A passing loop (UK usage) or passing siding (North America) (also called a crossing loop , crossing place , refuge loop or, colloquially, a hole ) is a place on a single line railway or tramway , often located at or near a station , where trains or trams travelling in opposite directions can pass each other. Trains / trams going in the same direction can also overtake, provided that the signalling arrangement allows it. A passing loop is double-ended and connected to the main track at both ends, though a dead end siding known as a refuge siding , which is much less convenient, can be used. A similar arrangement is used on the gauntlet track of cable railways and funiculars , and in passing places on single-track roads .
23-678: Grass Valley may refer to: Places [ edit ] Grass Valley, Western Australia , a small town in the Avon Valley United States [ edit ] Grass Valley, Oregon , a city in Sherman County Grass Valley (Piute and Sevier counties, Utah) , a valley in Piute and southern Sevier counties in central Utah California, Nevada, Utah, Colorado Roman Catholic Diocese of Grass Valley ,
46-895: A former diocese based in the eponymous California city in Nevada County, formerly covering Northeastern California and most of Nevada; most of Utah, and part of Colorado State of California Grass Valley, California , a city in Nevada County Grass Valley, Oakland, California , a neighborhood Grass Valley Wilderness , a wilderness area in the Mojave Desert managed by the BLM State of Nevada Grass Valley, Nevada , census-designated place in Pershing County Grass Valley (Eureka and Lander counties, Nevada) ,
69-408: A radio system to set the points from a distance. The design of crossing loops may have to be modified where there are severe gradients that make it difficult for a train to restart from a stationary position, or where the terrain is unsuitable for a normal loop. A crossing loop on steep gradient may have catch points on the downhill end to reduce the impact of runaways. Since central operation of
92-604: A valley in Nevada Grass Valley (Pershing and Humboldt counties, Nevada) , a valley in Nevada Other uses [ edit ] Grass Valley (company) , a television and film technology company See also [ edit ] Grass Valley speckled dace , an extinct species of fish Little Grass Valley, California , a census-designated place in Plumas County Topics referred to by
115-512: Is different from Wikidata All article disambiguation pages All disambiguation pages Grass Valley, Western Australia Grass Valley is a small townsite 13 kilometres (8 mi) east of Northam, Western Australia in the Avon Valley area. The town is named after a local property of the same name that was established in 1833 by William Nairn. The Northam to Kalgoorlie Eastern Goldfields Railway line passes through
138-478: Is referred to as a dynamic loop. For example, the Windermere branch line will be getting one to permit a 2tph service pattern. Some railways fit catch points at the ends of crossing loops so that if a train overruns the loop, it is derailed rather than collide with an opposing train. Since the available space for crossing loops is usually limited, they do not normally have an overlap (safety margin) between
161-646: The Grass Valley Bush Fire Brigade, supported by over 50 local volunteer members. The Brigade has one appliance being a 4.4B (4,000L, 4WD, Broadacre) truck, although it has been recognised for over 10 years that a second appliance is desperately needed to adequately protect the district. The Grass Valley fire district is the largest fire district within the Shire of Northam and the Brigade is the second most active Brigade in regards to call-outs in
184-646: The Middle East. The town is a receival site for Cooperative Bulk Handling and had a Type B structure in the 1970s. The post office within the town is reputed to be the smallest in Australia. The town also has an excellent tavern dating back to the golden days of the once-important rail head. The town is situated on the Golden Pipeline heritage trail. The pipeline passes through Grass Valley. Grass Valley and surrounding districts are serviced by
207-452: The Shire. The Grass Valley Fire Shed is located on the corner of Wilson St and Keane St, Grass Valley on the site of the old Grass Valley school which ran from 1899-1945. Crossing loop Ideally, the loop should be longer than all trains needing to cross at that point. Unless the loop is of sufficient length to be dynamic , the first train to arrive must stop or move very slowly, while
230-484: The curve. This layout is mostly used at local stations where many passenger trains do not stop. Since there is only one passenger platform, it is not convenient to cross two passenger trains if both stop. This type of passing loop is common in Russia and post-Soviet states. A disadvantage of the platform and through arrangement is the speed limits through the turnouts at each end. In the example layout shown, trains take
253-529: The left-hand track in their direction of running. Low-speed turnouts restrict the speed in one direction. Two platform faces are needed, and they can be provided either at a single island platform or two side platforms (as shown). Overtaking is not normally possible at this kind of up-and-down loop as some of the necessary signals are absent. Crossing loops using up-and-down working are very common in British practice. For one thing, fewer signals are required if
