Photos

Bolt Up Sequence

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Bolt Up Sequence Stage 1

Cut from the tailgate in 20 chock sections. Place 1 “w” strap over the top of the chock (ie perpendicular to the face) anchored with 2 bolts set at 6.8 metres. Set rows 1 & 3 after row 2 at 7.3 metres & 6.3 metres.

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Bolt Up Sequence Stage 2

Take the shearer to the tailgate. Advance the pans and cut from tailgate to maingate and back to tailgate, then advance the chocks. Set row 4 at 5.3 metres.

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Bolt Up Sequence Stage 3

Advance the pans and cut from tailgate to maingate and back to tailgate and advance the chocks. Set row 5 at 4.3 metres.

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Bolt Up Sequence Stage 4

Advance the pans and cut from tailgate to maingate and back to tailgate and advance the chocks. Set row 6 at 3.3 metres.

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Bolt Up Sequence Stage 5

Advance the pans and cut from tailgate to maingate and back to tailgate and advance the chocks. Set row 7 at 2.3 metres. The chocks have now reached their final position. The next 2 shears that are to follow will provide face for the chocks to be removed.

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Bolt Up Sequence Stage 6

Advance the pans and cut from tailgate to maingate and back to the tailgate. Set row 8 at 1.3 metres.

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Bolt Up Sequence Stage 7

Install the relay extension bars. These allow the pans to be pushed a further 1.0 metre without the chocks needing to move. Advance the pans and cut from the tailgate to the maingate and back to the tailgate. Set row 9 at 0.3 metres. Set an extra bolt every 2nd chock for mesh at an angle over the coal face.

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Final Bolt Up Sequence Stage

The face is meshed using angled bolts from stage 7 and bolts where needed to hold the mesh onto the face. A rib strap is installed along the bottom of the mesh and bolted every 1 metre.

This now completes the bolt up cycle. The bolts that were used at this mine were 2.1 metre mild steel bolts. A mild steel bolt was used rather than a high tensile bolt because it is able to bend more.

The conditions at South Bulli did not require support to be installed at the maingate or tailgate. Some other mines in the Ilawarra region do provide support to the gate roads.This support is in the form of either:

  • Polyurethane Resin injections into the tailgate, maingate and face areas
  • Flexi Bolts (Cable Bolts ??)
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