Hong Kong is one of the world´s most densely populated metropolises. The neighbouring Shenzhen, founded in the 1980s, is the fastest growing city in China. As a reminder of the time when Hong Kong was under British control – no more than 20 years ago – there are still control points between the two cities.

The existing six land control points are major bottlenecks due to the massive traffic. That’s why the Hong Kong government launched a big development project in 2014 to open a seventh road connection. It involves a tunnel excavation where Robit’s tools have been put to the test.

Different rock, different methods

To accommodate the high volume of the traffic, two tunnels are being built side by side, one for each direction. Excavation for the 4.8-kilometre-long tunnels has been started at both ends, using different techniques. TBM is the method of choice at the north end on the Shenzhen side; at the south end the rock is so hard that the drill & blast method yields results faster and more efficiently.

Dragages Hong Kong, the main contractor, organized a bidding tender for the drill & blast work. Robit’s tools, represented by Merman Technology, proved to be the most competitive. The drilling work is performed by Robodrill, using tunneling jumbos and Montabert drifters.

– Before reaching the hard rock, there was a great deal of forepoling. Some of the ground was more challenging and softer than we expected, says Antti Mäkinen, Robit’s Sales Director for Southeast Asia.

– Robit supplied the ring bits, pilots and casings for the forepoling stage, as well as the tools – shanks, couplings, drill rods, and button bits – for drill & blast.

Smooth sailing for all parties

– I’m happy to say this has been a successful project from the very start. Our client has been extremely satisfied with Robit’s services, deliveries and products. I would also like to give my warmest thanks to Mr. Jacky Lee, the CEO of Merman, who has been providing excellent support to our client throughout the entire project.

In a large scale project like this, what have been the biggest challenges so far?

– As far as our tools are concerned, we have faced no problems. The major challenges have more to do with organization than technology, precisely because of the vast scale of it all. Planning the delivery schedules for all the various delivery points has taken a lot of effort, Mäkinen explains.

– Actually, this has been a learning experience for all of us. Cooperation with Dragages and Robodrill has been very fruitful. We frequently visit the work site, evaluate the processes, methods and tools, in a joint effort to make things run ever more smoothly.

The learning experience underneath the hills of northern Hong Kong continues. A staggering 770,000 total drill metres with Robit’s tools is to be completed by the end of 2017. The new Boundary Control Point is scheduled to open a year later.

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