Core Plugs, Figure 2 Cores are extracted from the colony using a variety of methods, shown here is a powerful hydraulic drill rig
clamped in place with the operator about to commence cutting.
Core Plugs, Figure 3 When the core has been removed, a hole is left in the colony and this is plugged with a tapered, conical,
concrete plug. These plugs are pre-washed in sea water to eliminate soluble toxins and are hammered home in level with the natural
surface.
CORE PLUGS
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