The 56B is conventional core barrel type simple, it means without an inner tube. The B range allows you to extract soil samples in homogeneous formations.

Here are the technical characteristics of the range B:
Diameters: 46, 56, 66, 76, 86, 101, 116, 131 and 146 mm.
Lengths: 500, 1 000, 1 500 and 3 000 mm.
Core barrels heads available alone.

Due to the absence of the inner tube and less consecutive pieces, the cost per meter drilled is less than with a double core barrel. We can add that the cutting surface of the bits is smaller, which permits to lower the price of use and increase the speed of penetration in the soil.
However, we precise that the conservation of the core is harder in heterogeneous terrains because there is no inner tube.