August 27, 1999
Japan Marine Science and Technology Center (JAMSTEC)

Loss of Large Rosette Water Sampler Caused by Cable Broken

1. The facts
On Wednesday, August 25, 1999, a large rosette water sampler was used (Fig. 1) to carry out a CTD survey [Note 1] on the Mirai (an oceanographic research vessel belonging to JAMSTEC) off the coast of Kushiro (Fig. 2). At 22:45, the ship's crew finished sampling water at a depth of 4,168 meters and began to reel in the sampling instrument. Immediately thereafter, the cable broke when the instrument was at a depth of 4,128.6 meters, causing the loss of the sampling instrument.
The accident did not involve injury to any personnel.

2. Cause of accident
Our preliminary outlook is that the cable broke because it worked itself off the lower spool on the traction winch [Note 2]. The cause will be determined for certain after the ship is berthed at the Port of Hachinohe.

3. Revised plan
The original plan was to use the large rosette water sampler to study the structure of circulation in the sub-tropical Pacific Ocean as well as the Arctic Ocean. We will readjust the project schedule and continue our survey using a small rosette water sampler.

1. A CTD survey is one of the most basic oceanographic surveys, and involves the sampling of salt concentration (C) and water temperature (T) at a randomly selected depth (D). The sampled water is put through various analyses.
2. A specialized winch used for reeling in especially long cables.

For further information, contact the Japan Marine Science and Technology Center.
If you wish to talk with someone in the Ocean Research Department, ask for Dr. Takizawa. Tel: +81-468-67-5571
If you wish to talk with someone in the Public Relations, Training and Education Division, ask for Mr. Taya or Mr. Kimura. Tel: +81-468-67-3806

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