1 Report on Visit to USA and Australia in Connection with Dedicated Freight Corridor

1

Report on Visit to USA and Australia in Connection with

Dedicated Freight Corridor

2

The Core Group

• Board (ME) has nominated a core group for finalizing the technical Specifications pertaining to track and bridges, consisting of :

– EDCE(P), EDCE(B&S) & ED/W from Railway Board,

– ED/Track & ED/B&S from RDSO and – Dean from IRICEN.

3

The Core Group

• The terms of reference of the core group are:– Review the genesis of Maximum Moving

Dimensions on IR and also identify factors limiting its relaxation on the existing network.

– Compare standards presently prevalent on IR with those obtaining on some of the major freight railway system world over.

– Study international experience in rolling stock designs with a view to determining their relevance to both existing as well as future traffic streams of IR.

4

Terms of Reference

• The terms of reference of the committee are:– Recommend and optimal Maximum Moving

Dimensions for the Eastern and Western corridors of the DFC project and other new lines that could be taken up in future.

– Recommend the Maximum Moving Dimensions on feeder routes for Eastern Corridor and Western Corridor keeping in view running of 25 tonne axle load wagons of coal and steel traffic on Eastern Corridor and double stack containers on Western corridor.

– Suggest an implementation strategy for upgrading feeder routes on the existing IR network to standards proposed for feeder routes.

5

The Sub-Group

• A sub-group of the committee consisting of following officers was deputed to USA and Australia to study the implementation of heavy axle load in railway systems of these countries.

– Shri V. K. Jain, EDCE/Planning, Railway Board– Shri Anirudh Jain, ED/Track, RDSO– Shri P. K. Sanghi, ED/Works, Railway Board– Shri Suresh Gupta, Dean, IRICEN

6

Visit of the Sub-Group

• Places Visited in USA:– During the 5 days’ stay in USA the study

team visited the following firms:• M/s.Zetatech Associates at, Cherry Hill near

New York • TTCI at, Pueblo • BNSF at, Los Angeles • ALAMEDA Corridor at, Los Angeles and • APM Terminal at, Los Angeles

7

Visit of the Sub-Group

• Places Visited in Australia:– Australian Rail Track Association, New

Castle.– Transport Management Group, Sydney.– Queensland Railway, Brisbane.– Freight Facility of QR, Acasia Ridge.

8

US Railroads and visit to Zeta Tech Associates

• Track km is about 2 lac 75 thousand km. • Most US Railways are privately owned and runs only

freight trains.• AMTRAK operates all US long distance passenger

trains.• Rail Road employment has fallen from 4 lac 50 thousand

workers in 1980 to 1 lac 55 thousand in 2003. Average annual wage is 62 thousand dollar per annum.

• Track gauge is 1435 mm. • Economic regulation of US Rail Road is the responsibility

of the Surface Transportation Board (STB).• Safety regulation is the responsibility of the Federal Rail

Road Administration (FRA).

9


• Association of American Rail Roads (AAR) is a private trade association and its principal roles are to set mechanical standards for rolling stock, settle accounts between multiple rail carriers, sponsors rail road related research etc.

• USA is running double stack container since 1977. Its axle load is 30 T, although a number of Rail Roads have begun purchasing stock with 32.5 and 35.5 designed axle load. But main axle load is 30 T

• Traction is diesel.• Structurally 60 kg rails are sufficient to support 30 T axle load.

However, USA is mainly using 67 – 71 kg rails on timber and concrete sleepers.

• On timber sleeper, spacing is 20” from centre to centre and on concrete sleeper, spacing is 24” from centre to centre.

• Hardness of the rail is 380 BHN.

10


• Rail grinding is must for higher axle load operation. One machine with 120 stone is able to grind about 10000 km in a year. Operational speed is 20 kmph. Mainly grinding has been outsourced.

• Rail lubrication on curves is essential.• Thick Web Switches with swing nose crossing is essential.• Elastic fastening is mainly safe lock (e-clip).• There are about 25000 number of rail fractures per year.• Number of accidents on rail fracture account is about 100.• Track is inspected by a staff twice a week on freight route.• TRC – 3 to 6 months depending on traffic density.• No regular inspection by Supervisors or officers.• Hard ballast is used and ballast cushion is more than 300 mm.

11

Transportation Technological Centre Inc (TTCI), Pueblo

• A large number of research projects regarding rail hardness track fittings, ballast and bridge monitoring are in progress at TTCI.

• TTCI has developed laser based Rail Flaw Inspection System. This will cover the entire rail cross-section at a speed of 32 kmph.

• TTCI has developed a proto type of Ultrasonic Crack Wheel Detection System. This system is capable of inspecting the wheel at a speed of 8 kmph.

• TTCI has developed proto type laser based Ultrasonic Crack Axle Detection System. This can detect any defect in axle body at a speed upto 32 kmph.

12

BNSF Railways, Los Angeles

• Average length of train is 7000 feet which is going to be extended to 8000 feet.

