Cable percussion (cable tool) drilling is the oldest, simplest, and most reliable
technology available of borehole drilling, at the least capital cost.
It will drill any material and requires no mud, pits, pumps, chemicals,
or compressors, yet will drill rock.
The method uses tools suspended on a wire rope, which are lifted and dropped to
break up and remove material from the bottom of a hole. A variety of tools can
be used. Clay cutters and stubbers allow rapid drilling in clays and in sands
having some clay content, to remove solid plugs of material. Other bits perform
in harder materials.
This non-invasive and sensitive borehole drilling method, allows discovery,
testing and development as drilling proceeds. It is an appropriate method for
water wells, environmental drilling, site investigation, remediation, and prospecting.
At only 400 Kg, this machine can be man-handled to places inaccessible to heavier
equipment.
Designed for drilling contractors & NGOs with a WATSAN programme, it is a useful
means of finding sites for hand dug wells. The presence or absence of boulders
can be quickly determined, in addition to the depth, quantity and quality of
groundwater, eliminating the high failure rate of randomly sited dug wells.
Forager Trailer-tripod cable tool borehole drilling rig with 1250 Kg winch & 10 hp Lister-Petter diesel
FORAGER - ADVANTAGERS
Forager drilling is simple. It requires no additional materials, auxiliary pumps,
mud chemicals or additional engines to operate.
The single engine, and the winch with two levers, does all the work. The only
other input that may be required in some materials is a little water. This is a
small amount, to form a slurry with crushed or broken material, allowing it to be
bailed out of the hole. For clay cutting or drive barrel drilling no additional
water is necessary; hence the description as 'dry drilling'.
Using a clay cutter/Drive barrel
The method will drill in any material from soft sands and clays to hard rock like
granite.
The rig is entirely mechanical with no hydraulics or electrics and, no clutch.
Setup is quick, and as the frame is light, is all done by hand using the balanced
weight of the machine to help push up the tripod. This is a one-man job with no
need of mechanical assistance.
The shell & auger (drive barrel) drilling method is non invasive. It does not cause modifications to the strata - it
is simply removing material from the hole. This is similar in effect to the
traditional pick & shovel hand digging method which was used to excavate open pits and
wells.
The Forager drilling system is based on a high quality free-fall winch, which
hoists and then lets fall a set of drilling tools to break up and recover materials
to create a bored hole. Tools can include clay cutters, stubbers, rock crushers, bailers and drive sampling tubes.
Clay cutters and stubbers take advantage of the property provided by the winch and tools
in free-fall to cut a core, or plug, in any cohesive material (clays and sands with some
clay content), which is removed from the tools at ground level. Rock crushing tools
break up hard materials which can be removed with a bailer after adding enough
water to form a slurry. Water extracted by bailing gives a good indication
of the yield, and water quality at any level, without having to install pumps.
The machine is well balanced and can conveniently be wheeled by hand between sites
without using a towing vehicle - including while carrying the drilling tools. The
winch can be utilised to haul the rig to more difficult places, crossing streams
etc. as the engine is sufficiently level to be run while the rig is folded and
on its road wheels. Being able to 'walk' the rig between village sites can save
considerably on the need for and cost of transport in support of a drilling
programme. This facility also enables drilling to take place where there is no
normal vehicular access. The rig, together with tooling, is canoe portable.
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FORAGER CABLE PERCUSSION RIGS
Brutally rugged high quality rigs with very low inputs - quick one man set-up and
operation; they cover the entire range of materials, with nothing extra to buy
if the ground is harder than you thought. Machines are permanent, long life and
maintanable, using high quality components.
At their heart is the engine & winch combination; we use our own highly successful
design of clutchless freefall drilling winch and good quality engines.
They are suitable equipment for contractors and NGOs producing typical rural water
wells for hand pumps. Faster and cheaper than hand digging for rural development
programmes - not stopped by boulders, and a profitable commercial investment for
drilling water wells, site investigations, window sampling, remediation wells and
other environmental drilling. Can be used for setting drive points, hydraulic
(jet) percussion drilling, peizometers & insitu testing, geothermal drilling, and
prospecting.
