Long Piston Coring

In June 2001, MESH organized a workshop to discuss the feasibility of long piston coring on UNOLS vessels. The workshop was sponsored by MESH and by several research and facilities programs within the NSF Division of Ocean Sciences. The workshop was attended by scientists representing various marine Geology and Geophysics disciplines that rely on sediment core acquisition, by marine technical personnel from the large UNOLS vessels, and NSF Program Directors from both the research and facilities sections.

Here is a list of the findings and recommendations of the workshop:

1. In order to penetrate 40 m into typical marine sediment lithologies, a coring system with a weight on the order of 20,000 lbs will be required.
   
   
2. Empirical observations and modeled values for pullout tensions experienced by long piston cores weighing 10,000 to 22,000lbs fall in the range of 30,000 lbs up to extreme values of 50,000 lbs (modeled for high shear strength sediment lithologies).
   
   

3. These likely pullout tensions fall well within the range of capabilities of the large UNOLS vessels for stern deployment of a coring system, based on an analysis of ship strength and stability conducted by Glosten Associates.

4. Synthetic rope with the necessary strength and reliability is commercially available for a reasonable cost.

5. A traction winch can be designed to safely handle the synthetic rope that is required by these pullout tensions. A safe and suitable deck layout can be accommodated on the large vessels.

6. A portable coring system (including winches) can be designed for use on more than one large vessel.

Click here for a pdf version of the full draft workshop report.