• Train load is 10000 to 11000 tonne.• Entire Habard yard is covered by 22 Video Cameras and

visual view is available in Control room. This helps in safety.

• 50% of security has been outsourced.• Commodities had been divided in high density and low

density. Low density commodity is being moved on wagons with articulated bogies. Fuel saving is 10 – 15%.

• Truck chassis can be directly loaded on wagons. 145 chassis are carried per train.

13

APM Terminal and PIER 400, Los Angeles

• This is owned by MAERSK, an International Agency dealing in container movement.

• It deals 10000 TEUs per week. 150 cameras are provided to monitor the entire activity on PIER.

• There are 12 tracks of 2200 feet length. Generally a single train of 7000 feet length is accommodated on 4 lines.

• Entire operation is computerized.

14

Alameda Corridor, Los Angeles

• This is passing through heavily habitated area and connecting to ports. Total length is about 20 miles, out of which, 10 miles pass through a trench.

• This was constructed in less than 4 years (1998-2002) at a cost of about Rs. 2.2 billion dollar.

• There are 3 lines. • Rail section is 136 LB (67 kg) on concrete sleeper.• Lines are bi-directional.• Track is inspected by a staff twice a week. No regular

inspection by Supervisor or Officer.• AREMA standard is being followed in inspection.

15

Australian Rail Track Corporation, Sydney

• Total length of track under ARTC is about 10000 km.

• Total number of employees is about 25000.• For controlling overloading, motion weight

bridges have been installed immediately after loading point. In case any wagon is found to be overloaded, excess material is removed there itself and no overloading wagon is allowed to go.

• Rail grinding is a normal feature and done through Service Contracts.

16

Australian Rail Track Corporation, Sydney

• For sharp curves of radius less than 400 m, grinding is done after passage of 10 GMT and for straight track, grinding is done after passage of 20 GMT.

• CWRs are continued through bridges. • Their Bridge standards are given in Australian standard

for Bridge Design AS 5100 – 2004.• Clearances between MMD and line side structures are

determined based on Kinematic envelop. Generally, clearance between static MMD and line side structures is more than 600 mm.

17

Transport Management Group, Sydney

• Australia is running 40 t axle load wagons in iron ore routs in BHP (Billiton).

• The work of segregating freight and passenger traffic is presently going on.

• Iron ore wagons are conventional 3 piece bogies.• They are using a software for developing kinematic

envelope.• There are around 100 railway companies in Australia.• Double stack containers are running between Perth and

Broken Hill.

18

Transport Management Group, Sydney

• Queens Land Railways is running upto 150 kmph on Narrow Gauge (1067 mm)

• Coal traffic is having 30 MT axle load and they are thinking of 32.5 MT.

• Rail grinding is a must beyond 25 T.

• By proper grinding and managing wheel & rail profile life of rail can be doubled

19

Queensland Railway, Brisbane

• QR has approximately 9500 km of narrow gauge, standard gauge & dual gauge track throughout the state of Queensland. But the whole of 26 tonnes axle load route is on narrow gauge (1067 mm).

• QR is the biggest mover of freight in Australia, transporting almost 161.8 million tones in 2005.

• QR operates 1000 train services daily and moves more than 4,40,000 tonnes of freight.

• QR transports 160000 commuters on long distance and metropolitan suburban journeys each day.

20

Queensland Railway, Brisbane

• QR operates rolling stock ranging in axle load size from 15.75 to 26 tonnes.

• QR operates the innovative tilt train which can travel at speeds up to 160 km.

• Centre to centre track spacing is 4.2m minimum. • The complete track is on Continuous Welded Rails (CWR) including

those on bridges. • QR has got some lines of dual gauge track on concrete sleepers

with three rail seats.• In Metro rail also grinding is being done for noise purpose. • Swing nose crossing is better for heavy axle load operation.• Length of one train is 1800 m, train loads are in range of 10000

Tons, 6 X 4000 HP locomotives haul these trains.• There are no passenger services on heavy axle coal lines.

21

MMD for DFC

• Dedicated Freight Corridor (DFC) has been announced to be constructed in Howrah-Delhi and Mumbai-Delhi sectors.

• The axle load projected to run on this DFC is 30 tons.

• With most of the traffic expected to be carried on this DFC consisting of low density commodities like Fertiliser and Coal, there is a need to enlarge the Maximum Moving Dimension (MMD) so as to accommodate sufficient quantities to generate required axle load.

22

Inter-operability Requirements

• Looking at the DFC in isolation, there shall not be any problem in increasing the MMD to whatever extent.

• But the wagons designed to run on the new corridor will have to run on existing system either when they are running empty or in the originating and destination spokes.

• This necessitates a study of our existing SOD and to identify the means to progressively adopt larger, wider and higher, wagons so as to fulfill the objective of carrying higher axle loads.

