Mumbai | Sunday mega blocks: Backbone of Central Railway’s maintenance strategy

What happens on a Sunday mega block on CRCentral Railwayrsquos suburban rail network spread over CSMT to Karjat ndashKhopoli and Kasara on the main line CSMT to Panvel Bandra on the Harbour line Thane to Panvel on the Trans Harbour line and Nerul Belapur to Uran on the Port line runs over 1810 Suburban train services daily on its vast 325 km Suburban network It also runs more than 210 Mail amp Express trains on the Main lines dailySuburban services start from the first train starting its journey at 0206 hrs to the last train reaching its destination at 0230 hrs serving people and ensuring a safe and smooth journey for all This implies that the train services operate around the clock and more than 40 lakh people travel daily in these trainsWhat is a Mega BlockRunning such a large number of train services puts a huge burden on the infrastructure which results in wear and tear This includes rails sleepers signalling equipment Over Head Equipment Electrical fittings track fittings etc These need to be maintained regularly to ensure efficient and uninterrupted train operationsThe time for maintenance available every day is not adequate since the time margin between the last train and the first train is hardly a couple of hours This duration is further affected due to various reasons like late running of longdistance trains technical issues and failures at any intermediate locations Snags due to heavy rainfall during the monsoon etcAlso nighttime working has limitations like reduced visibility and is not as convenient and productive as daytime working Besides temperaturesensitive work like destressing cannot be carried out during the night when the temperature is lowHence it is essential to plan a periodical time slot once a week for maintenance work which is called a Mega BlockMega Block can be termed as a lsquoBreathing space for infrastructure workrsquo and is usually taken up sectionwise on Sundays since the volume of passengers travelling is comparatively less and besides cancellation of a few train services or changes in train running schedule on weekdays inconveniences a significant number of commutersHow is Mega Block plannedMega Block planning begins with the identification of critical maintenance or replacement works that require track isolation and cannot be carried out under traffic Based on asset condition monitoring failure analysis and project timelines a priority list of work is drawn upThis is followed by joint coordination amp integration meetings with Engineering Signal amp Telecommunication Electrical and other concerned departments to plan work in such a way as to ensure concentrated efforts for maintenance Detailed job charts are prepared indicatingbull Work site and nature of workbull Machine amp Manpower deployment planbull Safety precautions and disconnectionreconnection protocolsbull Preblock testing and postblock commissioning strategiesThe block proposal is integrated at the Divisional Control Office for overall traffic block plan and final execution is done only after confirmation of material availability readiness of skilled manpower and site clearanceWhat happens in Mega BlockAlthough the operation of the Mega block involves work related to multiple departments the major departments involved are as Engineering Signal amp Telecommunications and ElectricalEngineering DepartmentThe Engineering department is responsible for all work related to Track laying Construction of Foot Over Bridges Launching of Girders and maintenance of the same It includes Road Safety Works like the construction and maintenance of Road Over Bridges Road Under Bridges It also includes upgrading railway tracks rails sleepers ballast and other infrastructure to ensure efficient smooth and safe train operationsThe various works carried out by the Engineering department arebull Replacement amp Maintenance of Track components including Rails Sleepers Switches Switch expansion joints Glued joints Turnouts etcbull Renewal of Ballastbull Rectification of defective or irregular track layoutsbull Inspection amp maintenance of special track layoutsbull Tamping work for lining levelling and twist correction of sleepersbull Deep screening of fouled ballastbull Destressing of Long welded rails to ensure stability and prevent buckling or fracturingbull Welding work to ensure continuity of rails eliminating rail joints USFD testing to detect internal flaws in rails amp welds to enhance track stability and ensure track safety and reliabilitybull Inspection of fish plates and landing joints to ensure track integrityWork done during monsoonbull The railway team leaves no stone unturned to ensure seamless operations of trains during the monsoonbull Pumps