Six 45 cm (18 in) diameter hydraulic rams (three on
each side, each powered by a 55 kW electric motor)
rotate the bridge back on large bearings to allow
small ships and boats (up to 25 m (82 ft) tall) to
pass underneath.  The bridge takes as little as 4.5
minutes to rotate through the full 40° from closed
to open, depending on wind speed.

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