Friday, March 30, 2018

Permitted locations for LWR/CWR


As a rule, complete track renewals (primary) shall provide for LWR/CWR  wherever permissible by the provisions of this Manual. Also existing rails on permitted locations may be converted in to LWR/CWR, provided they meet the requirements laid down in the Manuals for Welding of Rail Joints by Alumino Thermic (SKV process)/Gas Pressure/Flash putt Process, as the case may be.
New constructions/doublings/gauge conversions/retired alignment/permanent diversion shall be opened with LWR/CWR, wherever permissible by the provisions of this Manual.

In goods running lines, goods yards, reception yards and classification yards, rail
joints may be welded to form LWR if the condition of all the components of track is generally sound and without any deficiency, subject to such relaxation as may be approved by Chief Engineer, in each specific case.

ALIGNMENT (As per CS.No 11) 

LWR/CWR shall not be laid on' curves sharper than 440 metre radius both for BG and MG. However in temperature zone 1 LWR/CWR may be laid on curves upto 360m radius (5º curve) on B.G. with following additional precautions.

LONG WELDED RAIL - Definitions

Long Welded Rail (LWR) (ACS No. 8 of 2002) is a welded rail, the central part  of which does not undergo any longitudinal movement due to temperature variations. A length greater than 250metre on Broad Gauge (BG) and 500 metre on Metre Gauge (MG) will normally function as LWR. The maximum length of LWR under Indian conditions shall normally be restricted to one block.

Continuous Welded Rail (CWR) is a LWR which would continue through station yards including points and crossing.

Short welded rail (SWR) is a welded rail, which contracts and expands throughout its length.

Notes: Normally the length of SWR is 3 x 13 metre for BG and 3 x 12 metre for MG. Provisions for laying and maintenance of SWR are contained

Breathing Length is that length at each end of LWR/CWR, which is subjected to expansion/contraction on account: of temperature variations. Usual breathing lengths in BC and MG for different types of track structures and for different temperature zones.

Switch Expansion, Joint (SEJ) is an expansion joint installed at each end of LWR/CWR to permit expansion/contraction of the adjoining breathing lengths due to temperature variations.

Maintenance in Electrified Area

Precaution to be taken during works in electrified area: -

• Engineering staff should be aware of rules framed for working in electrified areas.
• The track should be left when train is 250m away.
• No work shall be done in danger zone i.e., within a distance of 2m from live parts without taking “permit to work “.
• The trees and its branches should be atleast 4 m away from the nearest live conductor. They should be cut or trimmed periodically. The cutting and trimming should be done in the presence of TRD staff.
• Fallen wire should not be touched before power is switched off and wire is suitably earthed.
• Any break down in the OHE traction bond should be reported to TPC.
• While working on station roofs and signal gantries adjacent to live OHE, the metallic tape and tools should not be used.


Precautions during work in track circuited area :-

• Level of ballast should be 50mm below the bottom of rail.
• The side drains, cross drains and the longitudinal drains if any should be well in gradient so as to drain out water quickly.
• The metal sleepers should not be used neighboring the insulated joints.
• The Burr formed at the end of rail at insulated joint should be scratched.
• There should be perfect insulation in fastening at insulated joints.
• The tools and equipments should not be placed at joints, else circuit may break.
• Packing under the insulated joint should be proper.
• Cutting of rail should be in the presence of S & T staff.
• The steel tape should not be used in track circuited sections.
• Gauge-cum-level equipment should be insulated.
• Push trolley should be insulated.
• Diplorry should not be put in track circuited sections without prior permission of S.M.
• Glued joint should be used in place of ordinary insulated joint.
• J-clips should be used in insulated joints.
• Bond wires should not be disturbed if it is disconnected during maintenance, it should be restored after the work.
• Pulling back of rails in track circuited area should be done in the presence of S & T staff.


(1) General – Should a diversion be decided upon, the work should be commenced as quickly as possible.

(2) Classification of diversions – These may be classified as – 
(a) Temporary                                                                          (b) Semi-permanent

A temporary diversion is one which is not likely to be in use, for more than 10 days. All trains must “Stop-dead” before entering a temporary diversion and proceed at 10 Km./h. speed.

A semi–permanent diversion, is one constructed for the special purpose of facilitating the reconstruction of the line and/or bridges likely to be in use for a period of more than ten days. On a semi-permanent diversion, trains may proceed at a non stop reduced speed after adequate period of consolidation.


General precautions to be taken before monsoon –

It is necessary to take certain precautions, and carry out certain essential works
before the commencement of monsoon, such as

(1) All catch water drains and side drains must be cleared of silt, vegetation and other obstructions to ensure free flow and quick drainage of storm water. The waterways of bridges must be cleared of vegetation and other obstructions. If silting is noticed in some spans, it should be removed to ensure that the full waterways is available for the discharge of flood water. During desilting, care should be taken to remove the silt only upto the bed level.

(2) Protective and river training works must be maintained in good condition and
repairs carried out wherever necessary. Scour holes should be filled with boulders.

(3) The High Flood Level (HFL), Full Supply Level (FSL) in the case of canals, and Danger Level (DL) must be painted. The danger level mark shall be painted with bright red band across each pier adjacent to the abutment so as to be clearly visible to the Patrolmen, Special Watchmen and Drivers. Flood gauges shall be painted on important bridges as specified.


Action during Accidents including Breaches

Observance of Rules –

(1) Any occurrence which does or may affect the safety of the Railways, its engines, rolling stock, permanent way, works, passengers or servants which affects the safety of others or which does or may cause delays to trains or loss to the Railway, is termed an accident. Occurrence outside the Railway limits threatening the safety of the line or trains should also be reported as accidents. For instance a flood outside Railway limits may seriously threaten the safety of the line and should be treated as an accident.

