Modifications and Innovations over the years

Modifications and Innovations over the years


In order to achieve economy, improve reliability and keep pace with the advancements in technology of various equipments, lot of modifications have been made in design and construction practices of various systems over the years. The details are listed below:

1.
Input HT power supply :



Purchase of Electric Power was made at 25 kV in earlier days e.g. in Allahabad Division of Northern Railway and Bhusawal Division of Central Railway. However, in subsequent RE Projects, Power Supply is being taken at HT voltages of 66/110/132/220 KV.



Earlier power supply was taken through three phase double circuit Tr.line. However, presently normally 2 phase single circuit Tr.line on double circuit towers are being constructed as a cost effective measure.





Similarly, for bay extension works in grid substations (GSSs) of SEBs, earlier three phase equipments like CBs, Isolators, CTs, bus bars etc. were employed, which have been reduced to two phase equipments suitable for Railways requirements.

i.


This arrangement has been further made cost effective by way of T-Off arrangement in place of conventional connection from GSS, wherever feasible, thus reducing the cost of Tr. lines and Switching stations considerably.

ii.
To reduce penalty on account of low power factor and exceeding maximum demand and to achieve the benefit of diversity factor, a single point supply from SEB and subsequent distribution to various TSSs through Railway owned Tr.line has also been adopted in some Railways.

iii.
Further NTPC/PGCIL supply is being planned at one or two centralized locations and distribution through Railways owned, three phase double circuit 132 kV transmission lines, to further reduce the tariff and also to improve the system reliability.

2.
Substations (TSS) :

i.
Up gradation of original 8/10/12.5 MVA power transformer to higher capacity 21.6 MVA.

ii.
Further, enhanced spacing between TSSs with development of higher capacity Transformers resulted in reduction of nos. of TSSs and accordingly a considerable saving in capital as well as maintenance cost.

iii.
No. of Transformer in TSSs were earlier kept as two in all TSSs. However based on techno-economical consideration, presently alternate traction substations are provided with single and double transformers. This has been possible after up gradation of capacity of traction transformer from 12.5 MVA to 21.6 MVA.

iv.
In addition, on single line sections, Double transformer TSSs are being provided with one 12.5 MVA released transformer and the other new 21.6 MVA  transformer.

v.
Reduction in TSS area.

vi.
Reduction in area of control room building.

vii.
Development of a miniaturized microprocessor based Control and Relay panel (Anupam panel) in TSSs for improved power supply reliability.

viii.
Indigenous development of integrated feeder protection module by using concept adopted by Japanese Railways.

ix.
Evolving Delta-I relay indigenously for protection against high impedance faults based on concepts adopted by Japanese Railways.

x.
Design and development of panto flashover relay.

xi.
Use of SF-6 circuit breakers/Vacuum Circuit Breakers and Interruptors in place of Oil Circuit Breakers and Interruptors.

3.
OHE system :

i.
Reduction in cost of foundations due to reduction in volume, based on computerised designs for calculation of volume with actual loading parameters. In conventional systems, design is based mostly on RDSO provided charts. Due to new computerised design techniques, a saving of about 30% in volumes of foundations has been achieved in Ludhiana-Amritsar section.

ii.
Utilizing the copper scrap for fabrication of catenary and Jumper wires has resulted in cost saving in procurement of conductors.

iii.
Use of 5 kVA ATs at LC gates, IBH, way side stations in place of 10 kVA ATs used earlier.

iv.
Adoption of 2 x 25 kV AT system on Indian Railways by suitably customizing Japanese technologies suiting to Indian Railways requirements.

v.
Quantum of RC/BT provided for the protection of telecom overhead lines has been reduced due to revision of permissible induced voltage from 5V earlier to 60V presently.

vi.
Use of Continuous cast contact wire eliminated contact wire snapping cases improving the reliability.

vii.
ATD three-pulley type : This has resulted in reduction in breakage of SS wire ropes, which were frequent with winch type regulating equipments.

viii.
Developments of fit and forget type of fittings resulting in reduction of maintenance cost.

ix.
Use of metallised carbon panto strips and subsequently switching over to pure carbon panto strip resulting in reduction of wear and tear of contact wire thereby saving of maintenance cost on account of replacement of contact wire.

x.
Design and development of OHE Recording-cum Test Car for condition monitoring of OHE under live line conditions. This helps in introducing the concept of need based directed maintenance in OHE.

xi.
Improving the reliability of insulators used in OHE through R&D efforts for evolving a suitable material composition Use of composite insulators in place of Porcelain insulators.

xii.
Adoption of thermal measuring and image recording system for identifying bad OHE joints.

xiii.
Switching stations: As an innovation, switching stations on pole mounted interrupters are now being developed, due to which construction of building is not required.

 


4.

Remote Control system :

i.
Strowger type remote control equipment based on electro mechanical system, has been replaced with Microprocessor based and lately with  PC based system.

ii.
Use of PC based SCADA (Supervisory Control and Data acquisition) system has resulted in flexibility in report generation and later analysis of failures. Better monitoring and control of system has been possible with this system. SCADA helps in better monitoring of power factor and maximum demand of TSSs, thereby minimizing the penalties being imposed by State Electricity Boards.

iii.
Mimic diagram board (MDB) has been replaced with PC monitor (2 to 5 in nos.), as a result of technological up-gradation.

iv.
Standardization of Supervisory Control and Data Acquisition (SCADA) system with the aim of achieving interchangeability between the remote terminal units (RTUs) of various suppliers has been done.

