1.0 OHE Maintenance Depots

1.1 In the overall interest of minimum capital and recurring costs with electric traction, the number of OHE maintenance depots need be optimized. The general conditions that govern the location and the spacing of the OHE maintenance depots are as under:-

(i) The total equipped track kilometres to be maintained by each depot;

(ii) Beat of the depot on either side;

(iii) Traffic density obtained on the section and the time factor in reaching the farthest point;

(iv) The proximity of major yards with considerable equipped track kilometres;

(v) Availability of educational, medical and other infrastructure facilities in the vicinity.

1.2 The total staff required for OHE maintenance for a given section is arrived at, based on the prevalent yardsticks for maintenance and the schedules of maintenance laid down for various equipments. The total staff is distributed amongst the maintenance requirements of OHE under their respective jurisdictions. The .staff requirement for the maintenance as per the yardstick is in no way linked with the number of OHE Depots in a particular sections.

1.3 The total equipped track kilometres normally assigned for maintenance to a single OHE depot should be at least 150 track kilometres which amounts to 250 to 300 EETKMs (Electrical Equated Track km) to ensure that the installations to be maintained by a single depot do not become unwieldy. On a normal double line section this would work out to a spacing of 60 RKMs between successive OHE maintenance depots. In the case of depots in the vicinity of terminal/major yards (having large wired Tkm.), the spacing would correspondingly get reduced. In view of the concentration of work load in major yards, it will be necessary to locate maintenance depots in or around the vicinity of the major yards.

1.4 The beat of the depot on either side should not normally exceed four block sections (occasionally five) so as to ensure quick transportation of staff to the breakdown spot even if it happens at the farthest end of the jurisdiction of the depot.

1.5 The location of the depot should be such that reasonable educational and medical facilities are available at the place as otherwise the staff would be generally reluctant to stay at such a place.

1.6 The standard lay-outs of OHE depots have undergone several changes over a period of time, with varied concepts like major depots, minor depots etc. emerging to meet specific requirements. The essential difference between major and minor depot is the provision of a tower wagon with its shed and associated track connections and OHE Depot Workshop in a major depot.

1.7 The standard OHE maintenance depot need only be provided with a drilling machine, bench grinder etc. be standard layout of OHE depot with workshop is shown at Fig. A6.01, the schematic layout of Divisional Repair
shop to be provided as an adjunct to one of the OHE depots is shown at Fig. A6.02.

1.8 Secondary activities/facilities in OHE maintenance depots, such as smithy, carpentry, welding etc. can be provided at a central plan either at the Divisional Headquarters or at one of the maintenance depots, depending upon convenience of location. Such a facility will have standard workshop equipments, such as lathe, hacksaw cutting machine, welding set, vertical drilling machine etc. Alongwith the above, a store can be provided where large quantities of OHE materials which are required for major breakdowns for the entire section can be stored, relieving the other maintenance depots from the responsibility of storing large quantities of materials which are required only occasionally. This would also increase the utilization of staff such as welders, black smiths, carpenters, and incidentally is likely to result in overall savings of the staff in the ancillary categories and equipments.

2.0 PSI Maintenance Depots

2.1 Besides the OHE maintenance depots, PSI maintenance depots are provided for maintaining the various power supply equipments installed at traction substations, switching stations, booster transformer stations, auxiliary transformer stations etc. It is advantageous to locate the PSI maintenance depot alongwith the OHE maintenance depot so as to achieve some economy in requirements of T & P, transport and other infrastructural facilities. 

2.2 Normally the average spacing between traction substations is 60/70 km. On trunk routes with high traffic densities, where operation of 45001 trains is to be catered for, sub-stations are provided at reduced spacing of 40 to 45 km. With PSI depots spaced at 60/70 km., each depot will be called upon to maintain one or two traction sub-station and 5 to 6 switching stations, besides booster transformer and auxiliary transformer installations on the sections. A sketch showing the suggested layout for a PSI maintenance depot is shown at Fig A6.03.

