1911 Encyclopædia Britannica/Tramway > 자유게시판

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The continuity of the trail of the trolley wheel is provided for on the underside of the insulator by fixing a hardwood strip between the ends or by the ribs on the castings with air gaps. The lower carbon contact is carried on a smooth iron strip which is connected to the availability cable via a flat copper ribbon spring. The current is fed to the conductor rails by heavy copper conductors of from 500,000 to 1,000,000 circular mils cross part, insulated and lead-covered, laid in duets alongside of or between the 2 tracks of double-observe systems. The conductors are out of reach, they'll simply be doubly or trebly insulated, and with their insulators are open to inspection. The wires on adjoining sections are linked by part insulators. They weigh 22 ℔ per yard and are supported on insulators at intervals of 15 ft. The road wires are clamped to the metallic ends. 15 ft. by the insulators, the ends of separate rails being matched at and held by an insulator help.

9 in. apart, each second yoke being now continued out under the operating rail which is fastened to it. The latter alternative was regularly adopted, owing to the costs of parliamentary process being too heavy for the enterprise. After a tramway is laid, particularly in a macadamized street, the heavy vehicular traffic use the observe, and the put on may be very much greater than on different components of the carriage-way. Electric Tramways.-Electricity is now the usual motive power for tramway service, and is utilized in three foremost ways: (1) the overhead or trolley system; (2) the open conduit system; and (3) the floor contact or closed conduit system. The reversed kind of stairway has now been abandoned and the straight sort, well protected by railings, is usually fitted. Fig. 7.-Section of Centre Conduit (London County Council kind). Centre conduit development has been adopted in London, Nice, Bordeaux, New York, Washington, &c. American follow in conduit development has grow to be pretty properly standardized (fig. 8). The conduit is oval in form, its main axis being vertical, and is formed of concrete. Cable traction, with the expensive monitor construction it necessitates, and the limited velocity of haulage, what is electric cable belongs to the previous. The difficulty in regard to points and crossings is overcome by bringing the slot into the centre of the monitor at junctions and switch-outs.

Its chief drawback is the issue it introduces in connexion with points and crossings. With feeding points at each mile, the zero wire is electrically ample on most Overhead Trolley.roads, but from a mechanical standpoint 00 wire is the smallest it's desirable to erect. The overhead conductors are usually hung about 21 ft. The working expenses of the various systems of traction are largely affected by the age of the tramway, the locality, and, in the case'of electric traces, by the fee at which energy is obtained. The price of the everlasting way and its electrical gear along with the cables at Wolverhampton on the Lorain floor contact principle amounted to £8601 per monitor mile. Fig. 5 exhibits a cross-section of the observe at a yoke. In the G.B. contact box (fig. 11) contact is made direct to a naked feeder cable carried in a pipe under the packing containers.

Fig. 10.-Cross-part of Stud, Skates and Magnets. It's claimed that with small single-deck automobiles a quicker service will be maintained, as they are easier to load and unload and usually handler. Their use practically doubles the covered seating capacity of the automotive and supplies accommodation for smokers, a troublesome matter on a single-deck car. A demi or one-man car has been labored in some towns. Higher speeds and faster acceleration have been obtained, and bigger and more comfortable vehicles could possibly be worked. The poles which carry the span wires and the Bracket arms are positioned not greater than forty yds. These yokes encompass the conduit proper and are provided with extensions on every aspect for the attachment of the rails. On the Edinburgh system the conduit was formed of concrete, with forged-iron yokes spaced at intervals of 4 ft. Wolverhampton; (2) the Dolter system at Torquay, Hastings and Mexborough, and (3) the G.B. The first cable tramway was constructed at San Francisco in 1873. In England the first cable system was a short size at Highgate in 1884. Cable tramways have been also laid down at Edinburgh, Birmingham, Matlock and Brixton (London).