Structure gauge

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Increasing the structure gauge for a larger loading gauge can involve substantial work. The UK's Midland Main Line being upgraded in 2014. 2014 Replacement of New Road Bridge, Milton Ernest, Bedfordshire.png
Increasing the structure gauge for a larger loading gauge can involve substantial work. The UK's Midland Main Line being upgraded in 2014.
In narrow curves, long cars like this 26.4 meter long express train car protrude further into the gauge than on a straight track. (180deg curve near Konigstein im Taunus) DSC01964 enge Kurve Am Bangert.jpg
In narrow curves, long cars like this 26.4 meter long express train car protrude further into the gauge than on a straight track. (180° curve near Königstein im Taunus)

A structure gauge, also called the minimum structure outline, is a diagram or physical structure that sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. It specifies the height and width of station platforms, tunnels and bridges, and the width of the doors that allow access to a warehouse from a rail siding. Specifications may include the minimum distance from rail vehicles to railway platforms, buildings, lineside electrical equipment cabinets, signalling equipment, third rails or supports for overhead lines. [1]

Contents

A related but separate gauge is the loading gauge: a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. The difference between these two gauges is called the clearance. The specified amount of clearance makes allowance for wobbling of rail vehicles at speed or the shifting of vehicles on curves; consequently, in some circumstances a train may be permitted to go past a restricted clearance at very slow speed.

Road traffic application

The term can also be applied to the minimum size of road tunnels, the space beneath overpasses and the space within the superstructure of bridges, as well as doors into automobile repair shops, bus garages, filling stations, residential garages, multi-storey car parks, overhangs at drive-throughs and warehouses.[ citation needed ]

Eurocode 1: Actions on structures has a definition of "physical clearance" between roadway surface and the underside of bridge element. The code also defines the clearance that is shorter than the physical clearance to account for sag curves, bridge deflection and expected settlements with a recommendation of minimum clearance of 5 metres (16 ft 5 in). [2] In UK, the "standard minimum clearance" for structures over public highways is 16 feet 6 inches (5.03 m). [3] In United States, the "minimum vertical clearance" of overpasses on Interstate Highway System is 16 feet (4.9 m). [4]

See also

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A railway platform is an area alongside a railway track providing convenient access to trains. Almost all stations have some form of platform, with larger stations having multiple platforms.

Gauge may refer to:

<span class="mw-page-title-main">Track gauge</span> Spacing of the rails on a railway track

In rail transport, track gauge is the distance between the two rails of a railway track. All vehicles on a rail network must have wheelsets that are compatible with the track gauge. Since many different track gauges exist worldwide, gauge differences often present a barrier to wider operation on railway networks.

<span class="mw-page-title-main">Loading gauge</span> Maximum dimensions for railway vehicles and their loads

A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and keep clear of platforms, trackside buildings and structures. Classification systems vary between different countries, and gauges may vary across a network, even if the track gauge is uniform.

<span class="mw-page-title-main">Engineering tolerance</span> Permissible limit or limits of variation in engineering

Engineering tolerance is the permissible limit or limits of variation in:

  1. a physical dimension;
  2. a measured value or physical property of a material, manufactured object, system, or service;
  3. other measured values ;
  4. in engineering and safety, a physical distance or space (tolerance), as in a truck (lorry), train or boat under a bridge as well as a train in a tunnel ;
  5. in mechanical engineering, the space between a bolt and a nut or a hole, etc.
<span class="mw-page-title-main">Clearance car</span> Type of railroad car

A clearance car is a type of railroad car in maintenance of way service. Its purpose is to check the clearances around the tracks and ensure that trains conforming to the railroad's standard loading gauge or dynamic envelope will not encounter any obstruction. Additionally, by measuring the actual clearances along a route, the railroad can determine whether outsize loads can be accommodated along that route, and the largest size feasible.

Standards for Interstate Highways in the United States are defined by the American Association of State Highway and Transportation Officials (AASHTO) in the publication A Policy on Design Standards: Interstate System. For a certain highway to be considered an Interstate Highway, it must meet these construction requirements or obtain a waiver from the Federal Highway Administration.

<span class="mw-page-title-main">Gauntlet track</span> Railway piece that features overlapping rails on the same sleepers

Gauntlet track or interlaced track is an arrangement in which railway tracks run parallel on a single track bed and are interlaced in such a way that only one pair of rails can be used at any time. Since this requires only slightly more width than a single track, all rails can be carried on the same crossties/sleepers. Trains run on the discrete pair of rails appropriate to their direction, track gauge or loading gauge.

<span class="mw-page-title-main">Kap Shui Mun Bridge</span> Overpass in western Hong Kong

The Kap Shui Mun Bridge (KSMB) in Hong Kong, part of Lantau Link of Route 8, is one of the longest cable-stayed bridges in the world that transports both road and railway traffic, with the upper deck used for motor vehicles and the lower deck for both vehicles and the MTR. It has a main span of 430 metres (1,410 ft) and an overall length of 750 metres (2,460 ft). It spans the Kap Shui Mun marine channel between Ma Wan and Lantau islands and has a vertical clearance of 47 metres (154 ft) above sea level. The bridge was completed in 1997.

<span class="mw-page-title-main">Defect detector</span> Device used to detect defects on trains

A defect detector is a device used on railroads to detect axle and signal problems in passing trains. The detectors are normally integrated into the tracks and often include sensors to detect several different kinds of problems that could occur. Defect detectors were one of the inventions which enabled American railroads to eliminate the caboose at the rear of the train, as well as various station agents placed along active routes to detect unsafe conditions. The use of defect detectors has since spread overseas to other railroad systems.

<span class="mw-page-title-main">Oversize load</span> Truck with unusually large or heavy load

In road transport, an oversize load is a load that exceeds the standard or ordinary legal size and/or weight limits for a truck to convey on a specified portion of road, highway, or other transport infrastructure, such as air freight or water freight. In Europe, it may be referred to as special transport or heavy and oversized transportation. There may also be load-per-axle limits. However, a load that exceeds the per-axle limits but not the overall weight limits is considered overweight. Examples of oversize/overweight loads include construction machines, pre-built homes, containers, and construction elements.

<span class="mw-page-title-main">Hillsborough River Bridge</span> Bridge in Prince Edward Island, Canada

The Hillsborough River Bridge is a bridge crossing the Hillsborough River estuary between Charlottetown and Stratford in Queens County, Prince Edward Island. The current road bridge, built in 1962, replaced a 1905 rail bridge crossing the same span which was known by the same name.

The Berne Gauge or Berne Convention Gauge is an informal but widely used term for the railway loading gauge considered the standard minimum loading gauge in most of Europe. The term arises from the international railway conference held and consequent convention signed in Bern, Switzerland in 1912. The official name of this gauge is the Gabarit passe-partout international, and it came into force in 1914.

<span class="mw-page-title-main">Well car</span> Type of railroad car

A well car, also known as a double-stack car, is a type of railroad car specially designed to carry intermodal containers used in intermodal freight transport. The "well" is a depressed section that sits close to the rails between the wheel trucks of the car, allowing a container to be carried lower than on a traditional flatcar. This makes it possible to carry a stack of two containers per unit on railway lines wherever the structure gauge assures sufficient clearance. The top container is secured to the bottom container either by a bulkhead built into the car — possible when bottom and top containers are the same dimensions, or through the use of inter-box connectors (IBC). Four IBCs are needed per well car. In the terminal there are four steps: unlock and lift off the top containers of an inbound train, remove the bottom containers, insert outbound bottom containers, lock assembly after top containers emplaced. Generally this is done car-by-car unless multiple crane apparatus are employed.

<span class="mw-page-title-main">Trailer-on-flatcar</span> Practice of carrying truck semi-trailers on railroad freight cars

Trailer on flatcar, also known as TOFC or piggyback, is the practice of carrying semi-trailers on railroad flatcars. TOFC allows for shippers to move truckloads long distances more cheaply than can be done by having each trailer towed by a truck, since one train can carry more than 100 trailers at once. The trailers will be moved by truck from their origin to an intermodal facility, where they will then be loaded onto a train, typically by a rubber tired gantry crane, for the bulk of their journey. Alternatively, trailers may be driven onto the flatcars via ramps by a terminal tractor. Near the destination, the trailers are unloaded at another facility and brought to their final destination by a tractor unit.

<span class="mw-page-title-main">South African Class Afro 4000</span>

The Passenger Rail Agency of South Africa Class Afro 4000 of 2014 is a South African diesel-electric locomotive.

The track spacing is the distance between the track centres of double-track railway lines. There are standard distances derived from the standard loading gauge in a country. For high-speed trains and in tighter curves that distance needs to be increased.

<span class="mw-page-title-main">Road signs in Vietnam</span>

Road signs in Vietnam follow Chinese and French road signs. Some signs are written in both Vietnamese and English. The signs are prescribed by the Ministry of Transportation of Vietnam.

<span class="mw-page-title-main">Bridge strike</span> Type of accident

Bridge strike or tunnel strike is a type of transport accident in which a vehicle collides with a bridge, overpass, or tunnel structure. Bridge-strike road accidents, in which an over-height vehicle collides with the underside of the structure, occur frequently and are a major issue worldwide. In waterways, the term encompasses water vessel–bridge collisions, including bridge span and support structure collisions.

In civil engineering, clearance refers to the difference between the loading gauge and the structure gauge in the case of railroad cars or trams, or the difference between the size of any vehicle and the width/height of doors, the width/height of an overpass or the diameter of a tunnel as well as the air draft under a bridge, the width of a lock or diameter of a tunnel in the case of watercraft. In addition, there is the difference between the deep draft and the stream bed or sea bed of a waterway.

References

  1. "Structure Gauge and Kinematic Envelope".
  2. Eurocode 1 - Actions on structures - Part 1-7: General actions - Accidental actions (PDF). The European Union. July 2006. Retrieved 31 August 2023.
  3. Preventing of Strikes on Bridge Over Highways - A Protocol for Highway Managers & Bridge Owners (PDF) (2 ed.). Network Rail on behalf of Bridge Strike Prevention Group. p. 6. Retrieved 29 August 2023.
  4. "Right of Passage: The Controversy Over Vertical Clearance on the Interstate System". U.S. Department of Transportation Federal Highway Administration. Retrieved 27 August 2023.