The axle load of a wheeled vehicle is the total weight bearing on the roadway for all wheels connected to a given axle. Axle load is an important design consideration in the engineering of roadways and railways, as both are designed to tolerate a maximum weight-per-axle (axle load); exceeding the maximum rated axle load will cause damage to the roadway or rail tracks.
On railways, a given section of track is designed to support a maximum axle load. The maximum axle load is determined by train speeds, weight of rails, density of sleepers and fixtures, amount and standard of ballast, and strength of bridges and earthworks. Higher operating speeds can be achieved by reducing axle loads and increased load-carrying capacity. Operating above the specified load can cause catastrophic failure of track components.[citation needed] The diameter of the wheels also affects the maximum axle load of a Talgo RD wagon.
United Kingdom
The standard rail weight for British railways is now 113 lb/yd (56.1 kg/m). Before the 1990s, most diesel locomotives were built to a maximum axle load of 19 long tons (19.3 tonnes; 21.3 short tons) so the maximum locomotive weight was 76 long tons (77.2 tonnes; 85.1 short tons) for a four-axle locomotive and 114 long tons (115.8 tonnes; 127.7 short tons) for a six-axle one. Higher axle loads are now permitted, e.g. the Class 67 locomotive is a four-axle machine weighing 90 tonnes (88.6 long tons; 99.2 short tons), giving 22.5 tonnes (22.1 long tons; 24.8 short tons) on each axle.[citation needed]
Australia
The Fortescue Railway uses 68 kilograms per metre (140 lb/yd) rail on concrete sleepers and has a maximum axle load of 40 t (39 long tons; 44 short tons), which as of 2008[update] was the highest axle load of any railway in the world.[1] In 2011, it was proposed to increase the axle load of the railway to 42 tonnes (41 long tons; 46 short tons).[2][needs update][3]
Kenya
In 2022, sixteen new metre-gauge locomotives were supplied by CRRC with axleloads of 12.5 tonnes, 14 tonnes, and 18 tonnes respectively.
Bridge loading
Bridges may have to carry several locomotives or wagons at the same time, especially on longer spans; in that case they require separate calculation of maximum allowable axle load. A weak bridge may limit the axle load of the full line. Theodore Cooper developed the E10 loading system for calculating the strength of bridges.[citation needed]
The term axle load is also applicable to trucks, and this context is complicated by some trucks having more than two wheels per axle. The axle load remains the same, but the load borne by the individual wheels is reduced by having more contact area (more wheels, larger tires, lower tire pressure) to distribute the load.[4]
^"Fortescue opens the world's heaviest haul railway". Railway Gazette. 2008-07-14. from the original on 2016-02-22. Retrieved 2016-02-18.
^Peter Ker (2011-10-24). "Fortescue takes another step in plan to boost Pilbara railway loads". The Sydney Morning Herald. from the original on 2018-05-11. Retrieved 2012-08-06.
^Hjort, Mattias; Haraldsson, Mattias; Jansen, Jan (2008). "Road Wear from Heavy Vehicles: An Overview" (PDF). NVF committee Vehicles and Transports. p. 17+36. ISSN 0347-2485. from the original on 2016-08-18.
axle, load, axle, load, wheeled, vehicle, total, weight, bearing, roadway, wheels, connected, given, axle, important, design, consideration, engineering, roadways, railways, both, designed, tolerate, maximum, weight, axle, axle, load, exceeding, maximum, rated. The axle load of a wheeled vehicle is the total weight bearing on the roadway for all wheels connected to a given axle Axle load is an important design consideration in the engineering of roadways and railways as both are designed to tolerate a maximum weight per axle axle load exceeding the maximum rated axle load will cause damage to the roadway or rail tracks Contents 1 Railway use 1 1 United Kingdom 1 2 Australia 1 3 Kenya 1 4 Bridge loading 2 Roadway use 3 See also 4 References 5 External linksRailway use EditOn railways a given section of track is designed to support a maximum axle load The maximum axle load is determined by train speeds weight of rails density of sleepers and fixtures amount and standard of ballast and strength of bridges and earthworks Higher operating speeds can be achieved by reducing axle loads and increased load carrying capacity Operating above the specified load can cause catastrophic failure of track components citation needed The diameter of the wheels also affects the maximum axle load of a Talgo RD wagon United Kingdom Edit The standard rail weight for British railways is now 113 lb yd 56 1 kg m Before the 1990s most diesel locomotives were built to a maximum axle load of 19 long tons 19 3 tonnes 21 3 short tons so the maximum locomotive weight was 76 long tons 77 2 tonnes 85 1 short tons for a four axle locomotive and 114 long tons 115 8 tonnes 127 7 short tons for a six axle one Higher axle loads are now permitted e g the Class 67 locomotive is a four axle machine weighing 90 tonnes 88 6 long tons 99 2 short tons giving 22 5 tonnes 22 1 long tons 24 8 short tons on each axle citation needed Australia Edit The Fortescue Railway uses 68 kilograms per metre 140 lb yd rail on concrete sleepers and has a maximum axle load of 40 t 39 long tons 44 short tons which as of 2008 update was the highest axle load of any railway in the world 1 In 2011 it was proposed to increase the axle load of the railway to 42 tonnes 41 long tons 46 short tons 2 needs update 3 Kenya Edit In 2022 sixteen new metre gauge locomotives were supplied by CRRC with axleloads of 12 5 tonnes 14 tonnes and 18 tonnes respectively Bridge loading Edit Bridges may have to carry several locomotives or wagons at the same time especially on longer spans in that case they require separate calculation of maximum allowable axle load A weak bridge may limit the axle load of the full line Theodore Cooper developed the E10 loading system for calculating the strength of bridges citation needed Roadway use EditFurther information road wear The term axle load is also applicable to trucks and this context is complicated by some trucks having more than two wheels per axle The axle load remains the same but the load borne by the individual wheels is reduced by having more contact area more wheels larger tires lower tire pressure to distribute the load 4 See also EditFederal Bridge Gross Weight Formula Gross axle weight rating Rail profileReferences Edit Fortescue opens the world s heaviest haul railway Railway Gazette 2008 07 14 Archived from the original on 2016 02 22 Retrieved 2016 02 18 Peter Ker 2011 10 24 Fortescue takes another step in plan to boost Pilbara railway loads The Sydney Morning Herald Archived from the original on 2018 05 11 Retrieved 2012 08 06 FMG Axle load Hjort Mattias Haraldsson Mattias Jansen Jan 2008 Road Wear from Heavy Vehicles An Overview PDF NVF committee Vehicles and Transports p 17 36 ISSN 0347 2485 Archived from the original on 2016 08 18 External links EditManaging rail degradation on the Malmbanan Thomas Nordmark and Dr Per Olof Larsson Kraik Railway Gazette International June 2007 Retrieved from https en wikipedia org w index php title Axle load amp oldid 1131242154, wikipedia, wiki, book, books, library,
