MAINTENANCE FACILITIES

Q – Which factors are considered for deciding about the creation of a new Diesel Shed? How would you select the site for construction of a Diesel Shed?

Requirement of a new diesel shed should be based on the following points –

Working out total requirement of locomotives. Requirement of locomotives is worked out on taking into consideration the future growth of passenger and freight traffic and length of addition section / track being added on the Railway. Power plan for each division is made considering the future traffic growth for next six months and can be helpful in calculating the loco requirement. As a thumb rule, one loco is required for every 5 Km on single line and foe every 3 Km on a double line.

Calculate total loco holding as well as loco holding capacity of various diesel sheds of the Railway.

Compare total loco requirement with loco holding as well loco holding capacity and calculate the net deficiency or surplus. Global view should be taken for this comparison.

If the total loco requirement is more than the loco holding of a particular railway, then first check the holding capacity and whether there is a scope for homing additional locos or not. If spare holding capacity is sufficient, there is no need for a new diesel shed. But if the spare holding capacity is not commensurate with the additional loco requirement and the berthing capacity of existing diesel sheds can be increased, then sheds should be expanded to take care of additional requirement. However in absence of any scope for further expansion of sheds, construction a new diesel shed can be though of.

While deciding about the diesel shed, distance of the nearest existing diesel shed from the farthest point should also be taken into consideration.

Electrification of the route in near future is also an important factor for deciding about the construction of a new diesel shed.

Once it is decided to set up a new diesel shed, following factors to be considered for the selection of the site –

Availability of land and its cost. Transport facilities, accessibility through road, rail and other modes. Availability of power and its cost. Communication facilities and its linkage with other cities. Educational facilities – Adequate schools, Medium of instruction, Quality of

education, etc. Housing facilities. Ancillary units and industrial development. Human Resources – Availability of local staff, willing trained staff to be posted

there, etc. Distance from farthest point of the section, where locos are to be provided. Will it

be easier to pay attention to the isolated sections? Vicinity to other diesel sheds. Ease of maintenance – Weather / climatic conditions, distance from main city, etc. External threats – Flood prone areas, seismic zone, terrorist threats, general law

and order situation, etc. Other related activities based at the proposed place like coaching / freight

maintenance depot, crew changing point, terminal section, yard operation, relief equipments, etc.

Scope for any future expansion.

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Q – What are the various factors considered while deciding the lay out of a diesel shed homing 100 diesel locos? What point should be considered while constructing the shed? Explain with a sketch various service facilities provided in diesel shed. What are various M&P items required in the shed?

Following factors may be considered while finalizing the shed lay out –

A unidirectional movement of locomotive in the shed is preferable. Separate entrance and exit points should be provided to a avoid bottlenecks. The layout should permit a locomotive to skip stage of servicing without

hampering the flow of other locomotives. The shed should have covered accommodation in its repair area for about 25-

30% of the fleet homed. The yard of the maintenance shed should be able to hold at a time about 50% of the total holding of the shed.

Each line in the covered repair area of the shed should be able to hold 3 locomotives. The lay out should provide for possibility of expansion width-wise i.e. by providing more lines side by side. Expansion along the length of the running lines should not be adopted.

The work area in the shed should be divided into two distinct portions, one dealing with servicing and light maintenance and the other with heavy repairs. Facilities should be provided in the same sequence in which an incoming locomotive is to be attended to.

Following points should be considered while constructing a shed –

A 3-level working floor arrangement should be provided. The rail level in the repair area is the same as the general shed floor level. The depressed floor area out side the rails is kept lower than the shed floor level so as to be able to attend effectively to the bogies and under-gear. The point level between the rails is kept still lower to enable proper examination of under-gearing. Above the depressed floor level, a platform level is provided, which is at the same height as the locomotive floor. To attend to all the components of the locomotives above the under frame. Ramps or steps should be provided to conveniently connect the three working levels with the general floor level in the shed.

