OHE Breakdowns PDF

BREAKDOWNS 5.0 Knowledge of Rules All officers and Supervisors of the Traction Branch should be fully conversant with the “Rules for Reporting Accidents” and other instructions in force for dealing with accidents and breakdowns. The instructions given in the following paragraphs are to be treate...

BREAKDOWNS 5.0 Knowledge of Rules All officers and Supervisors of the Traction Branch should be fully conversant with the “Rules for Reporting Accidents” and other instructions in force for dealing with accidents and breakdowns. The instructions given in the following paragraphs are to be treated as supplementary instructions applicable specially to traction installations; they should not be taken as nullifying or contradicting the instructions contained in other official manuals. Electrical accidents are dealt with in the Volume I. 5.1 Types of Breakdowns The types of break-downs pertaining to electric traction can be broadly divided into the following categories:- 1. Sub-station and switching stations 2. Remote control equipment and cables 3. OHE feeder lines and transmission lines 5.2 Breakdown Gangs Accident and breakdowns involving traction installations and electric rolling-stock should normally be attendee to by the maintenance gangs themselves. It is however, essential that adequate number of experienced traction staff should be selected and housed in railway quarters close to traction installations, so that their services can be utilized at short notice for dealing with breakdowns and accidents whenever required. In electric suburban sections, however, ‘breakdown gangs’ of adequate strength may be located at selected points to deal promptly with OHE failures, particularly during the hours of peak traffic. 5.3 Emergency Stores and Breakdown Equipment 1. For each OHE depot/sub-depot, the actual quantity of OHE stores lime masts, conductors, insulators, fittings etc. which should be earmarked specially for use in breakdowns will be laid down by Sr. DEE(TrD). To start with, all materials required for 3 kilometers of single line may be kept. Based on experience, the minimum and maximum quantities may be revised from time to time. An inventory of such OHE stores should be maintained by the supervisor-in-charge of the depot/sub-depot and stocks recouped periodically so as to ensure that the minimum quantity is always available. During periodic inspections by officers, scrutiny of this inventory should be one of the important items in order that the required stores are always made available. 2. OHE inspections Cars, wiring trains, breakdown lorries and all break-down tools, tackles, straining screws, clamps, ladders etc. shall be maintained in good condition and kept ready for use at all times. Though it will be equipment is in good working order, supervisors and officers at all levels should specially check their condition during their periodical Over Head Equipments Page 119 inspections. A periodic review should also be made regarding the adequacy of such spares and tools. 3. The CTFO (PSI) and CTFO (RC) should also have in their custody spares and tools pertaining to their work as per scale to be laid down by Sr.DEE (TrD) for dealing with breakdowns and accidents. 5.4 Record of Staff Emergency Staff To enable the TPC to summon staff as required, a register showing the residential addresses of specified staff of the Traction Distribution branch, particularly those residing in railway quarters or close to railway stations, should be maintained station-wise by TPC. The list of office and residential telephone numbers of officers and supervisors should also be kept up- to-date by him for ready reference. In view of the importance of communication facilities in an emergency every telephone should be tested at least once a month. 5.6 SUB-STATION AND SWITCHING STATION BREAK-DOWNS 5.6.1 Traction Transformer Breakdowns Breakdowns of any one traction transformer or associated circuit breaker at a traction sub- station (whether owned by the Supply Authority or the Railway) should not normally affect the working since 100% stand-by is available for the transformer at nearly all sub-stations. 5.6.2 Central Repair Shop Failure of traction transformers, requiring the lifting of core and winding are extremely rare. However; repair and overhaul facilities should be provided at a central pint on each railway. At each Central Repair Shop, the following facilities are generally required. 1. A crane bay with the railway line leading into it, so that the traction transformer may be brought in directly into it. The crane hook should be high enough to permit unloading of the transformer from the wagons and placing on the floor, and also for lifting the core out of the transformer tank. 2. To underground transformer oil storage tanks, one for old oil and one for new oil. 3. A 2500 litre/hour, electrically driven oil purification plan with pumps and interconnecting pipes and valves to empty old oil from transformers, to fill-in new, purified oil into the transformers, to dry out the oil in the transformers etc., as required. 4. An enclosure with oil testing set to test dielectric strength of oil. 5. A small workshop with a few essential machines to carry out urgent repair work. 6. A test-room and laboratory fully equipped with testing equipment for carrying out repair, calibration and testing of all types of relays and instruments used on the traction system. Over Head Equipments Page 120 5.6.3 Mobile Power Van A mobile power van should also be provided on each railway which has to maintain traction transformers. On this the following equipment should be provided. 