23

DIMENSION 2004MAXIMUM MOVING

Existing MMD

24

MMD for Dedicated

freight Corridor

25

Track Side Structure Profile for

Feeder Routes

26

Track Side Structure Profile for Dedicated

Freight Corridor

27

Clearance between Moving Dimension and Fixed Structure

• The clearance between Moving Dimensions and Standard Dimensions (Fixed structure) depends primarily on the lateral and vertical movement of the vehicle.

• Profile of a rolling stock drawn after taking into account the lean, swing and sway etc. is known as Kinematic Profile.

28

Clearance between Moving Dimension and Fixed Structure

• The clearance between Static and kinematic profile is required to be enhanced further to take care of:– a passenger or his luggage projecting out of a

moving train, – freight stock running with bulging/ open doors, – track being out of alignment and – lean of the line side structures etc.

29

Track Tolerances for Clearance Purposes

Factor Expected tolerances

Straight Track

<300 m Radius

<300 m Radius

Rail side wear ± 5 + 25, - 5 + 25, -5

Gauge widening ± 0 ± 0 +10

Gauge (from 1676 mm) ± 20 ± 20 ± 25

Track alignment (from design)

± 50 ± 50 ± 75

Cross-level (from design) ± 30 ± 30 ± 30

Rail Level ± 100 ± 100 ± 100

30

Possibility of Increasing the Height

• Height of a wagon is restricted by Cover Over Platform at its edges and OHE & other structures at the center.

• Thus, height of the wagon at sides can not be raised beyond 3735 mm, unless COPs are surveyed and modified.

• Similarly, at center, this may be raised beyond 4265 mm, only after survey and modifications to the structures/OHE.

31

Feasibility of running larger wagons on existing system

• Indian Railway’s have experience of running BOBR wagons, with a width of 3500 mm.

• This experience shall be utilized to decide the width of new wagons to be manufactured for DFC with inter-operability in mind.

• However, increase in width alone may not meet the volume requirements.

32

PROFILE OF BOBR WAGON

33

Infringements on Feeder

Routes, Outside Stations

34

Infringements on Feeder Routes, Inside Stations

35

Infringements on Feeder Routes, for Structures permitted

under Sch-II

36

Comparative MMDs and

Fixed Structure Gauges-

AAR V/s IR

37

Feasibility of Larger Rolling Stock on Feeder Routes

• Due to constraints of existing structures, it may not be feasible to run one standard MMD on all feeder routes.

• It is the practice in US railroads and in Australia to have different MMD for different commodities and run them on identified corridors, cleared for them.

• We can adopt a similar, commodity based approach for different feeder routes.

38


• In US, width is fixed as 3250mm (10’-8”) and the height varies, maximum being 6150mm (20’-2”) for Plate H. Clearances to track side structures are accordingly fixed.

MMD Type Width ft Width mm Height ft Height mm

Plate-B 10’-8” 3250 15’-1” 4600

Plate-C 10’-8” 3250 15’-6” 4725

Plate-E 10’-8” 3250 15’-9” 4800

Plate-F 10’-8” 3250 17’-0” 5180

Plate-H 10’-8” 3250 20’-2” 6147

39

MMD in AAR Plate-H for

Double Stack Containers

40

AAR Fixed structure

Schedule for Plate-H

41


• In Australia, both width and height of wagons vary, depending on the route on which they are running.

• There are specified clearances for track side structures for each type of Rolling Stock.

• Australian Railways have 6 different MMDs. Called Rolling Stock Out Line - ‘A’ to ‘F’

42

MMD and Fixed Structure Profiles for Rolling Stock Outline A on ARTC

43

MMD and Fixed Structure Profiles for Rolling Stock Outline E on ARTC

44

MMD and Fixed Structure Profiles for Rolling Stock Outline F on ARTC

45

Feasibility of Running Larger MMD on Existing System

• Following inference can be drawn:– A wagon can be constructed, up to an MMD width of 3500

mm, to operate on feeder routes with suitable precautions. – Height at center of these wagons shall be restricted to

4495mm and at side to 4205mm. – These wagons shall be door less or have only sliding doors.– Routes shall be identified and modifications carried out to

COP and over head structures/OHE, where ever required.– These wagons shall be confined to identified and

modified routes only, so as to provide vital links to DFC.– On routes where Larger MMDs are required due to traffic

like Double Stack Containers or Auto racks, route specific MMD may be specified.

46

MMD for DFC

• Proposed MMD to be adopted on Dedicated Freight Corridor shall be as follows:

– Width: 3500mm.– Height: 7100mm.– Sides shall be tapered inwards from a height

of 4880 mm to give a top width of 3200 mm. – This MMD shall be the MMD for DFC to be

adopted for such services as are confined only to the DFC.

47

MMD for Inter-operability

– Running of larger wagons on existing network is possible only on specific sections, built as per Schedule–I after removing all existing infringements permitted under schedule-II and imposition of suitable speed restrictions wherever actual clearance becomes less than 380 mm.

48

Formation

• Formation width in embankment/ Cutting and centre to centre spacing shall be as follows:

– Single line 6.85m (As existing)– Double line 12.35m– Centre to centre spacing of tracks5.50m

• Suitable thickness of sub-ballast/ blanket shall be provided as site requirements.