Flooring should be easily washable so that split oil can be effectively removed. All flooring should be finished with a hard top to withstand abrasion resulting from handling of heavy parts and movement of material trollies etc. Wooden flooring is not recommended. Concrete flooring is acceptable.

Flooring is the heavy lifting bays of the shed should be adequately strengthened. Special reinforcement is required in the location where heavy duty high lift jacks are installed.

To minimise cracking and to facilitate repairs flooring should be divided into rectangular panels, with sides not exceeding 2 meters, using dividing strips.

The platform and ramps as also steps should be protected with steel or cost iron edging of non-skidding type.

Pits should have convex flooring and efficient drainage. Stilt arrangement consisting of steel beam on stub columns should be flowed, so far as possible for supporting track in the pits, since it permits better lighting and ventilation of pits.

The edge of the elevated platform should be suitably raised to provide a rim to prevent tools and materials from rolling off. This also reduces the possibility of men slipping at the edge.

The minimise the dust nuisance in working areas, a length of approximately 30 meters beyond the cover area should be paved.

A uniform roof height should be preferably adopted for all bays to enable convenient construction and dispersion natural light. The minimum height is governed by the requirement of heavy lifting bay.

The roof should be of a construction that caters for maximum natural light in working area. Translucent corrugated sheets suitably arranged in “pepper-pot” form.

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Roof extractors and exhaust fans should be provided at suitable locations to remove smoke and fumes.

Fabrication of roof structure by welding is preferable in order to conserve steel. The repair area in the shed should be made as dust proof as possible. All large

should be provided with rolling or other type of shutters. Suitable provision should be made while laying out end columns of bays, which

may require to be extended at a later date, so that minimum alteration are required to be structure and the foundation.

To protect personnel working on the elevated platform from falling down, when the line is not occupied by a locomotive, chain guards should be provided. These be fixed in such a manner near the edge of the platform that they can be removed easily when a locomotive is placed alongside.

Servicing facilities –

Following service facilities should be provided in a diesel shed for smooth and efficient functioning –

1) Washing and cleaning – A washing apron and pit laid with concrete and provided with good drainage, suitable hydrant points and adequate supply of water should be located well away from the shed building to clean the under-gearing and body of the locomotives. Manual washing with brushes (fitted with long handle) IS RECOMMENDED FOR SMALL SHED. Automatic washers, with mechanised sprays, brushes etc. can be justified only for very big running sheds with large number of locomotives. Hose and nozzle arrangement for spraying the under-gearing with water under pressure will ensure proper removal of grease and oil from the chassis. Provision of a boiler to give a steam jet will be an additional help.

2) Fuel supply installation – For fuelling the locomotives.3) Lubricating oil storage and dispensing system.4) Cooling water treatment and dispensing – Diesel engine water should be

treated in accordance with maintenance instructions laid down for different classes of locomotives. The most widely used treatment is that with chromate.

5) Repair Area – The repair are of the shed is generally divided into two parts – (i) Light repair bay (ii) Heavy repair bay including overhauling sections for various sub-assemblies.

All the major schedules upto half yearly are carried out in light repair bay. This area is further divided into two parts – Mail loco repair bay and goods section including Quarterly and HY schedule.

In the sub-assembly overhauling area, separate areas should be demarcated for specialised repair groups such as –

Diesel Engine Electric rotating machine Cyl. Head, piston, connecting rod, etc. Turbo Expressor Governor Fuel injection room Cooling equipment and radiator Brake equipment and valves Pump, shafts, gears etc Speedometer, gauges etc Under-gearing components Electrical test room including Excitation cards, BKT, reversor, etc. Filter cleaning Small motors Dynamic balancing Air Brake Gasket Room Millright section

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Fitter benches should be suitably provided in each of the demarcated areas. For ease of handling during repairs, suitable hoists and chain pulley blocks etc.

should be provided. Special stands and carriers etc. for different components should be provided in

the different repair areas. For example connecting rod and piston assemblies removal from the engine should be stacked on a rack with the connecting rods suspended from the gudgeon pins. Special holding trays etc. should similarly be provided for bearing shells, fuel injection nozzle etc.

