Day 14: 14 January 2019

In response to my colleague Colin de la Harpe’s question regarding the appearance of the Endurance on the seabed, I have written that I believe she will be in a state of considerable disorder but that her timbers are likely to be reasonably well preserved.  To probe the question further there are three other factors we need to ponder:  how she fell through the water, what happened on impact, and how the latter will be reflected in her disposition upon the seabed.

The two factors that probably most influence a sailing vessel as it sinks through the water, are its shape and drag.   Because of the streamlining of their lower and forward hull, most ships tend to descend keel-first or somewhat down at the bow.  In four decades of looking at shipwrecks I have only seen two wrecks upside down on the seabed,  and in both cases they had left the surface in somewhat unusual circumstances and were in water of relatively little depth that did not allow them time to establish some level of equilibrium within their fluid environment as they were going down.

Turning to drag.  With a sailing ship the masts, yards and canvas will always impose a significant element of drag upon a sinking hull which usually ensures a mainly upright or down-at-the-bow plunge.  We have seen in Hurley’s photographs of the Endurance that her masts were not upright when she made her final slide.  If we zoom in closer we can see that her poles are still roped to the hull by both standing and running rigging.  In other words, as the Endurance sank through the water there would have been an incredible trail of masts, yards and canvas behind her which would have created a much greater hydrodynamic drag than in a normal sinking scenario.

In summary, we can say that, as long as the Endurance left the surface in a reasonably coherent state, she would have landed keel first or somewhat down-at-the-bow, and that, although she may have heeled somewhat on to the turn of her bilge, she most likely came to rest in an upright or semi-upright position.   Whether a Roman ship carrying 8,000 amphorae, a South-East Asian junk full of porcelain, or a 19th century ship-of-the-line stripped down for action,  this has nearly always been my experience of ships on the seabed.   However, with the Endurance there is another factor involved which takes her outside my normal range of experience, and that is her extreme depth - and this I will address tomorrow.   

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Sea perfectly calm, temperature -4C.    This morning we were off the tip of Cape Framnes where at 0924 hours we began a ROV dive to 400 m for the marine biologists  to study the seabed which, until 50 years ago, had been under an ice shelf.  In real time the video was relayed to the lounge where it was watched by most who were at that time off-duty.

Once the ROV was back AUV 9 was launched for further trials but again had trouble submerging and had to be recovered for further ballasting.   There is now little doubt that the next dive will succeed and a mission profile has been prepared for its first dive under ice.

At 22.30 the Agulhas II went along side an enormous floe, about seven kilometres in length, to prepare for the first under-ice AUV trial.  The ice was multi-year, thus of varying thickness from 3 to 7 m with a much gnarled surface that had been cause by pressure ridges and rafting events.

We are now concluding the trials phase of our programme.  From now until the 24 January we shall be concentrating on science.  As they like to sing in the Marriage of Figaro, Tutto è disposto (everything is ready).

Noon position:  66  01.2  S,  060   21.8  W