49

Grades and Curvature

• Curvature should be limited to 700m (2.5 degree).

• Ruling Gadient shall be decided based on topography, loads to be carried and the haulage capacity.

• 1 in 150 compensated, except at isolated places where cost of providing such a gradient is exorbitant may be considered.

50

Comparative Track Parameters

Item IR, Present Status

North American Railroads

Australian Railroads

Gauge 1676 mm 1435 mm 1067mm and 1435 mm. In BHP: 1435 mm.

Axle Load 22.82 MT 30 MT 25 MT, 30 MT on some dedicated freight lines, 37.5 MT on BHP Billiton Iron Ore line.

RAIL - Weight 60 and 52 kg per m.

136 RE i.e. 68 kg per m.

60 kg per m. 68 kg per m in dedicated freight lines for 30 MT and 39 MT axle loads

Rail - Grade 260 BHN Premium Rail with 380 to 400 BHN

340 to 380 BHN,Premium Rail with 380 to 400 BHN in BHP.

51




Sleepers Mono Block PSC Mostly hard wood, Mono Block PSC in some cases.

Mono Block PSC

FASTENINGS Elastic, Pandrol Type

Elastic, Pandrol Type

Elastic, Pandrol Type

Sleeper Spacing 60 cm, 1660 per km

50 cm, 2000 per km in case of wooden sleepers and 60cm or 1660 per km for PSC

60 cm, 1660 per km


52




Ballast Crushed Rock, LA abrasion value 30%

Crushed Rock, LA abrasion value 20%

Crushed Rock, LA abrasion value 20%

RAIL GRINDING Not existing Implemented fully, need based concept

Implemented fully in a need based concept on dedicated freight lines. Once a year on other lines.

RAIL INSPECTION

By manual USFD, need based concept.

USFD car under need based concept averaging once in 3 to 4 months.

USFD car under need based concept averaging once in 3 to 4 months.


53

Relationship between axleload and rail section used

45

50

55

60

65

70

75

80

10 15 20 25 30 35Axleload (t)

Ra

il S

ec

tio

n (

kg

/m)

Survey of current practices, carried out by JRP-2, initiated by World Executive Council of UIC indicates the following relationship between Rail Section and Axle Load:

Track Structure

54

An analysis of the above Chart provides following insights:

• Larger and heavier rail sections are being used for higher axle-loads, world over.

• Currently, standard rail section for medium (20t to 30t) axle-loads appears to be the 60kg/m.

• Smaller sections currently in use on some railways will, probably, eventually, be replaced by heavier sections.

• Railway systems running axle-loads in excess of 30t use 68kg/m rail sections.

• One railway system uses 75kg/m rail section for axle-loads lower than 30t. This is because of problems with rail fracture at extreme low temperatures.

Track Structure

55

Relationship between axleload and rail hardness (tangent track)

200

250

300

350

400

450

10 15 20 25 30 35

Axleload (t)

Rai

l Har

dnes

s (H

BN

)

The Survey also indicates that rails with Higher BHN are being used for higher axle loads:

Track Structure

56

Dimensions Unit UIC 60 136 RE136RE-

CN136RE-

OPT UIC 68

Section Weight kg/m 60.00 67.42 67.71 67.36 68.00

Rail Height mm 172.00 187.74 186.53 187.74 177.00

Foot Width mm 150.00 152.40 152.40 152.40 150.00

Head Width mm 72.00 74.61 74.61 74.61 72.00

Area mm2 7686.00 8588.00 8625.00 8581.00 8721.00

Ixx cm4 3055.00 3917.00 3949.00 3910.00 3528.00

Zxx cm3 335.50 387.00 390.00 397.00 359.80

Iyy cm4 512.90 600.00 602.00 600.00 636.50

Zyy cm3 68.40 79.00 79.00 79.00 84.90

Choice of suitable rail section:

Track Structure

57

Relationship between axleload and wheel diameter

800

900

1000

10 15 20 25 30 35Axleload (t)

Wh

ee

l Dia

me

ter

(mm

)

As per the survey larger diameter wheels are used for higher axle loads.

Wheel diameters have been associated with axle-load for the combined reasons of heat dissipation and contact stresses and the relationship of these parameters is shown below :

58

Wheel Diameter:

Generally, following wheel diameters are adopted for various axle loads:

Axle load Range Wheel Diameter (mm)

Less than 22t 864mm

22t to 37t 915mm

35t and higher 965mm

Wheel diameter will have to be decided in advance to design suitable track structure.

59

Rails:

60 kg, 90 UTS rails can withstand a maximum of 25 t axle loads at 100 kmph.

Rail stress calculations for 30 t axle load at various speeds indicate that a section higher than 60 kg 90 UTS is required.

For 30 t axle load, 68 kg (90UTS ) rail section shall preferably be used.

Track Structure

60

PSC sleepers:

• Existing PSC sleepers have been designed for 22.5 t axle loads. They can withstand axle load of 25t, as checked in RDSO.

