The Tsing Ma Bridge is the only link between Hong Kong International Airport and the rest of the city – so ensuring that it is kept in tip top shape is critical.
The suspensions cables are responsible for carying the weight of the bridge, and every vehicle travelling across it.
So a catwalk along the top of each cable provides inspection crews easy access.
But at 2160 metres long, it would be a long walk – so they can ride a mobile gantry atop the main cable.
And with towers 206 metres high, another mobile gantry allows crews to inspect the vertical suspension cables that holds up the bridge deck.
But what about the underside of bridge? Enter this unassuming looking truck.
Workers enter the basket located at the end of the hydraulic arm.
And can then be lowered beneath the bridge.
With the arm manoeuvrable enough to pass between the closely spaced cable stays.
The first bridge inspection vehicle was a Palfinger PB 4 acquired on the opening of the bridge in 1997.
Which was replaced by a Barin AB 23/SL in 2012.
A second bridge inspection vehicle was acquired in 2017, to be parked at the other end of the bridge, following concerns that traffic congestion might delay emergency responders.
Statistics
- Max horizontal outreach: + 18.0 m / – 11.5 m
- Max working height and depth: + 28.0 m / – 28.0 m
- Max basket load: 280 kg
Barin AB 23/SL bridge inspection unit.
- Down reach 30 metres
- Platform under reach: 23 metres
- Overhead working height: 26.5 metres
- Max basket load: 250 kg
Sources
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