Shanghai, which means "on the sea", is China's largest city in terms of population and one of the largest metropolitan areas in the world with over 20 million habitants.

Shanghai has an extensive public transport system which includes buses, taxis, and a rapidly growing metro system. The Shanghai Metro rapid-transit system has grown from a single subway line in 1995 to 8 lines in 2009 covering 235 km and including 162 stations.

The Metro rapid-transit system of Shanghai has become one of the newest and fastest-growing rapid transit systems in the world. It is continuously growing and according to the overall plan of the Shanghai Shentong Metro Group another 8 Metro lines will be constructed just in time for the World Expo in Shanghai. By 2010 Shanghai will have 16 Metro lines covering more than 400 km and making up over 35% of the city’s mass transit system.

The Shanghai Shentong Metro Group is the owner and investor of Shanghai’s Metro rapid-transit system, whereas 4 companies operate the Metro Network. These operating companies are subdivisions of the Shanghai ShenTong Metro Co. Ltd. which is mainly engaged in the operation and development of Shanghai’s Metro line subway.

The construction and maintenance of Metro lines is a project with a high degree of responsibility. The tiniest flaws in the tracks as well as the smallest failures in the welds of the tracks can cause accidents when the train is in operation. It is essential to ensure the quality of the tracks and welds in order to minimize the risk of broken track welds and ensuing disasters. Therefore, a technical inspection by an independent third party is necessary to guarantee accuracy.

In April 2009, Shanghai ShenTong Metro Co. Ltd awarded the contract to SGS Industrial Services China and Xuzhou Railway Engineering Department to provide independent technical inspection of the track welds of 8 Metro lines under construction.

The main target of the SGS Industrial Services China third party inspection is to verify that the track welds conform to all quality standards. A team of 6 experienced, highly skilled and well-qualified SGS inspection engineers ensures that failed welds will be identified, analyzed and eliminated. Moreover the SGS engineers ensure that the track welding is in accordance with the applicable codes and norms of the Chinese Railway Ministry.

In order to identify failed track welds the SGS experts apply the Ultrasonic Testing (UT) method. The Ultrasonic Inspection (UT) process involves transmission at high frequencies of short wavelength sound waves in order to identify flaws and detect corrosion. The UT method is one of many Non-Destructive Testing methods offered by SGS.

SGS Industrial Services is one of the biggest Business Lines of the SGS Group, a global service provider for technical verification, inspection, testing and conformity assessment ensuring that the customer’s installations, material, equipment, facilities and projects meet all quality and performance requirements, whether they are regulatory, voluntary or customer based.

Contact information:

Leaf Huang
Industrial Services Materials Lab

SGS-CSTC Shanghai Tongji Engineering Testing Co., Ltd.
SGS-CSTC Standards Technical Services Co., Ltd.
1/F, 17th Building Block1365, Kangqiao East Road, Pudong District, Shanghai, China
t: +86 (021) 6818 3233*506
f: +86 (021) 6818 3122

About SGS

The SGS Group is the global leader and innovator in inspection, verification, testing and certification services. Founded in 1878, SGS is recognized as the global benchmark in quality and integrity. With more than 55,000 employees, SGS operates a network of over 1,000 offices and laboratories around the world.