Speed of Trains
Speed of Trains
one of the most important operational indexes of railroad transportation, expressing the number of kilometers traveled by a train per unit of time, usually an hour or day. A distinction is made between the design, running, route, scheduled, overall, and total speeds of freight and passenger trains.
| Table 3. Speed of sound in some solids | |||
|---|---|---|---|
| Material | Speed of longitudinal wave cl (m/sec) | Speed of shear wave cs (m/sec) | Speed of sound in a rod clrod(m/sec) |
| Fused quartz ............................. | 5,970 | 3,762 | 5,760 |
| Concrete................................ | 4,200–5,300 | — | — |
| Methacrylate resin .......................... | 2,670-2,680 | 1,100-1,121 | 1,840-2,140 |
| Flint glass ............................... | 3,760-4,800 | 2,380–2,560 | 3,490-4,550 |
| Polytetrafluoroethylene ...................... | 1,340 | — | — |
| Ebonite ................................ | 2,405 | — | 1,570 |
| Iron ................................ | 5,835-5,950 | — | 2,030 |
| Gold................................... | 3,200-3,240 | 1,200 | 2,030 |
| Lead .................................. | 1,960-2,400 | 700-790 | 1,200–1,320 |
| Zinc................................... | 4,170-4,210 | 2,440 | 3,700-3,850 |
| Nickel.................................. | 5,630 | 2,960 | 4,785–4,973 |
| Silver .................................. | 3,650-3,700 | 1,600-1,690 | 2,610–2,800 |
| Brass L59 ............................... | 4,600 | 2,080 | 3,450 |
| Aluminum alloy AMG ........................ | 6,320 | 3,190 | 5,200 |
The design speed is a locomotive’s maximum possible speed under the most favorable conditions. The running speed is a train’s average speed along a section excluding the time needed for acceleration and deceleration. In the USSR under safe traveling specifications the running speed of laden trains is restricted to 90 km/hr, that of empty rolling stock to 100 km/hr, and that of passenger trains to 120–140 km/hr; on the Leningrad-Moscow line the limits are between 160 and 200 km/hr. The route speed is the average speed of a train including the time needed for acceleration and deceleration at stops; it is substantially lower than the running speed. The scheduled speed is the average speed of a train between neighboring service depots including the idle time at intermediate stations. In the USSR the average route speed of trains is 47–50 km/hr, and the average scheduled speed of freight trains is 34 to 35 km/hr.
The overall speed is the average speed over the entire route traveled, from the point where the train is made up to the point where it is broken down. It depends on the type of traffic (freight or passenger), on the kind of route (double-track or single-track line), on whether electric, diesel, or steam traction is used, and on other factors. The total speed is the average rate of progress of freight from the time that the freight is accepted for transport to the time of delivery at the destination, including idle time along the route. The total speed in transporting passengers is usually determined from timetables.
E. D. KHANUKOV [23–1546–]