the bridge has a height restriction of 41 metres for vessels passing underneath. on 23 october 2015, a barge attempted to pass under the bridge with a broken-down crane that could not be lowered. the crane had a maximum height of 43 metres, but was tilted slightly to 41 metres. the bridge has an actual clearance of 47 metres, but potentially due to the high tide and wave action, the crane struck the bridge and damaged its underside. the tsing ma bridge has a higher height clearance of 53 metres but a source said the captain of the tugboat towing the barge may have opted to take kap shui mun to save time.