(2) Rules for reporting and joint enquiries into the accidents are contained in the
Accident Manual issued by Railways and in the Railway (Notices of and Enquiries into Accident) Rules, 1973, issued under Section 84 of Indian Railway

(3) Rule 2.11 of General Rules, 1976 Edition enjoins that –

(a) Every Railway servant shall –
(i) see that every exertion is made for ensuring the safety of the public ;
(ii) Promptly report to his superior any occurrence affecting the safe or proper working of the railway which may come to his notice; and 
(iii) Render on demand all possible assistance in the case of an accident or obstruction. 

Laying of Sleepers

Locations where Concrete Sleepers are used-

Concrete sleepers should normally be used only with LWR/CWR track. Hence the condition for laying LWR/CWR should equally apply for laying concrete sleepers.

Use of concrete sleepers on long lengths of track where provisions of check rails or guard rails is necessary, is prohibited unless special arrangements are made to
provide the necessary flange way clearance.

Where concrete sleepers are used in yards with fish - plated track, the sleeper spacing at fish plated joint shall be kept uniform. In addition 1m long fish plates may preferably be provided at such joints. (Cs.No102)

Conditions for laying Concrete Sleepers:

i) Track should be deep screened.
ii) Cuttings having rocky bed should have clean ballast cushion of at least 300  mm.
iii)On Arch bridges formation cover min. 1 m.
iv) On other bridges ballast cushion not less than 300 mm.

Laying of Concrete Sleepers –

RENEWAL - Permanent Way Renewal

Classification of Renewals –

All track renewals can be classified generally into one of the following categories :

(1) Complete Track Renewal (Primary) abbreviated as C.T.R.(P)
(2) Complete Track Renewal (Secondary) abbreviated as C.T.R.(S)
(3) Through Rail Renewal (Primary) abbreviated as T.R.R.(P)
(4) Through Rail Renewal (Secondary) abbreviated as T.R.R. (S)
(5) Through Sleeper Renewal (Primary) abbreviated as T.S.R. (P)
(6) Through Sleeper Renewal (Secondary) abbreviated as T.S.R. (S)
(7) Casual Renewals.
(8) Through Turn-out renewal (TTR)
(9) Through Fitting renewal (TFR)
(10) Through Weld renewal (TWR)
(11) Through Bridge timber renewal (TBTR)
(12) Scattered renewal

(2) Primary renewals are those where only new materials are used and secondary
renewals are those where released serviceable materials are used.

(3) Scattered Renewal- In this case, unserviceable rails, sleepers and fastenings are replaced by identical sections of serviceable and nearly the same vintage track components. These are carried out in isolated locations and not more than 10 rails and/or 250 sleepers in a gang beat in a year. Such renewals are a part of normal maintenance operations.

Thursday, March 29, 2018

Track Management System

In periodicity based system of maintenance we deploy the resources at the length not needing the attention due to following reasons:-

1. We don’t have fast data processing system.
2. Manual analysis of inspection results is laborious job.
3. We don’t have decision support system.

To overcome above difficulties TMS has been evolved in form of centralized computer software which generates track component data, inspection data and work report data to provide useful information for taking better decision.

The concept of need based maintenance can be introduced everywhere in railways by track management system.

Design of TMS:- At present TMS is having around 21 Modules. TMS has also been developed which contains almost all the decision support system and MIS.

Input (Modules):-

CTR and TGI Value

CTR ( Rly. Bd. Letter 90/Track-III/TK/72 dt. 18.7.90)

Rev. CTR (item 840 of 66th TSC)

TQI ( RDSO Report no. C-223)

TGI ( Rly. Bd. Letter 94/Track-III/TK/23 dt. 25/31.08.95)
TGI(for a block) =(2UI+TI+GI+6AI)/10
TGI for a KM = (Sum of TGI of all blocks) / No. of blocks


Maintenance Guidance using TGI Values
As per Rly. Bd.’s letter Dated 30.12.96

Track Recording and Oscillograph Car


1. 1963 -- Amselar T R C
2. 1975 -- Electronic T R C
3. 1978 -- Track Reco. Cum Research Car (TRRC)
4. 1985 -- Microprocessor Based T R C
5. 1989 -- Phase I T R C μ-P Based + Limited Data storing
6. 1992 -- Phase II T R C (TGMS)
7. 1997 -- Phase III T R C Contactless Sensor

Track Recording by Mechanical / Electronic Equipment –
The following track recording equipments are in use in Indian Railways at present :–
(1) Track recording cars.
(2) Hallade track recorder.
(3) Oscillograph car.
(4) Portable accelerometers.

Track Recording Car – There are two types of track recording cars currently in use in Indian Railways, one mechanical and the other electronic. With these track recording cars, it is possible to have a continuous record of the track geometry under loaded conditions, by running the cars at nominated intervals.

Mechanical Track Recording Car (B.G.)–
(1) It has two bogies one of two axles and the other of three axles. The measuring
bogie has a base of 3.6 metres, and is three axled with an axle load of 7.0 tons. It
gives a continuous record of –

(a) Unevenness - Left rail. Short Chord 3.6 m & Long Chord 9.6 m
(b) Unevenness - Right rail. Short Chord 3.6 m & Long Chord 9.6 m
(c) Gauge – Variation over 1676 (B.G)
(d) Twist – At lower base of 3.6 m & higher base of 4.8 m.
(e) Alignment – Left rail. Short Chord 7.2m & Long chord 9.6m.
(f) Alignment - Right rail. Short Chord 7.2m & Long chord 9.6m.
(g) Speed

Frequency of Track Recording -
Track geometry monitoring of Metre Gauge routes is not to be done by track recording car. The Broad Gauge routes should be monitored by TRC as per the following frequencies (except for the routes where track recording is to be dispensed with):-

Track categories for various Parameters – The track charts record - Imperfections in the form of peaks and the magnitude of the peaks is an indication of the extent of the defect. For each track parameter, track should be classified kilometre-wise based on the number of peaks and their magnitude occurring in that kilometre. The specified values for different categories for various parameters are given below

Note : -

(i) 10 points exceeding the outer limit of an irregularity under each category is allowed in 1 Km. length of track. If more than 10 peaks in one Km. cross the outer limits of ‘A’ category the kilometer is classified ‘B’ and so on. Based on the number of peaks and extent of irregularity the track is classified into ‘A’, ‘B’, ‘C’, and ‘D’ categories separately for each parameter-gauge twist, unevenness and alignment.

