Day 13: 13 January 2019

Our team-leader, John Shears, would never say anything as insensitive as ‘sit down and shut up’.  He doesn’t have to, he has a set of facial expressions which are infinitely more eloquent.

Soon after leaving Penguin Bukta we held a meeting in the ship’s auditorium in which the Chief Scientist and heads of research each gave a talk on their respective areas of responsibility.  It was all getting-to-know-you type stuff.  I was talking about finding the Endurance, and thought I was doing ok until I glanced at John and noted something in his look that reminded me of the incomparable Mr Bennet*, as in ‘That will do extremely well, you have delighted us long enough’.   So I concluded and returned to my seat to what Variety magazine used to call ‘a little torpid mitting’. 

Anyway, at that moment I was responding to a good question put to me by my esteemed colleague Colin de la Harpe (who is measuring CO2 levels in the water to see how well the Weddell Sea is performing as a sink for all the fossil-fuel gases in the atmosphere).   Colin wanted to know what the wreck – if we find it – is likely to look like.  It’s an excellent question, and in view of what I said  yesterday about the state of preservation of organic materials on the Endurance, now is the moment to look at Colin’s question again.

We need to distinguish between the wreck’s condition and its state of preservation.   Let’s consider condition first.  When she sank the poor old Endurance was a mess.   Her planks had sprung, beams had snapped , decks had buckled, seams had opened,  and key elements of her primary structure had been torn asunder.  In addition, the ice had sliced through her standing rigging releasing her shrouds so that the masts came down.  This is perhaps something we can look at in more detail in a future blog, but, in summary, and as Hurley’s pictures demonstrate, at the time of her plunge she looked like something that had been dragged around Cape Horn backwards, twice, and whatever her disposition on the seabed, it will reflect that disarray.

Turning now to her state of preservation.  On the seabed a wooden ship will always deteriorate.  There will be chemical decay, bacterial attack and there will also be a range of mechanical forces at work.  However, the purity of the Weddell Sea, its deep cold, moderate bottom currents and the absence of light at 3000 meters, should inhibit the ability of these agents and factors to inflict ruin on the wreck.

Potentially more worrying is the dreaded shipworm, or teredo navalis, a wood-consuming marine parasite that is to wooden ships what deathwatch beetles are to timbre-frame houses.  Basically, they are voracious bivalve molluscs that enter the wood as larvae about the size of pinheads, but then metamorphosed into a pallid reddish ‘worm’ that turns into the grain swelling quickly to the width of one’s small finger and up to an extraordinary 2 foot in length.  My early work was on ancient ships in the Mediterranean where the hulls and upper works were all gobbled away; the only timbers to survive were those that went into the seabed .  The sub-bottom is essentially anaerobic, or oxygen free, and here the teredo, and gribble worms in general, cannot survive. 

The happy news is that studies conducted in the 1980s, and again more recently, have confirmed that wood-consuming marine parasites do not exist in Antarctic waters.  This is not surprising as reproduction is generally restricted to between 11 and 25 C, but having said this, in recent decades the teredo has become established in Port Stanley harbour (latitude 51 41’) where I have found them on 19th century shipwrecks.  In short, with regard to wooden shipwreck preservation, the Weddell Sea could (but for different reasons) be like the Baltic, where wooden ships have survived for centuries because of low salinity and the brackish nature of the water; or, like the Black Sea where wooden shipwrecks do equally well because at  a certain depth it becomes a dead zone where the anoxic conditions make it impossible for most benthic communities to survive.    

It is, however, possible that the hull of the Endurance became infested with marine borers when she passed through the tropics so that, when she sank, she took with her the seeds of her own destruction to the seabed; but this is highly unlikely as her hull was sheathed in greenheart, an exceptionally hard wood that was considered to be largely teredo-resistant. 

In short, although the wreck of the Endurance will be in some disorder, its timbers, nevertheless, should be in a relatively good state of preservation.  Colin’s question invited me to speculate on what she might look like.  Here I have just touched on two matters; there are other considerations and I will try to return to these tomorrow.

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A day of some frustrations.   Ship again trying to drive away the floes using its stern thrusters or fast-response boats.  At midday the large Eclipse ROV went down for under-ice trials.  It was gone about two and a half hours and went about 195 m horizontal under the ice.  There were some buoyancy issues and a couple of jubilee clips snapped because of the cold, but otherwise it went well.

For the first time we also deployed the brand-new Hugin AUV (no. 9) that had been especially designed with an upward looking sonar for under-ice scrutiny.  There were, however, ballasting problems as it could not get its nose down low enough to dive.  This, however, is the purpose of the trials and theses issues will be resolved.   More trials tomorrow.

Noon position:  66  29.8 S,  059  59.3 W

  • Of Pride and Prejudice renown.