The Stonecutters Bridge when completed. The design has been highly praised for its aesthetic merits.

May 2007 − The construction of an astonishing new bridge has reached a milestone: a stainless steel skin on the East Tower of the Stonecutters Bridge in Hong Kong is about to be completed. As the stainless steel crowns the bridge on its towers, Stonecutters Bridge will be a landmark in Hong Kong: straddling the Rambler Channel at the entrance to the busy Kwai Chung Container Port, this bridge will be one of the longest cable-stayed bridges in the world when completed in 2009. The clear span is 1,018 m and the total length 1,596 m. The deck is one of the highest in in the world to allow passage of super container passage

The towers, the most conspicuous feature of the bridge, are built as steel-concrete composite structures. Above the 175-meter level, stainless steel envelopes the top 118 meters, providing stiffness and damping for the structure. The stainless steel will free the bridge operators from maintenance – a major consideration because of the difficulty of accessing the top section.

The maritime location and the hot, humid climate of Hong Kong combine to make the environment of the Stonecutters Bridge highly corrosive, demanding a stainless grade that can withstand the test. The bridge engineers selected duplex 2205 owing to this grade’s proven qualities for such an environment. Materials consulting was provided by Arup, which was instrumental in introducing the duplex concept for the project. Duplex stainless steels have recently emerged as the preferred materials in a broad range of structural applications owing to their high strength, which allows for designs with considerably lighter structures compared to austenitic grades.
 
By the time the contractor was ready to select the duplex supplier for the Stonecutters Bridge in 2004, Outokumpu had built a good reputation in duplex stainless steel plate for bridges. For example, Outokumpu was at that time supplying duplex 2205 plate for the Menorca Bridge in Spain, the world’s first road bridge that uses only stainless in the load-bearing structures. For its merits, Outokumpu won the Stonecutters Bridge duplex plate contract in October 2004.
 
Outokumpu’s delivery for the Stonecutters Bridge was completed in late summer 2006 and consisted of approximately 2,000 tons of duplex 2205 plate and pipe.

Outokumpu is the world-leading supplier of duplex stainless steels and operates the world’s largest stainless hot rolled plate mill, located in Degerfors, Sweden. The success of many of Outokumpu’s bridge projects is also explained by Outokumpu’s capability to supply ready-to-assemble bridge components, with plates cut to size and bent at the plant and at Outokumpu plate service centers, with all required openings in place and edges prepared for welding.

The skin segments for the Stonecutters Bridge were finished by a fabrictor in China from plates delivered by Outokumpu in customized sizes with 1K surface. The plates were polished to a finish lower than 0.5 µm and shot peened to provide the right and consistent level of reflection both daytime and nighttime.

Ready-to-mount duplex skin-segment pairs for the Stonecutters Bridge’s East Tower. Photo courtesy MHYH JV		The first pairs of the skin segments on the East Tower in March 2007. Photo courtesy MHYH JV

Owner:
Highways Department of the Hong Kong Special Administrative Region

Design team:
Arup Hong Kong

Main contractor:
Maeda-Hitachi-Yokogawa-Hsin Chong Joint Venture (MHYH JV)

Materials consulting:
Arup (also other design services and construction supervision)

Construction commencement / completion:
April 2004 / June 2009

Contract sum:
US$ 2,760 million

Outokumpu supply:
Approximately 2,000 tons of duplex 2205 plate and pipe, plates in customized sizes and with 1K finish

For more information, contact:
Anders Finnås
Building & Construction, New Applications
Outokumpu Hot Rolled Plate, Degerfors, Sweden
Tel. +46 586 47 131
Email: anders.finnas()outokumpu.com