According to the astronomical annals in the History of the Song, after the clock tower was completed in wood, it was copied in bronze, using a total of "20,000 catties" (around 12,000 kg) of the metal.
根據宋史天文志，水運儀象台在做成大木樣後，翻製成銅，共用銅「兩萬斤」（約為現在的一萬兩千公斤）。