Permanent Ways, Rail Tracks and Infrastructures

Group 2 of BSREM 2-1Permanent Ways, Rail Tracks and Infrastructures It is a steering base for the train.It is a fundamental part of the railway.It represents the primary distinction between this form of land transportation and all others in that provides fixed guidance system.Assembly of rails, supporting ties/fastening over which vehicles travel.What is Railway Track?Infrastructure Diagram of a Railway Track

Types of RailsRail WeldingFlash Butt WeldingThe surfaces of the work pieces are positioned end-to-end. As a rule, flash-butt welding is subdivided into preheating, flashing and upsetting. Preheating is carried out under low welding pressure. Once the welding joint is heated, flashing commences and joint surface material is burnt off, resulting in even joint surface. After arriving at preset flashing loss, upsetting commences, resulting in an irregular "fin" on the surface of the upset metal consisting of molten and oxidized material.

Aluminothermic Welding or Thermite Welding

In this process, molten steel is poured into a mould surrounding the gap between rail ends to be joined. The rail ends are connected by the liquid metal. The principle of aluminothermic welding is based on exothermic chemical reaction of aluminum powder and iron oxide, producing sufficient heat to cause melting.

Railway sleepers, or railroad ties as they are known in the US, which are laid horizontally underneath tracks to hold rail lines in place at the correct gauge, form the backbone of rail travel.What is sleeper or tie?Wooden Sleeper

Traditionally, timber sleepers have been used because of their availability , cost, lightness for handling, workability, resilience, good insulating properties, and low sensitivity to shocks. The main disadvantage are the need for continuous maintenance, largely because of progressive loosening of rail fasteners, and susceptibility to weathering and biological attack.

Concrete SleepersThe primary advantage of concrete sleepers are long life, uniformity of quality and dimensions, and high resistance to wear and biological attack. The main disadvantages in the past have been the initial cost, weight, and sensitivity to shock.Support the weight of the track and the considerable cyclic loading of passing trainsProvided to give support, load transfer and drainage to the track and thereby keep water away from the rails and sleepers.Made up of stones of granite or a similar material should be rough in shape to improve the locking of stones. Their purpose is to hold the wooden cross ties in place, which in turn hold the rails in place.

What is Ballast?

Rail gauge is the width between the inside faces of a pair of rails.

Rail Gauge

Narrow GaugeMetric (mm)EnglishMetric (mm)English6602' 2"7532' 5 5/8"6662' 2 7/32"7602' 5.9"6702' 2 1/3"7622' 6"6862' 3"7852' 6 29/32"6932' 3 9/32"7872' 7"7002' 3 1/2"7912' 7 5/32"7052' 3 3/4"7922' 7 9/507122' 4"7942' 7 1/4" 7162' 4 3/16"8002' 7 1/2"7202' 4.3"8022' 7 57/100"7242' 4 1/2"8132' 8"7302' 5"8202' 8 1/4"7372' 5 1/64"8262' 8 1/2"7422' 5 1/8"8382' 9"7502' 5 1/2"8502' 9 1/2"Meter GaugeMetric (mm)EnglishMetric (mm)English8642' 10"9913' 3"8692' 10 7/32"1000 *Meter Gauge3' 3 3/8"8762' 10 1/2"10033' 3 1/2"8802' 10 13/20"10093' 3 3/4"8852' 10 3/4"10163' 4"8892' 11"10293' 4 1/2"8912' 11 3/32"10393' 4 91/100"9102' 11 1/2"10503' 5 1/4"9143'10553' 5 1/2"9253' 2/5"10643' 5 7/8"9503' 1 2/5"1067 *Cape Gauge3' 6"9553' 1 3/5"10903' 7"9643' 2"11003' 7 5/16"9723' 2 1/4"11063' 7 1/2"9783' 2 1/2"11183' 8"9803' 2 9/16"12194'9883' 2 9/10"12454' 1"Normal GaugeMetric (mm)EnglishMetric (mm)English12704' 2"14224' 8"13214' 4"14324' 8 3/8"13504' 5 1/8"1435 *Standard Gauge4' 8 1/2"13654' 5 3/4"14404' 8 7/10"13724' 6"14454' 8 9/10"13914' 6 3/4"14484' 9"14104' 7 1/2"14734' 10"14164' 7 3/4"14954' 10 7/8"Broad Gauge