6) Shed building – The shed building, besides providing for the repair area, machine shop etc., should accommodate the following –

Battery charging and storage room – preferably at one end of the shed building, where fumes and gases can be easily exhausted to the atmosphere.

Instrument repair and testing room Fuel injection repair and testing room Engine governor repair and testing room Brake testing room Flaw detector room (Magnetic and Zyglo etc) Filter storage Tool room Lockers and washing room Laboratory Driver’s lobby and lockers Booking office Supervisors’ office room Shed officers’ room Office room and record room Library Lecture and meeting room Fire fighting equipments RPF post Load box room Pit wheel area.

7) Shed stores –

The shed stores should have approach by both rail as well as road. The approaches should not interfere with other movements in the maintenance shed.

Proper bins and racks should be provided for storage and handling of components, to avoid damage during handling and in storage.

Adequate lifting facilities should be provided for handling heavy components. Use of forks lift trucks for this purpose is preferable.

Special provision should be made for storage of rubber components since these are subject to deformation if not properly stacked and to ageing in the presence of air and due to effect of temperature.

While designing store building, due regard should be paid to the fire fighting precautions.

To reduce material handling to a minimum and same time, small components frequently required should be stocked at platform level near work areas. Heavier components such as brake-shoes etc. can be conveniently stored at the depressed floor level.

8) Lifting and material handling facilities – Overhead cranes of suitable capacity should be provided to serve heavy

repairs area, free floor space, a part of the machine shop and stores. Crane capacity should be sufficient to lift the heaviest single repair able component or assembly.

Heavy duty high lift electrically operated jacks may be provided at suitable location in the heavy repair area for lifting the locomotive. It should be possible to alter spacing of the jacks to suit locomotives having different spacing of lifting pads.

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Hoists should be provided at all suitable work locations. Wherever it is possible to provide these facilities and dispense with overhead cranes, the shed structure can be made lighter.

Hand carts and trolleys should be used for movements of components. Fork lift truck should also be provided in large maintenance sheds.

9) Illumination – Good illumination is necessary for efficient repair work. In the repair area

fluorescent light or mercury vapour lamps giving an even illumination of atleast 200 lux at platform and floor levels should be provided.

Pits should be provided with bulk head fittings for direct lighting of the under-gear of the locomotive. Here also minimum illumination level of 200 lux is necessary.

Low voltage plug points should be provided at all work areas, including the pits, for use of portable hand lamps with flexible leads. Moveable trolleys with provision of swivelling light can be an alternative to fixed pit lights.

10) Auxiliary Building – A small shed should be provided in the vicinity of the main shed building for

stabilising spare wheels and bogies. A 3-tonne gantry should serve the stabling line and the next to it for proper loading and un-loading of the wheels.

Under-floor type of wheel lathe should be provided in a large maintenance shed for in-situ re-profiling of worn locomotives wheels. A separate shed for the under-floor wheel lathe is preferable.

A load-box for testing a locomotive under power should be provided in every home shed. This applies to shed handling only diesel-electric locomotives.

11) Compressed Air – Air compressor should be installed in a place where minimum disturbance due to vibrations and noise is caused to the surrounding. A separate compressor room is recommended out side the main shed building. Compressed air pipe lines should be laid so as to reach all working areas and adequate number of points should be provided to tap the air supply. The layout should permit provision of additional tapping points at a later date near locations such as machine shop, fitter repair benches, blacksmith shop etc.