1. An engine-generator set rated to deliver 100 kVA at 415 ac 50 Hz, 3-phase 4 wire along with necessary oil storage tanks. 2. A 2500 litres / hour electrically driven oil purification plant. 3. A small mobile workshop to attend to urgent on-the-spot repair work, comprising a motor driven drilling machine, grinding machine, a power driven hacksaw, a welding machine and oxy-acetylene flame cutting equipment. 4. Portable flood-lights with trailing cables to light up accident sites to facilitate repair work. The mobile van can be used for purifying transformer oil of traction transformers in situ when required, eliminating the need for bringing the transformers to the Central Repair Shop. At stations where no 3-phase, 415 V supply is available from a nearby source, the engine set is operated to meet the heater load of the oil purification plant and also the drive the motors. The mobile van would also be useful to flood-light an area such as when there is an extensive OHE breakdown. 5.6.4 Breakdown of Circuit Breakers, Interruptors If a circuit breaker or interruptor requires major repairs, it should be brought to the PSI maintenance depot after replacing it by a spare one. 5.6.5 Rail and Road Access Every traction sub-station should have all-weather road access in addition to rail access for transporting heavy equipment to and from the installations. For switching stations too, road access should be provided wherever possible. Suitable fittings and tackle should be available to move an interruptor or circuit breaker from the PSI maintenance depot on a motor trolley or OHE inspection Car and unload it by the side of any switching station and take it in. a suitable platform and a firm pathway leading to the gate should be available and maintained well. 5.7 BREAKDOWNS OF REMOTE CONTROL EQUIPMENT 5.7.1 Procedure for Manning Sub-Stations and Switching Stations 1. Whenever Remote Control working is not possible due to any fault on the P&T cable or in the remote control equipment concerned or failure of the battery etc. CTFO (RC) or TPC shall suspend remote control operation of the particular section or switching station concerned until the defect is rectified. During this period it is necessary to arrange for manning the switching stations by posting suitably qualified staff, who are authorized to carry out emergency switching operations manually as instructed by TPC. Such staff will be referred to as ‘Operator’ in the following paragraphs. To meet such emergencies, TPC shall maintain a register of authorized operators, who have been trained, examined and declared by AEE (TrD) as competent. 2. Whenever an operator is placed on duty at a switching post when the remote control equipment is not functioning due to any reason, the following instructions shall be adhered to Over Head Equipments Page 121 a) Before taking over his duty, the Operator shall make himself conversant with the equipment he is required to operate and the rules that are laid down by the Administration for operation of the equipment. b) He shall carry out orders issued to him by TPC over the telephone, observing the rules laid down for exchange of telephone messages. c) He shall maintain a log book showing the details of operations carried out by him in the order in which they were done, interruption to power supply, abnormal occurrences, defects in plant requiring attention, and other information if any. The log will be signed by both the relieving and relieved Operators at every change of shift as a token of having taken over and handed over all equipment correctly. d) The Operator shall be responsible for all the plant and equipment, spare parts, stores and furniture (at the sub-station or switching station) during his shift. e) Whenever a switching station is manned, the Operators shall work in accordance with the duty rosters exhibited. The regulation of the shifts shall be effected by TPC. f) The operator on shift duty is forbidden to leave the post station unless he is relieved by an authorized person. No interchange of duties or variation of duty hours is permitted without the prior permission of TPC, and staff who are unable from any cause to take their shift, shall at once notify TPC. g) Whenever an Operator is posted at a switching station or sub-station he shall always be accompanied by another person e.g. a Khalasi, who can use the telephone intelligently. 5.7.2 Restoration of Remote Control CTFO (RC) shall arrange for expeditious rectification of the defect and restoration of remote control. It is undesirable to continue any controlled post on local control for prolonged periods. 5.7.3 Breakdown of Tele-Communication Between TPC and Sub-Stations, Switching Stations etc. If the TPC circuit becomes defective for any reason, several alternative channels of telecommunication are available. Should the P&T cable itself break-down all circuits through it may be inoperative. In such cases, essential messages may e passed through the P&T telephones, railway local telephones network, railway wireless network or microwave network. Urgent messages from TPC to traction sub-stations could also be passed through the Operators of grid sub-stations. Close co-ordination should be maintained between the officials of the Traction Distribution Branch, S&T branch and DOT authorities to ensure quick restoration of normal communication facilities. 5.8 OHE BREAKDOWNS 5.8.1 Importance of Expeditious Repairs Every breakdown of OHE, even if minor in nature, should be attended to urgently as it generally interferes with traffic. Since electrified lines carry a high density of traffic, the effect on traffic will be quite severe if restoration is not arranged expeditiously. Over Head Equipments Page 122 5.8.2 Types of OHE Breakdowns The common types of OHE breakdowns are as under- 1. Uprooting of or damage to OHE masts on account of cyclone, derailments etc. 2. Entanglement of pantographs with the OHE, 3. Snapping of OHE conductors 4. Flash-over or other damage to insulators 5. Faults on account of stray wires etc 6. Theft of OHE conductors. 5.8.3 Look-out for OHE Defects The engine crew of all trains should keep a sharp look-out and report to the TPC from the nearest station any defects noticed by them in the OHE. All break-downs or defects in OHE which are likely to affect the train services, noticed by any Railway servant shall be reported immediately to TPC. If TPC cannot be contacted, the nearest Station Master or Cabin Assistant Station Master shall be advised. The SM/CASM to whom such breakdowns or defects are reported shall convey the information immediately to TPC through the control or other available telephone. The person reporting a breakdown to TPC should give as detailed information as possible on the nature of the breakdown, its location, if masts have been uprooted or both lines in a double track section have been affected etc. The person conveying the information to TPC should not leave the vicinity of the telephone without TPC’s permission, as the latter may want to contact him again to elicit further information. 5.8.4 Action to be taken by TPC If required, TPC shall direct the nearest available Electrical Department official to proceed to site to obtain full details. Simultaneously the TPC should switch off power supply to the affected lines and inform the Section Controller. Though initially power may have to be switched off over a whole sub-sector, the faulty elementary section should be identified and isolated as quickly as possible so that power supply to the affected lines and inform the Section Controller. Further, it should be possible in many cases to block the lines for electric locos and EMUs only, permitting movement of steam and diesel trains. It may also be possible to move electric locos and EMUs at restricted speed or to coast through the affected section with pantographs lowered if the damage is only slight. It is for TPC to decide after careful study of information available from the site and in consultation with traffic officials the extent of restriction to be imposed on traffic. Over Head Equipments Page 123 5.8.5 Protective steps 1. On receipt of information about OHE break-down, the SM/Section Controller shall also take such steps as deemed necessary to regulate traffic on the affected lines and issue caution order where required. Single line working may be introduced, if feasible. 2. It is the duty of every railway servant who notices hanging OHE conductors to take immediate preventive steps to ensure that no person comes into contact with them treating such conductors as live until an authorized person from OHE section arrives at site and makes the OHE dead and earth it. 5.8.6 Breakdown Staff 1. On receipt of the first report about the breakdown, TPC shall direct the nearest OHE maintenance gang to proceed to site immediately with available breakdown vehicles for dispatch of staff without waiting for full details of the breakdown. 2. A quick assessment should be made on the basis of information available and where necessary one or more gangs from both sides of the site may be asked to proceed to the site. If the accident spot cannot be reached by rail-borne vehicles on account of the line being blocked by other trains, road vehicles equipped with emergency stores, tools and staff may be directed to the site. In sub-urban sections with large number of roads running along side the track, this method may help in tackling the repairs much more quickly. 3. If the OHE Inspection Car or wiring train is required to attend to the break-down, the Section Controller, on request from TPC shall arrange for quick passage of the OHE Inspection Car or wiring train to the site of the accident. 5.8.7 Officers and supervisors to proceed to site On receipt of information about an OHE break-down the ATFO(OHE), CTFO (OHE), DEE/AEE(TrD) shall proceed by quickest available means to the scene of accident. The Sr. DEE (TrD) should also proceed to the site in the circumstances of the case require his personal supervision and direction. In the event of a major break-down likely to result in interruption of traffic for more than 12 h, CEDE should also proceed to the site for supervising restoration. 5.8.8 Assistance to be Sought 1. It should be remembered that restoration of traffic in the event of accident or breakdown is the responsibility of the Division as a whole. The Electrical Department Officer in-charge of the restoration work should, wherever required, ask for assistance from the Engineering, Traffic or other Officers as necessary. He should also keep the DRM fully posted with arrangements made and the expected time of restoration. 2. When circumstances warrant, the assistance of OHE gangs of another contiguous Division may be sought for by contacting AEE(TrD) or Sr. DEE/DEE(TrD) of the Division concerned. The officers who receive such requests from neighbouring divisions should treat the matter as of utmost importance and render all possible assistance. Over Head Equipments Page 124 5.8.9 Continuous Communication with TPC The Officer or Supervisor in-charge of supervising repair work should maintain continuous communication with the TPC from the site of breakdown. For this purpose an intelligent person should be posted to man the nearest emergency telephone socket continuously to transmit and receive messages as required. It is very important that the field staff remains on call all the time until normal service is restored, since no provision exists in the emergency telephone circuit for the TPC to ring up the emergency telephone stations at the site. 5.8.10 Detailed Assessment by the First Supervisor / Officer Reaching Site. The first Supervisor or Officer of the Traction Branch reaching the site of the breakdown should make a quick assessment of the extent of damage and the time required for restoration. He will ascertain from TPC the details of break-down gangs and equipment directed to the site and if the circumstances warrant, ask for additional gangs and breakdown equipment to be sent to the site. On receipt of these details, TPC should arrange for additional gangs and equipments to be sent to the site expeditiously. In the meanwhile, isolation and repair works should be started at site. Further details on the extent of damage and estimated time as obtained from the Supervisor / Officer at the site from time to time will be passed on from TPC to the Section Controller to enable him to review the arrangement for regulating the traffic initially made. In the event of major breakdowns affecting main line traffic, Sr. DOM/DOM of the Division should personally take over regulation of traffic arrangements. 5.8.11 Preservation of Evidence When a pantograph gets entangled with the OHE, it is often very difficult to establish whether the damage originated from a faulty pantograph or a defect on the OHE. The first Officer or Supervisor of the Electrical Department arriving at site of a breakdown particularly those involving entanglement of pantographs with the OHE, should make a very careful note of all relevant details pertaining to the breakdown and also prepare a sketch indicating the particulars. He will also arrange for preservation of such evidence as may be useful subsequently for investigating the cause of the breakdown. Items to be checked on the pantograph and OHE are indicated in the fig. 5.8.12 Safety Rules to be observed While speed is the essence of emergency working, rules prescribed for safe working shall never be infringed. Repair work may commence only after an emergency power block has been obtained and all other precautions necessary for protection of the staff taken. On completion of the repair work, the power block may be cancelled according to the prescribed procedure. Over Head Equipments Page 125 5.8.13 Temporary Repairs for Restoration of Traffic In the first instance, repairs to the OHE should be kept to the barest minimum necessary for restoration of traffic with least possible delay. Work must proceed simultaneously at many points. After affecting temporary repairs, the Officer or Supervisor in-charge of the work should personally check the whole area and satisfy himself that the installations are in order and safe. He may impose such speed restriction as necessary for movement of electric and other than electric trains till permanent repairs are carried out. Permanent repairs should be arranged and speed restrictions removed and normal operation restored at the earliest opportunity. 5.8.14 Clearance of Line for Steam / Diesel Traction If the breakdown is extensive and restoration of electric traction is unlikely in a short time even with temporary repairs, the line should be cleared for diesel / steam traction as soon as possible, so that traffic may be kept moving until repairs to the OHE are completed. After steam / diesel traction is introduced full precautions should be taken for protection of staff working at site. 5.8.15 Wiring trains If the OHE has suffered extensive damage, the OHE wiring train should be requisitioned to speed up the work. The wiring train generally consists of a stores – cum tool van, a workshop van, a staff and kitchen van, a reel wagon loaded with one drum of catenary wire and one drum of contact wire, wagon loaded with materials for temporary diversions, a BFR loaded with structures, a hand-operated crane to facilitate erection of masts, a power car with two diesel generator sets for supplying power to the workshop van and for lighting, two brake vans, an adequate quantity of OHE material and flood-lights with trailing cables. The vans have platforms with side-railings to facilitate working on the roof. 5.8.16 Interference with OHE During Restoration In clearing the line traffic, breakdown staff are forbidden to disturb the OHE masts or to cut the OHE conductors except under the specific orders of Sr. DEE (TrD)/DEE(TrD). If it becomes necessary to slew the OHE conductors to facilitate crane working, this should be arranged to be done by the Electrical Department staff. It should be borne in mind that indiscriminate cutting of OHE conductors will necessitate introduction of splices which are not conductive to good current collection. Also introduction of such splices is liable to delay restoration of normal electric services. 