Competitor Dart rigs are
mechanically simple and easy to operate. The rigs are designed for use by a
single operator and drilling can begin within minutes of arrival on site.
Because the units are
light in weight, site disturbance is minimised, making the Competitor Dart
ideal for use on environmentally sensitive sites. The rigs are highly mobile
and manoeuvrable: they can be tracked up slopes and can pass through a
standard domestic doorway. The rig is ideal for work on sites with
restricted access, close-up against walls and inside buildings, where it
would otherwise be difficult to obtain samples.
Sampling is achieved by a
percussive method. The drive mechanism consists of a hydraulic drive with a chain-driven drop
weight that repeatedly strikes an anvil, driving the rods and sample tubes
into the ground. The rig can drive sample tubes into all soil types, but it
is not designed for sampling or coring in hard rock.
The weight and the drop
height are adjustable, enabling Standard Penetration Tests (SPT) and Dynamic
Probing (Lost Cone) Tests (DPH and DPSH) to be carried out as well as soil
sampling. Blow rates up to 50 per minute can be achieved when driving sample
tubes into the ground.
After tools have been
driven into the ground to the required depth, they can be easily extracted
using the integral hydraulic jack that has a 7-tonne pullback capacity.
Extraction of sample tubes is achieved without having to re-position the
rig.
The Competitor Dart rig is based on seven years experience of manufacturing and
operating soil sampling rigs. Our prototype rig has completed extensive
field trials in the UK over the last 18 months using all aspects of drive
sampling from geotechnical to environmental investigations.
The Dart is
operator-friendly and its use far less physically demanding whilst being
much faster than other drive sampling rigs. Ease of use has been our
priority in the months of design needed to bring this machine to the
forefront of percussive soil sampling.
The Competitor Dart rig
has the facility for extraction of up to 5 metres of drill rods without
uncoupling the drillstring, a feature that makes soil sampling much faster
than other drive sampling rigs. However, this method can only be used when
the rig is mounted to an undercarriage or other stable structure, but not in
standalone mode.
In many situations it is
necessary to break through a hard surface prior to sampling or testing the
ground. For this purpose the Competitor Dart rig can be supplied with an
optional rotary attachment, designed for coring through concrete or other
hard surfaces at ground level. With the rotary attachment fitted to the
rig, it is not necessary to purchase additional concrete coring equipment or
employ specialist concrete coring contractors, resulting in a significant
reduction in project costs.
To prevent the borehole
from collapsing when extracting samples, casing tubes can be driven into the
ground at the same time as the soil samplers. This method, referred to as
our Simultaneous Casing System, has been designed specifically for use with
the Competitor rigs. As well as preventing collapse of the borehole, the
method ensures that there is no cross-contamination between successive
samples, even when sampling very loose ground.
See also:
Overview
Rig Options
Spare Parts
Technical Specification
Ancillary Equipment