(ii) The number of peaks in each kilometer exceeding the outer limit for the ‘B’
category isindicated as a suffix.

(2)The following limits of track tolerances are prescribed for the guidance of the Engineering officials on the suitability* of standard of maintenance of track for sanctioned speeds above 100 Km/hr. and upto 140 km/hr on BG track.

(i) Alignment defects - (versine measured on a chord of 7.5 metres under floating
a) On Straight Track - 5mm; values upto 10mm could be tolerated at few isolated
b) On Curves- + 5mm over the average versine, Values up to +7mm could be
tolerated at few isolated locations**. Total change of versine from chord to chord
should not exceed 10mm.

(ii) Cross Level Defects - No special tolerance limits. As regards cross levels, the
track should be maintained, to standards generally superior to that at present
available on main line track on which unrestricted speeds upto 100 Km/hr. are

(iii) Twist- (to be measured on a base of 3.5 m)

(a) On straight and curve track, other than on transitions - 2mm/metre except that
at isolated locations**, this may go upto 3.5mm/metre.
(b) On transitions of curves - Local defects should not exceed 1mm/metres, except that at isolated locations** this may go upto 2.1 mm per metre.
(iv) Unevenness rail joint depressions (versine measured on a chord of 3.5m) - 10mm in general and 15mm for isolated locations**.
(v) Gauge variations - No special specifications. The maximum limits for tight and slack gauge should be within limit
(*) Suitability - Suitability refers to good riding quality for passenger comfort and not from stability point of view.
(**)In above `few isolated locations' has been taken as not exceeding 10 per km

(As per 96) 

The stability of trains against derailment depends upon several factors such as track geometry vehicle characteristics and state of their maintenance and speed of the particular vehicle at relevant point of time etc. rail wheel interaction is thus a complex phenomena and therefore safety tolerances for track alone cannot be prescribed in isolation. With in this view safety tolerances maintenance of track have not been prescribed on Indian railways. Each derailments faced therefore needs careful examinations of all available evidence in respect of track rolling stock, speed anc other factors considered relevant to arrive at cause.

The provision and tolerances mentioned in above para and elsewhere are with
a view to maintain track geometry for good riding comfort.

Oscillograph Car: -

(1) Brief description of the car :– The main equipment in this car is an Accelerometer, which consists essentially of a mass attached to one end of thin flexible plate, the other end of the plate being fixed firmly to the casing of the accelerometer. The space within the accelerometer casing is filled with a damping fluid (usually silicon liquid). The cantilever plate is strain gauged so that the deflection of the mass ‘m’ is sensed. This is calibrated to indicate the acceleration to which the mass is subjected. This acceleration is recorded in the form of an accelerogram. Thus the vertical and lateral acceleration on any part of the vehicle where the accelerometer is installed can be recorded. In track monitoring runs the accelerations at the loco cab floor are recorded by keeping the accelerometer as close to bogie pivot as possible.

(2) Details of recording: – the following parameters are recorded in the oscillograph car runs:–

(a) Vertical acceleration of loco cab.
(b) Lateral acceleration of loco cab.

In addition to the above, timing marks-one for every second-telegraph and km.
marks and even marks such as station buildings, bridges etc., are also recorded on the chart. The primary spring deflections left and right are also recorded.

(3) Frequency of recording –On B.G. routes oscillograph cars are used to monitor all group A routes. These cars are run once in six months to assess the riding quality of track as distinct from actual track geometry recorded by the track recording cars. The recording is done at the maximum sanctioned speed of the section.

Analysis of oscillograms and interpretation of results –

(1) The Oscillograms obtained from the oscillograph car are analysed for the vertical and lateral acceleration.

(2) The analysis of records is done on the following lines :–

(a) All peaks are to be measured from the base zero line i.e.,no allowance is to be
given when the trace shifts because of cant deficiency on curves. However, for the purpose of “ride index” calculations, lateral acceleration peaks are to be measured from the shifted base line on curves.

(b) The vertical and lateral accelerations above the threshold values are separately counted: Threshold value of acceleration may be taken follows :–

(i) In Loco Cab floor – The threshold value of acceleration in vertical mode is taken as 0.20 g. for locos (Diesel and Eletric). The threshold value of acceleration in lateral mode is taken as 0.20g. for diesel and electric locos with double stage suspension (i.e., for WDM-3, WDM-4, WDM-1, WDM-2/3 and WAG-2) with the exception of WDM-2 modified with single stage suspension. In case of other locos, with single stage suspension (i.e.,WDM-2 std., WAM-1, WAM-4, WAG-1, WAG-3,WAG-4,WCG-2, WCAM, WCM,WCM-2, WCM-4 and WCM-5) the threshold value may be taken as 0.30g.

(ii) On Passenger Coach Floor :– The threshold value of acceleration for both vertical and lateral modes shall be taken as 0.15g.
(iii)The analysis is done kilometer-wise and results are given, after counting the
peaks above threshold value for the particular locomotive –Station Yards, Other than Station Yards(Isolated locations), Active continuous stretches, Speed grouping table is also prepared.

Use of Oscillograph Car recordings :–

(1) Threshold values of acceleration are given. For ensuring good riding, track should be attended to at such locations where peaks above threshold values are noticed.
(2) Efforts should be made not only to check the extent of defect but also to find out whether it is occurring in an active patch; as such condition may lead to excessive oscillations.


• Frequency of track irregularity
• Spacing of the track defects
• Speed of the vehicle
• Direction of movement
• Natural frequency of vehicle

Portable Accelerometers-

(1) General- OMS-2000 equipment’s are portable accelerometers used for Oscillation monitoring using a portable accelerometer and transducers converting the oscillations to electrical signals which can be recorded electronically and
processed on PC.