5.
Signalling :

i.
RE organisation has continuously upgraded and adopted modern signalling technologies, to improve reliability, availability, maintainability and safety in train operation in line with various policy guidelines issued by Railway Board and RDSO thus, increasing line capacity and providing efficient train control and operation system. Some of the vital technological innovations introduced in signalling systems over the years are as mentioned below:

ii.
Multi Aspect Colour Light Signalling (MACLS) is being provided as a standard at all stations, along with introduction of 25 kVAC, thereby enhancing visibility of signals, boosting the confidence of loco pilots, hence increasing line capacity besides safety and punctuality in train operation. With this, Overhead systems has been replaced with the Under Ground power cables, which is much more reliable, safe and maintainable.

iii.
RE organisation is providing MACLS at all midsection Level Crossing Gates along with electrification, thus improving further enhancement in safety at level crossing gates.

iv.
To overcome the problem of fusing of filament of Signal Lamps, triple pole lamps were provided by RE organisation. In line with the latest guidelines of Railway Board now LED signals with associated modules is being provided by RE organisation at all installations to ensure enhanced visibility to loco pilots, at the same time deriving the long term benefit of maintainability and cost reduction due to longer life of equipment and reduction in power consumption.

v.
Track circuiting is being provided by RE organisation, as a vital safety aid for automatic check of occupation/ clearance of track portion being controlled by the signals, as a policy guideline and adopted as mission area by Railway Board subsequent to the fatal train accident at Ferozabad station of Northern Railway in 1995.

vi.
At stations where PRC sleepers are not available and replacement of steel sleepers is not feasible viz. at steel girder bridges and typical station yards etc. for track circuiting, an alternate technology of Axle Counters have been used to carry forward the vital safety work by RE organisation.

vii.
As the volume of train operations to be controlled grew over vital routes, it became more and more cumbersome to operate first generation signal interlocking system i.e. mechanical lever frames. RE organisation has provided second-generation interlocking system called Relay Interlocking system, which were subsequently evolved into Route setting type Central Panel Operation.

viii.
Besides up gradation in technology, RE organisation has computerised all the vital Signalling Documentation by adopting Computer Aided Drawing as a standard practice for proper upkeep, ease of modification at later date and standardisation of signalling documentation.

ix.
Second Distant Signal has also been provided by RE organisation on Rajdhani and Shatabdi Express routes where permissible train speed is exceeding 120 KMPH, to cater for higher braking distance of 1.5 Km, thus providing confidence to the loco pilots to control and run their trains at the maximum permissible speeds and in turn improve punctuality and safety of these high speed trains.

x.
With the adoption of Central panel operation, to overcome the problem of last vehicle check, Block Proving by Axle Counter (BPAC) has been evolved and adopted as per policy guidelines by Railway Board. RE organisation has quickly adopted the technology and provided the same over all such vital sections.

xi.
With the advent of fail safe electronics in Railway signalling world over and adoption of the same in the recent years by Indian Railways, RE organisation has ushered into the arena of State-of-the Art technology by commissioning of Solid State Interlocking (SSI)/ Electronic Interlocking (EI) at four stations in Bhadrak-Kapilas section of East Coast Railway in 2004-05.

xii.
SMPS (Switch Mode Power Supply) based on Integrated Power Supply (IPS) as developed by RDSO, is being provided by RE organisation as a techno economical solution providing most efficient, reliable, modular and maintainable power supply for vital signalling installations, as per policy guidelines of Railway Board.

xiii.
Networked Data Logger system is being provided as policy guidelines of Railway Board for real time recording and monitoring of all events of signalling equipments at station. This is further being used for preventive and predictive maintenance besides extensively being used for directed maintenance by maintenance organisations.

xiv.
RE organisation has ushered into the field of Communication based signalling with commissioning of OFC based UFSBI (Universal Fail Safe Block Interface) equipments for block transmission in Villupuram-Pondicherry section.

6.

Telecommunication :

i.
With the electrification, Over Head Telecom wires were replaced by Under Ground cables along with the provision of Emergency Communication sockets all along the railway track, to avoid induction effect on telecom circuits.

ii.
With the advent of OFC technology world over and considerable reduction in cost of OFC system and in view of the prevailing Law & Order situation in some parts of the country, as per policy decision of Railway Board in 1996, RE organisation marched ahead in providing new generation technology by laying 24 Fibre OFC along with 4 Quad cable. Subsequently, due to increase in requirement of Quad pairs, as per Railway Board’s policy guidelines, 6 Quad cable is being laid by RE organisation. The inherent benefits of OFC cable being immune to AC induced effect in 25 kV RE area, anti theft prone due to near nil resale value, techno-economical superiority over any available communication system, besides providing vast channel capacity for long range backbone network of voice and data circuits has proven boon to Railway operation. With further shift in technological developments and to keep abreast of modern technology and to derive optimum techno economical benefits, RE organisation switched over from earlier version of PDH (Plessiochronous Digital Hierarchy) equipments to state of the art SDH (Synchronous Digital Hierarchy) equipments as per Board’s policy guidelines.

iii.
Centralised Network Management System (NMS) is being provided as an integral part of the OFC system for online monitoring and maintenance of entire OFC network commissioned over the section of Railway by RE organisation, to ensure reliability and availability of quality voice and data channel thus empowering Indian Railways to cater for speedier, cost effective and safe train operations.

iv.
RE organisation is having close liaison with RDSO regarding latest technologies and improvements in various equipment and material adopted in Railway electrification to bring in State-of-the-Art technology. Maintenance problems being faced by Zonal Railways are being kept into consideration while designs are made, as well as to keep cost of electrification work optimum. RE organisation works with spirit and enthusiasm, with committed team of Officers, Supervisors and Staff to work in close co-ordination with Zonal Railways to complete the works in targeted time to achieve the corporate objectives of Railway transportation.