ALTEX Arctic Cruise
October 7 - November 7, 2001
Tromso, Norway to the Arctic Circle
October 15, 2001: Day #9
Mike Pinto writes: We are moving south in search of an area to conduct the first under-ice test of the AUV. Ideally, the area should be large enough for open water deployment and recovery with a well-defined margin of consolidated ice.
Earlier in the day, the JPL group continued the task of collecting ice cores on the floe next to the ship. Fortunately, they got the power auger working which made their task much easier in the -3.3 degree C (26 degree F) air temperature and 13 knot winds. While the coring was going on, we all had the opportunity to spend an hour on the pack ice taking in the beauty, snapping some photos, and tossing a few snowballs, all under the watchful eyes of a Coast Guard sharpshooter keeping a lookout for polar bears.
Many of us took a tour of the Healy's mechanical systems. The Healy's two 4.8 meter (16 feet) diameter props are powered by two alternating current electric motors that generate 11,190 kilowatts (15,000 hp) each that can turn each prop up to 175 rpm's at full power! Electricity to run the motors and the house system are provided by four 12-cylinder engines coupled to massive generators. The diesel engines can generate 597 kilowatts (800 hp) per cylinder. The entire system is computer controlled from a central command center. One interesting sidelight is that the Healy is one of the first military vessels to incorporate a sophisticated equipment monitoring system to determine maintenance needs. Historically, preventive maintenance dictated equipment be maintained at specific intervals, even if it was working perfectly well. Data are collected and reviewed both on the ship and on shore to determine equipment maintenance tasks, saving both time and money over earlier maintenance schemes.
In the early evening, news came in on the validation of CTD data obtained by the AUV. Dr. Ned Cokelet plotted AUV CTD data against data obtained by a CTD cast in the area of the AUV operations. The data correlated very well. This correlation is of critical importance to the future of the AUV as a platform for collection of science data.