Bürkle Mole Drill Head for clay and damp soils, interchangeable head for soil samplers, iron/steel, 5350-1015

Clay soils and damp, cohesive sites offer greater resistance to a soil sampler than dry, loose subsoil. The material sticks to the flanks, the auger head finds it harder to penetrate, and, depending on the design, fewer samples remain stuck when it is withdrawn than were actually extracted. The ‘Mole’ auger head for clay and damp soils is designed precisely for these conditions, with narrow flanks that encounter little resistance in the soil whilst still reliably carrying away the cohesive material.

Narrow flanks for cohesive soils

Bürkle supplies several interchangeable drill heads for the ‘Maulwurf’ soil sampler, each tailored to a specific soil type. The version for clay and damp soils has narrow flanks which, compared to the wider sand and gravel heads, offer less surface area in contact with the soil and therefore require less force when turning in. In damp, cohesive soils, this is an advantage, as the material adheres well to the drill head anyway and does not require a large surface area to remain in the drill tip.

Cleaning between two sampling points

Precisely because clay-rich material adheres so well, a residue often remains in the drill head after a sample has been taken. If the next sample is taken at a different point on the same site, the head should be cleaned beforehand; otherwise, old and new material will mix, distorting the analysis results. During contaminated site investigations and ground investigations involving multiple drilling points, this brief cleaning between locations forms part of the standard procedure when using the ‘Mole’ system.

Use with the ‘Maulwurf’ handle

The drill head is not a standalone device, but an interchangeable part for the ‘Mole’ handle with pole. A soil sample can only be taken when used in conjunction with the 750-millimetre-long handle; the drill head itself does not have its own handle. For deeper drilling, a 100-centimetre-long extension (5350-1010) is also available, which allows the drilling depth to be increased without having to change the handle itself.

Typical applications

The drill head for clay and wet soils is used wherever cohesive, water-saturated material needs to be reliably extracted, for example in:

• Site investigation in cohesive, clayey soils
• Soil mapping in damp floodplain and marsh soils
• Contaminated site investigations at locations close to the water table
• Agricultural soil sampling in heavy, loamy soils

When clay is not the only soil type

If the soil in an area varies between clayey and sandier sections, the ‘Combination’ drill bit covers both properties in a single bit, rather than switching between two bits. If the site is in a drier, sandier area, the ‘Sand’ drill bit is the more suitable choice, as its wider flanks hold loose material more effectively. If there are isolated stones in the clayey subsoil that block the narrow drill head, the stone-catcher drill head removes them first before continuing to drill with the main head.

Material and storage

The drill head is made of iron/steel, the same material code as the Mole handle itself. As a purely mechanical tool with no electronics or battery, it requires no calibration and has no charge level that needs to be checked before use. For storage between uses, room temperature is sufficient; a dry place in a vehicle or storeroom is adequate, provided the head is stored clean and free of any adhering sample material.

Technical details

Contents

• Mole drill head for clay and damp soils

The Mole handle with shaft is not included in the scope of delivery and must either be provided separately or ordered at the same time.

Service and procurement

Anyone working on a site with varying soil types usually orders the drill head for clay and damp soils from LT Laborhandel together with one or two additional heads for the remaining sections, so that the handle does not remain unused on site. If you have any questions about selecting the right drill head for your specific site, please contact LT Laborhandel directly for assistance.