Short Note on Fabrication of Glued joint IN SITU

Fabrication of Glued joint IN SITU.

 General:- 

1. Glued joints are laid at place where insulation of rails as well as continuity of rails is required .

2. Normally Glued joints are fabricated in shop floor and transported to the site however as the glued joints fabricated at the site save effort needed in transportation and also save at least two thermit welds. Welds. Which are a weak link in track. Repairs to a failed/damaged glued joint can also be conveniently done at site, carefully fabricated glued joint in the field can given as good a service as a shop fabricated glued joint.

Fabrication works:- 1. In case the fabrication is being done in running track, minimum traffic block of 2 hours shall be taken and track protected with banner flag and detonator. Rail should be made free of fittings over as length of 2.00 m on either side.

2. Grinding of rialto a length of 50cms on either end should be done with the AG-9 grinder and it shall be ensured that no rolling mark, rust dents are in contact with the fishplate.

3. Both the fishplates shall be ground to make the surface free form dust dents grease etc.

4. The gap shall be maintained slightly more than 10mm to accommodate the end post (to achieve this tensor shall be applied)

5. The rail end shall be aligned laterally and vertically with straight edge using suitable wedges. After aligning no hammering/disturbance to ends should be done.

6. The rail and fishplates surface shall be cleaned with acetone and dried completely.

7. The resin and hardener shall be thoroughly mixed to get homogeneous mixture. The mixed glue shall be consumed within it pot life (Generally 30 minutes)

8. A thick layer of glue shall be applied on mating surface of the fishplates simultaneously be two workmen.

9. One piece of clean glass cloth carrier shall be placed on the fishplates and evenly pressed so that the glue squeezes out through the glass cloth. The oozing shall be uniformity spread over. A layer of glue shall be applied on inside of the insulating channel followed by then placement on the glued glass cloth carrier on the two fishplates.

10. A layer of glue shall then be applied on the outside of the insulating channel and a clean piece of glass cloth carrier shall be laid. The oozing glue shall be uniformly spread.

11. Glue shall be applied to both the faces of end posts and placed between the two rail ends. The tensor may be tightened to place the end post firmly if the same is loose due to more gap. Alignment checked again at this stage and corrected i disturbed.

12. The insulating bushes duly dipped in glue shall be placed in rail holes. The bonding surfaces of the rail shall then be coated with a layer of glue and the fish plates made ready shall be placed in position in contact with the rail web.

13. H.T.S. bolts washers and nuts well cleaned and free from oil, dust etc. Shall be placed in position and tightened with torque wrench. The torque shall be increased gradually on all the bolts, care shall be taken to tighten inner bolts first and than outer bolts. Finally all the bolts shall be tightened with the torque of 105 kg-M.

14. The above `operation shall be finished within 45-60 minutes so that minimum 60 minutes setting time is achieved.

15. About 20 minutes after initial tightening, all the bolts shall be re-tightened with the torque of 105kg-M

16. The joint shall be finished by covering all the visible edges of glass cloth carrier with glue.

17. After re-tightening the bolts. Joint is left for setting with tensor in clamped condition.

18. After setting, the removed fittings are restored in position tensor removed and traffic block shall be cancelled.

19. Before passing the traffic, it shall be ensured that no extra material like settled glue3 etc. Remains on top of the head & gauge face side of the rail.

20. Traffic may be passed at restricted speed of 30 kmph for about two hours after which the speed restriction shall be relaxed to normal.