High capacity crawlers to dominate in China

China shows great potential in the demand for large crawler cranes, according to Construction Machinery, IC's partner magazine in China. Most demand comes from the power industry, where China will focus on developing 600,000 kW power stations and reduce the number of those less than 200,000 kW. This policy implies strong demand for 300 to 800 tonne capacity crawlers.

According to Xuzhou Heavy Machinery, the largest producer of mobile cranes in China, by the end of 2006 Chinese manufacturers will be able to offer 10 crawler models in the 100 to 450 tonne range and, by 2008, this will increase to 800 tonnes. In the meantime, international manufacturers are promoting their 1,000 tonne class machines. Demand from major construction projects for these machines will stimulate Chinese industry into developing even larger products.

Domestic manufacturers are quickly improving their technical competence. Xuzhou says it has enhanced its crawler crane product with 29 key technologies, including rope winching, superlift operation control, programmed control of machine motion and automatic hydraulic boom back stops.

In the pursuit of higher quality, Xuzhou Heavy Machinery says it has invested in advanced machining and assembly centres and other modern manufacturing methods. Components including engines, transmissions and hydraulic valve blocks are sourced outside China.

Following the launch of its first 150 tonne crawler in 2003, in 2005 Xuzhou Heavy Machinery launched a 300 tonner, the first among Chinese manufacturers. This year, it has introduced 220 and 260 tonne capacity models and, CM understands, will soon complete the design of 450 and 600 tonne crawlers.

Xuzhou “absorbed the advanced technologies for manufacturing crawler cranes from the international industry,” for example, “up-to-date structure design, gantry technology, light lattice booms with large capacity, powerful crawler chassis capable of travelling on a 30 degree slope, CAN-bus, and electronic proportional control. Multiple boom combinations are provided with quick erection devices and a method to simplify reeving.”

The new Xuzhou 220, 260 and 300 tonners can travel with 70% of rated load and slew 360 degrees with the rated load. Maximum main boom is 96 m and the maximum jib combination is 60+57 m for the 220 tonne model, 66+60 m for the 260 tonner and 60+60 m for the 300 tonner.

The 260 tonner uses a new gantry plus balance beam structure. Hydraulic pin connections are used on the boom, slew unit, carbody and crawlers. For self-erection the A-frame is self-raising as is the mast, the crawler frame is self-mounting, the counterweight is self-loading and boom is self-erecting. A pressure lubrication system is used to help durability and reliability and reduce maintenance. Power comes from a Euro III diesel engine with electronic fuel injection.