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Fittings and Fastenings of Rails.pdf
- 1. TRACK FITTINGS ANDFASTENINGS By Dr. T. Vijaya Gowri Associate Professor, B. V. Raju Institute of Technology
- 2. Definition All those fittingswhich are required for connecting the rails end to end and for fixing the rails to the sleepers in a track are known as fixtures and fastenings.
- 3. Purpose of TrackFittings And Fastenings 1.The purpose of providing fittings and fastenings in railway tracks is to hold the rails in their proper position in order to ensure the smooth running of trains. 2.These fittings and fastenings are used for joining rails together as well as fixing them to the sleepers. 3. They serve their purpose so well that the level, alignment, and gauge of the railway track are maintained within permissible limits even during the passage of trains.
- 4. Functions of TrackFittings And Fastenings The different functions of these fitting are : 1) To keep the rails in the proper positions. 2) Connection of rail to rail. 3) To set points and crossings properly 4) To allow for expansion and contraction of rails.
- 5. Types of TrackFittings They include 1) Fish plates 2) Spikes 3) Bolts 4) Chairs 5) Keys 6) Blocks 7) Bearing plates Chairs Fish plates Spikes Keys Blocks Bearing plates
- 6. FISH PLATES ◦ Theseplates are used to maintain proper alignment of the rail line. ◦ They maintain the continuity of the rails and also allow expansion or contraction of rails caused due to temperature variations. ◦ Generally these plates are made of mild steel and 20 mm in thickness. ◦ They are 45.6 cm long and provided with 4 no. of 32 mm diameter holes at 11.4 center to center.
- 7. FISH PLATES ◦ Indianrailways generally adopt following two types of fish plates : 1) Bone shaped fish plate 2) Increased depth fish plate ◦ Bone shaped fish plate is used for connecting flat footed rails. ◦ The increased depth fish plate is generally used for connecting Bull-headed rails.
- 8. Common types ofFish Plates-Joggled Fish Plate ◦ This is a specially forged fish plate. It is suitable for the temporary repair of cracked welded rail joints with clamp assembly to suit various rail sections. ◦ Used as an emergency clamp, joggled fish plate enables quick and temporary repair, allowing continued movements through the section at a reduced line speed.
- 9. Common types ofFish Plates-Compromise Fish Plate ◦ These are designed fish plates to join two different rail sections of rail tracks for various customers when they require them.
- 10. SPIKES ◦ They areused to hold the rails to the wooden sleeper. ◦ A good spike should have following qualities : ◦ 1) It should have sufficient strength to hold the rail in position. ◦ 2) It should help in maintaining proper gauge. ◦ 3) It should be easy to fix and replace from the sleepers.
- 11. SPIKES ◦ Indian Railwaysuse following types of spikes : 1. Dog spikes 2. Screw spikes 3. Standard spikes 4. Elastic spikes
- 12. Dog spikes ◦ Adog spike, also called cut track spike, is often used to fasten T-shaped railway track to wooden sleepers, to secure a rail and tie plate to the ties in track, which has a pointed penetrating head with square shank, and the underside of the spike head is sloped to compromise the top of the rail base.
- 13. Screw spikes ◦ Railscrew spikes (also called sleeper screws or square head rail bolts) are medium or large metal screws used to fasten rail tie plates and rail track on the wooden or concrete sleepers.
- 14. Standard Spikes ◦ Thecommon track spikes are the 5/8”*6” and the 9/16”*5-1/2” for smaller rail sections, and they are usually secured in either 200 lb. kegs or 50 lb. kegs.
- 15. Elastic Spike ◦ There’sa special rail spike called elastic spike. The elastic spikes are made of spring steel. ◦ There’re double shank elastic spike and single shank screw spike. ◦ The single shank elastic rail spike is manufactured by shearing the double shank elastic rail spike
- 16. BOLTS They are usedfor connecting : 1) Fish plates to the rails at each rail joint. 2) Chairs or bearing plates to timber sleepers. 3) Sleepers to bridge girders,etc
- 17. BOLTS The different typesof bolts used in Indian Railways are : 1. Hook bolts 2. Fish bolts 3. Fang bolts 4. Rag bolts Rag bolts
- 18. BOLTS ◦ Hook boltsare used for fixing timber sleepers to bridge girders. They are popularly known as dog bolts. ◦ Fish bolts are used to connect fish plates to the rails at rail joints. ◦ Fang bolts are used for fixing side chairs to the sleepers. ◦ Rag bolts are generally used to connect longitudinal timber sleeper or concrete sleepers to the walls of ash pits. Hook bolts Fish bolts Fang bolts Rag bolts
- 19. CHAIRS ◦ They areused to hold the double headed and bull headed rails in required position. ◦ They are made of cast iron having two jaws and a rail seat. ◦ In order to fix the double headed or bull headed rail to a chair, the rail is placed between the two jaws of the chair. ◦
- 20. CHAIRS A. Cast steelchairs B. Mild steel and Cast iron slide chairs.
- 21. KEYS They are smalltapered pieces of timber or steel to connect rails to chairs on metal sleepers. Types of keys generally used are : 1) Timber keys 2) Metal keys 3) Stuart's keys 4) Morgan keys
- 22. BLOCKS ◦ They areinserted in between the two rails running close to each other and bolted to maintain the required distance ◦ They may touch either the webs or the finishing faces or both.
- 23. BEARING PLATES ◦ Theyare the plates placed in between the flat footed rails and timber sleepers on a track. ◦ They serve as chairs for flat footed rails. They are made of cast iron, wrought iron or steel.
- 24. BEARING PLATES ◦ Generally,they are of following types : 1) Flat bearing plates 2) canted bearing plates ◦ Flat bearing plates are used at locations where rails are laid flat. Also they are used in turn out tracks under points and crossings. ◦ Canted Bearing plates are used on soft timber sleepers beneath outside rail on curves, on sleepers placed on either side of rail joints, bridges etc. where rails are laid at an inward tilt of 1 in 20.
- 25. Reference ◦ Satish Chandraand Agarwal, M.M. (2007) "Railway Engineering" Oxford Higher Education, University Press New Delhi.