Cable Percussion Tooling

Dando supply all types and sizes of tooling and sampling equipment for use with its cable percussion drilling rigs, including sinker bars, shells, clay cutters, casing and SPT & U4/U100 equipment.

Please see further down for product codes and descriptions.

Sinker Bar

The sinker bar is a weight which is fitted immediately behind any drilling tool required to advance the hole. An intermediate sinker bar can be used to add extra weight to the drilling tools.

Shell

Used for drilling soft formations, such as sands and gravel, and for cleaning the hole.

Clay Cutter

The clay cutter provides a rapid method of penetrating plastic clays and similar cohesive soils.

Clack Valve

Clack valve for shell, can be either steel or leather.

Swivel Rod

Permits the tool string to be rotated easily.

Shell/ Claycutter Shoe

Dando offers a variety of shoes for use with its shells and claycutters including plain, serrated, chisel and gravelling types.

Stubber

Used in similar conditions to the claycutter, but easier to empty of plastic clays.

Cross Chisel

Useful for breaking up large stones when drilling in hard formations.

Casing

Casing can be used as a temporary support in non-cohesive or weak collapsing formations as well as a permanent method of lining a borehole.

SPT Equipment

Standard penetration testing is carried out to determine the density, strength and consolidation characteristics of soil using split barrel samplers. It can also provide disturbed samples for identification of soil components. The recorded blow count is used to determine the resistance to penetration of the soil involved, which can be related to the unconfined compressive strength. The penetration resistance is related to the number of blows required to cause the assembly to be driven 12 inches (300mm) into the ground, after seating using I 401b (63.5Kg) weight falling 30 inches (760mm).

U4/U100 Equipment

(U.4./U I 00) is designed for standard undisturbed soil sampling and extraction of 100mm (4”) cores of cohesive strata for laboratory testing. The main component is the jarring link and drive head adaptor. A core tube with a hardened steel cutting shoe fitted to one end, is attached to the drive head and lowered into the borehole on boring bars. The weight of the latter is usually sufficient for driving the core tube into the formation and a careful check should be kept on the depth of penetration. The standard core tube is 457mm (18″) long and is machined to limits internally. To shear off a core cleanly give the boring bars a full turn in a clockwise direction before extracting.

Undisturbed soil samples should preferably be sealed both ends. For longer cores, two tubes can be coupled together with the special barrel shaped adaptor.