South Staffordshire Tramways

The Electric Construction Corporation developed the overhead-wire tram system that began operating in 1893 when the South Staffordshire Tramways were electrified.

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.

Arrangements are also provided so that the engines can be run non-condensing if required. The dynamos, one of which is driven from each engine by means of cotton ropes, are of the usual Elwell-Parker type, and give an output of 260 amperes at 300 volts, when running 400 revolutions per minute, the field magnets being shunt wound. The driving pulleys are carried between two bearings, and there is a coupling between the pulley and armature shafts, so that the latter can at any time be removed without taking off the ropes or dismounting the pulley.
Each dynamo is connected by cables carried under the floor to a patent Elwell-Parker automatic magnetic contact, which also acts as the main switch for the machine.

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.

The trolley wire is carried at a height of 20ft. from the surface of the streets by poles along one side of the road only; arms projecting from the poles - Fig. 7 - carry the insulators supporting the wire. A special arrangement, suggested by Mr. Dickinson, the Tramway Company's engineer, makes it unnecessary that the trolley wire should be at a regular distance from the centre of the rails, the collector being designed so as to allow a variation of several feet. Where there is a double line of rails the pole arm carries two insulators and two trolley wires, one for the up and one for the down line. Automatic overhead switches are fixed at the turn-outs, so as to guide the collector wheel along the right wire.

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 under trucks - Fig. 2 - carry two Elwell-Parker series wound motors - Fig. 3 - each capable of running continuously with a load of 15 horsepower, the normal speed being 400 revolutions per minute; the armatures are geared up to the axles by means of cast steel double helical wheels and pinions, having a ratio of 4 to 1. One motor is considered to be amply sufficient to take a fully loaded car up the heaviest gradient of 1 in 28 occurring on the line. The practice of using two motors on each car appears to have been brought over from America, where the lines are not so well laid, and where, also, they have to contend with snow and ice throughout the winter. On very few lines in England do we consider that it will be necessary to use two motors, although it will be necessary that the one motor shall be more than 15 horsepower, unless a simple form of gear for varying the speed with a constant speed of motor be used. Driving switches are fitted at both ends of the car, and arranged so that either or both of the motors can be in use, the regulation of speed being effected by putting resistance into the motor circuit.

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.


The South Staffordshire Tramways generating station.

The following description of the tramway is from the Railway Engineer, volume 14, number 1, January, 1893:

The South Staffordshire Tramways have an aggregate length of about 23 miles. They connect Darlaston, Wednesbury, West Bromwich, Handsworth, Great Bridge, Dudley Port, Dudley, Walsall, and Bloxwich with each other, and last year 4,000,000 passengers were carried.

About nine miles-viz., from Darlaston and Wednesbury to the Pleck, thence to Walsall Bridge, where the line again separates, one branch going to Bloxwich and the other to Lichfield Road - has been fitted to work by electricity upon the over-trolley wire system.

The installation has been carried out entirely by the Electric Construction Corporation of Wolverhampton. The sub-contractors for the cars were the Lancaster Carriage and Wagon Co., and Brown, Marshalls & Co., for the stationary engines and boilers of 150h.p. Messrs. Musgrave & Son, of Bolton, and the posts to carry the overhead wire were divided between Messrs. James Russell & Sons and Messrs. John Russell & Co.

The motors are of the Elwell-Parker type. The posts are placed at the side of the road, and the bracket arms carrying the trolley wire stretch out over the road 7 to 10ft., but give a clear height of 21 ft. By a kind of universal joint the collector is allowed a variation of several feet, so that it is not necessary for the trolley wire to be directly over the middle of the line.

One of the tram trucks from the South Staffordshire Tramways has survived. It was acquired by the London Science Museum in 1912, and went directly from the Darlaston tram depot to be put into store. It has recently moved to the National Tramway Museum at Crich, and must be the oldest tram truck in the world that is still in its original condition.

The truck arrives at Crich.

Courtesy of the National Tramway Museum.

The truck, after being unloaded from the transporter.

Courtesy of the National Tramway Museum.


The truck at the Science Museum's store. Courtesy of Mike Ballinger.


Another view of the truck at the Science Museum's store. Courtesy of Mike Ballinger.

This close-up view of the truck clearly shows the two electric motors. The gears can also be seen on the back wheels. The commutators appear to be in good condition, but unfortunately the brush gear is missing.

Courtesy of Mike Ballinger.

 

In 1989 Ian Walden, who was the Chief Executive at the Black Country Living Museum wanted to borrow the truck with the idea of copying it and building a replica South Staffs tram. Unfortunately he was unable to borrow the truck and so the project didn't materialise.


Return to the
previous page