5.8.17 Temporary Diversions Sometimes with derailments and accidents occurring in electrified sections, temporary diversions have to be laid to clear the traffic with other than electric traction. A quick means of wiring such diversions so as to resume electric traction without waiting for the main line to be commissioned is described below. Over Head Equipments Page 126 The constructional details of the arrangement for such diversions on BG may be seen in Fig.5.1 The portal type structures are made out of 80 mm diameter GI pipes using two right angled ‘T’ joints. Guys are used in both perpendicular and parallel directions to the track so as to give extra safety against heavy wind load. The contact wire is suspended with the help of special fittings made of MS flats form the catenary wire stretched between the two upright of the structure and insulated by two 9-tonne insulators as shown in the figure. The 80 mm diameter GI pipes are placed in 150 mm diameter MS pipes welded on to a 10 mm thick 450 mm x 450 mm MS base plate which in turn is bolted by 10 mm diameter through bolts to a 4880 mm long crossing sleeper Over Head Equipments Page 127 Put under the rails. The weight of the rails keeps the crossing sleeper and thereby the structure in position. The void between the 80 mm diameter and 1509 mm diameter pipes is wedged by wooden wedges and also filled up with sand and covered by bituminous compound so as to prevent rusting of the GI pipe due to the seepage of water through the sand. Since the whole structures is attached to the track as above, the chances of tilting or sinking of the structure with shrinkage or settlement of the temporary un-consolidated embankment are eliminated. The contact wire is anchored at both ends at a height of 6 m existing masts and ‘fly guys’ are provided from the anchor mast to the base of the next mast so that no separate foundation is necessary for anchoring and also the guy can be removed easily at the time of dismantling. The advantages of the above type of construction are as under:- 1. It is cheap. 2. The structures weigh less than 150 kg and 4 men can easily erect or dismantle them. 3. Since no foundations are required, time is not lost in excavation for foundation and consequently the structures can be erected quickly. 4. The equipment can be dismantled and erected at new sites quickly. 5. The traffic can move at the speed restriction imposed for the permanent way and no extra speed restriction on account of OHE is necessary. 6. The materials used for the work are easily obtainable. The new fabrications required can easily be manufactured in workshops and stocked at depots for quick use in emergencies. 5.8.18 Funds Required for Dealing with Breakdowns Funds required for dealing with breakdowns may be obtained from station earnings in accordance with para 714 of the Indian Railways Permanent Way Manual reproduced below:- 1. The Divisional/District Engineer or the Assistant Engineer on his behalf may drew upon the station earnings according to such instructions as prescribed by the Administration under note to para 1405G, for the following purposes:- a) Payment to daily labour employed at the site of breach or accident. b) Purchase of tools or materials required in connection with accidents which cannot be supplied in time by the Stores Department. c) To provide food to engineering labour at the site of breach or accident with the assistance of Station Masters or Inspectors of the Commercial Department. The supply of food free of charge is permitted in special circumstances at the discretion of the Administration to facilitate expeditious restoration of traffic. When food is supplied free at the site of an accident to engineering and other labour the expenditure per head per day shall not exceed the prescribed limit. 2. The Accounts Officer should be advised immediately by telegram of each sum taken from station earnings. In all cases, Engineers obtaining advances from station earnings should, do so under a clear receipt. On the receipt, the object for which the money has been procured should be clearly stated. Over Head Equipments Page 128 A complete account should be submitted at the earliest possible date to the accounts department supported by pay sheets and vouchers. 3. All payments to labour should be witnessed by the Assistant Engineer at site. 5.8.19 Log of Events and Reporting of Break-downs 1. In all major break downs TPC, senior officials and Officers concerned shall maintain a detailed log of events in their diaries noting the time and brief details which may help in fixing the responsibility for any avoidable delay in restoration. 2. The DRM should submit to CEE and COM a detailed report covering every major break-down of OHE or other traction installations giving all essential information including- 1. nature of break-downs and lines affected with detailed sketch; 2. chronological account of action taken to effect repairs and restore traffic; 3. repercussions on traffic and rough estimated cost for repairing the damage; 4. cause of break-down and staff responsible, if any, 5. any other special features including an objective analysis of the time taken for repairs and restoration of traffic with a view to see if these could have been done more expeditiously and if so measures proposed to improve the performance in future. 5.8.20 Protection of Staff In addition to ensuring that work on OHE is commenced only after obtaining a power block as stated in para 20825 above, the supervisor in-charge shall take all measures for protection of staff and for exhibition of hand-signals as per GR and SR, particularly when the line under repair and the adjacent lines are not blocked for other traffic. 5.8.21 Use of cranes Special care is necessary when steam or hand cranes are used at the site of break-downs. The movements of the cranes shall be carefully controlled by the person in-charge so as not to come within 2 m of live OHE, in addition to the usual precautions necessary to prevent infringement of adjacent tracks which have not been blocked for other traffic. Over Head Equipments Page 129