• For 30 t, new design has been done. Outer shell dimensions have been changed along with HTS configuration.

• The PSC sleepers have also to be designed for Points & crossings, Level crossings, SEJs, Bridge approaches etc.

• It is possible to use the existing plain track sleeper with increased Sleeper density for 30 ton axle load. Further studies are required, with respect to rubber pad and maintenance tamping.

Track Structure cont.

61

Elastic fastening system:

The elastic fastening system being used is suitable only for present level of operation i.e. 20.32 t axle load. Based on experience, they may be continued for loads up to 25 t.

The design parameters for heavier axle load need to be fixed for the fastenings system and fastenings designed accordingly.

Track Structure Cont.

62

Points & Crossings:

The existing points & crossings layouts and SEJ’s are suited for 22.9 t axle load.

For heavier axle load Thick web switches, Swing nose crossing, Improved SEJ may be required as per the existing practices in some other world railways.

Track Structure Cont.

63

Need for Rail Grinding

64

Contact Between Wheel and Rail

Wheel centrally placed on the track

65


Hertzian Normal contact stress distribution over contact areas

66

Need for Rail Grinding Cont.

• The normal contact stress on the top of the rail and wheel tread surface depends on the wheel to rail load, wheel and top of rail radii, and the interacting materials properties.

• Hertz’s theory is valid for contacting surfaces under the following assumptions:– The contacting bodies are homogeneous and isotropic– The contacting surfaces are frictionless– The dimensions of the deformed contact patch remain

small compared to the dimensions of contacting– bodies and principal radii of curvature of undeformed

surfaces– The contacting surfaces are smooth

67


• When a wheel set is moving in a curve, if the yaw angle becomes large, it is possible to have the wheel contacting the rail at two different points.

• Two-point contact results in two contact patches: – (A) on the rail crown and – (B) at the gauge side of the railhead.

• Because of the wheel to rail angle of attack, the gauge side contact patch is moved forward.

• Increasing the angle of attack results in an increase of the distance between contact patches and thus an increase in creep forces.

• In the flange contact zone of the high rail, a level of contact stress of 3000 MPa is common.

68


Location of the Contact Zonesunder Two-point Contact Conditions(FA=110 kN, Fb=66kN )

69


• Typically, contact stress on the top of the rail running surface (region A) range between 1300 and 1700 MPa.

• The increase in wheel load increases contact stress on the top of rail surface.

• Hollow wear of the wheel tread results in high contact stress. Contact stress could rise to 6000 MPa for a 2 mm hollow worn wheel.

70

Need for Rail Grinding Cont

• Both the magnitude and distribution of contact stress is significantly influenced by wheel/rail profiles and whether single - or two-point contact conditions exist.

• Conformal profiles tend to result in larger contact patch having decreased levels of contact stress as compared with non-conformal profiles.

71

Effect of Traction on Contact patch

72


• Optimized wheel and rail profiles are those which provide for the best performance for a given application.

• Performance is generally judged on the following criteria:– Resistance to Wear– Resistance to Fatigue– Resistance to Corrugation Development– Minimization of the Ratio of Lateral to Vertical Truck

Forces– Minimization of Noise– Maximization of Truck Stability

73


• Recommendations for optimizing wheel/rail profiles in terms of the contact stresses:

• Avoid contact stress that is greater than three times the strength of material in shear.

• Distribute contact points across the wheel tread and railhead by profile design and rail grinding so that not only are the high rail, tangent, and low rail profiles different, but in tangent track there is more than one contact band

• Vary gauge clearance in tangent track intentionally.

74

Need for Better USFD Testing

• With spate in Gauge corner cracking, improved USFD techniques will be required.

• USFD shall be capable of Covering > 94% of head, entire web and area of foot under the web.

• Sperry’s USFD has the above capabilities. Efforts are on in RDSO and TTCI to develop better methods.

• Rate of generation of flaws and rate of growth of flaw observed in successive rounds of USFD testing in different section will decide the frequency of testing.

75

Need for a Better Suspension Bogie

• The vehicle, when moving forward on the track, experiences vibrations of varying frequencies which excite the various modes of the vehicle structure, body and the payload.

• The dynamic modes are generally in bounce, roll, pitch, nosing, and sway.

• Any railway vehicle requires at least two wheel sets. The manner in which these wheel sets are coupled to the vehicle has a significant influence on the performance of the rail and the wheel.

76

• As a result of vertical vehicle dynamics, Heavy dynamic loading is generated. Dynamic loads as high as 4 times the static load have been recorded.

• These Dynamic loads are transmitted from the vehicle through the wheel into the track super and substructure.

• Track elements such as rail, rail pads, sleepers, ballast and the sub-ballast layer, are thus directly influenced by the dynamic performance of the railway vehicle.

• The typical exciting mechanisms are:– Vehicle body dynamics in the frequency range between 1 and 30

Hz– Out-of round wheels (10 to 20 Hz)– Wheel flats (10 to 20 Hz)– Rail irregularities, such as rail joints and wheel burns/ skid

marks.


