Shaft enlargement arrangement for a boring system

A boring system comprising:

• a shaft enlargement arrangement comprising:
• a hollow column proximate a lower end of the boring system;
• a reamer section comprising a downwardly tapering first cutter head arrangement that is rotatably fitted to the hollow column, with first drive means being provided to rotate the first cutter head arrangement relative to the hollow column so as to bore downwardly a hole having a diameter corresponding substantially to a diameter of the first cutter head arrangement;
• a boring head arrangement fitted to an operatively lower end of the enlargement arrangement, the boring head arrangement terminating in a downwardly tapering second cutter head arrangement to bore a leading or pilot hole having a diameter that is less than the diameter of the first cutter head arrangement as the boring system proceeds to bore downwardly;
• a thrust section to allow the boring head arrangement to advance relative to the reamer section;
• and
• a gripper arrangement to secure the shaft enlargement arrangement within the bored hole and to control the advancing of the boring head arrangement relative to the reamer section;
• a plurality of support decks configured to be locatable above the shaft enlargement arrangement within the hole bored by the first cutter head arrangement with the shaft enlargement arrangement being separable from the rest of the boring system;
• an aboveground support rig arrangement comprising an overhead support assembly and a headgear arrangement to lift and lower the shaft enlargement arrangement and the plurality of support decks;
• and
• a mobile service deck configured to be locatable above the plurality of support decks and to which a spreader bar is connected or connectable, wherein the mobile service deck is configured to be lifted, separated and temporarily accommodated between the headgear arrangement, to enable the spreader bar to be used to fetch a component or item within a shaft of the hole and hoist it to surface.

A boring system comprising:

• a shaft enlargement arrangement comprising:
• a hollow column proximate a lower end of the boring system;
• a reamer section comprising a downwardly tapering first cutter head arrangement that is rotatably fitted to the hollow column, with first drive means being provided to rotate the first cutter head arrangement relative to the hollow column so as to bore downwardly a hole having a diameter corresponding substantially to a diameter of the first cutter head arrangement;
• a boring head arrangement fitted to an operatively lower end of the shaft enlargement arrangement, the boring head arrangement terminating in a downwardly tapering second cutter head arrangement to bore a leading or pilot hole having a diameter that is less than the diameter of the first cutter head arrangement as the boring system proceeds to bore downwardly;
• a thrust section to allow the boring head arrangement to advance relative to the reamer section;
• and
• a gripper arrangement to secure the shaft enlargement arrangement within the bored hole and to control the advancing of the boring head arrangement relative to the reamer section;
• and
• a plurality of support decks locatable above the shaft enlargement arrangement within the hole bored by the first cutter head arrangement, with the shaft enlargement arrangement being separable from the rest of the boring system, wherein one of the support decks comprises a hoisting arrangement, the hoisting arrangement comprising a vacuum system to suck dry muck and cuttings into a vacuum tank, with the vacuum tank then discharging the dry muck and cuttings via a retractable chute into a kibble, which may then be hoisted up to surface.