Sietas type 180

**Sietas type 180a**
	Eke Möbius in Bremerhaven
Ship data
Ship type	Hopper excavator
Shipyard	JJ Sietas shipyard , Hamburg-Neuenfelde
Construction period	2008 to 2012
Units built	2
Ship dimensions and crew
length	118.47 m ( Lüa ) 106.70 m ( Lpp )
width	21.10 m
Side height	7.70 m
Draft	Max. 5.70 m
measurement	6725 BRZ / 2185 NRZ
crew	16
Machine system
machine	diesel-electric; 2 × electric motor
Top ; speed	13 kn (24 km / h)
Energy ; supply	4 × diesel engine
Generator ; power	6,650 kW (9,041 hp)
propeller	2 × fixed propellers
Transport capacities
Load capacity	9899 dw
Volume	7347 m³
Others
Classifications	DNV GL; 100 A5 Hopper Dredger
Registration ; numbers	IMO no. 9524140 ; IMO no. 9524152
Remarks
Data	Eke Möbius

The type 180 is a suction suction dredger of the Sietas shipyard in Hamburg-Neuenfelde , of which two units were built in the version of the sub-type 180a.

history

The Hamburg-based water and port construction company Josef Möbius Bau GmbH , which belongs to the Austrian Strabag Group, ordered a suction dredger of the type 180 and the sub-type 180a in the summer of 2008. It was subsequently decided to have both units built in the version of the extended sub-type 180a. The keel laying of the two ships with hull numbers 1305 and 1306 took place on December 12, 2008. The type ship is the Werner Möbius , which was delivered on October 29, 2010. The second ship, the Eke Möbius , was christened on September 28, 2012 and delivered on August 31, 2012. It is named after the wife of Werner Möbius, who was chairman of the company's supervisory board. The ship was built for the maintenance and deepening of fairways , for port dredging and for land reclamation and was designed in cooperation with the Dutch Vosta LMG , a company with roots in the Lübeck mechanical engineering company founded in 1873 and the Scheepswerf Stapel , founded in Enkhuizen in 1903 . Vosta LMG supplied the basic design and the specific components for the dredging equipment. The Sietas shipyard took on the detailed design and construction of the ships.

Ship description

The basic type 180, of which no ship was built, was planned with a length of 105.00 m and a hold capacity of 5500 m³. The sub-type 180a is 118.47 m long, 21 m wide and measured at 6725 GT. It has a load capacity of 9800 tdw and a loading space of 7500 m³. A noticeable feature of the underwater hull is the pronounced bulbous bow , it serves not only to optimize the ship's speed but also to increase the displacement. The bridge house with the mess rooms, lounges, chambers and the galley is located in the fore section . The provision rooms and the air conditioning room are in the intermediate deck, the drinking water and sewage system as well as the refrigeration compressors for the air conditioning are arranged on the lowest deck. On the port side of this deck are the watertight sliding bulkhead doors (which can be operated both locally and centrally) to the port wall. On the starboard side, the watertight bulkhead doors, which can only be operated locally, to the starboard wall passages, which lead aft to the pump room and the engine rooms. In addition, the huge gate valve for the suction line of the dredge pumps from the front, port-side sea chest is located here .

Power supply and propulsion system

The propulsion system, dredging pumps, workshops and the engine control room are located in the aft ship . A power management system controls the generators and electric motors for free driving or excavation operation in such a way that fuel consumption, machine wear and exhaust emissions are minimized. The four non-reversible MaK four-stroke diesel engines from Caterpillar, each with a nominal output of 1,630 kW, are installed in the intermediate deck of the engine room . They drive the three-phase generators, which feed their electricity into the primary on- board network with a voltage of 690 volts at a frequency of 50 Hertz. The 690 volt main busbar is divided into three busbars connected via tie switches. The middle rail is supplied by two diesel generators, the outer rails by one each. The main busbar feeds the large electricity consumers such as traction motors and excavator pumps.

A 700 kVA transformer to supply the secondary 400 volt on-board network is connected to each of the outer partial rails. This supplies the other electrically operated three-phase motors to drive the auxiliary machines and the single-phase power consumers such as lighting, sockets and small heat consumers.

The Eke Möbius is driven by two electric traction motors. This means that 13 knots are reached when the boat is free. Two nodes are planned for excavation operations. The ships operate 24 hours a day with a crew of 16, consisting of the captain, the officers, the engineers, the dredger, the electrician, the cook and the deck crew. Both ships sailed under the German flag and were classified by Germanischer Lloyd (now DNV GL).

Unlike the Werner Möbius , the Eke Möbius was equipped with two Becker oars, which gives it a much better maneuverability. Both ships have two fixed propellers. Thanks to the diesel-electric drive, the propellers can be controlled quickly and independently of each other. The oars can be operated both together and in independent mode. This allows maneuvering in a relatively small space.

Dredging system

The excavator system was supplied by Vosta LMG and the excavator automation by SAM Electronics. With the suction head, the suction pipes of the dredger can reach depths of up to 35 meters. The dredging pumps are located in the lowest engine room deck. They are designed so that the entire load space can be loaded in just under an hour. The huge double-walled centrifugal dredging pump with a flow rate of around 10,000 m³ / h, which is set up directly in front of the engine room bulkhead, is on the starboard side and is driven by a 2,000 kW electric motor from VEM Sachsenwerk in Dresden. The pump speed is continuously reduced to 204 or 141 / min via a gearbox and a frequency converter . The low pump speed is set when excavating and the high speed when discharging the dredged material. Two smaller centrifugal pumps are driven by a 1,000 kW electric motor (690 V) via a split gear. They provide pressurized water in order to ensure good liquefaction of the dredged material with special nozzles in the suction head. When pumping ashore or when dumping through the eight bottom valves in the hopper space, the dredged material is loosened with flushing water from these pumps.

The ships

Sietas type 180a
Building name	Construction number	IMO number	Keel laying, launching, delivery	Client	Renaming and whereabouts
Werner Möbius	1305	9524140	12.12.2008 08.06.2010 29.10.2010	Josef Möbius Bau, Hamburg	2017 Beachway , so in 2020
Eke Möbius	1306	9524152	12.12.2008 20.04.2012 31.08.2012	Josef Möbius Bau, Hamburg	2017 Medway , so 2020 in motion