Complex sentence: The British hope the island capital administration will grow into a city to rival Singapore and Hong Kong, but the dream was never reached especially when the coal production does not become fruitful that causing most investors to withdrew their investment.
Split into simpler sentences: The British hoped that the island's capital would grow into a city to rival Singapore and Hong Kong, but the dream was never reached. Especially when the coal production does not become fruitful that causing most investors to withdrew their investment.