A spiral (sometimes called a spiral loop or just loop) is a technique employed by railways to ascend steep hills.
A railway spiral rises on a steady curve until it has completed a loop, passing over itself as it gains height, allowing the railway to gain vertical elevation in a relatively short horizontal distance. It is an alternative to a zig-zag, and avoids the need for the trains to stop and reverse direction while ascending. If the train is longer than the length of each loop it may be possible to view it looping above itself. [1] [2]
The term "loop" is also often used for a railway that curves sharply and goes back on itself: if the railway crosses itself, then it forms a spiral or helix; otherwise, it forms the much more common horseshoe curve or bend. [3] [4]
Replica of the Brusio Spiral Viaduct at 10°28′44″N84°49′25″W / 10.47900°N 84.82374°W on the Tren Turistico Arenal, 10 km east of Nuevo Arenal, Guanacaste. [38] [39]
The Darjeeling Himalayan Railway originally had five or six spirals but only five in operation at any one time. The line also has six reverses or zig-zags. [56] [57]
There are three spirals on the 1,000 mm (3 ft 3+3⁄8 in) gauge railway line from Kenya to Uganda. This railway has been superseded by the Mombasa–Nairobi Standard Gauge Railway, which has removed the need for spirals by constructing tunnels and bridges. [73] [74] [75] [76]
The Circle line is a spiral-shaped London Underground line, running from Hammersmith in the west to Edgware Road and then looping around central London back to Edgware Road. The railway is below ground in the central section and on the loop east of Paddington. Unlike London's deep-level lines, the Circle line tunnels are just below the surface and are of similar size to those on British main lines. Printed in yellow on the Tube map, the 17-mile (27 km) line serves 36 stations, including most of London's main line termini. Almost all of the route, and all the stations, are shared with one or more of the three other sub-surface lines, namely the District, Hammersmith & City and Metropolitan lines. On the Circle and Hammersmith & City lines combined, over 141 million passenger journeys were recorded in 2019.
The Piccadilly line is a deep-level London Underground line running from the north to the west of London. It has two branches, which split at Acton Town, and serves 53 stations. The line serves Heathrow Airport, and some of its stations are near tourist attractions such as Piccadilly Circus and Buckingham Palace. The District and Metropolitan lines share some sections of track with the Piccadilly line. Printed in dark blue on the Tube map, it is the sixth-busiest line on the Underground network, with nearly 218 million passenger journeys in 2019.
The Rhaetian Railway, abbreviated RhB, is a Swiss transport company that owns the largest network of all private railway operators in Switzerland. Headquartered in Chur, the RhB operates all the railway lines of the Swiss canton of Grisons, except for the line from Sargans to the cantonal capital, Chur, which are operated by Swiss Federal Railways (SBB CFF FFS), as well as the line from Disentis/Mustér to the Oberalp Pass and further on to Andermatt, Uri, which is operated by Matterhorn Gotthard Bahn (MGB). Inaugurated in 1888 and expanded from 1896 onwards in various sections, the RhB network is located almost entirely within Grisons, with one station across the Italian border at Tirano.
A hairpin turn is a bend in a road with a very acute inner angle, making it necessary for an oncoming vehicle to turn about 180° to continue on the road. It is named for its resemblance to a bent metal hairpin. Such turns in ramps and trails may be called switchbacks in American English, by analogy with switchback railways.
The Tehachapi Loop is a 3,779-foot-long spiral, or helix, on the Union Pacific Railroad Mojave Subdivision through Tehachapi Pass, of the Tehachapi Mountains in Kern County, south-central California. The line connects Bakersfield and the San Joaquin Valley to Mojave in the Mojave Desert.
The Boston, Revere Beach and Lynn Railroad was a 3 ft narrow-gauge passenger-carrying shortline railroad between East Boston and Lynn, Massachusetts, from 1875 to 1940. Part of the railroad's right of way now forms the outer section of the Massachusetts Bay Transportation Authority's Blue Line rapid transit service.
A horseshoe curve is a class of climbing curve in a roadbed that reverses turn direction (inflection) twice on either side of a single tight curve that varies through an angle of about 180 degrees or more.