(2) Operation- The OMS Accelerometer is kept in the cabin of locomotive or on the coach floor, as close to the bogie pivots as possible. It is preferable that same
coach and the same vehicular position are used in successive runs. The accelerations recorded are transferred to electronic recorder and are readable on
the LCD display on real time basis. The stored data can be downloaded on TMS
Computer for maintenance planning. This equipment measures the Track Performance by measurement of vehicle response in terms of vertical and lateral accelerations. The real time output of the equipment is in the form of value of peaks exceeding the limiting value, their location and Ride Index. These values
are available for both vertical and lateral accelerations.

(3) Frequency of Recording:

(A) Broad Gauge: Speed above 100 Kmph Once every month.
Others Once in two months
(B) Meter Gauge: Speed above 75 Kmph Once every month
Others Once in two months
The above schedule is only a guideline. Chief Engineers may vary it, depending
upon the availability of instrument and its use. For the time being A, B and C
routes are to be covered once a month and other routes can be covered as per
capacity and need.

(4) Recording of Defects: To assess the track quality, vertical and lateral acceleration peaks exceeding the values as below are to be considered:
Broad Gauge:
High Speed Routes above greater than 0.15g.
110 Kmph On A & B routes
Other Routes upto greater than 0.20g
110 Kmph
Meter Gauge : greater than 0.20g

(5) Classification of Track Quality - To classify a continuous section's (PWI's
jurisdiction/sub-division/ division) track quality, the following criteria is to be
used (average total number of peaks per km.):

The above criteria are for judging the quality of track. However, if the average
number of peaks of vertical and lateral accelerations exceeding 0.30g is more than 0.25 per km or more than one in any particular kilometer, the track will need
attention : At locations where peaks of lateral and vertical accelerations exceed
0.35g, the track will have to be attended to urgently.

Monitoring of the riding quality of track– While the track recording cars can
record the track geometry, the Hallade track recorders, the Oscillograph car and
the portable accelerometers record vertical and lateral accelerations, on which
depends, the riding quality.

Hallade track recorder –

(1) General– The Hallade track recorder is an instrument which produces a graphic record of defects in alignment and surface of the track over which it is carried.
The main parts of the instrument are –
(a) a drum rotated at a fixed speed by a clock work mechanism which carries a strip of paper 100 mm. wide covered over a carbon on which the chart is plotted,
(b) four sets of pendulums sensitive to movement in different directions which
records the oscillations in those directions of the vehicle and track.

(2) Frequency of testing with Hallade – On routes where Hallade track recorder is exclusively used for the track monitoring the following frequencies may be adopted:-

Riding Quality and Riding Index

The riding comfort experienced by a passenger in a coach depends not only on his individual sensitivity but also in displacement, acceleration, rate of change of
acceleration and factors like noise, dust humidity and temperature etc. There are 2 important methods of evaluation which are commonly used for expressing comfort:-

1. Method of fatigue time.
2. Method of ride index

The Riding quality is the function of track defect its frequency and vehicle characteristics. Therefore it is essential to limit the size of defect for safety of train operation.


R.I. = 0.896 x {b³ x F(f)/ f }¹/¹º
Where, b = Average of cubes of acceleration peaks (cm/sec²).
            f = Frequency in Hz.
          F (f) = Function of frequency that takes into account the human reaction to
                     frequency of acceleration.

INSPECTION OF TRACK - Object of Inspection

The object of inspection is to:-

1. Asses the riding quality and actual condition of track.
2. Measure track parameters and track geometry.
3. Ensure safe movement of traffic.
4. Implement track policies and solve problems.
5. To have man to man contact for improvement in work and motivation.
6. Welfare/ grievances redresal.

Methods of Inspection:- 

A) Manual Inspection

1. On Foot Inspection:-

Each and Every part of the track is inspected daily by keyman in his beat. Mate and PWS also inspect their gang beat regularly. PWIs and ADENs also inspect their section as per schedule. This inspection is helpful in detailed and close inspection of track componenents, track features and track parameters, but only a
limited area can be covered in a day.

Works Requiring CRS Sanction

Works requiring the sanction of Commissioner of Railway Safety and Notice
therefore –

(1) Under section 20 of Indian Railways Act and chapter VI of the “Rules for opening of a Railway or Section of a Railway for the public carriage of passengers,1933”, the sanction of Commissioner of Railway Safety is required for the execution of any work on the open line, which will affect the running of trains carrying passengers and any temporary arrangement necessary for carrying it out, except in cases of emergency.

(2) For the commencement and opening of the following works, when they are
connected with or form part of Railway already opened, the sanction of the Commissioner of Railway Safety shall be obtained :

(a) Additions, extensions or alternations to running lines.
(b) Alterations to points and crossings in running lines.
(c ) New signaling and interlocking inst. or alterations to existing installations.
(d) New stations, temporary or permanent.
(e) The construction (but not the removal) of an ash pit on a running line.
(f) Heavy re-grading of running lines involving lowering/ raising of track in excess of 500mm.

Safe Working of Contractors (As per Cs.No 95)

Safe working of contractors -

 A large number of men and machinery are deployed by the contractors for track renewals, gauge conversions, doublings, bridge rebuilding etc. It is therefore essential that adequate safety measures are taken for safety of the trains as well as the work force. The following measures should invariably be adopted:

(i) The contractor shall not start any work without the presence of railway supervisor or his representative and contractor supervisor at site.

(ii) Wherever the road vehicles and/or machinery are required to work in the close vicinity  of railway line, the work shall be so carried out that there is no infringement to the railway’s schedule of dimensions. For this purpose the area where road vehicles and/or machinery are required to ply, shall be demarcated and acknowledged by the contractor. Special care shall be taken for  turning/reversal of road vehicles/machinery without infringing the running track. Barricading shall be provided wherever justified and feasible as per site conditions.

MAINTENANCE (PROTECTION) Speed Restriction and Indicators

Categories of Engineering Works –

Engineering works can be broadly divided into three categories –

(1) Category 1 – Works of routine maintenance: requiring no speed restriction, not necessitating exhibition of hand signals and involving no danger to trains or traffic.These include works of routine maintenance such as through packing, picking up slacks and overhauling of track etc.