are installed at strategic locations for enhanced pumping out of rainwater from railway tracks during the rainsbull Work of Desilting and cleaning of drains culverts is carried out with loading of muck onto muck special wagons amp trains for disposalbull Work of cutting amp trimming tree branches which pose a risk to safe running of trainsbull Erection Installation of Tunnel Portal Rockfall barrier Boulder netting Canadian fencing and Boulder catching sumps on the ghat section before monsoon to ensure safe train operations bull In addition major works like replacement of Girders Structural repair amp maintenance work of Foot Over Bridges Road Under Bridges and Dismantling of redundant structures are also undertaken during mega blockManpower amp Machinery UsedThe work is carried out with a workforce of more than 200 workers including both railway personnel and contractual workers under the direction amp supervision of technically competent Officers and Supervisors having adequate experienceFollowing machines are used for the workbull Track Relaying Train for renewal of Sleepersbull Ballast Cleaning Machine for ballast cleaning of plain track and turnoutsbull Dynamic Track Stabiliser Machine for stabilising of track ballast bedbull MultiPurpose Tamping Machine for spot attention of plain tracks amp turnoutsbull Continuous Tamping Machine for lining levelling twist correction amp tamping of sleepersbull UNIMATE Point Crossing Tamping Machine for tamping of turnoutsbull Utility Track Vehicle for loadingunloading of materials like rails sleepers and other heavy Permanent Way MaterialsIn addition other machines like Poclain amp JCB for loading of muck USFD testing machines for testing of rails amp Welds GEDO machines for track survey and Rail cuttingdrilling equipment Welding equipment Gas cutting equipment etc are also usedSafety PrecautionsThe entire work is done with adequate safety precautions like obtaining Caution Orders Placement of protection boards Use of hooters at work to alert the workers of approaching trains Retroreflective jackets for enhanced visibility and use of safety tools like Banner flags Red amp Green flag Detonators Safety gloves helmets safety belt Mould shoes etcSignal amp Telecommunication DepartmentThe Signal amp Telecommunication department is responsible for the installation renewal repair and maintenance of all Signal equipment and safetyrelated interlocking worksThe various works carried out by the Signal amp Telecommunication department arebull Replacement of overaged Track Circuits Digital Axle Counters enhancing detection accuracy and reducing maintenance requirementsbull Replacement amp Overhauling of wornout or defective Point Machines to ensure smooth and dependable turnout operations critical for safe train routingbull Replacement of Dilapidated or corroded signal posts to maintain structural integrity and reliable signal displaybull Replacement Removal of Defective glued insulated joints vital for track circuit insulation to restore track circuit separation and maintain detection integritybull Meggering of Signal cables to assess insulation resistance and replacement of damaged cables to improve system reliabilitybull Renewal of rusted junction boxes post boxes and execution of proper track circuit bonding to ensure uninterrupted signal and track circuit functioningbull Testing amp Commissioning of New Installations including signals point machines relays and circuits to ensure safe integration with the existing systemBesides the work of shifting Signal posts to a new location due to various reasons like yard remodelling introduction of new lines or changes in track alignment along with the shifting of signal cables to improve visibility is also done during a mega blockManpower amp Equipment UsedThe work is carried out with a workforce of more than 200 workers including skilled railway personnel and contractual workers under the direction amp supervision of technically competent Officers and Supervisors having adequate experience These works are carried out with the help of equipment like Insulation Tester Earth Testing Kit Digital Multimeter and Clamp Meter and Track Shunt Resistance Meter Relay Testing Kit Cable Jointing Tools etcIn addition other equipment like handheld termination amp splicing tools Portable lights DAC tool kits Spanners hammers etc are also usedSafety PrecautionsThe entire work is done with adequate safety precautions like Safety gloves helmets safety belts moulded shoes etcElectrical DepartmentThe Electrical department is responsible for providing electric supply for train operations through Over Head EquipmentOHE and maintenance of EMUs Its work during mega block involves installation replacement repairs and maintenance of all infrastructure related to