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#1732773068992276-450: The longer and heavier high-speed turnouts may be beyond the capability of manual lever operation. Refuge sidings are used at locations with gradients too steep for heavy freight trains or steam haulage to depart from conventional passing loops, or confined spaces where a passing loop cannot be built. An extra parallel siding is often built at stations on refuge sidings so that two stopping trains can pass, and an extended catch point opposite
299-485: The loop line may be omitted. If the passenger train from one direction always arrives first, the platform on the loop line may also be omitted by extending the platform past the loop in that direction. The through road has straight track, while the platform road has low-speed turnouts at either end. A possible advantage of this layout is that trains scheduled to pass straight through the station can do so uninterrupted; they do not have to reduce their speed to pass through
322-411: The platforms may be provided on both the main and loop tracks or possibly on only one of them. The main line has straight track, while the loop line has low-speed turnouts at either end. If the station has only one platform, then it is usually located on the main line. If passenger trains are relatively few in number, and the likelihood of two passenger trains crossing each other low, the platform on
345-454: The points and signals from a single signal box is convenient, and since there are practical limits for the distance to these points and signals, crossing loops can have a system-wide effect on train sizes. Line capacity is partly determined by the distance between individual crossing loops. Ideally these should be located at inverse -integer intervals along the track by travel time. The longest section between successive crossing loops will, like
368-401: The points in and out of the loop operated manually, albeit more recent examples have so-called self-restoring switches that allow trains to exit a loop without needing to change the points. Other forms of remote operation included centralized traffic control , in which a train controller changes points and signals from a remote office; and driver-operated points, which enable train crews to use
391-419: The refuge siding may be added so as not to interfere with passing trains. If a crossing loop is several times the length of the trains using it, and is suitably signalled, then trains proceeding in opposite directions can pass (cross) each other without having to stop or even slow down. This greatly reduces the time lost by the first train to arrive at the crossing loop for the opposing train to go by. This system
414-460: The same term [REDACTED] This disambiguation page lists articles associated with the title Grass Valley . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Grass_Valley&oldid=1001965153 " Categories : Disambiguation pages Place name disambiguation pages Hidden categories: Short description
437-535: The second to arrive may pass at speed. If one train is too long for the loop it must wait for the opposing train to enter the loop before proceeding, taking a few minutes. Ideally, the shorter train should arrive first and leave second. If both trains are too long for the loop, time-consuming "see-sawing" (or "double saw-by") operations are required for the trains to cross (see Tawa railway station ). On railway systems that use platforms , especially high-level platforms, for passengers to board and disembark from trains,
460-503: The starting signals and the end of the double line. In Australia, the Australian Rail Track Corporation (ARTC) policy provides for overlaps of about 500 m and 200 m respectively in an effort to avoid derailment or collision. Many crossing loops are designed to operate automatically in an unattended mode. Such loops may be track-circuited with home signals cleared by the approaching train. Some loops have
483-538: The town and includes a crossing loop . The railway was built through the area in 1894. Land was set aside for a townsite in 1898 and the town was gazetted in the same year. The surrounding areas produce wheat and other cereal crops. During its heyday of the 1950sā90s the town's local farmers were the largest producers of chaff (feed for racehorses) in Western Australia. The product was sought after by buyers throughout Western Australia as well as Asia and
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#1732773068992506-425: The tracks in the station are signaled for one direction only; also, there is less likelihood of a collision caused by signalling a train onto the track reserved for trains in the opposing direction. In France, they often use spring switches and the speed is equally restricted in both directions. The speed restriction in one direction can be eliminated with higher-speed turnouts, but this may require power operation, as
529-420: The weakest link in a chain, determine the overall line capacity. Long and short trains can cross at a short loop if the long train arrives second but leaves first. It is best if all crossing loops are longer than the longest train. Two long trains can cross at a short loop using a slow so-called see-saw process, which wastes time. Countries generally have a principle on which side trains shall meet, either on
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