Draga cilindrica
This instrument has been utilised since the seventies to tear up and collect rock samples, concretion and calcrete from slope outcroppings.
The dredge is composed of a large thick iron cylinder: 500 mm in diameter and 1200 mm in length, 250 Kg in weight. The front is equipped with alloy steel teeth, whereas the rear part carries a grill with square holes large enough to allow the mud to flow through while keeping the blocks of the rocky outcrop in.
The dredge operation has to be supported by an adequate winch, able to drag and support stress of up to 10.000 Kg.
It is recommended to apply a count-meter and a dynamometer to the winch, in order to verify the tension data on the wire on-line. Simultaneously this data can be sent to a program that will graph the trend.
Divulgazione
G. Busatti, P. Colantoni, A. Magagnoli, M. Mengoli – Il dragaggio del fondo marino strumentazioni e metodologie – Rapporto Tecnico n. 14, IGM – CNR, Bologna, 1981.
Cylindrical Dredge
