Marine Ecosystems Research Department - jamstec japan agency ...
Marine Ecosystems Research Department - jamstec japan agency ...
Marine Ecosystems Research Department - jamstec japan agency ...
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Japan <strong>Marine</strong> Science and Technology Center<br />
OD21 Program <strong>Department</strong><br />
significantly to advancing earth and life sciences.<br />
Construction of CHIKYU began at the end of FY<br />
, with the main contract for construction awarded<br />
to Mitsubishi Heavy Industries, Ltd. In FY outfitting<br />
of equipments on hull parts and interior works<br />
at laboratory/accommodation areas were carried out at<br />
the Tamano Shipyard of Mitsui Engineering and<br />
Shipbuilding Co., Ltd., which is in charge of hull construction.<br />
In this fiscal year, hull construction was<br />
almost completed. Regarding the drilling part of the<br />
vessel, equipment for pipe handling and mud circulation,<br />
drilling control system and derrick were fabricated.<br />
At the beginning of FY , sea trial on the hull<br />
part will be carried out. After that, CHIKYU will be<br />
shifted to the Nagasaki Shipyard of Mitsubishi Heavy<br />
Industries, Ltd., and outfitting of drilling related<br />
equipments will be started.<br />
Observatory<br />
Station<br />
Borehole<br />
Sensor<br />
Vehicle<br />
(2) <strong>Research</strong> and Development on a Borehole<br />
Observatory System<br />
The borehole is not a mere relic after recovering the<br />
core sample from the sea floor, rather it is a scientifically<br />
very important window for monitoring the<br />
earth's interior. The BENKEI borehole reentry/observatory<br />
deployment ROV is a tool to deploy observatories<br />
and to conduct various measurements inside boreholes,<br />
for the purpose of scientific research. It has<br />
been developed over three years since FY .<br />
Figure is a photo showing the appearance of<br />
BENKEI.<br />
The BENKEI system consists of a borehole sensor<br />
lowered into a borehole; an observatory station, to<br />
Fig. 3 Appearance of BENKEI<br />
function as the platform (hereinafter referred to as the<br />
"station"); a vehicle to transport, deploy, and recover<br />
the station; and a support vessel, the KAIREI, to monitor<br />
and control all these instruments. Table shows the<br />
principal specifications of the BENKEI system. The<br />
primary cable, launching, and recovery system on the<br />
KAIREI are used for not only the KAIKO, but also the<br />
BENKEI. The maximum operation depth of the<br />
BENKEI is , meters. One of the important missions<br />
of the BENKEI is the preliminary survey inside<br />
boreholes before deploying a long-term borehole<br />
observatory. The BENKEI system can measure pressure,<br />
temperature, pH and borehole diameter up to a<br />
Table 2 Principal specifications<br />
Maximum operation depth 6,000m<br />
Maximum operation borehole depth 1,000m<br />
Vehicle dimension – weight in air (weight in water)<br />
Station dimension – weight in air (weight in water)<br />
Sensor dimension – weight in air (weight in water)<br />
Maximum sensor payload (weight in water)<br />
5m 2.6m 2m 48.0kN31.4kN<br />
2.3m 2.8m 35.3kN24.5kN<br />
205mm 5.1m 1.8kN1.1kN<br />
4.5kN3.3kN<br />
173