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Canal building was revived in this age because of commercial expansion from the 12th century.
River navigations were improved progressively by the use of single, or flash locks.
Taking boats through these used large amounts of water leading to conflicts with watermill owners and to correct this, the pound or chamber lock first appeared, in 10th century in China and in Europe in 1373 in Vreeswijk, Netherlands.
Another important development was the mitre gate, which was, it is presumed, introduced in Italy by Bertola da Novate in the 16th century.
This allowed wider gates and also removed the height restriction of guillotine locks.

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