Siemens and Siemag will supply two new winders to the Majialiang coal mine by the end of next year.

The contract is the latest in a number of successes for Siemens in China with more than 80 Chinese shaft winding installations already equipped with the company’s technology.

Datong, located in Shanxi province, extracted 122 million tonnes of coal in 2008.

The Majialiang mine, near Shuozhou, has an annual production capacity of 12 million tonnes of coal.

The two new winders will be installed in a service shaft which is 537.5m deep.

Siemens will supply the entire drive equipment, the medium and low-voltage distribution systems and transformers, as well as the automation technology, including human-machine interface equipment and safety systems.

The mechanical components will be supplied by Siemag.

The larger of the two winders is equipped with a 3600-kilowatt synchronous motor and enables a double cage with a payload of 50t to achieve a speed of 9.97m a second.

The second machine has a power output of 435kW and can wind 8t at 6.67m/s.

Simatic programmable logic controllers are used in the automation system.

For safety reasons, the control and monitoring system has a two-channel structure.

The signals of the two channels are continually compared with each other. An error triggers the safety circuit, which immediately stops the drives and applies the safety brake.

Siemens is also responsible for system integration, supervision of the installation work and commissioning, and will provide customer training for the electrical equipment and the brake systems.