Dair-class Fisheries Research Vessel

### Sensors and Processing Systems

Fisheries Sonar, Navigation Radar, 2x Multi-Beam Echosounders, Crow's Nest, Meteorological Sensors

## Notes

### Notes

Dynamic Positioning System, Deckspace for up to three ROVs, 2 winches, 2 cranes, 1 trawl, A-Frame, Dry and Wet Laboratories, 2 dinghies

The **Dair-class Fisheries Research Vessel** is the newest vessel in a long line of research vessels built by Silverport Dockyards Limited. Optimized for Fisheries Research, the Dair-class Fisheries Research Vessel can also be used in other Hydrographic research, for example undersea-mapping, or research on marine life in general.

## Design

The Dair-class Fisheries Research Vessel is a classical monohull-design built of steel, 66 metres in length, 14.6 metres in width with a standard displacement of 2,500 tons and a maximum draught of 5.3 metres. Six decks give enough work and living space for a crew of 14 men and up to 22 scientists and/or students.

Scientists and students share the mess hall with the sailors, providing a unique experience for the students, who learn not only about their subject matter, but also about those regularly working on their subject matter. The mess hall can easily be converted into a number of different functions, from a cinema, to a lecture hall to a makeshift sickbay and many more functions (to celebrate the commissioning of Dair, the mess hall was converted into a ball room).

The hull is reinforced to handle ice, but is not to be used as an ice-breaker.

A Diesel Generator, providing 4,000 kW of electrical power, is used to give the vessel the energy it needs to operate, from the sensors to the pump-jets to the coffee maker. Although the generators, the same as used on the Scoth-class Corvettes used by the SDF-Navy, are very reliable, the vessel also carries an Emergency Diesel Generator rated for an output of 1,000 kW, which can power the vessel in case of generator failure or simply more power being needed. Both generators are rested on shock-absorbers to reduce the acoustic emissions for both reduced fish-avoidance and increased crew comfort.

Propulsion is handled by two pump-jets with vectored thrust capabilities, including reversing by bucket, allowing the vessel to attain speeds of up to 16 knots, or 29.6 km/h, resulting in high manoeuvrability and low acoustic emissions. A bow-thruster makes docking easier and omits the need for a tugboat.

In its whole, this arrangement is also known as Integrated Electric Propulsion, or IEP for short, which saves maintenance costs and space aboard.

The Dair-class Fisheries Research Vessel has provisions to stay at sea for up to 35 days.

### Sensors

The Dair-class Fisheries Research Vessel is equipped with a multitude of sensors, one of them being a navigation radar, more precisely a Nuacht N-4 Navigation Radar, used on a variety of vessels of all sizes built and maintained by SDY.

Foremost amongst the other sensors is a Fisheries Sonar, a small, yet capable device optimized for finding fish. Due to sound travelling differently through fish then through water, the reflection of that sound, or Ping, can be used to detect schools of fish or other sea-dwellers, thus allowing for locating these, observation and other measurements, for example density of the swarm. The Fishing Sonar is unsuited to find submarines.

Another important suit of sensors is a set of two Multi-Beam Echosounders, which can be used to map the ocean floor for navigational purposes. The range of these Echosounders is rated as up to 5,000 metres below the waves.

In addition to those systems, the Dair-class Fisheries Research Vessel is equipped with a suit for Meteorological Research, thus weather prediction.

For the application of the most powerful sensors naturally available to the human eye, however, the Dair-class Fisheries Research Vessel is equipped with a Crow's Nest: The Crow's Nest, or crannóg, is a small post at the top of the main mast, which is equipped with a number of optical instruments, from telescopes to cameras, including night-vision and infrared vision modes, as well as a position for a person or three to stand and made own observations using binoculars.

### Other Equipment

The Dair-class Fisheries Research Vessel is equipped with a number of systems for more direct research and positioning. One of them is a Dynamic Positioning System, which allows the vessel to hold position despite waves and currents by using the own engines to keep position.

Work aside from the vessel can be done by up to three Remote Operated Vehicles, or ROVs, for which deckspace is set aside, as well as up to two dinghies or workboats, neither of which are included into the delivery (we recommend the Majestic-class Boat as a workboat). We recommend, that none of these ROVs or workboats is heavier then twenty tons, the maximum lift weight of the two cranes, the same ones as used on the Geabhróg-class Seaplane Tender. The cranes can also be used to lift cargo or equipment on and off of the vessel.

Sternwards, the Dair-class Fisheries Research Vessel is equipped with an A-Frame, which can be used to recover smaller craft or a trawl for sampling.

To analyse these samples, and other data, the Dair-class Fisheries Research Vessel is equipped with Laboratory Space. 75 square-metres are allocated to Dry Laboratories and 70 square-metres are to be used for Wet Laboratories, which can be expanded by fixing up to five containers onto the deck, without limiting the remaining deck-space.

Additional samples can be collected by a Seawater Intake System, stored in tanks big and small, together holding 5 cubic-metres of fluids. A fish sorting area is connected to the largest tank to collect living samples and to keep them alive.

The Dair-class Fisheries Research Vessel is also equipped with the most advanced computer systems available for the civilian market, a Type 901 Datalink (a close cousin of the Type 900 Datalink) linking all scientific instruments aboard together, including the possibility of linking personal computers into the network. That system can also be used for entertainment purposes, but is not designed as such.

## History

As people living with and on the seas, fishery has always had a very important role for the Selkie, one which did not change over time and space. Our cuisine, which knows many fish-dishes, our myths, which involve the seas in many ways, those and more reflect that.

Enter the Trosc-class Fisheries Research Vessel, being planned by Caillte Maritime Solutions Engineering Office of Wembury with three units built by SDY and in service from 1986 to 2013. These small vessels, around 40 metres in length, provided the oceanographic research institutes of the Free Lands with the vessels they needed to conduct research and to train their youth. One of those vessels was sold to another nation in 2001, the other two were decommissioned by 2013 – and the search began anew.

While the SDF-Navy procured their own vessels to do the job, the scientists were always a bit sceptical of going to the Navy for their research materials, always searching for alternatives (the *Caorthann* not being one due to the *Caorthann* being a  Polar Research Vessel) and, by 2016, having that alternative greenlighted: The Pattern 297-T, based on the Pattern 297 Fishing Trawler, or, as she is known today, the Dair-class Fisheries Research Vessel.

With the first vessel, *Dair*, being launched in late 2017, being commissioned in May 2018, the marine research institutes of the Free Lands finally had an own vessel of substantial size again, soon to be followed by two more.