77

Need for a Better Suspension Bogie• In its simplest form, the suspension of a railway

vehicle comprises four springs vertically coupling the four journal bearings on two wheel sets to the body.

• The four springs can be designed within the space and for the load of a relatively small and light vehicle.

• However, as the vehicle becomes heavier and larger, the ability to accommodate track twist by means of spring deflection clashes with the demands on coupler height differential limits between a loaded and an empty vehicle.

• As the carrying capacity of the vehicle increases, the wheel base increases. This leads to increased demands on vertical deflection to accommodate track twist.

78

Need for a Better Suspension Bogie• A Bogie provides solution to the problem caused by

increased wheel base.• A bogie is the equivalent of a short wheel base

vehicle with a limited but adequate vertical spring deflection to accommodate track twist.

• In addition, the carrying center plate is of limited diameter. This coupling can be designed to permit additional track twist by means of providing sufficient side bearer clearance.

• The bogie has become standard equipment under railway vehicles.

• There are two basic types of bogies; the rigid frame and the three-piece bogie.

• Three piece bogie is most commonly used bogie type for freight wagons.

79

Three Piece Bogie

80

Need for a Better Suspension Bogie• The three-piece bogie, comprises two side frames,

each resting in a longitudinal orientation, on the journals of the wheel sets.

• The side frames support a cross member — the third piece — termed a bolster.

• The bolster is fitted with a center pivot, which couples the bogie to the vehicle body.

• The three pieces, two side frames and a bolster, are each simply supported beams.

• This makes the bogie a statically determinate structure and allows the structure to articulate under conditions of track twist without loosing vertical wheel load.

81


• The conventional three-piece bogie has been the standard freight bogie for many years because of its low manufacturing and maintenance costs.

• One advantages of this structure for vertical suspension is efficient accommodation of track twist.

82


• Three piece bogie has several disadvantages:– it does not have adequate vehicle stability at higher

speeds; – it has poorer curving performance that results in

higher wear between the wheel flange and the rail gauge corner; and

– it may result in derailments due to excessive lateral forces and a high curving resistance.

– the side frame forms part of the unsprung mass on the wheelset.

– Furthermore, the lateral dynamics of the bogie is not optimal.

83


• A suspension arrangement is thus required between the two wheelsets of a bogie, which ensures a virtually pure rolling motion of the wheelset in a curve and adequate hunting stability on straight track.

• Such designs are found in self-steering and forced-steering bogie designs.

• The main advantages of steering bogies are:– reduced flange and lateral rail wear,– improved lateral to vertical wheel/rail force ratios, – Lower curving resistance, and – better derailment and hunting stability.

84

BRIDGES

85

General

• Both in America & Australia most of the Railway Bridges are ballasted deck Bridges

• In America most of the bridges are over 100 years old. Based on construction material the length of bridges is as follows:

- Wooden – 18%- Concrete – 28%

- Steel – 54%

86

General (Cont’d….)

• In America about 8 billion dollars are spent annually on replacement of infrastructure (Track & Signals) of this 340 million dollars is on bridges.

• Wooden Bridges are mostly small span bridges, thus their number is high. These are being replaced by precast concrete bridges.

87

General (Cont’d…)

• Bridge evaluation is done based on visual inspection, study of load spectrum & measurement of strains in critical components.

• Rating of Bridge is done based on residual life and capacity to take higher axle loads.

88

RATING OF EXISTING BRIDGES

• Each bridge shall be assigned two ratings; NORMAL and MAXIMUM. The stated normal and maximum ratings of each bridge as a unit shall be the lowest of the ratings determined for the various components.

89

RATING OF EXISTING BRIDGES (Cont’d….)

Normal Rating• Normal rating is the maximum load level which

can be carried by an existing structure for an indefinite period of time.

Maximum Rating• Maximum rating is the maximum load level

which the structure can support at infrequent intervals.

90

Construction of Bridges

• Precast bridges are assembled on steel pile group driven into ground to serve as foundation.

• These steel piles extends upto the pier cap. Top ends of steel piles, mostly RSJs are embedded into the recess provided in the pre-cast pier cap by grouting.

• On the top of pier cap, precast slabs are supported.

• Even the wing walls are precast.

91

Construction of Bridges (Cont’d….)

• AAR is using precast, prestressed slab & girders in their concrete bridges.

• To study the effects of various forces coming from heavy haul, a bridge having two PSC spans of 35’ & 55’ respectively are under testing in TTCI, Pubelo.

• Concrete of 90000psi (650 kg/cm2) or higher is used in precast components.

92

DESIGN

• There are bridge loading standards on the line similar to IR to which, bridges falling in various classes of rail roads are designed. Most common loading standards are Cooper E-80 & Cooper E90. (Chapter 8,9,15, 19 & 29 of AREMA Manual for Railway Engineering 2003 Volume II,Structures.)