The Cincinnati, Lebanon and Northern Railway (CL&N) was a local passenger and freight-carrying railroad in the southwestern part of the U.S. state of Ohio, connecting Cincinnati to Dayton via Lebanon. It was built in the late 19th century to give the town of Lebanon and Warren County better transportation facilities. The railroad was locally known as the "Highland Route", since it followed the ridge between the Little and Great Miami rivers, and was the only line not affected by floods such as the Great Dayton Flood of 1913.
A double-track railway usually involves running one track in each direction, compared to a single-track railway where trains in both directions share the same track.
Wood Island station is an MBTA Blue Line rapid transit station located off Bennington Street in the Day Square section of East Boston, Boston, Massachusetts. The station is adjacent to and named for the former Wood Island Park, a once heavily used recreational area for East Boston residents. Most of the park was destroyed in the mid 1960s to expand Logan International Airport. It was built in 1952, replacing a pair of Boston, Revere Beach and Lynn Railroad stations that served the area.
Caernarfon railway station is the northern terminus of the narrow gauge Welsh Highland Railway, located in the town of Caernarfon, Gwynedd, Wales. It was opened on 11 October 1997 when the line was constructed from Dinas.
The Nantlle Railway was a Welsh narrow gauge railway. It was built to carry slate from several slate quarries across the Nantlle Valley to the harbour at Caernarfon for export by sea. The line provided a passenger service between Caernarfon and Talysarn from 1856 to 1865. It was the first public railway to be operated in North Wales.
The Colorado and Southern Railway was an American Class I railroad in the western United States that operated independently from 1898 to 1908, then as part of the Chicago, Burlington and Quincy Railroad until it was absorbed into the Burlington Northern Railroad in 1981.
The Western River Railroad is a 2 ft 6 in narrow gauge rail transport attraction in Tokyo Disneyland, which opened on April 15, 1983. Its route is 5,283 feet (1,610 m) long and takes guests through the Adventureland, Westernland, and Critter Country sections.
The four Hex River Tunnels consist of a twin tunnel of 0.5 kilometres and three single tunnels of 1.1 kilometres, 1.2 kilometres and 13.5 kilometres, on the Hexton railway route between De Doorns and Kleinstraat through the Hex River Mountains of the Western Cape Province, South Africa. The line, which connects De Doorns in the Hex River valley with Touws River in the Great Karoo, is part of the main rail route between Cape Town and Johannesburg. Of the 30 kilometres of track, 16.8 kilometres are underground. Construction of the line eliminated the bottleneck of the Hex River rail pass.
The Albula railway line is a single track metre gauge railway line forming part of the core network of the Rhaetian Railway (RhB), in the canton of Graubünden, Switzerland. It links Thusis on the Hinterrhein at 697 m (2,287 ft) and Filisur at 1,080 m (3,540 ft) with the spa resort of St. Moritz in Engadine at 1,774 m (5,820 ft).
The Septemvri–Dobrinishte narrow-gauge line is the only operating 760 mm narrow-gauge line in Bulgaria. It is operated by Bulgarian State Railways (BDŽ). The line is actively used with four passenger trains running the length of the line in each direction per day. The journey takes five hours through the valleys and gorges between the mountain ranges of Rila, Pirin and Rhodopes.
The Domodossola–Locarno railway line, informally called the Centovallina in Switzerland and the Vigezzina in Italy, is a metre-gauge railway negotiating the dramatic mountainous terrain between Domodossola, Italy, and Locarno, Switzerland. It passes through the Vigezzo Valley and Centovalli.
The Mitcheldean Road and Forest of Dean Junction Railway was an independent railway company incorporated in 1871, to provide a northerly outlet for iron ore and coal products from the Cinderford and Whimsey area in the Forest of Dean, to the Hereford, Ross and Gloucester Railway line; mineral traffic to industrial centres in South Wales and the Midlands was foreseen.
Paddington is a London Underground station served by the Circle and Hammersmith & City lines. It is located adjacent to the north side of Paddington mainline station and has entrances from within the mainline station and from Paddington Basin. The station is between Royal Oak and Edgware Road and is in London Fare Zone 1.