12) Laboratories – In every diesel locomotives maintenance shed, it is essential to have a well equipped laboratory to exercise control on lubricating oil, fuel oil and cooling water. The laboratory is also helpful in carrying out metallurgical and chemical inspection of parts and supplies received in the shed. Following major equipments are necessary in the laboratory –

Spectrograph for lube oil testing Magnaflux testing machine Rubber tensile testing machine Zyglo testing machine Oscilloscope Ultra sonic testing machine

13)Cleaning and washing – Keeping the equipment clean goes a long way in ensuring trouble free operation and long equipment life. Suitable cleaning and washing facilities are, therefore, absolutely necessary in every shed.

Cleaning of components immediately after their disassembly is necessary, before any inspection or repair can be undertaken. Degreasing and cleaning facilities whether of the vapour type or hot bath or spray-jet type are required in every shed. Wherever justified mechanised cleaning equipment should be provided.

Special cleaning plants are required for turbocharger, after coolers, oil heat exchangers, radiators, piston assembly, carbody filters, etc.

14) Shed offices – Offices for supervisors should be located near their place of work. This

ensure effective and constant supervision of the repair work. The driver’s booking office and lobby should be located near the point

where the locomotives are inspection and prepared for despatch. The General Administration and other office should provide for meeting

room.

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15) Plant and equipment – A list of machinery and plant required in maintenance sheds of different sizes is given below –

EOT Cranes 40 tons & 10 tons. Whiting jacks – 1 set of 5 jacks. Tram beam 3 ton cranes – 6 Pillar cranes with 1.5/1 to hoists – 16 Forklift truck (2 T) – 2 Platform truck (2 T) – 5 Pick up van – 2 Truck 3 Tons – 1 Monorail with hoist for battery room, heavy switch gear and piston

assembly. Hoist (100 Kg) for governor, heavy switch gear. Under floor wheel lathe Lathes – 5 Shaping machine and drilling machine Valve seat grinding and tool grinders Lap master Testing and calibrating equipments fro various sub-assemblies Carbody filter plant Welding plants Cordless drills, grinders, etc Dynamic balancing machine Spray painting equipment Hydraulic jacks – 4 Water and grid load box.Every shed should be provided with equipment required for testing and calibrating various tools, machines and fixture used in repair work.

16) Fire fighting – Adequate safety measures must be adopted against fire hazards in the shed. Since large volumes of petroleum products are handled, special precautions are necessary. Fire fighting equipment such as hydrants, hoses, extinguishers and fire alarm boxes etc. should be conspicuously visible both at day and at night.

17) Training school – For proper maintenance of the sophisticated equipment on diesel locomotives, the work force has to be adequately trained. Each large shed should, therefore, include a training school for imparting theoretical and practical training to various categories of staff. Provision of a hostel attached to the training school is necessary. The training school should be provided with a library with sufficient books and technical literature and audio visual aid for training. Model room in the training school should display cut-way models and working models of as many components as possible.

18) Staff Amenities – Toilet and washing facilities and water coolers should be available both inside

the shed building and for the use of office staff. Adequate precautions are necessary against dermatitis amongst workers

handling fuel oil, lubricants, chromates etc. Suitable cleaning agents and ample washing facilities in the vicinity of areas where these products are handled are necessary. Use of hand protection cream before staring work and non-irritant cleaning soaps after completion of work should be enforced.

Staff lockers rooms, cycle and scooter stand, canteen and other essential amenities should be provided in the shed.

Wash and change rooms.19) Environment friendly equipment –

Incinerators to dispose off waste material. Effluent treatment pants – It has become a necessity to curtail pollutants

and is a pre-requisite for getting ISO-14000.

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IncineratorEffluent treatment plant

Water Load BoxFuel

Installation

Light Repair Bay-Goods

Light Repair Bay-Mail

Heavy Repair Bay

Over Hauling Sections

Office BlockMain Store

Canteen

RPF Post Vehicle Section

Time Office

Dematerialized Water Plant Laboratory

Grid Load Box

Pit wheel Lath

Washing Plant

Cleaning Plant Battery Charging

Bahr Line

SHED LAYOUT