Are the most expensive research facility, both to build and run, required by oceanographic institutes. They take the scientists and technicians to the study areas, to enable them to collect samples, deploy instruments, and carry out analyses and measurements at sea. Some oceanographic disciplines such as geological oceanography have specific requirements that require dedicated vessels. For example, the Ocean Drilling Programme (ODP), which is collecting long cores from deep ocean sediments, operates a dedicated ship called the JOIDES Resolution; and some of the underwater vehicles like Alvin require dedicated tenders. One of the most unusual research ships was aptly named Flip, which steamed out to its operating position like a normal ship, but then upended to drift with the currents for several months. It had to be specially designed so that its aft bulkheads became decks.
Most research vessels are used for multidisciplinary operations and often remain at sea for several weeks, especially when operating in remote regions. They carry parties of up to 25, or in the case of Russian ships 50, scientists, and are fitted out with a range of laboratories. They need to be able to keep station, i.e. stay on a fixed position in all but the most extreme weathers and wave conditions, so instruments and samplers can be lowered on vertical wires. They also to have to be capable of maintaining low speeds of between 1 and 5 knots consistently and accurately. They are fitted out with a range of winches for towing devices, such as trawls, dredges, and undulating devices. The latter are towed on cables that are faired to reduce the drag so the device reaches greater depths and can be towed at speeds of up to 8 knots.
At least 10,000 metres (32,500 ft) of towing cable is needed to tow a trawl at a depth of 5,000 metres (16,250 ft). Trace element chemistry requires special cables and clean laboratories to prevent contamination of the samples. Many types of gear are now towed or lowered on conducting cables that both deliver power to the device and transmit the data it collects back to the ship. The ships usually have large A-frames or cranes to handle heavy equipment over the side. Others have moon pools, hatches in the ship's hull through which instruments can be lowered. Lowering instruments this way in the centre of a ship greatly reduces the effects of pitching and rolling on wire tensions.
As it is impossible for research ships to stay at sea all the time, many types of instruments are deployed on moorings which are usually anchored to the seabed with subsurface buoyancy, and are left in the ocean for months and even years. Some of these devices are now programmed to come to the surface and transmit their data via satellite links to the laboratories on shore.
Research vessels have to have the most up-to-date navigation equipment, powerful computers that constantly archive data that are collected continuously while under way, and satellite communications like Inmarsat for real-time processing of the data and receiving satellite imagery in real time. Because sound is used so much for probing the interior of the ocean and controlling instrumentation, research vessels have to be acoustically quiet. A noisy propeller can completely drown the signal from an instrument on the seabed at a depth of 5 kilometres (3 mls.) at a slant range of 10–15 kilometres (6.2–9.3 mls.).
Subjects: Maritime History.