A drawbridge is a bridge over a body of water that opens up to allow boats and ships to pass through.

The center decks raise to allow tall boats to pass.

In the 1870s work began to dredge a channel through the strait to allow larger boats to pass.

Also, the bridge had to be closed to allow large boats to pass under it.

A few years later, a steel swing bridge was built to better allow boats to pass through.

This changed to a system of tolls from 1704, which allowed other boats to use the Beck.

The canal was later widened to allow larger boats to pass through in 1849.

A canal on the north shore of the river allowed boats to navigate around the dam.

The stop lock was installed to separate the water systems of the competing canal companies, while still allowing boats to pass.

"Over all, technology has allowed big, powerful boats to be developed," Hall said.