current to counter the dropping off effect the further one got from the generating dynamo.

Information
Built:	1889
Builder:	Falcon Engine & Car Works
Motor:	Elwell & Parker electric motor (200v)
Power:	15 hp (11 kW)

The problem for engineers was how to run multiple motors in series at the same time. The solution was to divide the conductor into segments (in the Northfleet case about six and half metres long [2]) and for the tram to close the circuit as required as it passes over the segments. The Northfleet system used a buried conductor underneath one of the running rails with a slot for an "arrow" which opened the circuit at successive points by opening two "spring jacks". A dynamo on board the tram was used to maintain a steady supply to the motor which otherwise would have been subject to the circuit being opened and closed by other tramcars.

The tramway, which replaced an existing horse drawn tram, was narrow gauge (1067mm). This required special motors to be built for it. The Northfleet tram apparently worked well though was no more than an experiment, though a bold one which attracted a good deal of interest from engineers.

By the end of 1890 the tram had returned to living breathing horse power, though a more conventional electric tram system was started in 1901.

Northfleet tram [3]

Front of tram and detail of the motor, the narrowness of the motor can be seen [3]

Cross section of rail and conductor [1]

[1] "The Northfleet Series Electric Tramway", Nature (May 9 1889) p. 39
[2] Robert J Harley, North Kent Tramways (Middleton Press, 1994) Fig. 60
[3] "The Northfleet Series Electric Tramway - Dynamo and Cars", The Engineer (March 15 1889) p. 219

Guernsey Railway Trams

The Guernsey Railway opened as a steam tramway in 1879. The railway converted to electric operation in 1892 [1] using equipment supplied by Siemens and was one of the first street tramways in the British Isles equipped with overhead electric lines. The tramway ran profitably at first carrying an average of three thousand passengers a day [2] though like most such systems could not compete in the end against motor buses and closed in 1934.

Information
Number built:	19
Built:	1890-1905
Builder:	Brush, G.F. Milnes, Falcon Engine & Car Works, Guernsey Railway Company
Engine:	Siemens traction equipment (500v DC OHLE)

The tramcar fleet came from a number of sources including three ex-Cardiff Tramway cars and one rebuilt from a steam trailer by the railway company itself. The railway was powered by two Marshall engines and two Siemens generators providing one hundred amperes at five hundred volts. The tramcars also had Siemens motors and chain drives and could run up to twelve miles per hour.

After the closure of the railway the track was lifted within days and the tramcars sold. There have been plans to restore a heritage tram to the island though as yet no progress has been made on this.

Guernsey tramcar in operation, public domain image [2]

[1] Chas S Dunbar, Buses, Trams & Trollies (Hamlyn, 1967) p. 47 
[2] "A Guernsey Railway", The Street Railway Review (Vol 3 1893) p. 559