OHEIt is responsible for the upgradation and maintenance of all electrical equipment to ensure efficient uninterrupted smooth and safe train operationsDuring the block the Electrical department also carries out repairs amp maintenance of EMUs which are not in service on the days of the blockThe various works carried out by the Electrical department are as followsbull Replacement amp Maintenance of OHE Components like wornout contact wires catenary wires droppers insulators section insulators autotensioning devices and corroded bondsbull Switchgear amp Sectioning Works like Replacementrepair of Isolators Interruptors Air Break Switches ABS and Overhaul and testing of Switching stationsbull Foundation laying amp erection of new mastsportals Replacement of rusted or damaged masts and Realignment or height adjustment of OHE structuresbull Maintenance of turnout overlaps crossovers and neutral sections and adjustment of wire height and stagger at points and crossingsbull Earth resistance testing and improvement new earth pits and Replacementrepair of surge arresters and protection devicesManpower amp Machinery UsedThe work is carried out with a workforce of more than 200 workers including skilled railway personnel and contractual workers under the direction amp supervision of technically competent Officers and Supervisors having adequate experience Following machines are used for the workbull Tower WagonTW used for accessing OHE wires maintenance and replacement worksbull RailcumRoad Vehicle RRV which can be used for both rail and offtrack OHE worksbull Hydra Crane or JCB used for mast erection and unloading heavy equipmentbull In addition to Hand tool equipment Electrical testing instruments and Measurement amp Safety tools are also usedSafety PrecautionsThe entire work is done with adequate safety precautions like obtaining a Power block Earthi and discharge of OHE before work Placement of protection boards and banners and Use of insulated tools including special shoes with insulation to facilitate easy and safe working by the staffThe Manpower Behind Mega BlocksThe entire work during Mega Block by the Engineering Signal amp Telecommunication Electrical and other departments is carried out simultaneously on the entire section with efficient coordination of Senior Officers at the Divisional Headquarters the Control Office Officers and Supervisors on the field and the team of railway and contractual workmen so as to achieve the targeted work in the planned timespanMore than 500 railway personnel and contractual workers including skilled workmen along with technically competent Officers and Supervisors having adequate experience work collaboratively during Mega Blocks Their effort ensures the execution of multiple timesensitive tasks across disciplines in a limited windowWhen a majority of the Cityrsquos population is enjoying the Sunday holiday at home when the commuter traffic is less on Sundays and Festivals the entire dedicated team of Railway personnel are working in the field ensuring the safety and security of trainsWhy Mega Blocks are essentialMega Blocks are vital enablers of longterm reliability operational safety and network modernisation Unlike working on running tracks with extreme caution and limited windows during regular days Mega Blocks provide a dedicated time slot free from train movements allowing safe and uninterrupted execution of critical tasksMany worksmdashespecially those involving crossovers turnouts or locations affecting both UP and DN linesmdashrequire complete isolation of the section Mega Blocks make it possible to undertake these complex works efficiently without jeopardising safety All equipment installed or modified during Mega Blocks undergoes thorough functional testing ensuring the correctness of various aspects This minimises the risk of failures thereby enhancing the safety envelope of train operationsMega Blocks provide a dedicated time window usually during offpeak periods on Sundays or holidays when train operations are temporarily diverted over selected sections to facilitate critical maintenance renewal and upgradation works Given the volume of daily traffic even minor faults can have cascading effects on punctuality and safetyMega Blocks are not disruptionsmdashthey are strategic pauses They are the backbone of preventive maintenance capacity augmentation and safety assurance for Central Railwayrsquos highdensity suburban and longdistance operationsBy effectively utilising offpeak hours these blocks allow railway departments to work in synergy modernising infrastructure while ensuring continuity reliability and above all passenger safetyldquoBehind every Mega Block lies a Mega Effort ndash a silent yet powerful testament to the Railwayrsquos commitment to excellencerdquo