Years of accumulated corrosion led the 30 m high rainwater pipes in CLP power station turbine hall to leak and needed replacement. We were contacted by our client, one of the main contractors of CLP power station, to provide 3 nos. 22m L x 1.25m W x 6m H working platform on top of the I-beam which was 19 m above the ground. Unlike regular scaffolding that is supported from the ground up, we had to build the scaffold mid-air on top of the I-beam. The access tower to the platform from the ground level were obstructed by utilities and there were limited working space to work with. As such, we adopted pure tube and fitting method to cope with various unforeseen challenges and completed the job within time to full satisfaction of our client. This is a small job by size but needs the highest level of skills as margin of error is zero. If the concept is wrong, the scaffold will not hold up on the I-beam.