5 Tips to Stop Your Drill Core Getting Lost, Broken, or Delayed Before It Reaches the Lab

Wednesday 20 May 2026

Diamond core drilling in Australia typically costs between $200 and $400 per metre. On a 5,000-metre exploration program, that represents well over a million dollars of investment sitting in core trays before a single assay result comes back. Yet for all the planning that goes into drilling, the journey from rig to laboratory is where samples are most vulnerable.

Damaged core, mislabelled trays, and lost shipments do not just delay results. They can force expensive re-drilling, compromise geological interpretations, and raise questions at JORC Table 1 reporting. The drilling cost has already been incurred. Whether that investment holds its value depends entirely on what happens after the core leaves the ground.

Here are five practical steps to protect your drill core from the moment it is placed in a tray to the moment it arrives at the lab.

1. Label Every Tray at the Drill Site

Not at the core shed. Not the next morning. At the rig, before the tray is moved.

If using metal trays, paint the starting end of each tray white and mark the hole ID, tray number, and depth interval clearly using a black permanent marker on the tray end. This is not just good practice. The Geological Survey of Queensland requires end-of-tray labelling and depth sequencing as a condition of core library submission. Other state geological surveys, including those in Tasmania, South Australia, and the Northern Territory, have similar requirements.

If a tray arrives at the yard with no label or an illegible one, the yard cannot process it. That core sits unassigned in a queue while your program timeline slips. On remote projects where freight windows are tight, a labelling error at the rig can mean weeks of delay downstream.

2. Use Depth Markers and Core Blocks to Account for Every Run

Place a clearly marked wooden or plastic core block at the start and end of each drill run within a tray, and at every interval where core loss has occurred. This is the physical record that ties your core to its downhole position.

Skip this step and a 30-centimetre core loss mid-hole becomes invisible. Downhole depths start to drift, sample intervals shift, and geological contacts no longer match the log. That error does not stay contained. It compounds through every interpretation, cross-section, and resource estimate built on top of it. For oriented core programs, any loss of depth control also undermines structural measurements.

3. Stack, Strap, and Palletise to Australian Standards

Stack core trays on wooden pallets so the total pallet height, including the pallet base, stays below 900mm for stability and safe manual handling.

For plastic trays, stack side by side and then one on top of the other. For sheet metal trays, cross-stack by rotating every second row 90 degrees to lock the load together. Then shrink-wrap the pallet and/or apply steel or industrial-grade plastic strapping.

The Mineral Resources Tasmania core submission guidelines specifically reference the National Transport Commission Load Restraint Guide and recommend shrink-wrapping followed by strapping to secure trays to the pallet. If core contains identified asbestos-bearing material, an additional layer of plastic sheeting between two layers of shrink wrap is required, and the freight carrier must be informed.

Poorly palletised core shifts during transport. Core breaks, trays separate, and depth sequence is lost. On unsealed outback roads, a two-hour drive will punish any load that has not been properly secured.

4. Protect Core from Weather During Transport

Exposure to rain, wind-blown dust, or extreme heat during transit can alter sample chemistry, wash away fines from broken intervals, and contaminate core surfaces. In remote Australian conditions, these are not edge cases. They are the default environment.

At a minimum, place lids on the top layer of trays on every pallet. For long-haul freight, particularly open flatbed transport, cover the entire pallet with heavy-duty plastic wrap before strapping. This also protects labelling from fading or smearing during transit.

5. Match Your Dispatch Records to Your Core Before It Leaves Site

Before loading, create a simple manifest listing hole ID, tray numbers, depth intervals, pallet count, and the destination lab. Send it electronically to the receiving lab ahead of the physical shipment.

If 40 pallets arrive at a yard or lab with no manifest, they have no way to reconcile what was sent against what was received. Discrepancies identified weeks later are almost impossible to resolve. Under the JORC Code (2012 Edition), sample security and chain of custody are explicit reporting requirements. Your dispatch manifest is the first documentary link in that chain.

A photograph of each loaded pallet before departure, matched to the manifest, takes 30 seconds and can save days of investigation if something goes missing in transit.

The Bottom Line

Drill core is the single most expensive and irreplaceable product of an exploration program. The practices that protect it are not complex. They are labelling, packing, strapping, covering, and documenting. Five straightforward steps that take minutes at the site and save thousands at the other end.

The core is worth nothing if it does not arrive the way it left the ground.