All of the instrumentation that we deploy onto the seabed is bespoke built for the task in hand. This includes the simplest thing like wiring up high-pressure underwater connectors to be fitted to the pressure vessel end caps, which connect the external sensor packs to the data logger inside the pressure vessel itself. This can be quite a fiddly job for connectors with small pins or connectors with many pins as the example below shows. A steady hand, and nimble and heat-resistant fingers are definitely an advantage for this job. Here one of the OBS engineers is making a new set of connectors for use during the 13N research experiment. Soldering generates fumes and so we do this task at a soldering station that sucks away the fumes so that they are not breathed in.
We also have the capability to make our own printed circuit boards to our own design. In our lab we have a small, low volume, PCB manufacturing facility that etches the circuit design onto a board, applies the circuit tracks, presses the newly built board flat and ultimately cooks it in an oven. We can make boards with up to four layers, isolated from each other, but laid one on top of the other. We use this facility for prototyping new designs. Once we have a working and fully tested prototype, that has also been deployed at sea and tested under full experimental conditions, we will have a production run made by a specialist company.
Some of our more complicated boards can take up to a week to make in his facility, and then they still need to have the components installed and soldered onto the circuit tracks before “cooking” and “cleaning” – believe it or not, one of the stages is to wash them with water in a sink. Before they can be used they need to be thoroughly dried in an oven at low temperature to remove all the water trapped beneath the components.
So there is more to this seabed instrumentation game than might initially meet the eye. It takes a lot of planning, a lot of preparation, a lot of building and testing, and a lot of attention to detail!
PCB in the process of being manufactured.
The result of the first stage of process – you can see what the final PCB will look like even at this point.