A structure gauge, also called the minimum clearance 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 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, electrical equipment boxes, signal equipment, third rails or supports for overhead lines. A related but separate gauge is the

loading gauge 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 ke ...

: 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; 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

overpass An overpass (called an overbridge or flyover in the United Kingdom and some other Commonwealth countries) is a bridge, road, railway or similar structure that crosses over another road or railway. An ''overpass'' and ''underpass'' together form ...

es and the space within the

superstructure A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. Aboard ships and large boats On water craft, the superstruct ...

of bridges, as well as doors into automobile repair shops,

bus garage A bus garage, also known as a bus depot, bus base or bus barn, is a facility where buses are stored and maintained. In many conurbations, bus garages are on the site of former car barns or tram sheds, where trams (streetcars) were stored, and ...

s, filling stations, residential garages, multi-storey car parks, overhangs at

drive-through A drive-through or drive-thru (a sensational spelling of the word ''through''), is a type of take-out service provided by a business that allows customers to purchase products without leaving their cars. The format was pioneered in the United ...

s and warehouses.

Accidents

Motor vehicles hit railway bridges 1789 times in 2019 in the UK, where such incidents are known as bridge strikes, with several bridges being hit over 20 times in a single year. The total cost borne by the state was around £23 million. A high

overpass bridge An overpass (called an overbridge or flyover in the United Kingdom and some other Commonwealth countries) is a bridge, road, railway or similar structure that crosses over another road or railway. An ''overpass'' and ''underpass'' together form ...

near St Petersburg, Russia, is known as the "Bridge of Stupidity" because it is often struck by vehicles despite many warning signs. In May 2018, after it was struck for the 150th time by a GAZelle truck, a birthday cake was presented to the bridge. This made national news. Similarly, an

in Durham, North Carolina, USA, was frequently struck by vehicles, and made the news a number of times until it was raised in 2019. Infrared sensors which trigger warning signs when a high vehicle approaches were added to an underpass in Frauenfeld, Switzerland, only after several incidents. A similar situation exists at an underpass on Guy Street in Montreal.Truck removed
/ref> Another problem is the

Montague Street Bridge The Montague Street Bridge is a railway bridge in South Melbourne, Australia, an inner suburb of Melbourne. The bridge is located at 83 Montague Street, between Woodgate Street and Gladstone Lane. The bridge has a very low height clearance of , ...

in South Melbourne.

Gallery

Image:Gabarit-ferroviaire.svg, File:Lichtraumprofil.png, File:Pont Ducharme Est.jpg, Structure gauge limiting the height of vehicles for

Pont Ducharme The Ducharme Bridge (French: ''Pont Ducharme'') is a covered bridge with a lattice truss structure, which crosses the Bostonnais River in the center of La Bostonnais, Quebec. The bridge was built in 1946 and it is long. It was classified as ...

to . File:Lichtraumprofilbrücke (001).JPG, Calibration bridge in Germany, used to indicate the maximum height of vehicles on approaching a railway bridge

References

External links

Transport Canada, Standard Respecting Railway Clearance

GLOSSARY OF TERMS USED IN RAILROAD HIGH AND WIDE CLEARANCES

Railway line clearances and car dimensions including weight ..., Volumes 87-90

www.ipm.fraunhofer.de/railway

Clearance Guidelines for Industrial Railways (BC)

Rail infrastructure Road hazards {{Rail-transport-stub

Road traffic application

Accidents

Gallery

See also

References

External links