In from the cold …..

….. new year – new problems.

In our line of work we have a lot of things to think about that wouldn’t necessarily cross your mind, like:

  • what sort of pressures are reached at the deep ocean bed?
  • how do we keep the water out of critical systems at those pressures?
  • how do we get heavy things to float in water?
  • how do we get floaty things to sink?
  • how do you communicate with something the size of a milk bottle nearly 10 km away?


  • how cold is it at the deep ocean seabed?

This latter question is an interesting one, or better still, how deep does water have to get before it doesn’t freeze despite the surface temperature?

Well – due to the increasing pressure and the salinity of seawater itself as it cools, the oceans only freeze to a depth of a few 10s of metres.

Below that depth sea water rapidly cools to between 2-4 degrees Centigrade and remains at that temperature regardless of how deep the water gets, or how hot the water is in the top few 10s metres in more tropical or equatorial climates.

So we never really have to think about zero temperatures and certainly not temperatures below zero.

However – and it is quite a big however – we can’t just think about what happens during the “battle” data acquisitions at sea – we have to think about what would normally be considered as the instrument friendly conditions back at base – because – as blog readers may have noticed – we keep instruments that are currently being worked on out on our hard standing.

So – we hear you say.

Well the instruments are designed to operate in positive temperatures because the sea water they are deployed into never freezes.

The last few weeks have seen it get pretty chilly back at base, and over the last few nights its gone sub-zero.

So like migratory birds looking for warmer climes – our instruments that were outside have migrated into the lab.

And – we hear you say – what are we worried about?

Well most materials contract in the cold, and some become very brittle – and the flotation is made of – glass spheres!

Pressure and temperature cycling glass “ages” it and causes it to flake and spawl which makes it more prone to failure and implosion when deployed.

So not only do we have to think about the instruments on the seabed we also have to make sure they don’t get too cold when they come home.

Here they are packing out the lab. The rest are in a shipping container.

Not much room to do much else other than design work until it gets a bit warmer outside.

The Boss likes to see them like this – or more importantly this view. Very arty!