Bürkle Mole Drill Head with Stone Catcher, interchangeable head for soil samplers, iron/steel, 5350-1045

Sometimes it is not the ground itself that is the problem when taking a sample, but a single stone lying right in the borehole and blocking any other drill bit. The Maulwurf rock-catcher drill head is designed precisely for this situation. It catches and pulls out rocks that obstruct sampling with other drill heads, thereby clearing the borehole for the actual sampling head. Without this intermediate step, the only option would often be to try re-starting the borehole at a different point, which costs time and shifts the sampling location.

Not a substitute for the other drill heads

The stone catcher is not an alternative to the heads for clay, sand, coarse sand, combination, riverside or gravel, but rather a supplement. It does not take a conventional soil sample itself; its purpose is to remove an obstruction from the borehole before the actual sample is extracted using one of the other drill heads. In practice, this often means fitting the rock catcher to the handle part-way through, removing the obstructing stone, and then switching back to the appropriate head for the soil type.

When the stone catcher is worthwhile

The stone catcher is most useful where drill bits repeatedly get caught on individual stones, for example on sites with previous development, backfill or generally stony, scree-filled subsoil. If the entire ground is uniformly gravelly rather than just sporadically stony, the gravel drill bit is usually the better choice straight away, as it continuously collects the material rather than simply removing it.

Use with the ‘Mole’ handle

The stone catcher is also an interchangeable part for the ‘Mole’ handle with pole and cannot be used without it. The handle is 750 millimetres long; for deeper drilling, it can be extended with a 100-centimetre extension (5350-1010).

Typical applications

The stone catcher comes into its own whenever an obstacle in the ground interferes with the actual sampling process, for example when:

• Removing obstructing stones prior to the actual sampling
• Site investigation on stony, scree-covered areas
• Investigating contaminated sites on formerly built-up plots with construction rubble in the ground
• As a supplement to the other ‘mole’ drill heads where the soil composition is unclear

A supplement rather than a replacement

For the actual sampling after clearing the area, one of the other drill heads is used again depending on the soil type – for example, the ‘Clay and Wet Soils’ drill head for cohesive material, or the ‘Combination’ drill head for varying soil conditions. Anyone who regularly works on stony surfaces therefore usually carries the stone catcher in addition to the actual sampling drill head, not instead of it.

Material and storage

The stone catcher is also made of iron/steel, contains no electronics or battery, and is therefore resistant to rough contact with stones. No calibration is required at all. To store it between uses, a dry place at room temperature is sufficient, ideally together with the other Maulwurf accessories, so that it is to hand when needed.

Technical details

Contents

• Mole drill head, stone catcher

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

For sites with known construction rubble or stony ground, LT Laborhandel will, on request, assemble the stone trap together with the sampling head suitable for the soil type, so that both heads are ready to hand in the same toolbox from the outset. If you have any questions regarding the combination of the two heads, please contact LT Laborhandel directly.