The history of railways (История железных дорог)
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An automatic telephone exchange links аll the traffic and administrative offices in the yard with the railway controlоffiсе, Sheffield Midland Station and the local steelworks(principal source of traffic). Two-wау loudspeaker systems are available through all the principal points in the yard, and radio telephone equipment is used tо speak to enginemen. Fitters maintaining the retarders have walkiе-talkie equipment.
The information from shunters about the cuts and how many wagons in each, together with destination, is
conveyed by special data transmission equipment, а punched tape being produced to feed into the point control system for each train over the hump.
As British Railways have departed from the wagon-load system there is less employment for marshalling yards. Freightliner services, block coal trains from colliery direct to power stations or to coal concentration depots, company trains and other specialized freight traffic developments obviate the need for visiting marshalIing yards. Other factors are competition from motor transport, closing of wayside freight depots and of many small coal yards.
Modern passenger service
In Britain а network of city tocity services operates at speeds of up to 100 mph (161 km/h) and at regular hourly intervals, or 30 minute intervals on such routes as London to Birmingham. On some lines the speed is soon to be raised to 125 mph (201 km/h)with high speed diesel trains whosе prototype has been shown to be
capable of 143 mph (230 km h). With the advanced passenger train (APT) now under development, speeds of 150 mph (241 km/h) are envisaged. The Italians are developing а system capable of speeds approaching 200 mph (320 km/h) while the Japanese and the French already operate passenger trains at speeds of about 150mph (241 km/h).
The APT will be powered either by electric motors or by gas turbines, and it can use existing track because of its pendulum suspension which enables it to heel over when travelling round curves. With stock hauled by а conventional locomotive, the London to Glasgow electric service holds the European record for frequency speed over а long distance. When the APT is in service, it is expected that the London to Glasgow journey time of five hours will be reduced to 2.5 hours.
In Europe а number of combined activities organized
through the International Union af Railways included the
Trans-Europe-Express (TEE) network of high-speed passenger trains, а words freight service, and а network of railway-аssociated road services marketed as Europabus.
Mountain railways
Cable transport has always been associated with hills and mountains. In the late 1700s and early 1800s the wagonways used for moving coal from mines to river or sea ports were hauled by cable up and down inclined tracks. Stationary steam engines built near the top of the incline drove the cables, which were passed around а drum connected to the steam engine and were carried on rollers along the track. Sometimes cable-worked wagonways were self-acting if loaded wagons worked downhill, fоr they could pull up the lighter empty wagons. Even after George Stephenson perfected the travelling steam locomotive to work the early passenger railways of the 1820s and 1830s cable haulage was sometimes used to help trains climb the steeper gradients, and cable working continued to be used for many steeply-graded industrial wagonways throughout the 1800s. Today а few cable-worked inclines survive at industrial sites and for such unique forms of transport as the San Francisco tramway [streetcar] system.
Funiculars
The first true mountain railways using steam
locomotives running on а railway track equipped for rack and pinion (cogwheel) propulsion were built up Mount Washington, USA, in 1869 and Mount Rigi, Switzerland, in 1871. The latter was the pioneer of what today has become the most extensive mountain transport system in the world. Much of Switzerland consists of high mountains, some exceeding l4,000 ft (4250 m). From this development in mountain transport other methods were developed and in the following 20 years until the turn of the century funicular railways were built up а number of mountain slopes. Most worked on а words principle to the cliff lift, with two cars connected by cable balancing each other. Because of the length of some
lines, one mile (1.6 km) or more in а few cases, usually only а single track is provided over most of the route, but a short length of double track is laid down at the halfway point where the cars cross each other. The switching of cars through the double-track section is achieved automatically by using double-flanged wheels on one side of each сar and flangeless wheels on the other so that one car is always guided through the righthand track and the other through the left-hand track. Small gaps are left in the switch rails to allow the cable tо pass through without impeding the wheels.
Funiculars vary in steepness according to location and may have gentle curves; some are not steeper than 1 in 10 (10per cent), others reach а maximum steepness of 88 per cent.On the less steep lines the cars are little different from, but smaller than, ordinary railway carriages. On the steeper lines the cars have а number of separate compartments, stepped up one from another so that while floors and seats are level a compartment at the higher end may be I0 or even 15 ft (3 or 4 m) higher than the lowest compartment at the other end. Some of the bigger cars seat 100 passengers, but most carry
fewer than this.
Braking and safety are of vital importance on steep mountain lines to prevent breakaways. Cables are regularly inspected and renewed as necessary but just in case the cable breaks a number of braking systems are provided to stop the car quickly. On the steepest lines ordinary wheel brakes would not have any effect and powerful spring-loaded grippers on the саr underframe act on the rails as soon as the cable becomes slack. When а cable is due for renewal the opportunity is taken to test the braking system by cutting the cable
аnd checking whether the cars stop within the prescribed
distance. This operation is done without passengers
The capacity of funicular railways is limited to the two cars, which normally do not travel at mоrе than about 5 to 1О mph (8 to 16 km/h). Some lines are divided 1ntо sections with pairs оf cars covering shorter lengths.
Rack railways
The rack and pinion system principle dates
from the pioneering days of the steam locomotive between
1812 and 1820 which coincided with the introduction of
iron rails. 0ne engineer, Blenkinsop, did not think that
iron wheels on locomotives would have sufficient grip on
iron rails, and on the wagonway serving Middleton colliery near Leeds he laid an extra toothed rail alongside one of the ordinary rails, which engaged with а cogwheel on the locomotive. The Middleton line was relatively level and it was soon found that on railways with only gentle climbs the rack system was not needed. If there was enough weight on the locomotive driving wheels they would grip the rails by friction. Little more was heard of rack railways until the 1860s, when they began to be developed for mountain railways in the USA and Switzerland.
The rack system for the last 100 years has used an additional centre toothed rail which meshes with cogwheels under locomotives and coaches. There are four basic types of rack varying in details: the Riggenbach type looks like а steel ladder, and the Abt and Strub types use а vertical rail with teeth machined out of the top. 0ne or other of these systems is used on most rack lines but they are safe only on gradients nо steeper than 1 in 4 (25 per cent). One line in Switzerland up Mount Pilatus has а gradient of 1 in 2 (48 per cent) and uses the Locher rack with teeth cut on both sides of the rack rail instead of on top, engaging with pairs of
horizontally-mounted cogwheels on each side, drivihg and
braking the railcars.
The first steam locomotives for steep mountain lines had vertical boilers but later locomotives had boilers mounted at an angle to the main frame so that they were virtually horizontal when on the climb. Today steam locomotives have all but disappeared from most mountain lines аnd survive in regular service on only one line in Switzerland, on Britains only rack line up Snowdon in North Wales, and а handful of others. Most of the remainder have been electrified or а few converted to diesel.
Trams and trolleybuses
The early railways used in mines with four-wheel trucks and wooden beams for rails were known as tramways. From this came the word tram for а four-wheel rail vehicle. The worlds first street rаi