Railway Track Engineering 1(1)

Transportation Engineering  Akhtar Abbas  Assistant Professor

The University of Lahore www.uol.edu.pk/ce

Department of Civil Engineering, (07-05-2013)

Railway Engineering • Brief History of Railways • Railways originates in England, In 1784, mail coaches for carrying mails were introduced. • In 1789 cast iron rails resting on stone blocks were introduced. • The first ever railway in the world was opened for traffic on 27 September 1825 2

Railway Engineering • This railway line was run between Stockton and Darlington. The planning and design of railway line was carried out by George Stephenson. • In France the first railway was opened in 1828 with horse as a tractive power. Passenger traffic had started in 1832, but steam locomotive were used in 1842. 3

Railway Engineering • The first railway line in America was laid in 1833. • The first railway line in India was opened for traffic on 16th April 1853 between Bombay and Thana, a distance of 33 Km

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Railway Engineering •  Advantag  Advantage e of railways railways 1. Ra Raililwa ways ys hav have e hel helped ped in th the e mas masss migration of the people in search of the better prospect of livelihood 2. Ra Raililwa ways ys pro provi vide de safe safe and and conv conveni enien entt mode of transport to people 3. Rai Railw lways ays pla play y a vita vitall role role in tra transp nsport orting ing goods from one region to other. 5

Railway Engineering • Railway Track   A railway track is a combination of rails, formation, ballast, sleepers and fastenings It also called permanent way It costs nearly 40% of the total investment to the railways.

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Railway Engineering • Requirement of Ideal Track  1. Th The e gauge gauge of of trac track k shou should ld be be corre correct ct and and uniform 2. The ali alignm gnment ent of trac track k shoul should d be cor corre rect ct 3. In str straig aight ht reac reaches hes the rail lev level el shou should ld be same, while on curves proper super elevation should be provided 7

Railway Engineering 4. The gradient should be uniform. Any change in gradient should be followed by vertical curve. 5. The tra track ck sho should uld pos posses sesss suf suffic ficien ientt elasticity. 6. The trac track k shou should ld pos posses sesss anti anti the theft ft and sabotage quality. 8

Railway Engineering 7. The tra track ck shou should ld be be const construc ructed ted in such such a way that its maintenance cost is minimum. 8. The tra track ck shou should ld be be desig design n in suc such h a way that the load of train should be distributed uniformly over it. 9. The tra track ck sho should uld be high high re resis sistan tance ce to damage at the time of derailment. 9

Railway Engineering • Capacity Of Railway Track  The maximum number of trains that can be run safely on any given length of the track per hour. In actual practice it is some what less due to safety consideration. The maximum # of trains which can be handled in a yard per day is known as terminal capacity. 10

Railway Engineering • Formation The surface prepared to receive the ballast, sleepers and rails for construction the railway track is called formation or sub grade, depending upon the ground conditions, the formation may be in embankment or cutting 11

Railway Engineering • Function of Formation 1. It pro provi vides des a smoo smooth th and and uni unifo form rm bed bed on which the track is laid. 2. It bear bearss the the entir entire e load load tran transmi smitte tted d from from the moving loads to it through the ballast 3. It pro provi vides des dr drai ainag nage e faci facililiti ties es.. 4. It pro provi vide dess stab stabililit ity y to the the trac track. k. 12

Railway Engineering Design Aspects Width,, The width of formation depend Width upon the following factors 1. Nu Numb mber er of of trac track k to be be laid laid ove overr it 2. Gau aug ge of track. 3. Wi Widt dth h of of bal balla last st la laye yer. r. 4. Wi Widt dth h of of dra drain inss pro provi vide ded d •

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Railway Engineering • Height The height of the formation depends upon the topography of the alignment and the gradient adopted. • Side Slopes The side slopes of the formation depend upon the characteristics of the soil, as shear strength, angle of repose. 14

Railway Engineering •  Angle of Repose Repose is the steepest angle of descent or dip of  the slope relative to the horizontal plane when material on the slope face is on the verge of sliding. This angle is in the range 0° –  –90°. 90°.