(2) Category 2 –Works of short duration:

(a) Works such as casual renewals of rails and sleepers, adjustment of creep and lubrication of rail joints which are completed by sunset of the day of commencement and no restriction of speed thereafter is required, are termed “works of short duration”.

(b) Hand-signal and banner flags and fog signals shall be used at specified distances to afford protection to trains.

(3) Category 3 –Works of long duration:

(a) Works such as relaying, bridge construction, diversions which extend over a few days, or weeks during which period a continuous restriction of speed is to be in force, are termed as “works of long duration”.

Records of Material under Trial (As per 99)

1. CTEs of Zonal Railways may order limited trials of simple items which don’t infringe with existing provision of standard specification or instructions laid down in manuals/codes. Before undertaking the trial complete scheme of trial should be well chalked out including the parameters to be periodically measured/chalked official to measure/check, periodicity of measurement/checking and Performa in which measurements/observations to be recorded, CRS shall also be kept informed about such trials.

2. The Zonal Railways should periodically inform RDSO about such trials to maximize advantage.

3. Registers:-ADEN shall maintain a register.
4. Particulars of entries

Name of material, Kilometerage where laid, Date of laying, Object of trial, Nature and condition of ballast, Nature and type of formation, Track details, Behavior, Any other relevant information.

Welding of Rails

Welding and Its Necessity

Joining of two rails ends by the application of heat is called “WELDING”

A fish plated joint has been a necessary evil in the track. To over come the various problem posed by the fish plated joint such as battering, hogging, rail end
failure, noise pollution, distortion of track geometry etc and to reduce the maintenance cost welding is best solution.

Types of Welding:-

1. Gas Pressure Welding (Oxy-Acetylene Welding)
2. Electric Arc Welding
3. Thermit Welding
4. Flash Butt Welding

Alumina-Thermit Welding:-

Height Gauges on Electrified Section

(a) Adequate arrangements shall be made to erect height gauges on either side of the overhead equipment or other equipment at every level crossing so as to ensure that all vehicles and moving structures passing under the height gauge also pass under the overhead equipment or other equipment with adequate clearance.

(b) The adequate clearance referred to in sub rule  (a) shall be sanctioned under approved special instructions.

(c) Height Gauges should be located at a minimum distance of 8 meter from gate
posts. In exceptional circumstances where site conditions do not permit, Chief Engineer can give exemption in these standards subject to a minimum of 8 meter
distance from the centre line of the track. Road surface upto this point may be at the same level as the road surface inside the gate posts.

(d) Vehicles and moving structures, which can not pass under the height gauge without striking or touching it, shall not be permitted to pass the overhead equipment or other equipment except in accordance with special instructions.

Maintenance of Level Crossing, Examination of Gate equipment and Gateman

(1) By Permanent Way Inspectors –

(a) Obstruction of view : All trees, bushes or undergrowth that interfere or tend to interfere with the view from the Railway or road way when approaching level crossings, should be cut down taking care to comply with the procedure laid down.

(b) Inspection and Maintenance –

(i) Each level crossing except those laid with PSC sleepers must be opened out and the condition of sleepers and fittings, rails and fastenings inspected at least once a year or more frequently, as warranted by conditions. However, level crossings laid with PSC sleepers should be overhauled with each cycle of machine packing or more frequently as warranted by conditions and in no case shall opening be delayed by more than two years. In all cases, rails and fastenings in contact with the road shall be thoroughly cleaned with wire brush and a coat of coal tar/anti corrosive paint applied. Flange way clearances, cross level, gauge and alignment should be checked and corrected as necessary, and the track packed thoroughly before reopening the level crossing for road traffic.

Equipments at Level Crossing and Duties of Gateman

Equipment at Level Crossings –

(1) The equipment for a manned level crossing shall be as follows; in addition to such others as may be prescribed by special instructions :–

(a) 2 hand signal lamps, tri-colour provided with bright refle ctors,
(b) 1 hand signal flag, green.
(c) 2 hand signal flags, red.
(d) 1 staff suitable for exhibition of red lamp or red flag.
(e) 2 long spare chains with “stop” marked disc attachment at the center to cover the full width of the gate, for use in case the gates/barriers are damaged
(f) 2 spare small chains and padlocks for locking gates, in case locking arrangements of gates become defective.
(g) 12 detonators.
(h) 1 tin case for flags.
(i) 1 tin case for detonators.
(j) 1 canister for muster sheet.
(k) 1 can for oil.
(l) 1 tummy bar.
(m) 1 water pot or bucket.
(n) 1 mortar pan.
(o) 1 powrah.
(p) 1 rammer.
(q) 1 pick-axe.

Level Crossing

General Location:

As far as possible, new Level Crossings may not be located in busy station yards where heavy detention to the road traffic and other operational problems are  likely to be encountered. If provision of Level Crossing is inescapable, it may be located outside the outermost facing points. For Level Crossings already located within busy station yards affecting Railway operations and causing heavy detention to the road traffic, efforts should be made to replace them by Road Over/ Under Bridges as per extant rules or shift them outside the outer most facing points especially during planning of gauge conversions, yard remodeling and doublings and its operation from the cabin should be possible.

Classification of Level Crossings –

Small Track Machines

ON Track Machines

“It is big yellow coloured machine, for which you have to arrange blocks, arrange diesel and output is monitored by HQ”

“Track machines are an essential part of Track Engineers life. You cannot be
without them. So know them, care for them, and you will start loving them”

Need for Track Machines

• Modern Track cannot be laid and maintained manually.
• Mechanized maintenance of track was introduced in early sixties.
• Track machines are of two categories.
– ON TRACK machines
– SMALL TRACK machines.
• For ON TRACK machines, track machine manual was first published in march 2000.
• Small Track machines (STM) manual was first published in july 2005.

