The Thodésca-class Ocean Tugboat is a nuclear-powered ocean-going tugboat and the result of a request for proposal by the Department of Defence of the National Republic of Thermodolia to haul disabled vessels or vessels, which had broken down out of operational areas – or generally to haul vessels from one place to the other, when these vessels can't move under their own power.
Thodésca is a major harbour city in Thermodolia.
The Thodésca-class Ocean Tugboat is less of a boat and more of a ship displacing 1,600 tons, a monohull design with a length of 68.5 metres, a beam of 12.5 metres and a draught of 4.5 metres. Quite a bit of the weight comes from the armour over critical areas like the reactor and the reinforcing of hull and vessel against ice.
Crewed by 85 officers and men, the Thodésca-class Ocean Tugboat has only a relatively small crew for a vessel of this size and purpose. Unlike with other utility vessels of SDY, the crew is housed in cabins, with communal washing spaces. The cabins are two-man rooms for the enlisted men and with officers housed in single rooms. For recreation, there is a mess hall, which can be adapted to be used as a cinema and in other functions and a fitness room.
In cases of emergencies, this mess hall can be also used as a makeshift hospital with the sickbay, with fifty beds, being next doors. However, the Thodésca-class Ocean Tugboat does not replace a hospital vessel or a hospital on dry shore. The kitchen can cook for up to 250 people at the same time in a decent quality.
The Thodésca-class Ocean Tugboat is fully NBC-Protected as well as degaussed.
For its work as a tugboat and salvaging vessel, the Thodésca-class Ocean Tugboat is equipped with workshops, additional bilge pumps to bilge other vessels, who can't bilge themselves or can't do it in a sufficient amount themselves. Both to disiduate attackers and to put out fires, the Thodésca-class Ocean Tugboat is equipped with four hoses with a throughput of 1200 litres of water per minute with ten bars of pressure and a range of 65 metres. These hoses, very much akin to the water canons on the Corrán-class Offshore Patrol Vessel, can mix fire foam into the water pumped from the sea or shoot said water directly.
A twenty ton crane at the bow allows for work on vessels, as well as lowering the four dinghies aboard into the water. The vessel can also serve as base-vessel for divers, both for mine-clearance divers and repair divers, which can also rely on the services of two electrically powered underwater welders.
Everything, including said welders and the engines, is powered by a nuclear reactor with a total output of 75 megawatts. This reactor, a Ga-17 Mark IV, is the civilian version of the nuclear reactors used aboard many of SDY's military vessels. It is a pressurized water reactor, relying on a triple redundant cooling system, while also being armoured.
Two azimuth thrusters with ducted propellers allow for better course stability at lower speeds while also being less vulnerable against debris, although the efficiency deficits at higher speeds do not matter as much due to the over-abundance of power. This system is also of advantage due to increased manoeuvrability, which is further increased by a bow thruster.
The Thodésca-class Ocean Tugboat can attain an unburdened maximum speed of 22.5 knots or 41.7 kilometres per hour and a bollard pull of 550 tons.
The Thodésca-class Ocean Tugboat is equipped with armament for self-defence, a twin L70/76 millimetre turret, a Túirín T-12 Mark II like the Scoth-class Corvettes and several other vessels of the SDF-Navy use them, and four 40 millimetre AA-guns, which are more akin to multi-purpose guns for defence against aerial and surface threats.
The civilian version of the Thodésca-class Ocean Tugboat is disarmed.