The job involved painting with one coat of primer 75microns, one intermediate coat of 125 microns and final coat of 50microns; the final coat to be finished with a combination of two colours red and white. Painting has to be done from top to bottom and only through Rope Access Professional, as any other systems of height access are not safe and conducive.
The following have been the major challenges and the techniques for overcoming the same.
Climbing & Access: One major challenge was climbing 100mt manually through a confined ladder as all the process involved painting from top to bottom. In normal city high-rise buildings, a RAP can use the lift for reaching the terrace; but here climbing opens up the challenge of providing a fall protection system. This challenge was overcome by creating a vertical life line at every five meters. The team could use the life line to ascend by connecting a cow tail rope to the safety harness. On reaching the access point at 100mt height, a vertical access point was created, which became a life line throughout the project for the entire team to use it on a daily basis. - Material Lifting & Rescue Planning: Another challenge was to take the tools & material to the height of 100Mtrs. This was overcome by creating a cycling system (fig.1 & 2) using the traxion pulley. A slab mounted bracket was anchored to the RCC Slab at the base level and on the other end i.e. on the top of the chimney at 100mt height, tap ceiling was done using T-brackets, which were connected to the ladder for attaching the pulley. Now the traxion pulley was locked in the opposite direction and the rope had been tightened and knotted which would later be locked with the karabiner. The Shunt would be connected above the knot using a karabiner with free tack line. The material is then attached to the shunt and with the help of hand jammer, it would be taken to the required height. The same system is used for the rescue operation in case of emergency.
- Wind Pressure: The wind pressure at the site was severe, as the site was on the coastal areas. Therefore, the working plan had to be based on the downwind time. Based on the available data at the public platform, the engineers at the plant and the backend team of glass hoppers devised a working time between 6.00am to 2.00pm.
- Simul Rappelling for Better Finish: After surface preparation process, the painting is to be done for 250microns. For the final coat, the entire circumference is to be painted by all the RAPs simultaneously for better finish and to avoid patches due to over lapping. Therefore, Simul Rapelling technique was used that allows two RAPs to be at the same height. This is an advanced skill where two climbers descend on one rope at the same time or two ropes tied together, and one climber’s weight counterbalances the other. Thus, challenge of final coat of painting of the entire circumference from top to bottom was overcome by a team of 8 RAP pairing to provide better finish.
Vijay Kumar Executive-Operations & Safety Glass Hoppers