ON TRACK Machines


Maintenance of SWR

Regular maintenance operation –

(1) Regular track maintenance including all operations involving packing, lifting,
aligning, local adjustment of curves, screening of ballast other thandeep screening, and scattered renewal of sleepers may be carried out without restriction when the rail temperature is below tm. +25o C in the case of zone I & II and tm + 20o C in the zone III and IV. However on curves of less than 875 metres radius Broad Gauge,and less than 600 meters radius in Metre Gauge or yielding formation, the above temperature limit shall be restricted to tm. +15oC in the case of Zone I and II and tm. + 10oC in the case of Zone III and IV.

(2) If the maintenance operations have to be undertaken at temperature higher than that mentioned above , not more than 30 sleeper spaces in one continuous stretch shall be opened, leaving at least 30 fully boxed sleeper spacer between adjacent lengths which are opened out. Before the end of the days work it shall be ensured that the ballast is boxed up.

(3) As an additional precaution, during summer months, to be specified by the Chief Engineer, for attention to run down track, even if temperature is less the temperature specified not more than 30 sleepers in one continuous stretch shall be opened, leaving at least 30 boxed sleeper spaces between adjacent lengths which are opened up.

Wednesday, March 28, 2018

Short Welded Rail

Definitions –

(1)Short Welded Rail (SWR) is a welded rail which contracts and expands
throughout its length.

Note – Normally the length of SWR is 3X 13 M.for Broad gauge and 3X12 M. for

Metre gauge.

(2) Rail temperature is the temperature of the rail as recorded by an approved type of rail thermometer at site. This differs from the ambient temperature which is the temperature of air in shade at that place, as reported by the meterological department. The Indian Railways have been divided into four rail temperature zones.

Deep Screening

Deep Screening of Ballast-

(1) General –

(a) It is essential that track is well drained for which screening of ballast should be carried out periodically as described. Due to presence of bad formation, ballast attrition, excessive rain fall and dropping of ashes and ore, ballast gets choked up and track drainage is impaired. In such situations, it becomes necessary to screen the entire ballast right up to the formation level /sub-ballast level. Further through screening restores the resiliency and elasticity of the ballast bed, resulting in improved running quality of track. Such screening is called “Deep screening”, as distinguished from the shallow screening, which is done, during overhauling.

(b) Deep screening should be carried out in the following situations by providing full ballast cushion:

(1) Prior to complete track renewal.
(2) Prior to through sleeper renewal.
(3) Where the caking of ballast has resulted in unsatisfactory riding.
(4) Before converting existing track, fish plated or SWR into LWR or CWR; or before introduction of machine maintenance, unless the ballast was screened in recent past.
(5) The entire track must be deep screened atleast once in ten years.

(c) The need for intermediate screening between track renewals may be decided by the Chief Engineer depending on the local conditions.

Lifting, Lowering of Track and Creep

Lifting Of Track –

1. Lifting of track will become necessary during regarding and for elimination of minor sags, which develop through improper maintenance or yielding soil, to keep a good top.

2. Correct level pegs should be fixed at suitable intervals, before lifting is commenced.

3. Heavy lifting should always be carried out under suitable speed restriction and under the protection of corresponding engineering signals. Lifting should not exceed 75 mm. at a time so as to allow proper consolidation. The easement gradient for the passage of trains should not be steeper than 25 mm. in one rail length of 13 meters. The operation should be repeated until the required level is attained when the track should be finally ballasted, through packed and boxed, the cess being made up to proper level.

4. Lifting should commence from the down hill end carried out in the direction of
rising grade in case of single line. It should proceed in the opposite direction to traffic, in case of double line, care being taken not to exceed the easement grade.

5. While lifting track under bridges and overhead structures and in tunnels it should be ensured that there is no infringement of standard dimensions.

6. In case of curves, it is usual to set the inner rail to the correct level and grade and to raise the outer rail to give the required superelevation, care being taken to see that the cant gradient is within the permissible limit.

Annual Programme for Regular Track Maintenances

Annual Programme of Track Maintenance –

The annual programme of regular track maintenance and works incidental thereto shall be based on the programme given as shown below, with such variations to suit local conditions, as may be specified by the Chief Engineer. This applies to any system of maintenance

Systematic Overhauling

Systematic Overhauling –

(1) Sequence of operations-

Overhauling as described briefly should consist of the following operations in

(a) Shallow screening and making up of ballast.
(b) All items attended to, while doing through packing.
(c) Making up the cess.

(2) Shallow Screening and making up of Ballast–

(a) For good drainage periodical screening of ballast is essential.

(b) In the case of manual maintenance, the crib ballast between sleepers is opened out to depth of 50 to 75 mm. below the bottom of sleepers, sloping from the centre towards sleeper end. For machine maintained section, the crib ballast in theshoulders should be opened out to a depth of 75 to 100mm. below the bottom ofsleepers, sloping from the centre towards sleeper end. The ballast in the
shoulders opposite to the crib as well as the sleepers is removed to the full depth.
A slope is given at the bottom sloping away from the sleeper end. The ballast is then screened and put back. Care should be taken to see that the packing under the sleepers is not disturbed and the muck removed is not allowed to raise the cess above the correct level.


Through Packing: Conventional Maintenance By Beater Packing:–

General: Operations in sequence:- O M S A G P R B

Through packing shall consist of the following operations in sequence. The length of track opened out on any one day shall not be more than that can be
efficiently tackled before the end of the day:
  • Opening of the road.
  • Examination of rails, sleepers and fastenings.
  • Squaring of sleepers. Slewing of track to correct alignment.
  • Gauging. Packing of sleepers.
  • Repacking of joint sleepers. Boxing of ballast section and tidying.
  • Through packing is best done continuously from one end of a gang length toward
  • the other.
 Each of the above operations should be carried out as detailed below :–

(a) Opening of Road:


Types of Patrolling :

The following are the types of patrolling in vogue:
• Keyman’s daily patrol.
• Gang patrol during abnormal rainfall or storm.
• Night patrolling during monsoon.
• Security patrolling during civil disturbances and for movement of VIP specials.
• Hot / cold weather patrolling for long welded rails/ continuous welded rails.
• Watchmen at vulnerable locations.

