General: JANUS and URSUS are two conventional deep sea tugs / AHT's with
two propellers in fixed Kort nozzles. Timon flap rudders supplied by van der Velden Barkemeyer are placed behind each nozzle.
They are driven by Rolls-Royce rudder steering gears and can be moved independently. The tugs are classified according to Germanischer
Lloyd ice class E2. This corresponds to finnish-swedish ice class 1B (thickness of level brash ice of up to 60cm). According to
the class requirements the hull is built with a frame spacing of 600mm. The hull plating varies from 12 to 16mm with up to 30mm
locally in the ice belt area. The tugs are powered by four MaK main engines. Each propeller is driven by two engines, one 6M32
with 3,000kW (4,080bhp) and one 8M32 with 4,000kW (5,440bhp) at 600 pm. This so-called father & son configuration allows a more
economic operation at the often in offshore work occuring partial loads. At 3,000kW or 4,000kW a 6M32 or a 8M32 uses less fuel
than a 7,000kW 7M43 at the complying partial loads. The MaK engines can use Heavy Fuel Oil (HFO) allowing savings of approx. US$220
(Nov. 2007) compared to Marine Diesel Fuel (MFO), but at higher initial costs caused by the HFO heating system. The Renk AG
supplied the two type NDSL 2800 gearbox with a ratio of 1:4.286. The gears weigh approx. 30t each. The gears have a second
power-take-off for a shaft generator with an output of 1,200kVA. The controllabe pitch propellers came from Schottel GmbH, have
a diameter of 4.40m and turn at 140rpm. JANUS reached a maximum speed of 16.5kts on trials. Running only on two 6M32 (3,000kW)
a speed of more than 12kts was achieved. The maximum continous bollard pull was measured at 220t and 234t at 110%MCR (Maximum Continous Rating).
The higher bollard pull at identical engine outputs of JANUS compared to MAGNUS results from the larger propeller diameter (4.40m compared to 3.80m)
made possible by the larger draft of JANUS. The larger breadth and displacement don't matter here as the bollard pull
is measured at a stationary ship. The bunker capacities are: 190m3 MDO, 2,440m3 HFO, 130m3 drinking water, and 500m3 ballast
water. Two bow thrusters, one stern thrustern, the two cp propellers, and the two independent rudders make up a dynamic positioning
system according to DP2. The three type 330T LK thrusters were supplied by Schottel. Their controllable pitch propellers of 1,29m
diameter are driven by 400kW electric motors. The tugs are equipped with a fire fighting system according to FiFi1 standard.
Two Kumera fire fighting pumps a coupled to the front end of the 8M32 engines. The pumps deliver 1,200m3/h with 14bar
pressure to two fire fighting monitors and the self-protection deluge system. The complete system was supplied by FFS
(Fire Fighting Systems) from Norway. The self-protection system is installed inside the handrails of bulwarks and railings
Tank top deck:
From bow to stern there are the following compartments: bow thruster, sewage plant,
and generator compartment with two Caterpillar type 3412C gen sets with 625kVA each and the HFO heating plant. HFO tanks are
located an both sides of these rooms. Next is the engine compartment with the chain lockers for rig anchors, the four main engines,
the gears with shaft generators and the fire fighting pumps. Between the main engine sets a sea water desalination plant for the
supply of drinking water is placed.
The Platform deck has two large openings for the main engines in the engine room.
In front of the engines are their silencers, and between the silencers the chain lockers and the storage winch room. The Hatlapa
storage winch carries the 1,200m spare towing wire according to the classification rules. At the stern end of the engine room
are workshops at starboard and port. In the stern area are the stern thruster access, two rudder engine rooms, and the room
beneath the Karmoy pins and forks. The access from the engine room is via a tunnel through the HFO tanks behind the engine room.
At the bow end of the engine room the engine control room is located. In front of it follow a compartment containing HVAC and
refrigeration units and the bow thruster room. Beginning at the silencers HFO tanks are placed on each side of these rooms.
The deck consists of the open work / after deck and the accommodation area. A Hatlapa type
SWI 3000/4000 towing winch of the waterfall type is installed in a recess of the superstructure. The winch is electrically driven.
The drums are designed for 86mm wire but carry 76mm throughout on JANUS. The upper drum carries the main towing wire of 1,600m
length and 76mm diameter and provides a pulling power of 150t in the first layer at a speed of 10m/min and braking force of 320t.
The lower anchor handling drum has the same capacity but the wire length varies with the requirement of the job at hand. This way
the crew tries to get high pulling power by keeping the number of layers low. The lower drum provides a pulling power of 150/300t
in the first layer at speeds of 10/5m/min and a braking force of 400t. The frequency inverter controlled asynchronous electric
motors allow stepless operation of the winch. The maximum speed of the winch is 30m/min with accordingly smaller pulling power.