Metric (mm)EnglishMetric (mm)English15114' 11 3/8"18005' 10 7/8"1525 *CIS/Russian Gauge 5'18296'15495' 49/50"18806' 2"15755' 2"19456' 4 5/8"15815' 2 1/4"20006' 5"15885' 2 1/2"21347'1600 *Irish Gauge5' 3"21407' 1/4"16385' 4 1/2"24408'16455' 4 3/4"27439'1668 *Iberian Gauge5' 5 21/32"30009' 10 2/25"1676 *Indian Gauge5' 6"548618'16805' 6 1/8"600019' 8 11/50"17405' 8 1/2"820026' 11"17505' 8 7/8"900029' 6 5/16"17605' 9 1/4"The larger the gauge, the larger the size of wagons and locomotives, and more economical will be the operating costs.Use of narrow gauges are best for mountainous areas.Use of standard gauges are best for elevated tracks and high-speed trains.Use of broad gauges are best for bullet trains.

Effects of Rail Gauges on Train PerformanceBallasted Tracks - Tracks with ballast.Slab Tracks - Slab track, also called ballast less track, is a modern form of track construction which has been used successfully throughout the world for high speed lines, heavy rail, light rail and tram systems. A slab track means a reinforced concrete slab laid on a viaduct or other rugged bed, and secured to the bed using cement asphalt. Slab track technology offers proven higher performance in service and a longer life than traditional ballasted track. Ballast less track systems incur significantly lowermaintenancecosts compared to ballasted track.

Types/Classification of Rail Track StructuresSolid-bed Tracks blah blah blah Ballasted TracksBlah blahBlah blahComparison between Ballasted and Non-ballasted TracksNon-ballasted TracksCurves in the track are almost a science on their own. Careful calculations are required to ensure that curves are designed and maintained properly and that train speeds are allowed to reach a reasonable level without causing too much lateral stress on the track or inducing a derailment. There are both vertical curves and horizontal curves. There is also a section of track on either side of a curve known as the transition, where the track is changing from straight to a curve or from a curve of one radius to one of another radius.Track CurveIn track construction, the vertical distance that the outer rail is set above the inner rail on a curve, expressed as the vertical distance of the outer rail over the inner rail or as the transverse grade percent.Cant is the name used to describe the cross level angle of track on a curve, which is used to compensate for lateral forces generated by the train as it passes through the curve.Superelevation/CantDescribe the junctions in track work where lines diverge or converge so as to avoid "points" (UK) or "switches" (US). In the railway "trade", turnouts are referred to as "switch and crossing work".Transfer vehicles from one track to another.

What is Turnout?

There are now a range of modern track forms using a concrete base. They are generally used in special locations such as tunnels or bridges where a rigid base is required to ensure track stability in relation to the surrounding structures. The earth mat is a steel mesh screen provided on electrified railways to try to keep stray return currents from connecting to utilities pipes and nearby steel structures. Earthling must be strictly controlled otherwise serious and expensive problems will occur, made more serious and expensive because they involve other people's property.

Some slab track systems have the sleepers resting on rubber or similar pads so that they become "floating slab track". Floating track is used as a way of reducing vibration. Hong Kong Mass Transit Railway is fond of it, since its lines run through very densely populated areas.

Modern Track FormsKinematic/Dynamic Envelope of Rolling StocksThis area designates the limits the train can move laterally and vertically along the route.

Rail Track DesigningTampering of Ballasts

Maintenance of Rail Tracks

GaugingManualusing hand tools/light tools in repairing and maintaining the trackThrough a special vehiclemechanically using equipments such as ballast cleaner, ballast tamping machine, ballast regulator, ballast woofer, sleeper gant tray

http://www.railway-technical.coam/track.shtmlhttp://www.railwaysleepers.com/railway-sleepers/railway-sleeper-info/railway-sleeper-factshttp://www.esab.com/global/en/education/processes-flash-butt.cfmhttp://www.ewf.be/railsafe/RAILSAFE-short_description_of_the_aluminothermic_rail_welding_process.pdfhttps://bitre.gov.au/publications/1972/files/report_004.pdfReferences: