The roof garden at a Chai Wan school has made innovative use of old railway sleepers. Fifty-eight railroad sleepers used at the KCR Ho Tung Lau Maintenance Centre for 18 years have been converted into benches, fences and even a fish pond with the addition of waterproof mats at the S.K.H. Li Fook Hing Secondary School. 'We needed some wood for our rooftop greening project but didn't want to buy new stuff,' the school's lab assistant, Derek Yuen Shu-chuen, said. 'I often see wooden sleepers on the train lines when taking the East Rail, so I just called to ask if they could give us the worn-out ones.' 'We would have dumped the sleepers if they hadn't called,' KCR media and community relations manager Siu Kam-hang said. 'It was the first time we have given away our worn-out sleepers in bulk.' Every year, the corporation replaces about 200 sleepers, each worth HK$500 to HK$1,300. 'Normally, sleepers on the main lines can be used for 20 to 30 years,' engineer Lee Sai-wing said. 'The pine sleepers given to the school this time were imported from Indonesia in 1989.' More than 140 Form Five students helped sandpaper and apply coats of lacquer to the sleepers after the materials were sent to the school. 'It is exhausting, but I feel proud to do something for my school. It means a lot to me,' student Chan Yin-ching said. 'I would never have thought about reusing sleepers for greening,' he said, adding he would become more involved in recycling in the future. Besides wooden sleepers, the school also reused more than 60 wine crates as flowerpots and collected more than 50 pots of discarded tangerines to attract butterflies. 'We simply want to raise students' environmental awareness by reusing everyday materials,' Mr Yuen said. The project cost about HK$23,000, including a small solar cell to run two fountains in the fish pond. Mr Lee said wooden sleepers were now mainly used on turnouts and at train depots, as most of them had been replaced with concrete sleepers since 2000.