ITP55 Deployment Operations

The last of the four ITP systems to be deployed during JOIS 2011 was ITP 55, and it would not be easy. Complicating floe selection, the ice conditions were deteriorating as the cruise was heading out of the multiyear pack ice into marginal ice, and a thick fog limited helicopter operations within close proximity to the ship. However, a floe was found that was over 3 m thick near the center, tapering to 1.6 m at the edges which was sufficient for deploying the 3 buoys composing this particular Ice-Based Observatory (IBO).

While deployment of the ITP proceeded, other scientists surveyed the ponded floe. A prototype profiler with current probe was originally to be deployed as ITP 55, but difficulties during bench tests onboard the ship prohibited its use. Fortunately, ITP 42 had been recovered earlier during the cruise (see ITP 42 Recovery Operations) and that profiler tested well except for a bad battery pack, so would be used instead with the new battery pack from the prototype profiler. The recovered surface package was renumbered and prepared with new batteries, as well.

The deployment proceeded in usual fashion until the first inductive modem test with the profiler suspended on the wire revealed a problem. After a significant amount of troubleshooting on the ice it was determined that the problem resided with the inductive modem in the surface package. Rather than abort the deployment, it was decided to swap in the new surface package electronics that had been originally prepared for ITP 55 (which was composed largely of parts retrieved from recovered ITPs 24 and 4). While one member of the team returned to the ship and made the changeover, the other members proceeded to deploy the SIMB and Uptempo buoys.

When the new surface package arrived, the inductive modem test was a success, and the remainder of the deployment proceeded as expected. Despite all of the difficulties, the Frankenstein refurbished ITP deployment with IBO was accomplished in 4 hours – only 1.5 hours longer than expected.

More information and photos on the deployment operations conducted during the IBO deployment are also available at: https://www.whoi.edu/page.do?pid=74916.

The reconnaissance team on the ice is barely visible from the ship through the fog. (Mary-Louise Timmermans)

Jeff Pietro, John Kemp and Gary Morgan suspend the ITP profiler on the wire to make the first inductive modem circuit test.

Jeff Pietro, John Kemp and Gary Morgan suspend the ITP profiler (recovered from ITP 42 just over a week earlier) on the wire to make the first inductive modem circuit test. (Rick Krishfield)

When the inductive modem test fails, Rick Krishfield suggests reseating the cables, but unfortunately it is determined that the modem in the surface package (lower left) has a problem. (Mary-Louise Timmermans)

While the new surface package is being prepared on the ship by Steve Lambert, the rest of the team installs the SIMB. (Mary-Louise Timmermans)

Lambert is back with the new surface package, mostly refurbished from previously recovered ITP parts. (Mary-Louise Timmermans)

After a successful inductive modem test with the new surface package, the profiler is finally released down through the ice hole. (Gary Morgan)

ITP 55 surface package is positioned in pace by Lambert and Morgan while Pietro slips the tag line. (Mary-Louise Timmermans)

The team anxiously awaits the response from the final inductive modem test with the system deployed. Fortunately the result is positive! (Mary-Louise Timmermans)

ice thickness and freeboard measurements at the buoy sites of the last IBO deployed during JOIS 2011 are shown

Barely visible through the fog, the distribution, ice thickness and freeboard measurements at the buoy sites of the last IBO deployed during JOIS 2011 are shown. (Rick Krishfield)