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doi:10.2204/iodp.proc.302.106.2006

Technical planning

In 2001, the JOIDES ADPG developed the first formal plan for drilling on the Lomonosov Ridge (Backman, 2001). A subset of the proponent group (J. Backman and K. Moran) were members of the ADPG and presented the multiple-ship concept to the ADPG, which was composed of scientists, naval architects, drilling and coring experts, and managers, most with Arctic or high-latitude experience. Given the scope of the mandate, the ADPG also engaged additional outside experts by writing work statements for specific planning tasks that were contracted and managed by JOI. The results of these contracts were incorporated into the ADPG report.

The ADPG was tasked with 15 different aspects of planning for the Lomonosov Ridge expedition. The most important were recommendations on vessels and vessel configurations, drilling systems and drilling preparations, ice forecasting, and management.

The group recommended several ship options but ranked a three-ship operation the highest. This option included an ice-strengthened drillship with two supporting icebreakers, a 75,000 hp Russian nuclear icebreaker and one diesel-electric Arctic-class icebreaker (~25,000 hp).

Several different drill rigs and equipment were evaluated, with Seacore’s C200 the recommended choice. The recommendation was made because the Seacore system met requirements that included the ability to be mobilized on the selected ship and the ability to recover continuous core using ODP-type coring tools. The group recommended that the drilling system be tested on the selected vessel in advance of the expedition to provide ample time for testing and to allow time between the test and the expedition for any required modifications to be made.

Ice forecasting was determined by the ADPG to be important for selecting general transit routes but essential for

• Maintaining the drillship in dynamic positioning (DP) mode during drilling over extended periods of time,

• Making decisions on the relative positions of the vessels ahead of the drilling platform,

• Deciding on optimal icebreaking modes, and

• Providing long-term forecasting of the predominant heading of ice movement.

Because of the significant role of ice forecasting, the ADPG also recommended that an “ice management system” be incorporated into the drilling project. Based on Beaufort Sea drilling experience, these systems are a combination of ice monitoring techniques and icebreaking methods (break or deflect) and include techniques for surveying both regional and local ice conditions that include satellite imagery (Radarsat), airborne Synthetic Aperture Radar, helicopter reconnaissance, visual observations (local ice conditions), and weather forecasting. Ice management systems use this ice monitoring information to develop icebreaking and management operations on a daily basis. The ice management system for Expedition 302 was further developed by the Swedish Polar Research Secretariat (SPRS), under contract to JOI. SPRS engaged experts from Russia, Canada, Finland, and Sweden to assist them in developing the plan.

An overall project manager was recommended to oversee the planning of the program (beginning 2 y prior to the scheduled project). The ADPG further recommended that it was essential for this person to have Arctic experience and a good knowledge of drilling management. The group recommended that the expedition be led by an ice/vessel expert who would have Arctic operational management and multivessel drilling expertise.

To increase the potential for success of drilling in moving sea ice, the proponent team requested and was granted approval to position drill sites along seismic lines rather than at single points on a line. This increased the flexibility for siting holes where one location along a line could have severe ice conditions whereas another line location could have more favorable conditions.

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