Coring is one method of collecting rock and sediment samples for geological research. A coring drill bit is designed with a central opening, around which the drill bit cuts the borehole. The core samples enter this hole, into a special chamber – a coring barrel, as the coring bit advances and then the sample is returned to the ship by wire.
Chikyu uses a wireline coring system. A special wire & wireline system is used to run down inside the drill pipe to lock onto the coring barrel and return it and the core sample to Chikyu for analysis.
There are five kinds of wireline coring systems used on Chikyu, and these are designed for different kinds of sediment and rock sampling. Primarily, these are classed as either piston or rotary type.