What does it take to get a ship ready to go on expedition out into the Atlantic? Well quite a lot of what we call “mobilisation” has to go on. On this trip we will be using a video drop frame system. This is a frame that is loaded with camera, lights and other sensors that is towed via a very long cable from the ship, so that the cameras are just above the seabed enabling us to get good video footage of the animals that live there. From our side of things at Plymouth we had to get our video frame and all our equipment from Plymouth in the UK to Porto in Portugal. This meant packing it all up on a pallet days in advance, watching it leave Plymouth, and hoping to goodness that it arrived in Porto in time to board the ship.
When the equipment arrived it had to be craned onto the ship so we could then start unpacking it and rigging it all up for testing.
Re-building the video frame takes quite some time. Not only do we have to bolt all the equipment on to the frame but also the the fins which, granted make it look like a shark, but are actually there for a good reason, to help with the hydrodynamics and flying the frame above the seabed.
Our frame has an HD video camera, a standard definition video camera, a probe to measure conductivity, temperature and depth of the water (CTD), an altimeter (so we know how far off the seabed we are), and an ultra-short base-line (USBL) system that tells us where the camera frame is on the seabed. Once the camera frame was built we needed to test it to make sure it was well balanced and all the equipment was working properly. After some minor adjustments it seemed to be fine and working well.
Our friends at BGS also had to get their equipment ready, and I will let Heather Stewart from BGS explain how that went.
So, I write to you now we have time to draw breath after a hectic few days! After a frustrating start in Porto waiting on the two 20ft BGS containers to be delivered (they were in the port…somewhere! Just took the agent time to locate them), we had a packed schedule to get the vibrocorer unloaded and built before lifting the built vibrocorer, core bench and the single 20ft BGS container onto the R/V Belgica.
What is a vibrocorer I hear some of you say? A vibrocorer is basically a method of taking a core of sediment from the seabed. It has a core barrel with a cutting shoe on the bottom and a heavy weight on top. In addition to the heavy weight you have two motors that work together to produce a ‘vigorous’ up and down, vibration which shakes the core barrel into the ground. The core barrel has a core liner and a core catcher inside which will collect and retain the sample for the scientists waiting on board the vessel.
We managed to get this completed by Thursday evening and had a packed Friday morning finalising the vibrocorer set-up, carrying out a test launch and recovery and strapping everything down ready for sailing at 2pm.
For those of you who would like some more information on our vibrocorer….
The British Geological Survey have brought on this campaign an orange, battery operated, 3m vibrocoring system. Using a battery system, autonomous technology, means we do not need to use an umbilical power cable from the vessel, we can just use the vessel’s lifting wire. This makes the system simpler to install on different vessels and we can go down to 6000m water depth!
We are currently transiting to the SW Approaches as the weather was too bad for us to operate in the Ferrol Canyon, our first area of interest. We should arrive in the SW Approaches early afternoon on Sunday, fingers crossed for calm seas! Needless to say we are all really excited about getting both the vibrocorer and the Plymouth University video frame in the water tomorrow! Wish us luck!