The ZY21000/38/82D 8.2-meter ultra-large mining height two-leg shield hydraulic support was applied at Jinjitan Coal Mine in January 2016. The working face achieved a maximum daily output of 61,600 tons and an average daily output of 50,000 tons, with an annual production capacity of 15 million tons for a single working face. Designed and manufactured on the basis of *GB 25974.1-2010 General Technical Conditions for Hydraulic Supports* and with reference to relevant foreign hydraulic support test standards, this support passed 50,000 cycles of durability performance tests.
As the world's first complete set of 8-meter ultra-large mining height hydraulic supports put into application at that time, it operated continuously and efficiently underground at Jinjitan Coal Mine for more than five years, making it the first set of ultra-large mining height hydraulic supports that remained underground for five years without being lifted to the surface. It yielded 17 innovative achievements and won the first prize of the Science and Technology Award issued by the China Coal Industry Association.
