After introducing the F-Class®-Chain in all sizes from 22mm up to 48mm to the worldwide mining industry JDT was asked in 2010 to produce a 60mm chain for a new project at Shenhua Group in China.

For very high coal seams (up to 20m) the Chinese miners developed 7m high hydraulic support together with Zhengzhou Coal Mining Machinery Group. The SL1000/7m ultra heavy duty shearer was supplied by Eickhoff and the ultra-heavy duty scraper conveyor PF6H-1542 by CAT (formerly Bucyrus). The conveyor’s power was 3 x 1600kW.
JDT delivered the AFC-chain because the company wasthe sole chain manufacturer able to provide a chain with a breaking force of more than 4500kN (a 48mm Combi-chain breaks at 2900kN…) having a maximum vertical height of 135mm and a weight per meter less than 67kg.

The main additional advantages of using this chain were 7 years of experience with this type of chain worldwide and of course the patented “Short Studs” preventing nearly 100% kinking in slack chain situations, or the “diving in” of the trailing vertical link into the flight bar gap.

The 60mm F-Class®-Chain with its double-pitch size of 181mm (vertical) and 197mm (horizontal link) is also available in HO-quality. This means, the standard material is additionally alloyed with tungsten, which increases the breaking strength up to 5000kN and the toughness from 60J (standard) to 85J, which both could give increased safety factor as well as increased safety against shock loads, corrosion and abrasion.
While sprockets and flight bars were to be newly designed (but according to all other standard supplementary fitting to a standard round link) connectors with breaking load of 5000kN were successfully tested and available.