93

DESIGN (Cont’d…)

• In general the concept of Eudl is not used in the design of Bridges. Rather the actual axle loads for a certain number of locomotives & wagons are being considered. Loading diagram of Cooer E(80) is indicated in the next slide.

94

DESIGN (Cont’d.)

Loading Diagram

95

DESIGN (Cont’d.)The following forces are considered for

design of bridges.• STEEL BRIDGES:

(1) Dead load.(2) Live load.(3) impact load.(4) Wind forces.(5) Centrifugal force.

(6) Forces from continuous welded rail – (7) Other lateral forces.(8) Longitudinal forces.(9) Earthquake forces.

96

DESIGN (Cont’d.)• Concrete Bridges:

D = Dead LoadL = Live LoadI = ImpactCF = Centrifugal ForceE = Earth PressureB = BuoyancyW = Wind Load on StructureWL = Wind Load on Live LoadLF = Longitudinal Force from Live Load

F = Longitudinal Force due to Friction or Shear Resistance at Expansion Bearings. EQ = Earthquake (Seismic) SF = Stream Flow PressureICE = Ice PressureOF = Other Forces (Rib Shortening, Shrinkage, Temperature and / or Settlement of Supports)

From the above, it appears that for ballasted deck bridges CWR forces are not considered for design.

97

LWR on Bridges

• There is no restriction for providing CWR on ballasted deck bridges.

• CWR can also be provided on open deck bridges but they require special considerations.

98

Bridge Loading Standard in Australia

Australian Bridge Loading Standards 300 LA Railway Train Loads

99

DEDICATED FREIGHT CORRIDOR

B&S DIRECTORATE

100

NEW CONSTRUCTION:

• For construction of new bridges for dedicated freight corridor routes, with axle load of 30t with maximum track loading density of 12 t/m Heavy mineral loading (HM loading) to be followed.

• Most of the bridge designs for standard spans for HM loadings are available. However through girders are to be designed for revised MMD.

101

DETAILS OF HEAVY MINERAL LOADING:-

• In Heavy mineral loading different combinations of locos and wagons have been taken into considerations. Upto four locos and wagons of 30t axle load have been considered.

102

LOCOMOTIVES

Locomotives Single/double headed

Triple headed Four headed

Axle load 30.0T 30.0T 18.8T

Tractive effort 60.0T per loco 45.0T per loco 30.45T per loco

Braking force 25.0T per loco 25.0T per loco 22.00T per loco

103

TRAIN LOAD

• Axle load 30.0T

• Track loading density 12.0T/M

• Braking force per axle 13.4 % of axle load

104

• From construction point of view, ballasted deck bridges to be used from maintenance aspect.

• Long lasting paint to be used on steel bridges for reduced maintenance.

• Modular construction of bridges to be adopted for fast construction and better quality control with high performance concrete.

105

• Real time bridge load monitoring systems shall be installed on routes at selected points.

• Use of optical fiber communication network for real time remote monitoring of important bridges.

• Avoiding piers in canals and nallahs carrying sewage/polluted water having chemicals.

106

DETAILS OF STANDARD BRIDGE LOADINGS

S. No.

Standard Bridge

Loadings

Year of Introduction

Loading details

1. BGML 1926 Axle load : 22.9TTLD : 7.67T/MTotal TE : 47.6T

2. RBG 1975 Axle load : 22.5TTLD : 7.67T/MTotal TE : 75T

3. MBG 1987 Axle load : 25TTLD : 8.25T/MTotal TE : 100T

STRENGTHENING OF FEEDER ROUTES FOR 25T AXLE LOADS

107

• For permitting higher axle load i.e. 25 T on feeder route, existing bridges for superstructure have been checked for actual axle load for loco and wagon and as follows:

108

FITNESS OF STANDARD BGML, RBG AND MBG SPANS FOR 25T AXLE LOAD

(60 KMPH SPEED)

S. No.

Standard Bridge

Loadings

Details of Standard Spans Fit for 25T Axle Load

For BM For SF

1. BGML Upto 70m Upto 72m

2. RBG Upto 40m Upto 30m

3. MBG 100% 100%

109

FOR 60KMPH SPEED

• All spans upto 70m of BGML Loadings are fit for 25T Axle Load however span of 78.8m is fit for 50kmph.

• All spans upto 30m of RBG Loadings are fit for 25T Axle Load. However 31.9m span is fit for 50kmph speed.

CONCLUSIONS

110

• For RBG Loading SPANS 47.3m, 63.0m and 78.8m (all effective) are prohibited, however spans of 47.3m and 63.0m can be strengthened with minimum input while 78.8m RBG standard triangulated girder needs replacement.

• All spans of MBG Loadings are fit for 25T Axle Load

• Above conclusions are based on the assumption that the sections provided are exactly as per design requirement, whereas actual section provided may be on higher side.

