AN engineer did not tell a chemist where to take gas samples for analysis when a problem was discovered in a generator casing, an inquest heard yesterday. Mr David Ford, senior shift charge engineer with China Light and Power, was giving evidence in the case of engineers Mr Wong Kwong-yu, 38, and Mr Yip Ka-pui, 41, who died at an explosion at the Castle Peak power plant at 10.05 am on August 28 last year. He said he arranged for a chemist's analysis after noting that the hydrogen purity level in the casing of generator two in plant B had dropped to 85 per cent that day. The normal hydrogen purity level should be more than 95 per cent. The court heard that the chemist arrived at 2.30 am and finished taking gas samples at 5 am. Mr Ford had not specified where the chemist should take the samples. It was also decided to change the hydrogen supply from the high-pressure vessels to hydrogen gas bottles. Mr V. K. Zachariah, senior shift charge engineer, said he took over the shift from Mr Ford at about 8 am. He organised his staff, including Mr Wong, the acting plant control engineer, to start purging the generator with the hydrogen gas bottles. Purity recovered to 87 per cent after some purging. Mr Zachariah was later instructed by Mr Eric Gunstensen, the operational superintendent of the plant, to switch the hydrogen supply from gas bottles to the two high-pressure vessels. It was changed at 9.45 am. The hearing before Coroner Mr Warner Banks and a jury continues.