1. Keyman’s Daily Patrol –

Every portion of the permanent way shall be inspected daily on foot by the keyman of the beat in which the portion of the track falls. Provided that the interval between such inspections may, under special instructions, issued by Chief Engineer be increased to once in two days in the case of specified section of lines with light and infrequent traffic.

2. Gang Patrol during Abnormal Rainfall or Storm –

Realignment of Curve

Running on curves –

(1) For smooth and satisfactory running on curves –

(a) There should be no abrupt alteration of curvature and/or superelevation (cant), and
(b) The superelevation should be appropriate to the curvature, at each point.

(2) On Group ‘A’ and ‘B’ routes, gauge, versines and superelevation on each curve must be checked once in every four months and on other routes every six months. Such checks should also be carried out whenever the running over curves is found to be unsatisfactory. The versines, superelevation and gauge should be recorded by the PWI in the curve register as per the pro forma
Curve registers of groups ‘A’ and ‘B’ routes should also be provided with cumulative frequency diagrams for each curve to get a graphic idea about the condition of geometry of curve. The A.E.N shall check at least one curve of each Permanent way Inspector every quarter by taking its versine and superelevation as well as gauge from end to end. The decision to realign should be taken by the Permanent Way Inspector-in charge or Assistant Engineer. The realignment of curve should be carried out in dry season and not during rainy season except when this is unavoidable.

Criteria for realignment of a curve:

Basics of Curves

Curve is a line of which no part is straight and which changes direction without angles
• Necessarily evil
• Positive impediments for higher speeds
• Necessity arises due to physical and geographical features.

Curve Designation

• Curves are designated by their radii except on IR and US rail roads
• On IR degree of curve for designation
• Radii for calculation

Degree of Curve
Degree of curve is the angle subtended by 30.5 m chord

On IR the curves are measured by versines-which is mid chord offset on 20 m chord


• Vehicle running at a speed of V in a curve of radius R experiences a 
    centrifugal force = MV²/R
• Undesirable effects
– Possible passenger discomfort
– Possible displacement of loads
– Risk of vehicle overturning
– Risk of derailment
– High lateral force resulting in
• Curve resistance
• Wear of rail and wheel flange
• Lateral force on track

Reconditioning of Points and Crossing

• The point and crossing components gets worn out due to passage of traffic and the wear reaches permissible limits in due course of time.
• It is neither economical nor practical to replace them straight away. The life of these components can be prolonged by reconditioning and thus these can be utilized to maximum extent.

• Heat Treated/welded crossings will have same composition as that of 90 UTS rails but hardness of 330-340 BHN.
• MM rails are generally not used in manufacturing of points & crossings now


• Only suitable components should be taken up for reconditioning.
• Component should be in sound structural condition.Components containing cracks on the worn-out portion having depths more than 3 mm beyond condemning size should not be taken up for reconditioning .
• Wear should be within prescribed limit. 
• Component should be tested ultrasonically to decide service ability.

Maintenance and Inspection of Points and Crossing

• Points and crossings require more maintenance effort because of complex assembly and heavy forces applied by rolling stock.
• Manual Maintenance: Covers rectification of clearances, gauge, level &alignment; tightening of fittings; packing.
• Machine Maintenance: By UNIMAT tampers. Alignment, levelling and packing is done. Machine packing is essential for concrete sleeper layouts.
• Reconditioning: Switches and crossings are reconditioned if the wear comes close to permissible limits.
• Ensure efficient drainage.
• Ensure adequate ballast cushion
• Ensure correct spacing of sleepers.
• No junction fish plate at SRJ and HOC. At least one rail should be of the same section.
• Spherical washers are used on skew side. In I.R.S. turnouts with straight switches, these should be provided on the left hand side invariably in the switch assembly.
• Burred stock rail should be replaced.
• Creep anchors and box anchoring of one rail length ahead of stock rail.
• Desirable to weld SRJ and lead curve joints.
• Lubrication of gauge face of tongue rail.
• ST sleepers – Wooden blocks under crossing in case of ST sleepers.
• Gauge Tie Plate should be used on wooden layouts under switch and crossing.
• Tongue rail should bear evenly on all the slide chairs.
• No change of cant outside ATS and HOC for a distance of 20 m on BG and 15 m on MG.


Types of isolation:-
(1)Derailing Switch       (2) Sand Hump         (3) Catch Siding        (4) Slip Siding
(5)Long and Short Sidings                              (6) Snag Dead End Crossing

Derailing Switch

It is provided at one end of the line to isolate the train movement on adjoining line. It consists of one tongue rail and one stock rail with necessary fittings connected with the nearest point in such a way to inter lock the connected points to permit one train movement at a time on any turnout and thus to avoid the possibility of any accident due to rolling down of vehicle from adjoining line. It is normally kept in open condition, whenever it is required to admit the train on derailing switch the point is set and locked before train is allowed to enter.

Tuesday, March 27, 2018

Special Layouts

1.Symmetrical Splits               2.Diamond Crossings          3.Scissors Cross over

SYMMETRICAL SPLITS:Centre line of crossing lies on the centre line of track Diamond Crossings:- The diamond crossing shall not be flatter than 1 in 8½. This restriction of angle of crossing is due to the fact, that while approaching to nose of obtuse crossing the wheel is not guided by check rail for a distance of 407mm in case of 1 in 8½ and 643mm in case of 1 in 12 crossing with 52kg rail. Longer gap increases the chances of wheels taking two roads.

• Formed when two tracks cross each other
1).If same gauge – rhombus
2).If different gauge – parallelogram
3.)If at right angle – square diamond
• Right angle diamond to be avoided
• Slip are laid to provide arrangement to divert vehicles from one track to
1).Single slip                                                                     2).Double slip

Saturday, March 24, 2018

Points & Crossings: Introduction & Definitions

1. POINTS AND CROSSINGS are track components which facilitate diversion of railway vehicles from one line to another. On INDIAN RAILWAYS there are approx. 1, 10,000 points & crossings.

2. POINT is a pair of tongue rail and stock rail along with necessary fittings.

3. CROSSING is a device introduced in the track to permit movement of  wheel flange at the intersection of two running lines. It has certain gaps over which the wheel treads jumps.