111

Checking of longitudinal forces for running of 25t axle load

• Details of design longitudinal forces-BGML loading – Total Tractive Effort is 47.6TRBG loading – Total Tractive Effort is 75TMBG loading – Total Tractive Effort is 100T

• Longitudinal forces for wagons with 25T axle load and present available critical locos i.e. coupled WAG9 and coupled WDG4 have been worked out and checked with designed longitudinal forces for different standard loadings. Observations are as below:-

112

COMPARISION OF LONGITUDINAL FORCES BETWEEN STANDARD LOADINGS AND 2WAG9+BOXN WAGON WITH 25T AXLE LOAD

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

110.0

120.0

130.0

140.0

0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0

SPAN (M)

LF for BGML (T) LF for RBG (T) LF for MBG (T) LF for 25T LOADING (T)

113

COMPARISON OF LONGITUDINAL FORCES BETWEEN STANDARD LOADINGS AND

2WAG9+BOXN WAGONS HAVING 25T AXLE LOAD (9.33T/M T.L.D.)

Span (m)

LF for BGML

(in T)

LF for RBG

(in T)

LF for MBG

(in T)

LF for 25T loading

(in T)

25.6 45.2 60.0 83.3 52.8

31.9 47.6 70.0 100.0 52.8

47.3 58.0 77.9 100.0 70.4

63.0 66.0 105.3 107.0 70.4

78.8 72.9 128.2 123.6 70.4

114

CONTD…

i.e induced longitudinal forces for 25T axle load with 2WAG9 locos is more for Standard spans of 25.6m, 31.9m, 47.3m and 63.0m for BGML loading and other spans BGML loading and all spans of RBG and MBG loadings are safe for 25T axle load with respect to longitudinal forces.

115

COMPARISION OF LONGITUDINAL FORCES BETWEEN STANDARD LOADINGS AND 2WDG4+BOXN WAGONS WITH 25T AXLE LOAD

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

110.0

120.0

130.0

140.0

0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0

SPAN (M)

LONG

ITUD

INAL

FOR

CE (T

)

LF for BGML (T) LF for RBG (T) LF for MBG (T) LF for 25T LOADING (T)

116

COMPARISON OF LONGITUDINAL FORCES BETWEEN STANDARD LOADINGS AND

2WDG4+BOXN WAGONS HAVING 25T AXLE LOAD (9.33T/M T.L.D.)

Span (m)

LF for BGML

(in T)

LF for RBG

(in T)

LF for MBG

(in T)

LF for 25T loading

(in T)

13.1 35.5 37.5 50.0 37.0

25.6 45.2 60.0 83.3 59.6

31.9 47.6 70.0 100.0 59.6

47.3 58.0 77.9 100.0 79.5

63.0 66.0 105.3 107.0 79.5

78.8 72.9 128.2 123.6 79.5

117

CONTD…

i.e induced longitudinal forces for 25T axle load with 2WDG4 locos is more for Standard spans of 13.1m, 25.6m, 31.9m, 47.3m, 63.0m and 78.8m for BGML loading and other spans BGML loading and all spans of RBG and MBG loadings are safe for 25T axle load with respect to longitudinal forces.

118

• To over come this problem the tractive effort of locos have to be restricted to 30t/ loco while running on some spans of bridges designed for BGML loadings.

• This limitation will be applicable only if train stops on bridges with restricted spans of BGML loading.

119

MEASUREMENT OF LONGITUDINAL FORCES • The above conclusion has been drawn assuming

that 25% dispersion is allowed for longitudinal forces.

• Presently actual measurement for dispersion of longitudinal forces on the bridges is not available. A preliminary study by Southern Railway on one bridge with SERC/Chennai has been done using hydraulic jack on a plate girder. This study is very-very preliminary and not simulating the actual train load condition and hence can not be relied upon. Further studies in other Railways i.e. South Eastern and East Coast Railway with actual train load conditions is in plan.

• For concluding the actual transfer of longitudinal forces on the bridges detailed instrumentation studies has to be done.

120

MONITORING OF BRIDGES AFTER INCREASE OF AXLE LOAD

• We do not anticipate appreciable increase in maintenance efforts for the bridges designed for higher loading.

• For existing bridges, where higher loading has been permitted, more close intensive monitoring and instrumentation is required to assess the effect from fatigue and other considerations over years and will require additional maintenance efforts.

121

• The instrumentation shall include :-

Strain gauging of every critical member

Measurement of Acceleration

Measurement of Displacement

• Such instrumentation shall be done on selected critical bridges of the section. Initially, the recording shall be done for at least every three months for the first two years thereafter it can be reviewed.

122

• Frequency of visual inspection also need to be increased suitably.

• Such observations shall be continued atleast for a period of 10 years. Thereafter, further decision shall be made based on the output of the observations.

• This will decide future course of action with respect to: required maintenance efforts for the bridge strengthening/replacement of bridges required,

if any. It will provide basis for making future policy and guidelines for increasing of axle loads on the existing bridges.

123

Suitability of substructure for 25t axle load for feeder routes and superstructure for non standard spans to be checked by zonal railways.

124

Documents

1 Report on Visit to USA and Australia in Connection with Dedicated Freight Corridor