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Railway Engineering

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Railway Engineering

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Railway Engineering • CONSTRUCTION OF RAILWAY TRACK  IN DENMARK ON June 25'th 2010 BY  USING Plasser & Theurer equipment (Attached movie) • http://www.youtube.com/watch ?v=Bk82bgPUcAM 18

Rail Gauges The minimum perpendicular distance  between the inner face of the two rails. • In some countries gauge is measured at a point 14 mm below the t he top of rails. • It is difficult to spell out the reasons of  adopting different gauges in different countries or in a country. 19

Rail Gauges

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Rail Gauges

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Rail Gauges • Factors Affecting the Choice of Gauge  1. Tr Tra affic conditions If the intensity of traffic on track is more, a gauge wider than the standard gauge may be adopted. For such a condition a gauge width of 1676 mm (5’ -6”) is more acceptable as the cost of operation per tone-km will be less for more carrying capacity, known as Broad gauge (B.G) 22

Rail Gauges 2. Deve Develo lopm pmen entt of po poor or ar area eass To provide rail facilities for the development of poor areas, small gauge than standard may be adopted. It is known as narrow gauge. The width of  this gauge varies from 762 to 610 mm.

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Rail Gauges 3. Cos ostt of th the e tr tra ack  If the sufficient funds are not available for the construction of standard or Broad Gauge railway track, then meter gauge 1000 mm gauge is adopted for this area. 4. Co Cost st of co cons nstr truc ucti tion on There is not an appreciable increase in the cost of construction due to increase 24

Rail Gauges in the width of gauge due to following reasons I. Th The e cos costt of of bri bridg dge, e, tu tunn nnel els, s, st stat atio ion, n, st staf aff  f  quarter buildings, signals and level crossing etc. is same for all gauges. II. Cos Costt of eart earth h work, work, sleep sleepers, ers, ball ballast ast etc etc.. however will increase proportionally to the gauge width. 25

Rail Gauges III.The cost of acquisition of land for permanent land width increases proportionally with the increase in gauge width. IV. Cost of rolling rolling stock stock will be independent independent of gauge width.

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Rail Gauges 5. Spe pee ed of mo move vem men entt The speed of a train is proportional to the gauge . It is also a function of wheel diameter and the wheel diameter is kept 0.75 times the gauge width. Hence for higher speed Broad Gauge is prefered

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Rail Gauges 6. Topo Topogr grap aphy hy of of area area or or the the natu nature re of  of  country In hilly areas narrow gauges 762 to 610 mm gauge track is more useful as it is more flexible and can be laid of a smaller radius on the curve.

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Rail Gauges Types of Gauges 1. Broad Ga Gauge 2. Stan and dard gau aug ge 3. Meter Gauge 4. Narrow Gauge

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Rail Gauges

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Rail Gauges

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Rail Gauges • Disadvantages of Adoption of Different Gauges 1. In Inco conv nveni enienc ence e to pas passen senger gerss  At the place of change of gauge, passengers have to move from one train to another train. This trans-shipment causes great hardship to passengers such as climbing stair cases of over head 32 bridge,

Rail Gauges movement of luggage, getting suitable accommodation in the new train. 2. Tr Tran ansh ship ipme ment nt of go good odss a. Labor problem b. Da Dama mage ge of good goodss while while tran transs-sh ship ipme ment nt c. Th Thef eftt or Mi Misp spla lace ceme ment nt of go good odss d. To stor store e goods goods,, cost costly ly yards yards are req require uired d at the junctions of two gauges 33

Rail Gauges 3. Hind Hindra ranc nce e to fast fast mov movem emen entt of goods goods and passenger traffic 4. In Ineff effic icie ient nt use use of rai railw lway ay sto stock  ck   As meter gauge wagons wagons and locomotives locomotives can not be used on broad gauge 5. Du Dupl plic icit ity y of equ equip ipmen mentt at sta stati tion onss  At station where two two gauges meet, 34

Rail Gauges duplicate facilities such as platform, clocks, ticket office, sanitary arrangements, etc. have to be provided, which will involve extra expenditure. 6. Di Diff ffic icul ulty ty in wa warr ti time me 7. Di Diff ffic icul ulty ty in fu futu ture re

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Rail Gauges • Loading Gauge Loading gauge consist of a vertical post with an arm. A steel arc is suspended from the top. It is constructed at the exit of the goods yard. Function Its main function is to confirm that the top of the loaded wagon would clear all the 36

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Rail Gauges

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structures along the track such as tunnels and bridges etc. It represents the maximum height and width up to which a wagon should be loaded Construction Gauge By adding suitable clearance at the top side of loading gauge, construction gauge is obtained 38

Rail Gauges Function of construction gauge It decided the dimensions such as height and width of structure such as bridges and tunnels along the track, so that all wagons may pass through them without any damage to the structures.