2.3 If a Zonal Repair Shop is provided, necessity of transporting the equipments to the PSI depot may not arise. It is desirable and feasible to give all attention that is required for day-to-day maintenance of the equipments at site. For any major attention such as oil circulation of the breakers/auxiliary transformers, booster transformers, interrupters, etc. the equipment can be transported to the nearest traction sub-station, where power supply is available from the 100 kVA auxiliary transformer for working of the oil filtration plant. This results in minimum transportation of these equipments. Major repairs, which cannot be done at the sub-station, should be done only at the Zonal Repair Shop.

2.4 By combining the OHE and PSI depots, the OHE transport facility can be conveniently utilized for PSI work

as well. A common depot will be cheaper with a common compound wall and security arrangements. Better coordination and supervision can be obtained between OHE and PSI maintenance staff if both the depots are located together. It is likely to result in faster attention to breakdowns. In addition, it would be desirable to have this combined OHE/PSI maintenance depot at a station where traction sub-station is also located, wherever it is feasible, as PSI maintenance work is more concentrated at a traction sub-station.

2.5 Keeping in view the set up outlined above, it should be possible to locate the PSI depots at alternate OHE depots (instead of locating the same at each and every OHE depot). This would enable a minimum complement of PSI staff both supervisory and others at each of the PSI depots.

3.0 Scale of T&P for OHE Depots 

3.1 The list of T & P items to be procured by R.E. for OHE maintenance given at Annexure A6.01. This annexure also lists the items to be procured by R.E. for equipping each of the tower wagons as well as the break-down train.

3.2 The T&P recommended to be procured by R.E. for PSI maintenance is given at Annexure A6.02.

3.3 In addition, the T&P recommended to be procured by R.E. for Divisional Repair Shop for OHE is given at Annexure A6.03. Likewise, the T & P to be procured by R.E. for Divisional Repair Shop for PSI is given at Annexure A6.04.

3.4 The office furniture to be supplied by R.E. for field offices and depots is shown at Annexure A6.05.

3.5 Besides the above, it is felt that general user items of T & P can be procured by the Open Line and need not be provided by R.E. A list of such items is given at Annexure A6.06.

4.0 Transport Facilities for Maintenance Including Breakdown Attention

4.1 At present each major OHE Depot is provided with one heavy duty motor truck and one 4-wheeler OHE Inspection Car. These transport vehicles are adequate for attending to breakdowns and for normal day-to-day maintenance. For push trolley inspections of OHE by supervisors and officers, each OHE depot is to be provided with one push trolley. One Jeep with trailer is to be provided for each field officer at his headquarters. One motor trolley is to be provided for each station where an OHE officer is headquartered.

4.2 One wiring-cum-breakdown train is to be provided for each Division to meet any major OHE breakdowns which require wiring of OHE.

4.3 Transport facilities recommended for TRD maintenance are summarized at Annexure A6.07.

4.4 On sections with higher traffic density, eight wheeler high speed tower wagons would enable quicker transportation of men and materials to the site. With increased emphasis on quick restoration after accident, quicker attention to OHE breakdowns is called for to provide early restoration of OHE power supply.

                                                                                                                          Annexure A6.C 1 

                          T&P Items to be Procured by R.E. for OHE Maintenance Organization

                                                                                                                 Annexure A6.O2 

T&P for PSI Depots to be Supplied by R.E. Organization

                                                                                                                                           Annexure A6.03

T&P to be Procured by R.E. for Divisional Repair Shop (OHE)

                                                                                                                              Annexure A6.04

T&P to be Procured by R.E. for Divisional Repair Shop (PSI)

                                                                                                                         Annexure A6.05

Furniture to be Supplied by R.E. for OHE and PSI

                                                                                                                                 Annexure A6.06

T&P Items to be Procured by Maintenance Organisation for OHE/PSI

                                                                                                                                              Annexure A6.07

Transport Facilities for TRD Maintenance