Field equipment:

Our orange peel grab generally performed well in sediment ranging from soft mud to a coarse gravel. However, it did not trigger on several occasions for one of two reasons, insufficient line out (with a strong drift we found it necessary to pay out as much as 1100m of wire to reach bottom in 800m of water), or the release hook jammed in a shackle. Both problems were easily overcome once identified. The trigger mechanism on the sphincter corer also gave trouble, and required several attempts before it was modified to work satisfactorily. Nevertheless, it worked extremely well for the second part of the cruise.

The hydrographic winches on "Glacier" were ideally suited to our work. Continuous display of wire speed and load was particularly useful, as we soon found the optimal working speeds for each piece of equipment. The grab could be sent down at 80m/minute but if it came up much faster than 25m/minute the sample was washed. The sphincter corer could go down at 80 speeding up to 150m/ minute over the lower 70m, then up at 60. Faster retrieval risked the butterfly valve and the core. Operating speeds were important to establish not only for the most satisfactory operation of the equipment, but also because the engine room required 30 minutes notice to provide power for the ship to get underway.