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Rail Gauges

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Rail Gauges

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Rails • Rail is an iron beam. Its main function is to provide a most economical, smooth and level surface for the smooth passage of  heavily loaded vehicles at great speed. The two rails of the track also serve as lateral guide for the running of the wheel.

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Rails

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Types of Rails Rails can be classified into the following categories: 1) Do Doub uble le he head aded ed ra railil 2) Bu Bullll he head aded ed ra railil 3) Fla latt foo foote ted d ra rail 1. Do Doub uble le He Head aded ed Rai Raill It is of I section or dumb bell section. 44

Types of Rails It is the original rail. The idea was that when the head of the rail was worn out during the period of service, the rail could be inverted and reversed without incurring any extra expenditure. Such a rail have to be supported in chairs which rest on sleepers. Later it was found that during the service the bottom table of the rail 45

Types of Rails was dented by the long and continuous contact with the chair to such an extent that it was impossible to reuse it. Hence it was rejected and other types of rail was searched. 2. Bu Bull ll He Head aded ed Ra Rail il It is similar in shape to double head rail. The only difference between double 46

Types of Rails headed and bull headed rail is that in bull headed rail more metal is added to the head to allow the greater wear and tear. The lower head or table was kept of just sufficient size to be able to withstand the stresses to be induced by moving loads. This rail also required chair for fixing it to the sleeper. This proved the greatest draw back of this rail 47

Types of Rails 3. Fla latt Foo oote ted d Ra Railil It is inverted T shaped rail. It was developed by Charles Vignoles as earlier as 1836. It posses the following advantages over double headed and bull headed rail I. Fo Forr fix fixin ing g thi thiss typ type e of of cha chair ir to sl slee eepe pers rs,, no chairs are required. The foot of the 48

Types of Rails rail may be spiked direct to the sleepers. This effects economy to a great extent. II. For the sam same e weigh weight, t, this this typ type e of rail rail is stronger both vertically and laterally than the bull headed rails. III.This type of rail is cheaper than bull headed rails IV. This type of rail rail requires less less fastenings fastenings 49

Types of Rails than B.H. rails  V. F.F. rails distribute train load over a larger number of sleepers, which gives a better stability to the track.  VI. F.F. rails gives longer life to the track  and reduce maintenance cost. Some engineers feels that B.H. rails gives  better alignment, more solid and smooth  50 track 

Types of Rails

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Rails • Requirement of an Ideal Rail 1. It sho should uld be pos posses sesss adequ adequate ate lat lateral eral and vertical stiffness. 2. Th The e shap shapes es of the the bot botto tom m of th the e head head and top of the foot should be such that fish plate could be fixed easily. 3. The C.G C.G.. of the ra railil sect section ion sho should uld be located very near the centre of the height 52

Rails of the rail. 4. To allow the sufficient margin for the vertical wear, the depth of the head of rail should be sufficient. 5. The rail should be shaped suitably. 6. The metal distribution in head, web and foot of the rail should be proper and balanced. 53

Rails 7. The surfaces and gauge faces of the rail should be hard and capable of resisting wear. 8. The thickness of the web of the rail should be sufficient to withstand the load likely to come on the rail. 9. The width of the foot of rail should be sufficient to spread the load on large area 54 of sleepers

Rails 10. The contact area between the rail and the wheel should be sufficient to minimize the contact pressure.

