ST-Rods: the (un)folding CPT string

Patented SingleTwist technology

Because the rods have a self seeking bayonet thread (pictures above) they close effortlessly and require just a final, short, single twist to become firmly interlocked, hence the name SingleTwist-Rods. Having rods with this patented design, the transformation process during CPT pushing as well as pulling is like a natural flow and done almost entirely mechanically, making it very robust indeed.

Folder

The Folder, a reel with a single layer of rods, can be supplied with a diameter from 6 rods/winding upwards and with a width starting from a winding or two. This allows for folders holding between 5m and 75m of CPT string, depending on the application. In case of string damage, each full winding can be easily replaced with a spare one. And between jobs, one folder can be exchanged with another, provided they have the same diameter.

All it takes to put together an automated CPT system, i.e. one that performs a full CPT and a subsequent complete reel-in of the string on a single operator command, is a Folder, a Twister and a Sprocket, a wheel to connect the two. This very compact SingleTwist™ system (picture above) can be mounted on virtually any A.P. van den Berg pusher, including onshore COSON penetrometers and ROSON seabed systems.

Needless to say that, since the ST-Rods come fitted with an Icone cable, you enjoy the full bandwidth of A.P. van den Berg’s digital bus and you are compatible with all Icone sizes and all available click-on modules.