South Staffordshire Tramways.  From The Engineer, 18th November, 1892.

Early in the present year the South Staffordshire Tramway Company entered into a contract with the Electric Construction Corporation, of Wolverhampton, for the equipment of a section of its lines with plant for electric traction on what is generally known as the trolley wire system, the lines having hitherto been worked by steam locomotives. The plant is now practically completed, and the inspection by General Hutchinson and Major Cardew, on behalf of the Board of Trade, took place on Saturday, November 12th, so that the electric cars will very shortly come into service.

The lines over which the electric cars are to be run extend from the junction of Holyhead Road and Bridge Street in Wednesbury, through the centre of the borough of Walsall, to Bloxwich, with two branch lines, one running from the Pleck to Darlaston, and the other from Walsall to Mellish Road. The length of streets occupied by the tramways is just over eight miles, six miles having a single line with turn-outs, the other two miles having a double line, making a total length of track, and therefore of trolley wire, of over ten miles. The route taken by the lines is shown on the map - Fig. 5 - which also indicates the position of the generating station on the line between the Pleck and Darlaston.

Fig. 5. A map of the tramway.

The generating station at Pleck, Walsall.

The generating station is on the side of the canal, and has a basin for receiving the barges bringing coal, which discharge directly into the boiler room. The canal water is used for condensing.

The general arrangement of the buildings and plant is shown on the plan and section - Figs. 6 and 7. The three boilers are of the Lancashire type, 7ft. diameter, 30ft. in length, designed for a working pressure of 120 lb. per square inch. The three engines, which, together with the boilers, were made by Messrs. J. Musgrave and Sons, of Bolton, are of the horizontal coupled-compound pattern, each easily capable of indicating 125 horse power with the above steam pressure, when running at a speed of 100 revolutions per minute. The cylinders are 10½in. and 20in. diameter, 30in. stroke, both cylinders being fitted with Corliss valve gear; the flywheels are 10ft. in diameter, and grooved for seven l¼in. diameter ropes. A surface condenser is attached to each engine. The steam and feed pipes are arranged so as to give a duplicate service between the engines, boilers, and pumps.

Fig. 6. The generating station.

Fig. 7. A plan of the generating station.

These contacts are adjusted so that, in the event of an excessive current being demanded from the machines - due to any accident or short circuit on the lines - the circuit is opened, and any damage to the machines prevented.

All three machines feed in parallel on to common omnibus bars, between which and the feeders taking current out to the line there is a simple main switch. Ammeters are provided in each dynamo circuit, and a voltmeter with large dial indicates the electromotive force across the omnibus bars.

Multiple contact switches and resistance coils are connected in the shunt circuits for regulating the electromotive force.

A section of the switchboard showing the arrangement for each machine is illustrated in Fig. 4.

Fig. 4. The switchboard.

From the generating station the current is supplied to the 0 gauge copper trolley wire by underground feeders, these being insulated with vulcanised bitumen, lead sheathed, and armoured with a double layer of steel tape, so that they can be laid directly in the ground without further protection; the lengths and sections of the feeders are indicated in the map - Fig. 5.

The return circuit is completed through the rails and earth. At distances of approximately half a mile apart connections are made between the feeders and trolley wire by means of cables drawn up inside the posts. Each section of trolley wire is fed into at both ends, the current passing through fuses placed in an underground box - Fig. 8 - at the foot of the feeding posts. These fuse boxes are made on the diving bell principle, to prevent any possibility of water accumulating in them and rising sufficiently high to reach the connection. The covers are easily drawn up to allow of examination or insertion of new fuses. The map - Fig. 5 - shows the position of the feeding points and fuses.

Fig. 8. Underground fuse boxes.

Fig. 2. An under truck with motors.

Fourteen cars made by Messrs. Brown, Marshall, and Co., and the Lancaster Wagon Company, are being supplied for the equipment of the line, each carrying forty passengers, eighteen inside and twenty-two outside. The collector is fixed on one side of the roof of the car, the arrangement being clearly shown in Fig. 7.

Fig. 3. An Elwell-Parker motor.

The whole of the electrical plant has been designed, manufactured, and installed by the Electric Construction Corporation, who are also responsible for the other portion of the plant supplied to them by various firms as sub-contractors. The running of the line is also in the hands of the Electric Construction Corporation, they having undertaken to work it at a fixed charge per car mile for a number of years. Mr. Alfred Dickinson has been appointed to superintend the working on their behalf.