SPECIFICATION for FORAGER-1250 'STANDARD' BUILD
Winch single line (bare drum) pull: 1250 kg (2750 lbs)
Weight of drilling tools: 250 Kg (550 lbs)
Drum capacity: 110m (360 ft) of 10mm dia. wire
Speed of hoist on a bare drum: 38m/min. (125 ft/min.)
Tripod frame hoisting capacity 5,000 Kg (11,000 lbs)
Height under top sheave 4.575 mtrs. (15 ft.)
Lister-Petter diesel engines standard, but also other diesels
PICTURE RIGHT:
Forager drilling in chalk below superficial clays having driven 25m of 6" temporary casing - for water
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FREE-FALL WINCH
The main component of this drilling system is the Consallen F-1250 free-fall wire
winch, providing a bare drum single line pull of 1,250 Kg (2750 lbs) at a hoisting
speed of 38m/min. An overload protection device is fitted.
The winch is clutchless, being based on an internal epicyclic gearbox, and is operated
and controlled entirely by two external band brakes. A foot pedal operates the
drum brake and a hand lever controls a second brake, which causes the drum to reel in
when it is applied. Relaxing the hoist lever allows the tool string to fall freely
for maximum impact in the hole. However, control of the tool string when handling
it above ground is excellent, sensitive, finger light and easy. The foot brake can
be locked on with simple catch, allowing the operator to walk away from the machine,
leaving the tools suspended.
FREE-FALL WINCH
The winch drum has a dividing plate, providing an area of storage separated from
the active wire length. The substantial cage over the winch drum acts both as a
wire guide and protection. Weather proof covers are provided for brakes and the
belt drive.
The picture shows controls at the operating side, with a Yanmar engine alternative
to the normal Lister-Petter; other engines are also possible. The Yanmar has a
recoil starting system, as against the crank handle of the Lister-Petter.
As shown here, the winch is entirely mechanically powered via a belt drive from
the engine. The belt drive is permanent and cannot normally be disengaged. For
special purposes, the winch can be driven by hydraulics, which provide some
addtional control options.
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TOWING
The rig, when folded, can easily be towed by a small car or pickup - even carrying all the
drilling tools in the central cradle formed by the tripod. The balance of the
machine means that it can be wheeled easily by hand.
Shown here with the Lister-Petter diesel engine option - a cast iron engine 45 Kg
heavier than the Yanmar, with crank handle starting, and about 10% more torque than the
aluminium Yanmar.
The KIT - for local completion
For certain overseas purchasers the drilling machine is available in kit form.
It is supplied partially completed, with sub-assemblies ready for welding
to locally supplied rectangular and square hollow section (box section tubes).
Completion of the rig requires simple and commonly available skills and equipment
for hand cutting and welding. We have a separate CD which illustrates the work
required and the components supplied, which will be sent on request.
The advantages of this approach are that cost of the kit is less than would be
the case for equipment completely finished in UK, the freight cost is reduced,
and the import cost is less for self-coloured components than for bright galvanised
items.
Some additional information on the Kit version of the rig is shown on the
Price List for which a link is provided in the section below.
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OTHER TYPES of WORK -- (Other uses for this equipment)
Tripod type drilling machines shown here lend themselves to activities, other
than plain drilling, utilising the freefall features offered by the particularly
robust type of wire winch.
Driven wells (drive points or well points) can be made either at ground level,
after drilling a pilot hole, or in the bottom of an existing well.
Piles may be driven for foundations using either top or bottom driven methods
with open or closed tubes. Timber piles can also be driven by the drop hammer method.
The Machine is also offered as a short piling frame - either skid mounted or
wheeled, for moving about sites and road towing. Wheel sets are easily detchable.
Schematic of a Piling Frame version
The machine may be used for work-over duties such as well cleaning, development, surging and
bailing of existing wells and bore holes.
The chiseling action of a falling string of tools may be used for simple hydraulic
drilling with water flush & hand oscillation. This equipment is versatile and
reliable in many common formations, using very elementary tools based on cheap plumbing pipes.
Site investigation work can be undertaken, including the recovery of undisturbed
samples of the U4, U100, Acker and Shelby Tube type. Standard Penetration Tests (SPT)
and Cone Penetration Tests (CPT) can also be undertaken.
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PRICES
The current illustrated Ex Works UK Price List is available via the following link
button:
