OHE Maintenance Schedules PDF

MAINTENANCE SCHEDULES FOR OHE 4.0 Schedule of Inspections 1. In order to achieve high reliability and ZERO DEFECT OHE, and to ensure effective checks on the maintenance work a minimum schedule of inspections to be carried out each month by the officers and Senior Subordinates in charge of...

MAINTENANCE SCHEDULES FOR OHE 4.0 Schedule of Inspections 1. In order to achieve high reliability and ZERO DEFECT OHE, and to ensure effective checks on the maintenance work a minimum schedule of inspections to be carried out each month by the officers and Senior Subordinates in charge of operation and maintenance of OHE and associated system. 2. The schedule of inspections is the minimum quota for each official and should be independent of other tasks. They will not be of routine nature but shall be carried out in depth to identify: i. Deficiencies and short comings ii. Lack of skill amongst staff iii. Inadequacies in maintenance facilities iv. Constraints experienced v. Conditions of environment leading to poor quality of work 3. The inspecting officials should programme their inspections in such a manner as to cover the widest areas in their jurisdiction over the year and so stagger the inspections as to avoid over inspections of the same section repeatedly, in a very short time while neglecting other areas. A check list in brief for various inspections is indicated in para 4.13 4.1 General The OHE is subject to dynamic oscillations due to the constant contact and movement of the fast moving pantograph coupled with wind pressure. It is necessary to maintain the OHE in perfect condition through proper checks on its geometry and all parameters adopted in the design. The following schedules of maintenance for the OHE are required to be followed to ensure good current collection as well as safety of installations and personnel:- i. Foot patrolling ii. Trolley inspection iii. Current collection tests iv. Special Checks v. Annual Maintenance and OHE Inspection Car Check vi. Periodical Overhaul vii. Re-tensioning of unregulated OHE 2. The importance of OHE arises from the fact that it is extensive, with a very large number of insulators, fittings and other parts; failure of any one of which may result in dislocation of train services for appreciable periods until the defect / breakdown is rectified. The adjustment work is particularly important at cross-overs and at overlaps spans since any departures from the standards laid down could cause entanglement of the pantograph with the OHE, with serious repercussions. The need for a thorough detailed inspection of every part of the installation, mast by mast need not therefore be over-stressed. 3. The periodicity of schedules laid down below apply to the majority of installation. The periodicity may, however, be modified by CEE, where local condition so warrants. Over Head Equipments Page 97 4. As regards new equipments, if schedules have not been drawn up, tentative schedules may be evolved based on the Original Equipment Manufacturer’s guidelines and RDSO’s recommendations, keeping in the view the local conditions also and followed with the approval of CEE. 4.2 Foot-Patrolling of OHE The object of foot-patrolling is to make visual inspection of every part of the OHE (including feeder line) so that any defects and abnormalities noticed are recorded and reported to the maintenance gangs for attention. 2. An experienced OHE Linesman (accompanied by a Khalasi if demand necessary by local conditions) should be deputed to patrol the section on foot by day, so as to cover every part of the section including yards once a fortnight and suburban sections once a week. If this patrolling is done thoroughly, many of the defects will be noticed at the incipient stage, before they develop into major defects. ATPO or Chargeman should foot-patrol the section once in six months. 3. The Linesman on foot-patrol should be equipped with signal flags, an emergency telephone instrument and essential tools required for attending to defects on the spot e.g. spanners for tightening bond connections. 4. The Linesman on patrol duty should particularly look for the following: a. Chipped or damaged insulators; b. Displaced fittings and droppers; c. Excessive sagging and hogging of contact wire; d. Whether equalizing plate is titled; e. Free movement of auto-tensioning device and position of counterweight with reference to upper and lower limits of movement marked on the mast; f. Presence of protective screens, caution and warning boards and anticlimbing devices; g. Structural soundness of height gauges at level crossings; h. Bird-nests and pieces of stray wire likely to cause short circuits and branches of tress likely to infringe the OHE; i. Defective bonds and earth connections; j. Defects in return-conductor connecting booster transformers and its connection to rails. Oil leakage if any from BT & AT; k. Any obstructions including tree branches in the way of free movement of pantograph and trains; l. Signs of heavy sparking when trains pass; m. Isolators blades being fully in and for signs of sparking or overheating of isolators as also condition of locks; n. General condition of switching stations en-route; o. Tilting of masts especially on high banks and masts with sand-core foundations; p. Number plates. q. Any other abnormal / unusual situation. 5. Major defects noticed by the Linesman which endanger safety shall be reported forthwith to TPC through the nearest telephone. Full details should e given to enable the Over Head Equipments Page 98 TPC to decide on the course of action to be taken and if required to regulate train movements in the affected section. 6. The Linesman should himself attend to and rectify such of the minor defects (e.g., loose bond connections) which can be rectified by him on the spot without special assistance. To facilitate this, he shall carry with him a few essential tools. Other minor defects should be noted by him in his diary and entered by him in a Register maintained for the purpose in the depot / sub-depot. The roster of patrolling Linesmen should be so arranged that they will be able to return to the depot/ sub-depot for submission of report as above before going off duty for the day. Where this is not convenient, the Linesman must report the defects on telephone to the depot / sub-depot followed by a written report in the Register on the next day. The supervisor in-charge of the depot / sub-depot will carefully scrutinize the Register and take prompt action to rectify defects reported, making suitable entries in the Register. 7. Testing of Emergency Telephone Sockets: During patrol duty, the Linesman will speak to TPC from every emergency telephone socket in route. Such calls from patrolling Linesmen should be recorded in a Register by the TPC indicating the date, time and serial number / location of the socket tested. Defective sockets should be reported promptly to the S&T Department for rectification. 4.3 Trolley Inspection of OHE Inspection of OHE by push trolley is essential except in sections where use of trolley is prohibited. The object of such inspection is to enable supervisors and officers in-charge of OHE maintenance to observe closely the OHE under their charge and should be carried out during day time. The depot-in-charge (TPO or ATPO) should inspect his entire section once a month. CTPO / AEE(TrD) should inspect their respective sections once in 3/6 months respectively by push-trolley or motor-trolley as convenient. Sr. DEE/DEE(TrD) also should cover his entire section at least once a year by push-trolley or motor trolley. 2. Apart from trolley inspection as above, officers and senior subordinates shall travel be the cabs of locomotives and EMU trains as often as possible but atleast once a month to observe the general condition of OHE and to get a first-hand knowledge of operating conditions. 4.4 Current Collection Tests It is necessary to carry out periodic tests to detect points at which contact between the contact wire and pantograph is unsatisfactory resulting in sparking. Such current collection tests are performed at night. A mirror can be fixed in front of the look-out glass of the rear cab of a locomotive and adjusted so as to get a reflection of the rear pantograph which is normally in service. A person traveling in the cab can then observe through the mirror any sparking which may take place. The location where the sparking is observed and the severity of the sparking should be immediately noted down and the OHE at the location got checked up as soon as possible to find out and eliminate the cause of sparking. The current collection tests as above should be carried out by the depot-in-charge (TPO or ATPO) once in 3 months over his entire section. The CTPO/AEE (TrD) should accompany Over Head Equipments Page 99 the depot in-charge during such tests alternately so as to cover their sections once in 38/6 months respectively. DEE (TrD) should accompany the depot in-charge so as to cover his jurisdiction once a year. 4.5 Special Checks While the majority of items require attention only during Annual Maintenance and Periodical Overhaul, items listed below will require more frequent attention as indicated against each- 1. Insulators : Generally insulators need cleaning once a year along with the annual maintenance schedule. At locations subject to smoke pollution on account of steam locos or pollution due to industrial dust, the frequency of cleaning will have to be fixed based on the extent of such pollution. Where pollution is heavy, cleaning may have to be done more frequently. With the application of silicone grease, the interval for cleaning at such locations can be extended significantly. 2. Section insulators: Section insulators on the main lines such as at neutral sections and passenger yards should be attended to as under once in three months - a. Clean insulators and replace badly chipped or even slightly cracked insulators. b. Check runners for flash marks. c. Check level of the assembly and adjust as required. d. Check for excessive contact wire wear near anchor clamps. e. Tighten properly the PG clamps of droppers and stiffeners. f. Check the pantograph passes underneath the section insulator smoothly. 3. Isolating switches at Yards / Loading sidings. The continuity and soundness of earth connections should be checked once a month. 4. Bi-metallic clamps: These should be checked for tightness and signs of overheating once in 3 months. 5. Earth connections: Apart from general inspection of bond and earthing connections during foot-patrolling, all such connections should be specially checked for continuity and soundness of connections once in six months. Particulars of all earthing connections (other than structure bonds) should be entered in a Register station-wise for each section and the dates of six-monthly inspection entered therein. 6. Feeders: Foot-patrolling of 25kV feeders should be carried out every month. During this check, the Linesman shall also check that safety guards provided under the feeders properly earthed, if the clearances are adequate and caution notice boards are in position. 7. OHE supported on steel girder bridges should be examined as frequently as possible depending upon traffic conditions. 8. Bird nests – Vigil should be exercised especially during the nesting season and the nests removed as soon as possible. Over Head Equipments Page 100 9. Pre-monsoon checks: Some of the items to be attended are: i. Checking condition of insulators specially that of section – insulators at major yards having mixed type of traction; ii. Over-line structures for any water leakage on the OHE and PVC insulators at major yards having mixed type of traction. iii. Trimming of trees branches; iv. Condition of embankments with respect to stability of masts; v. Rod gaps. 4.6 Annual Maintenance and Checks by OHE Inspection Car 1. This schedule must be carried out by Inspection Car. During the schedule, fittings are not generally dismantled, but all fittings which are found defective must be replaced. In addition clearances, heights, staggers etc should be checked and corrected. 2. The details of work to be carried out during this schedule are as under:- (a) Mast, portals and cantilever supports: (i) Check rail level and setting distance against markings on the masts and entries in the Register. Variation above 30 mm in setting distance and 20 mm in rail level should be notified to the PWI for correction. Variations even within the above limits, should not be permitted if the Schedule of Dimensions are infringed. (ii) Check all steel parts and remove rust, if any, from painted steel work. Rusted portions, after cleaning, must be given two coats of zinc chromate primer followed by aluminium paint. (iii) Check all anchors for tightness of bolts, nuts and check nuts and pins. Lubricate all turn-buckles / adjusters and pulleys. (iv) Examine the base of each structure to ensure that muffs permit drainage of water. Clean the muffs removing any muck or dirt. Cracked or damaged muffs must be recast. (v) Check all bonds thoroughly. Defective bonds must be rectified and missing bonds provided. (vi) Check and tighten all G.I bolts and nuts. (vii) Check all galvanized pipes and fittings. Where galvanization is found to be chipped off, the fitting of pipe should be replaced. Minor chippings may be repaired using ‘cold galvanizing paint’. (viii) Examine register arm and all hooks and fittings for cracks. Check for cracks on steady arm tube also. (ix) Clean all insulators and carefully check for cracks and broken sheds. If more than 2 sheds are broken or there is any crack on the core the insulator should be replaced. (x) Check and adjust heights and staggers on the basis of setting distance and rail level marked. Close co-ordination with Permanent Way, Inspectors is required for keeping the permanent way at the correct location. (xi) Check presence and condition of caution notice boards, number plates, coasting boards, etc. Paint the boards as required. Ensure that they are all well secured. (xii) Ensure that the drain holes in the tubes are free and not clogged. Over Head Equipments Page 101 (b) Contact and Catenary Wires: (i) Check carefully condition of contact and catenary wires, particularly for links and twists in contact wire and broken strands of catenary wire. Any stranded conductor (catenary wire etc) should be spliced if more than 20 percent of the strands are broken. (ii) Check condition of PG clamps and jumpers after opening the clamps and tighten properly. (c) Droppers (i) Check droppers and tighten bolts wherever required. (ii) Make droppers vertical. (d) Turn outs (i) With OHE inspection Car running on main line check up if pantograph glides smoothly under the loco line OHE. (ii) With OHE inspection Car running on main line check up if pantograph glides smoothly under the man line OHE. (iii) Check stagger of both the OHEs at turn outs. (It shall not normally exceed 300 mm) (iv) Check that the main line OHE of overlap type turn out is about 50mm below that of the turnout OHE. (v) Check up cross contact bar, if any, for displacement and distortion. (vi) Check up rail level and setting of the obligatory mast. (vii) Check up for hard spots near rigid droppers, if any. (e) Section Insulators Assemblies: (i) Clean insulators and replace chipped or cracked insulators. (ii) Check runners for flash-marks, hit marks and proper adjustment. (iii) Check for excessive contact wire wear near anchor clamps. (iv) Check the level of the assembly and adjust if necessary. (v) Tighten PG clamps of droppers and stiffeners. (f) Isolators: (i) Check number plates for cleanliness and security. (ii) Check correctness of operation, alignment of contacts and arcing horns. (iii) Check earth continuity where applicable. (iv) Lubricate moving parts and locks. (v) Check interlocks where provided. (vi) Check that the distance between male and female contacts in open position is 330 mm to 500 mm depending upon the type of isolator. (g) Short Neutral Section Assemblies Carry out all checks as indicated in para 4.13.5 (h) Overlaps (i) Check height and stagger of OHE in the overlap section. Over Head Equipments Page 102 (ii) Check whether the normal minimum clearance of 500 mm is available between the two OHEs in an insulated overlap and 200 mm in an uninsulated overlap. (iii) Check whether the lifting of out-of-run OHE is correct. (iv) Check that parallel running of contact wires in the overlap for a minimum 2m in the panto sweep region. (j) Contact Sire thickness: Measure and record thickness of contact wire. (k) Neutral Sections: Carry out all checks as for an insulated overlap in case of overlap type neutral sections and as for section insulators in the case of section insulators in the case of section insulator type neutral section. (l) Overline structures / Tunnels (i) Check and record horizontal and vertical clearances and adjust OHE as required. (ii) Check for any flash-marks on the under side of the bridge structures. (iii) Check that the prescribed height of contact wire is available. (iv) Check that the gradient of contact wire on either side does not exceed 3mm/m. (v) Check that smoke screens are properly secured and have adequate clearance from OHE, if not, get these attended to by Engineering Department. (vi) In tunnels get necessary repairs done by Engineering Department. (vii) Check rail level mark on sides of tunnels. (m) Level Crossings (i) Check height and gradient of contact wire. (ii) Check condition of road surface and clearance of height gauge (a black band may be marked on the uprights at a distance of 4m from bottom face of the boom to facilitate measurement of clearance). (n) Regulating Equipment (i) Check ‘X’ and ‘Y’ dimensions in the case of pulley block type equipment and ‘Z’ and ‘Y’ dimensions in the case of which type equipment against prescribed values for the temperature at the time of checking. Making use of turn-buckles to adjust as required. (ii) Check that the compensating plate is vertical, if not, adjust as required. (iii) Lubricate pulleys and other moving parts. (iv) Check if 20 mm wide bands in black colour are painted on the mast to indicate upper and lower limits of movement of counter weight. (v) Check condition of stainless steel wire rope for any signs of corrosion and breakage of strands. (vi) Check condition of grooves on the drum of which type regulating equipment. Over Head Equipments Page 103 (o) Bonds & Earthing connection: (i) Check all bonds and replace defective or missing bonds. Paint all bonds. (ii) Inspect earths and record earth resistance. Earths having resistance of over 10 ohm should be attended to. (p) Masts : Check vertically of all masts with plumb-bob and take remedial action as required (q) Sites affected by accidents: Such sites should be specially checked and attended to. (r) Feeder lines: (i) Check guard wires at road crossings, if any. (ii) Check earthing of towers. (iii) Measure and record earthing resistance of towers. (iv) Clean insulators and replace those which are cracked or chipped. (v) Check the jumper connections, strain clamps, PG clamps and bi-metallic strip. (s) PG clamps; (i) Check and clean oxide from surface. (ii) Apply corrosion inhibiting compound. (iii) Tighten to the prescribed torque. 4.7 Integrated Blocks The annual maintenance schedule can best be organized by adopting the system of Integrated Blocks. In this scheme a 3 to 6 km block (Jumbo Block) is taken by introducing single line working in the off peak traffic hours between any two stations. Simultaneous work is carried out by permanent way, single OHE/PSI staff during day light hours. This saves considerable time for taking and returning blocks which forms a sizeable proportion of a short duration block. Effective use of available man-power can also be made by using extra gangs depending upon the nature of work. Such work may be organized for 2 or 3 days a week in selected sections and instructions issued in advance by appropriate planning. 4.8 Re-tensioning of Unregulated OHE The re-tensioning of unregulated OHE in accordance with the tension-temperature chart should be done ordinarily at the end of 6 months from the date of erection and again at the end of 12 months. Thereafter the tension should be checked up once in 2 years and re- tensioning done as required. 4.9 Periodical Overhaul 1. The aim of POH is to recondition and restore the installation in the condition it was when it was first commissioned, whereas preventive maintenance has for its objective to take Over Head Equipments Page 104 care of the wear and tear during normal service and forestalling possible failures by regular inspection and prompt attention. The POH should be thorough and cover every of the installation. The tests to be done at the time of commissioning of new OHE have been detailed in Chapter 8. the work involved during 4 year POH is somewhat greater in scope than the pre- commissioning tests, since after years of service many parts would have suffered wear and tear, of which necessary adjustment will have to be made or repairs dome to make good the wear, or the irreparable items replaced. The POH of OHE should be planned on a programmed basis so that every part of the installation receives detailed attention, repair and overhaul at an interval of 4 years. For programming POH, the entire section in each Division should be divided into smaller sections. POH gangs may be provided with camps at convenient locations so that heavy materials do not have to be carried from depot or sub-depot every day. Gangs can move to the site of work in convenient trains or by other means of transport. As far as possible, gangs for the work should be earmarked so that a uniform standard of is achieved. All POH work should be done under the direct supervision not lower I rank that an ATFO/TFO. To summarize, the object of POH is to make a through inspection of the OHE and to replace such of the worn-out or damaged parts by those which have been reconditioned earlier in the maintenance depots and kept ready. The parts removed are sent to the maintenance depots fro dismantling, through examination, re-conditioning if possible and re-assembly for use again as required. Maintenance charts, prepared in different colours may be made indicating the type of schedule each section has to undergo. The same chart can be used to indicate the progress of work and special works to be done to exercise check over the tasks and targets. 2. In addition to the items detailed under annual maintenance, the following items should be attended to during POH. (a) Masts, portals and cantilever supports: (i) At least one complete cantilever assembly per 10 track-km (this may be modified by CEE if considered necessary) should be removed and taken to the workshop for dismantling and detailed examination of various components after thorough cleaning. This test check would reveal the extent to which other cantilever assemblies have to be examined. (ii) All regulating equipment should be replaced by previously overhauled ones and the removed equipment should be sent to the workshop for overhaul. (iii) As the bracket is articulated, check the position with reference to the axis of the mast. The position will vary with temperature and distance from anti-creep. The register arm and steady arm should as far as possible be in the same plane as the bracket. (iv) Check adjustments of cantilever assemblies, their slope and displacements at every structure for compliance with the ‘as erected’ SEDs. Over Head Equipments Page 105 (b) Catenary and Contact Wires: (i) Dismantle all jumper connections, clean the conductors, (with emery paper in case of copper or bronze conductors and metallic brush in case of aluminium conductors) clips etc. if the pieces show signs of overheating, this may be because either they are not tightened properly or the clips are deformed and contact surface is insufficient. In the latter case, they should be replaced. In case of the contact wire, it is the groove that has to be cleaned with either a fine metallic brush or emery paper. The use of scraper or file is forbidden. Replace frayed or damaged jumpers. (ii) Remove kinks if noticed. (c) Insulated and Uninsulated Overlaps: (i) Check the position of contact wire with respect to tracks to comply with SEDs. (ii) Ensure that insulators of anchoring wires are crossing the plane of OHE in correct position as per plan. (d) Overline Structures: Check the height and gradient of the contact wire and tally the same with ‘as erected’ drawings. (e) Tunnels: (i) Check the height and gradient of the contact wire and adjust as per SED. (ii) 100 per cent OHE fittings in tunnels should be replaced with new or previously over- hauled fittings and the removed fittings taken to the Workshop for detailed examination. (f) Turn outs: Check the height and gradient of the contact wire and adjust as per SED. (g) Overhead Cross-feeders, Return Conductors and 25 kV Feeders: (i) Examine wires for frayed strands, overheating, pinching or corrosion, especially at suspension clamps and PG clamps. Tighten junction sleeves. (ii) While tightening PG clamps ensure that all joints are properly coated with Vaseline. (iii) Check tension in wires and adjust if necessary. (iv) Other overhead wires such as bypass feeders and earth-wires should be inspected. The insulator attachments should be dismantled, overhauled and put back in position. The insulators should be cleaned at the same time. (h) General: (i) During POH, fittings which do not provide prescribed margin of adjustment and proper fitting should be replaced. (ii) All fittings on masts should be checked against “as erected” drawings and any variation should be recorded and reported to Sr. DEE for changing the drawings. (iii) The position of splice should be recorded in the relevant lay out plans. Over Head Equipments Page 106 (i) Work to be done in Workshops: (i) Aluminium bronze fittings, bolts and nuts should be cleaned and carefully examined if necessary with a magnifying glass. Particular care should be taken to see that the threads are in good condition. Fittings which have developed cracks should invariably be discarded. (ii) All G.I fittings and pipes should be examined for deterioration of galvanization. Minor chippings may be repaired by using cold galvanizing paint. (Sand or emery paper should never be used for cleaning). (iii) In case of a major OHE break down, it is advisable to remove the bracket assemblies in about 8 to 10 spans on either side and examine them critically for cracks, twists, bends or other defects which may cause failures later on. (iv) The regulating equipment should be dismantled and every part should be cleaned. Bearings should be fitted back after lubricating. Rubber washers / rings should be replaced where necessary. Any grazing or rubbing on pulleys should either be repaired if possible or the damaged equipment should be replaced. All lubricating holes should be free for passage of grease. The stainless steel rope should be closely examined for damage to the strands. Particular attention should be given to the end fittings on the stainless steel rope. Only approved type of lubricant should be used for regulating equipment components. 4.10 Rehabilitation of OHE Depending upon the condition of the fittings, rehabilitation of the OHE may be undertaken after a period of 20 years. CEE may decide the assemblies to be replaced after a special drive for condition monitoring. 4.11 Transmission Lines 1. General The overhead lines should be inspected periodically to detect any faults and necessary repairs should be done immediately. 2. Patrolling of Overhead Lines from the Ground Patrolling of all overhead lines should be done before and after the monsoon. The frequency of patrolling of the overhead lines for the rest of the periods will depend on local conditions. The patrollers should write the inspection notes and pass them on to the maintenance gang for carrying out repairs. The patrollers should be equipped with inspection books, drawings, tape and binoculars. The main points to be noted while patrolling are as follows: a) Structures:- Learning structures, deformed members, buckled structures, missing fasteners and members; accessories removed, protective coatings like galvanizing or paints disappeared, suspension and strain insulator attachments damaged. b) Foundations – Signs of external damage; settled and washed out soil below normal ground level over foundations within uplift frustum perimeters; titled stubs; cracks or Over Head Equipments Page 107  breaks in chimney top; slippage of stubs from encasing chimney concrete; uneven settlement of footings; disappearance of gravel blanket protection; backfills embankment and its covers (rip-rap of revetment); damage to retaining walls, abutments and breast walls and disappearance of external earth backing retaining walls below designed lines. c) Insulators and Fittings – Damage to insulators, heavy surface pollution, missing locking devices like nuts, washers and pin, burnt out fittings, deflected strings, damage to protective coatings. The cracked insulators, bird droppings, dense spider webs, kites with threads hanging on the insulators string. d) Conductors and Jumpers :- Strands cut and opened up; loose jumpers out of shape and causing infringement of clearance of live wire to earthed metal parts, dead birds, fallen branches or fallen trees on conductors. e) Earthing Equipment:- Damaged, broken or missing earthing strips. f) Right of Way and Clearance – Shrubs and trees within right-of-way causing obstruction and infringement of clearance of bottom conductor to ground; objects within line clearance excavation. In no circumstances, however, clearance measurements should be taken from live line. g) Foreign Objects:- Construction works near lines causing infringement in line safety or electrical clearance; birds nests on structures; use of structure for applying permanent support or pull to other objects; huts newly constructed underneath lines, and embankments / fencing. 3. Inspection of Overhead Lines from Tower Tops Many breakdowns including slipping of conductor due to loose clamps, cracks in insulator porcelain, defects in insulator fittings, conductor, earth wire and accessories and their attachment points on structures can only be dispensed or seen by going on top of every structure. This inspection should be carried out by taking a shutdown of the line at least once in six years. Along with such inspection, repairs should also be carried out. Any replacement as required should also be made. 4. Special and Emergency Inspection A special inspection of the overhead lines should be carried out after severe wind / hall storms, quakes, snowfalls, forest fires, floods or heavy rains. Such inspection should be done after a sabotage too. The purpose of such inspection is to detect any damage or breakage on line and to effect necessary repairs. When an overhead line is subject to fault often, if should be inspected to ascertain the nature of fault, such as too much sag, tree branches touching the line etc and to find out remedial measures required with a view to avoiding their recurrence. 5. Maintenance Tests and Measurements Insulation resistance of line should be measured at convenient interval particularly at the time when the line is shutdown for repairs or maintenance. In regard to Over Head Equipments Page 108  measurements of earth resistance of metal structures, it should normally be carried out annually, however, local circumstances and experience may dictate increase or decrease. In this interval but it should not be less than once in two years. The clearance and shape of the jumpers should be checked at an interval not exceeding 3 years. 6. Line Repairs Tools The following special tools, apart from tools required for maintenance of civil works of the lines, should be kept, handy and in working order: a) Conductor jointing tools b) Bolted come-along clamps c) Winches d) Aerial trolleys e) Aerial rollers f) Thermometers g) Dynamometers h) Level and theodolite i) Measuring tapes j) Linesman’s ratchet 4.12 SCHEDULE OF MONTHLY INSPECTIONS Sl. No. Nature of Inspection Sr. DEE DEE AEE CTPO TPO ATPO 1 Locomotive Cab 1 1 2 2 2 2 2 OHE Inspection Car 1 2 3 4 4 6 3 Push Trolley 1 2 2 4 4 4 4 OHE Depot 1 2 4 4 - - 5 Station 1 1 2 4 4 4 6 Night Inspection - 1 1 2 2 2 7 Office Inspection 1 1 1 1 - - Notes: (i) These inspections are the minimum quantum per month (ii) In respect of Supervisory Staff, the inspections pertain to their respective jurisdiction. (iii) Brief check lists of items to be broadly covered are indicated. Detailed maintenance schedules prescribed should also be kept in view. (iv) Quota of Inspections by HQ officers may be laid down by CEE. Over Head Equipments Page 109 4.13 CHECK LIST FOR INSPECTIONS 4.13.1 OHE Depots & Subordinate Offices a) OHE Depots 1. Staff grievance register. 2. Quarter register. 3. Attendance register. 4. Availability of all drawing (latest), SWRs with latest correction slips. 5. Cleanliness of depot 6. Upkeep of Stores 7. Stock position of stores 8. Upkeep of wiring train, OHE inspection car, ladders, tools etc b) Subordinate office 1. Attendance register. 2. Compliance of audit & account inspection notes. 3. Compliance of Officer’s inspection notes 4. Test & Trail report. 5. Latest drawings & specifications 6. Planning & progress of section works. 4.13.2 Station a) SWR 1. SWRs with latest correction slips. 2. Display of traction working diagram and its correctness at SM room & cabins 3. Traction key Board and key register for its proper maintenance. 4. Knowledge of traction working of SM/ASM on duty. 5. Validity of the competency certificate of SM/ASM b) CLS Board in SM room/cabin. 1. AT standby supply c) Isolator: 1. Locking arrangements. 2. Correct alignment of blade tip in the fixed pole contact jaws. 3. Correct matching & alignment of arcing horns. d) General 1. Fire extinguishers, sand/water buckets, Respiration chart, First Aid Box, Tools and Plants. 2. Working of TPC phones and emergency telephone sockets. 3. History sheets of various equipments. Over Head Equipments Page 110 4.13.3 Cab Inspection a) Condition of OHE 1. Flashed / damaged insulators 2. Displaced fittings & droppers. 3. Balance weight in reference to upper & lower limits marked on masts. 4. Number plates, warning board for rusting and tightness. 5. BT : Oil leakage and deposits of pollutants on insulators. 6. AT : Oil leakage and deposits of pollutants on insulators. b) Obstruction to OHE 1. Birds nests 2. Tree branches near OHE c) Cab equipments 1. Emergency telephone 2. Focussing of head lights & flasher lights 3. Voltage on loco voltmeter at FP & SP locations. d) Driving technique of Driver 1. Exchange of signals with station staff 2. DJ opening & closing at neutral section 3. Observation of caution orders. e) Night Inspection 1. Incidence of sparking from the rear cab of locomotive 2. Other items as above. 4.13.4 Push Trolley Inspection a) Masts: 1. Implantation at selective locations. 2. Deflection of mast, on leading mast. 3. Areas affected by accident 4. RC to rail connection for any loose connection. 5. Connection bonds and earthing connection 6. Number plate 7. Muffing b) OHE fittings: 1. The isolator blade is fully in and also for signs of sparking or overheating. 2. Insulators for any chipping / flash marks / damages. 3. Displaced fittings & droppers. 4. Application of silicon grease on insulators. 5. Birds nests, stray wire pieces and tree branches likely to infringe the OHE. 6. Free movement and position of counter weight with reference to upper and lower limits marked or the mast. Over Head Equipments Page 111 c) L.C. Gate & over line structures 1. Protective screens at FOB/ROB 2. Height gauges at level crossings and height. d) Booster Transformer & Auxiliary Transformer 1. Oil level and leakage of oil. 2. Anticlimbing devices. 3. Jumper connections 4. Earthing 5. Fuses on ATs. 6. Colour of Silica gel e) General 1. Signs of heavy sparking on OHE when train passes. 2. General condition of switching stations enroute. 3. Emergency telephone sockets at important locations. 4.13.5 Inspection with OHE Inspection Car a) Mast, portals and cantilever supports. 1. Structures and galvanized tubes for rust & chipping off galvanization 2. Cracks on steady arm & register arm. b) Contact & Catenary wires 1. Kinks & twists on contact wire 2. Broken strands on catenary wire. 3. PG clamps, jumpers. 4. Contact wire wear at selected locations. 5. Height and stagger at selected locations. c) Section Insulators 1. Flash or hit marks on and adjustment of runners. 2. Level of assembly & alignment 3. Chipped / cracked insulator. d) Turn-out 1. Stagger of both the OHEs. 2. With inspection Car running on loop line, check up if the main line OHE passes smoothly under the pantograph. 3. With inspection car running on main line, check up if the loop OHE passes smoothly under the pantograph. e) Overlaps: 1. Height and stagger of OHE in the overlap section. 2. Whether normal minimum clearance of 500 mm is available between the two OHEs in an insulated overlap and 200 mm in the case of uninsulated overlap. 3. Check up whether lifting of out-of run contact wire is correct. Over Head Equipments Page 112 f) Overline structures 1. Horizontal & vertical clearances 2. Flash marks underside of the structures. 3. Gradient of contact wire on either side. 4. Insulation on catenary wire under the structure. g) Level Crossings 1. Height & gradient of contact wire h) Regulating Equipment 1. X-Y and Z-Y values with temperature. 2. Free movement of drum. 3. Lubrication of pulley and other moving parts. 4. Stainless Steel wire rope for opening of strands, broken or rusted strands. 4.14 Regulating Equipment 1. There are three types of regulating equipment in use at present viz. the winch type, pulley block type and 3 pulley type. With all the three types of equipment the chief task of maintenance is to ensure that the counter weight is free to move up and down in the guides without any chafting or obstruction. If the movement of the counterweight is obstructed, the tension of the OHE will not be correctly regulated resulting in poor current collection. The counterweight should not come down so low so as to touch the muffing in summer, nor should it strike the guide fixture at the top during winter. During yearly maintenance of the pulley block type of equipment dimension ‘X’ (i.e., the distance between in centres of the movable and fixed pulleys) and ‘Y’ (i.e., the distance between the bottom of the counterweight and the top of the muffing) should be checked against prescribed values and adjusted as required according to the tension length of the OHE and prevailing temperature. Small adjustments can be affected by using the adjuster provided. In the event of appreciable stretching of the contact and catenary wires at the terminations to get correct alignment and adjustment. In the winch type equipment, corresponding to dimension ‘X’ in the pulley block type dimension ‘Z’ i.e., the distance between the centres of the movable pulley and the winch drum is required to be measured. To facilitate checking, the position of the bottom of the counterweight corresponding to the lowest and highest temperature should be marked on the masts by means of black bands of width 20 mm. The position of the counterweight at ambient temperature of 35°C may be marked by a red band which can be seen during trolley inspection readily. The bottom of counter weight should coincide with the band mark. 2. The usual defects to be looked for in the pulley block type of equipment are:- a) damage to pulley grooves by the stainless steel rope due to misalignment of the equipment and the catenary wire being not vertically above the contact wire at the termination. b) Seizing of the needle bearings due to drying up of lubricant and consequent jamming of the pulley c) Jamming of guide pulley due to lack of lubrication and consequent grooving of the pulley. This can be checked by pushing up the counter weight and allowing it to descend due to its own weight. Over Head Equipments Page 113  d) Damage to neoprene washers provided between pulleys resulting in ingress of dirt and water into the needle bearings. e) Bent slidings rods obstructing the movement of the movable pulley. f) Blocking of grease nipples. These defects except for replacement of the guide pulley and attention to clocked grease nipples are not capable of being attended to in-situ. The complete equipment should be replaced with a spare one and the removed equipment taken to the workshop for attention. The main pulley and guide pulley bearings of the pulley block type equipment should be lubricated using approved type of grease which will be able to withstand 60°C without drying. Another important check required for the pulley block type equipment is to see that the stop nuts provided at the end of the guide rods are intact. These are provided to prevent the movable pulley coming off the guide rods in the event of breakage of the stainless steel rope. 3. The common defects to be looked for in the winch type equipment are: a) Over-riding of stainless steel rope and grazing of grooves, b) Breakage of strands of stainless steel wire rope, c) Seizure of pulley bearing, d) Tilting of anti-falling device. Stainless steel ropes should be examined periodically with a magnifying glass for pitting and other signs of corrosion. Regulating equipments should be checked periodically for free movement with the help of a spring balance. If pull required for a visible movement of counter-weight exceeds 10 kgs, the regulating equipment should be overhauled. Whenever a panto/ OHE entanglement takes place the regulating equipments of all the concerned OHEs should be checked thoroughly, particularly if any of them was overhauled more than two years earlier. Until such time a grease capable of retaining the properties for 4 years becomes available, all regulating equipments should be overhauled every two years. Priority should be given to those which cover the more vulnerable locations. During overhaul of regulating equipment special attention should be paid to the shape and dimensions of the winch frame arms (right and left) as they have a direct influence on the angle of incidence of the stainless steel wire rope on the winch drum. Whenever a regulating equipment is dismantled, the condition of the bearing grease should be checked. If it is found to have lost its oil content and exhibits the consistency of hard soap, the source and type of grease used initially should be investigated. The condition of rubber or felt seals provided to prevent the ingress of water into bearings should be checked and if they have deteriorated, the quality and source should be investigated and remedial steps taken. All seals should invariably be replaced during periodical overhaul unless their condition is found to be good enough to work satisfactorily for another four years. Over Head Equipments Page 114 4. Most of the points mentioned above are also applicable to pulley type regulating equipment which is now standard. 4.15.2 OHE Inspection Car (Tower Wagon) 1. OHE Inspection Car has a key role in the maintenance of OHE and for attending to break-downs. The satisfactory unkeep of the car is, therefore, of utmost importance. ATFO (OHE) should ensure that the car under his control is maintained satisfactorily and is available at all times for attending to OHE and for use in the event of break-downs. Each car should carry necessary tools for maintenance of OHE and attending to break-downs, such as tackles, straining screws, clamps, ropes, a minimum of two ladders as well as an adequate stock of insulators, lengths of contact and catenary wires and other OHE fittings. An approved list of tools and equipment to be carried in each car should be issued by DEE (TrD). ATFO (OHE) should ensure that tools and equipments as per the approved list are always available in the car. 2. A monthly mechanical inspection of the bogies and running gear of each car shall be done by a nominated TXR of the Mechanical Department, headquartered close to the OHE depot where the car is normally stabled. For each car on a zonal Railway, the TXR responsible for monthly mechanical inspection will be nominated and a joint circular to this effect issued by CME and CEE laying down his duties. The ATFO (OHE) in charge of the car will advise the TXR concerned the date on which it is required to be inspected and running repairs carried out. Such advise shall be given at least 48 hr in advance. ATFO (OHE) should ensure that this monthly advice is issued regularly and the car is offered for inspection and attended to every month. The TXR will arrange for examination of bogies, running gear, underframe, under-gear fittings and axle boxes only, in accordance with IRCA rules, Part III. He will also arrange for stenciling the date of monthly examination on the sole bar of the car. The POH of the car shall be done at an interval of 3 years in an EMU shop / electric loco shed / Elec. workshop, as decided by CEE. (Ref. Board’s Letter No. 84/Elec/140/4 Vol. 1 dt. 1.3.90). 3. The day-to-day maintenance of the diesel engines and driving gear of the car will be the responsibility of the ATFO (OHE) concerned. The OHE inspection car Drives should carry out the daily maintenance. Specialist staff conversant with the maintenance and overhaul of diesel engines and driving gear should be available on each division for attending to monthly and six monthly maintenance of the diesel engines and driving gear. If it is more convenient and depending upto the work load, two or three Divisions may be grouped together for the purpose of posting such specialist staff. 4. Taking into account the total number of OHE inspection cars and the need for relief of such cars for purpose of POH etc. In each Zonal Railway, one or more pare OHE inspection cars may be provided as necessary. Over Head Equipments Page 115 4.16 Salient Features of OHE Inspection Cars The salient features of the OHE inspections cars presently in use of on Indian Railways are as under:- 1. Mark II 4 wheeler manufactured by Kanchrapara Workshop / E.Rly. i. Diesel Engine - 83 HP (Simpson make) ii. Axle load - 6.8 tonnes iii. Pay load - 3 tonnes iv. Speed Potential - 40 km/h. v. Transmission - Gear box system vi. Brake system - Vacuum 2. Mark III 4 wheeler manufactured by Jamalpur Workshop / E.Rly. i. Diesel Engine - 185 HP ii. Axle load - 16 tonnes iii. Speed Potential - 75 km/h. iv. Transmission - Hydraulic / Hydro-mechanical v. Brake system - Compressed Air Brakes 3. OHE Inspection Car – 8 wheeler i. Diesel Engine - single 530 HP or twin 285 HP ii. Transmission - Volth’s Hydraulic iii. Axle load - 16 tonnes iv. Pay load - 10 tonnes v. Speed Potential - 110 km/h on level tangent track - 30-40 km/h on 1 in 60t rising gradient while hauling a loaded bogie flat wagon of 60t. vi. Brake system - Compressed Air Brakes vii. Paying out facility on one drum each of contact and catenary wires. viii. Small workshop fitted with drilling machine etc. ix. Two staff cabins with toilet. x. A small kitchenette, storage space for tools, spares and traction masts etc. xi. Adjustable lifting and swiveling platform. xii. Observation dome - To watch pantograph and contact wire interaction during motion. 4.17 Rules for Operation of OHE Inspection Car 1. General (i) Authorization: No OHE inspection car may be operated by any person unless he is specifically authorized to do so after he has been trained and examined for his knowledge of the rules prescribed. (ii) Scope The following rules shall govern the working of an OHE inspection car fitted with a pantograph for the purpose of inspection of OHE either during commissioning of completed Over Head Equipments Page 116 sections of OHE or during periodical inspections carried out by the OHE Inspection Car maintenance staff. All staff in-charge of operation of OHE Inspection Car shall make themselves fully conversant with and act according to the special instructions given below. (iii) Movement The movement of OHE Inspection Cars on tracks will be governed by all the rules governing movement of trains. (iv) Driving i) OHE Inspection Car shall be driven only by an authorized person, and no person shall be so authorized unless he has knowledge of the section (Road and Signals) on which the Car is to operate and is conversant with the operation and maintenance of car. He should also be in possession of competency certificate for the purpose. ii) The OHE Inspection Car shall be driven at a speed not exceeding 10 km/h when checking contact wire level and stagger. This shall be done by running on the first gear. Riding on the clutch for this purpose is prohibited. iii) If the OHE Inspection Car is driven for other than recording operations, the speed should not exceed the designed speed subject to the speed restrictions imposed in the section. iv) In every depot, at least two OHE staff shall be trained and issued with competency certificate to drive an OHE Inspection Car in the event of an emergency. 3. Pantograph Operation i) The pantograph mounted on the roof of the OHE Inspection Car is electrically bonded to the underframe by means of a cable connection. This cable connection should be checked before starting any operation for checking and adjustment of OHE. ii) The pantograph should normally be kept in the fully lowered position and clamped securely by means of the special clamp provided for the purpose. No string, cord etc shall be used for this purpose. iii) Before any person goes up to the roof of the OHE Inspection Car for commencing Inspection and adjustment, the section of the OHE concerned shall be made dead and earthed on either sides. Additional earths shall be provided where necessary. After earthing the OHE, an additional earth shall be provided near the OHE Inspection Car on the OHE of the track on which it is standing. An authorized person not lower in rank than a linesman shall then go up on the roof and remove the clamps to release the pantograph. iv) Under no circumstances should the OHE Inspection Car be worked with the pantograph raised without an earth on either side of it on the section of the OHE in which it is to be worked. v) In order to ensure that the pantograph does not enter a section where the OHE is live the OHE Inspection Car shall be protected on both the sides with banner flags and other signal flags. The driver shall always stop the OHE Inspection Car ahead of all turn outs, cross- overs, insulated overlaps and section insulators first and then proceed only after ensuring that the section ahead is dead and earthed. Banner flags then be removed for the purpose of admitting the OHE Inspection Car into the section ahead. Over Head Equipments Page 117 vi) At the end of the inspection and checking, the pantograph shall be lowered and clamped by an authorized person not lower in rank than a linesman working on the roof after earthing the OHE of the track on which the OHE Inspection Car operating. The earths on the OHE near the OHE Inspection Car shall then be removed after all persons working on the roof have come down. 4. Operation of Lifting and Swiveling Platform i. The lifting and swiveling platform shall ordinarily lie in the fully lowered position along the length of the OHE Inspection Car. ii. The swiveling platform shall be raised or lowered only when the OHE Inspection Car is stationary. iii. The platform shall be moved out of the normal position only when the OHE Inspection Car is stationary. iv. The OHE Inspection Car shall be moved only after the platform has been put back in the normal position. v. If the OHE Inspection Car is to be moved with the platform raised, it may be done at a speed not exceeding 5 km/h. Over Head Equipments Page 118