MARUM-MeBo70 drill rig

The central parts of the drill are the drill head and the feeding system. The drill head is a rotary unit that provides the required torque and rotation speed for rotary drilling and for making or breaking the threads of the drill string. The feeding system consists on the mast along which the drill head mounted on a guide carriage moves up and down. Cores are taken from the sea floor by simple pushing a push core barrel (push coring suitable for soft sediments) or by rotating and pushing a rock barrel (rotary drilling for hard rocks). A water pump provides sea water for flushing the drill string for cooling of the drill bit and for removing the drill cuttings.

Since 2008 the MARUM-MeBo70 is capable of drilling with wire-line coring technique. After drilling a 2.5 m section the core is recovered using a wire that is latched to the inner core barrel with an overshot. The outer drill string stays in the drilled hole during the entire drilling process. Therefore no casing is required and drill string handling time decreases drastically. Using wire line coring-technique the MARUM-MeBo70 can sample the sea floor down to 80 m.

Drill rig specifications

Hight	5.6 m (transport); 6.6 m (work)
Footprint (vertical)	2.3 x 2.6 m (legs raised); 7.0 x 7.3 m (legs extended)
Weight in air	Approximately 10 t
Weigth in water	Approximately 7 t
Maximum operation depth	2,000 m below sea level
Maximum sampling depth	>80 m
Maximum coring length	>70 m
Drill tool size	HWL (wire line)
Run length	2.5 m
Core diameter	57-63 mm
Maximum push thrust	5 t
Maximum rotary speed	400 rpm
Hydraulic power	130 kW