Hong Kong's third runway may stymie Shenzhen's big cargo vessels

A proposed third runaway at the Hong Kong International Airport could cost port terminals in western Shenzhen millions of dollars a year in lost business.

The project, already criticised for its HK$136 billion price tag and potentially adverse impact on the environment, may also hurt relations between the neighbouring cities.

The problem comes in the form a height restriction on shipping passing close to the runway. The restriction would extend beyond Hong Kong waters and into Shenzhen's marine territory and could mean a new generation of massive cargo ships could not access western Shenzhen ports like Chiwan and Shekou without a huge detour.

The Hong Kong and Shenzhen governments are understood to be in talks over a solution. But people with knowledge of the discussions say the initial proposals from Hong Kong do not address long-term sea traffic demands and may compromise the competitiveness of port facilities in western Shenzhen.

According to a document seen by the , the Airport Authority proposes to extend marine restrictions in place around the existing runways into Shenzhen waters to accommodate the third runway.

That would mean vessels standing 53 metres or taller out of the water could not use the Lunggu West Fairway, the most direct of the three routes into the western Shenzhen port terminals, at a time when shipping lines are increasingly using huge vessels standing 25 storeys or more.