4. The arrangement of Points & Crossings for diversion of traffic from one route to another is called a TURNOUT.  Turnouts are required to divert the railway vehicles from one track to another track with lead rails these tracks may be either parallel or diverging or converging. On Indian Railways more than 63400 route kilometer of track includes about 110000 points and crossings.



Definition of Bridge – It is a structure constructed spanning road, river, valley or
any other structure with a purpose to have through passage for communication. The bridges are constructed for Roadways as well as Railways.

Classification of Bridges-

1. Important Bridges- The bridges having total waterway of 1000 sq.m or total linear waterway of 300 m or more and the bridges classified as important by Chief Engineer / Chief Bridge Engineer, depending upon consideration such as depth of water way, extent of river training works and maintenance problems. 

2. Major Bridges- Major bridge is one of which has a total linear waterway of 18 m or more for multiple span and total linear water way of 12 m or more for single span. 

3. Minor Bridges- Major bridge is one of which has a total linear waterway less
than 18 m for multiple span and total linear water way less than 12 m for single


Track structure –

• Track foundation – constitutes the ballast, blanket and sub grade, which placed / exist below track structure to transmit load to subsoil.
• Sub-grade – The part of embankment or of cutting above subsoil by borrowed soil of suitable quality upto bottom of blanket/ballast
• Ballast – crushed stone with desired specifications placed directly below sleepers.

Ballast Profile for L.W.R. track


Ballast is the select crushed granular material placed as the top layer of the substructure in which the sleepers are embedded.

Functions of Ballast

1.Resist vertical, lateral and longitudinal forces
2.Provide resiliency and absorb energy
3.Provide large voids 4.Facilitate track geometry correction
5.Facilitate track drainage 6. .Reduce formation pressure

Requirements of Ballast
1. Tough & wear resistant
2. Hard without getting crushed under moving loads
3. Generally cubical having sharp edge
4. Non-porus & non-absorbent of water 5.Resist Attrition
6. Durable & should not get pulverized under weather condition
7. Good drainage of water 8.Cheap & economical in price

Ballast may be subdivided into following zones:

Laying of Sleepers

General - Sleepers shall be laid and maintained square to the rails on straights and radially on curves. Rail joints should be suspended.

Sleeper Spacing –

(a) The sleeper spacing on straights and curves shall be in accordance with approved plans. The sleeper spacing should be marked on the outer rail in case of curved track. Closer spacing should be provided at the joint sleepers of fish-plated joints and between the joint sleeper and shoulder sleeper.
(b) The following standard spacing should be adopted on fish-plated track

c) In the case of LWR on B.G. and M.G. the sleeper spacing shall be maintained at 65cm,

Elastic Fastening

Pandrol Clip or Elastic Rail Clip

Pandrol PR 401 clip (also called Elastic Rail Clip) is a standard type of elastic fastening on Indian Railways and was earlier manufactured by M/s Guest, Keens & Williams.

It is “fit and forget” type of fastening and very little attention required to maintain the same. The clip is made from Silico Manganese spring steel bar of diameter 20.6mm and heat treated. It exerts a toe load of 710 Kg for a normal deflection of 11.4mm. The toe load is quite adequate to ensure that no relative movement between rails and sleeper is possible. Pandrol clip can be driven with the help of 4 pounds hammer and requires no special tools. In order to ensure that the correct toe load is exerted, the Pandrol clip should be driven to such an extent that the outer leg of the clip flushes with the outer face of the C.I. insert. 
The Pandrol Clip can be fixed on Wooden, Steel, and Cast Iron with special arrangements. There are 3 types of ERC’s.

1. Round-Toe ERC 
2.Flat-Toe ERC
3.ERC mark II, III & IV

Comparison between Various Types of Sleepers

SLEEPERS AND FASTENINGS - Functions of Sleepers

Main function of Sleepers

• Holding rails to correct gauge and alignment.
• Firm and even support to rails.
• Transferring the load evenly from rails to wider area of ballast.
• Elastic medium between rails and ballast.
• Providing longitudinal and lateral stability.

Ideal Requirements of Sleepers

1. It should provide easy means of maintainability.
2. Handling of rails sleepers and fastening should be easy.
3. Quick restoration after accident is possible.
4. Material and design is available.
5. It should have anti-theft and anti-sabotage quality.
6. It should be overall cheap.
7. It should be fit for track circuiting.
8. The base area of sleeper should be sufficient to prevent crushing of ballast.

Friday, March 23, 2018

Maintenance of Rail Joints

Maintenance Of Rail Joints –

(1) Special care is needed for maintenance of fish plated joints to get better rail life as well as improved running.

(2) The efficient maintenance of joint depends on:
(a) Efficiency of fastenings.
(b) The efficiency of packing and correct spacing of sleepers.
(c) The provision and maintenance of correct expansion gaps
(d) The proper lubrication and fishing of the joints.
(e) The correct maintenance of gauge and cross levels and proper packing.
(f) Efficient drainage.

Defects in rail joints –

Some of the major defects, noticed at the rail joints and the preventive measures suggested to rectify or minimize the deficiencies /defects noticed are detailed below

(a) Slack sleepers – Maintenance of joints by Measured Shovel Packing in case of flat bottomed sleepers improves the condition of the joints. In the case of conventional maintenance by beater packing it should be ensured that the sleepers do not get tilted.

Rail Joints

Rail joints are the weakest part of the track. Due to discontinuity of rail in the horizontal & vertical plane, imperfection in the levels of rail heads at the joint & discontinuity in the wave motion of rail, joint suffer with severe blow under passage of wheels. The blow results in degradation of ballast, reduction in ballast resistance and affecting track parameter due to loose packing/ fastening.

Types of Joints

1) Suspended Joint

The rail ends are suspended between 2 sleepers and some portion of rail is cantilever at the joint. Due to cantilever action the packing under the joint sleeper get loose while movement of load. Suspended joint are very common and being adopted not only in Indian Railway but also in other countries of the world.

2) Supported Joint