Instead of warping heads the winch got two chain lifters which allow anchor chains to be moved from the towing deck into chain
lockers located on the platform deck. The starboard chain lifter is for a chain diameter of 76mm (3"), the other one for 127mm (5")
chains. All drums can be disengaged under load through friction clutches. The chain lifters are coupled permanently to the drum
axles. An emergency release is possible by special motor circuitry. The winch is surrounded by a steel frame structure with connectors
for 20' containers. It allows to carry a container or a storage reel above the winch. A spare anchor is fastenend to the superstructure
at the port side of the winch. The work area of the deck of approx. 297m2 is flanked by offshore-type cargo rails.
Protected by these rails two Hatlapa tugger winches with a pulling power of 10t at 15m/min are installed at starbord and port
sides in front of the towing winch. Directly behind the towing winch a large towing fairlead is fitted. The forward half of the
work deck is wood cladded. The typical deck equipment, like bollards and a hydraulically operated vertical Hatlapa spill with 5t
pulling power, is installed between cargo rails and bulwarks on either side. A stern roller of 5.00m length and 2.15m
diameter with a safe working load (s.w.l.) of 450t is installed for anchor-handling purposes. In front of the roller Karmoy forks
and pins are mounted. They have a s.w.l. of 650t and 300t respectively. The tugs can be equipped with an A-frame which has an
external power pack. The A-frame has a reach of 13m over deck and 9m behind the stern with SWL's of 200t and 250t respectively.
Inside the superstructure a number of rooms are located at both sides of the towing winch: These are at port the towing and salvage
store, a paint store, and a garbage room. At starboard these rooms are the fire fighting store, the emergency generator room with
a Caterpillar type 3056 gen set with 105kVA, and the CO2 room. In the bow area are stores. Between stores and towing winch are
rooms for cooled, freezed, and dry provisions, the galley, mess, changing room, hospital, office, and one single-berth cabin.
Two Palfinger Marine PTM 850 telescopic boom cranes with an SWL of 5.2t at 14m reach are
mounted on both sides at the aft end of the deck. At starbord a fast rescue boat/ workboat type FRB600-S and the accompanying
davit type DFR 600S II / MOR are installed. Both were supplied by Bootswerf Ernst Hatecke. The rescue boat is equipped with a 60hp
Yamaha outboard motor. The accommodation area is within the hull. Five officer's single-berth cabins with sanitary space, two
single berth crew cabins, four two-berth crew cabins, and one four-berth crew cabin are arranged arround the outer walls of the
deck. The center area is occupied by stores, laundry, and sanitary rooms. In front of the accommodation a large store is located
in the bow.
The suites of captain and chief are located in the front of the superstructure.
They consist of a day room, separate sleeping room, and sanitary space. At the aft end are two single-berth cabins sharing a
sanitary room. In-between are stores and lockers and the staircase. A Hatlapa anchor winch with two chain lifters and two warping
heads is mounted outside on the forecastle together with the chain stoppers. A Smit-brackett is provided for a fast towing connection.
The tug carries two type AC-14 high holding power anchors weighing at least 1,710kg. Each anchor is connected to 275m class k3
stud-link chain of 36mm diameter.
Racks with three inflatable 15-person life-rafts are mounted on either side at the aft
end of the deck. The rafts were supplied by Samsong. The largest area of the deck is occupied by the wheelhouse. It is set back
from the deck's fore-edge. The main control console is arranged over approx. 60 per cent of the width against the foreward
bulkhead. Two small control consoles are placed in the bridge wings. Between main and wing consoles settees are placed. Additionally
a divided control station is placed at the aft of the wheelhouse overlooking the work deck. The towing winch and the forecastle
deck are monitored by camera. The communications desk and the companionway are located in-between on the port side, the chart
table and a tea kitchen on the starbord side. Two settees and a table are arranged beside the companionway. The navigational and
communicational equipment is state of the art. As navigational equipment are available among others: Two Automatic Radar Plotting
Aid (ARPA)-Radar systems, two Electronic Chart Display and Information Systems (ECDIS), magnetic compass, three gyro compasses,
echo sounder, and Differential GPS (DGPS). The communicational equipment meets the Global Maritime Distress and Safety System
for worldwide travel (GMDSS A1 to A4) and contains Navigational Warning by Telex (NavTex), VHF / HF radio-telephone systems with
Digital Selective Calling (DSC) ability, Inmersat telephone, fax, e-mail, as well as Search and Rescue Radar Transponder (SART),
and Emergency Position Indicating Radio Beacon (EPIRB). The navigational and communicational equipment was largely provided by
SAM Electronics. JANUS and URSUS are a equipped with a Dynamic Positioning System from Nautronix to DP2-standard.
It carries the magnet compass and three remote-controlled Ibak search lights.
The platform bridges the wheelhouse and connects the two funnels. The mast, one radar
antenna, and two fire fighting monitors are fitted here. A second radar antenna is mounted on the mast.
The tugs have a crew of 18 officers and crew. The accommodation provides berths for 24
persons. This allows personnel of the client to travel with the tugs. The accommodation is fully air-conditioned.