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The requirement for roof supports to withstand greater loads has placed growing demands on the load bearing capacity of suitable test bays.
DBT’s large test bay, with a rated load of 12,000 kN, does not meet the needs of today’s heavy shield supports the company said. DBT decided to construct a new test bay to meet the requirements of future generations of shield supports.
The contract was placed with Stahl- und Apparatebau Hans Leffer GmbH, of Dudweiler near Saarbrücken, where DBT’s smaller test bays were also manufactured.
Work on the foundations started in August 2002 with the construction pit as large as a swimming pool. Erection of the steel structure started at the end of 2002. The heaviest individual parts weighed 35 tonnes, and a mobile crane was needed to move them into place.
Once specified safety nets are installed, the new test bay will be ready for operation. The first shield to be tested will be for the Australian longwall mine Tahmoor in New South Wales.
The overall height of the test bay is 9,640mm with an effective test area of 8,000mm x 4,000mm. Vertical load bearing capacity is 20,000kN and horizontal load bearing capacity is 6,000kN.