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Defects in Rails 

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Due to the passage of moving of a number of wheels and the friction between the wheel and the rail, the rail head gets worn out in course of time. The impact of moving loads, the forces due to rail wheel interaction , braking of  wheels and effect of weather conditions caused considerable wear and tear on 56

Wearing of Rails vertical and lateral planes of a rail head. Wear of rail head can be classified I. Wea earring on on to top or or hea head d of of a rail II. We Wear ar at the en end d of of a ra railil III. Wear on the sides of a rail

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Wearing of Rails I. Wearing on top of of ra rail The metal from the top of the rail flows and assumes the shape forming projections on the sides. These projections beyond the original section of  the rail are known as burrs.  Causes of Wear on top of a rail 1. Th The e hea head d of of rai raill wor worn n out out du due e to to the the 58

Wearing of Rails  Abrasion of the rolling wheels wheels over the rail. 2. Due to the concentration of heavy wheel loads on a very small area, high stresses in rail exceeding the elastic limit are produced. Due to these high stresses the metal from the top flows out. This factor is more significant than the first in producing wear in rails. 59

Wearing of Rails 3. The gri grindi nding ng acti action on of the san sand d part particl icles es between the wheel and rail also help to produce wear of a rail. 4. Cor Corros rosion ion of rail rail,, also also help help in in wear wear of of top top of a rail. II. Wear at the end of a rail  At the joints due to the hammering hammering action of the moving wheel cause the wear of  60

Wearing of Rails the rail at its ends. It is more pronounced than the wear on the top. This wear is also known as rail end batter. The rail end batter is measured as the difference between the vertical height of rail at the end and at a distance of 30 cm from the end. If the batter is up to 2 mm, it can be tolerated and it is called as average batter. 61

Wearing of Rails but a batter 2 and and 3 mm is is known as severe and in this condition rail end needs correction. If the batter is excessive and rail is otherwise alright , a portion of the rail may be cut off and it can be reused Effect of End Wear of a Rail Due to the impact blows of the t he moving wheels on the end of the rail, Results 62

Wearing of Rails 1. The con contac tactt surfa surfaces ces bet betwee ween n rails rails and sleepers get worn out. 2. Fis Fish h bolt boltss and and fish fish pla plates tes bec become omess loos loose. e. 3. Due to vib vibrat ration ionss at at the the joi joints nts,, the the settlement of the ballast takes place, which results in depression of the sleepers. The defect is enlarged due to the following factors. 63

Wearing of Rails i. Due to to he heavy lo loads an and la large jo joint opening iiii.. Du Due e to to bad bad co cond ndit itio ions ns of veh vehic icle le sp spri ring ngs. s. iii.. Due to poor iii poor mai mainte ntenan nance ce of the tra track. ck. III Wear on the sides of a Rail This is the most destructive type of wear and occurs when the tracks are laid on curves. 64

Wearing of Rails These type of wear is caused by the following factors. 1. On cu curv rved ed por porti tion on of th the e trac track k , the the centrifugal force causes thrust of the wheel flanges against the side of the outer rail head, which results in the grinding of the rail by the flanges producing side wear on the outer rail. 65

Wearing of Rails 2. On curved portion of the track, the vehicles do not bend to the shape of the curvature, resulting into biting of the inner side of the outer rail head by wheel flanges i.e., due to rigidity of wheel base. 3. Wear on inner side of head of the inner rail also occurs. It takes place mainly due to slipping and skidding action of wheels on curves. 66

Measure to minimize Wear to Rails i. By coning the wheels iiii.. By prov provid idin ing g the the sup super er ele eleva vati tion on on th the e track. iii.. By the iii the use use of spec special ial all alloy oy stee steell for for rails rails.. iv. By adop adoptin ting g good good mai mainten ntenanc ance e of tra track. ck. v. By re redu duci cing ng th the e exp expan ansi sion on ga gap p an and d number of joints. 67

Measure to minimize Wear to Rails vi. When the wear exceeds 5% of the total weight of the section. The rail must be replaced. vii. Regular tightening of fish bolts and packing of ballast will reduce wear

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RAILWAY TRACK ENGINEERI ENGINEERING NG

GOOD LUCK  FOR 

MID TERM •

"How can one be considered among the people of knowledge when  his worldly life is dearer to him than his Hereafter?"  • Prophet Isa (as) 71

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