Another ‘Vagabond’ Takes to the Sea

Shipyard Kooiman, based in Zwijndrecht, recently completed and handed over a new multi-purpose support vessel to HvS Dredging Support of Harlingen. Named Zwerver III, the vessel is a sister ship to Zwerver I, which was built at the facility previously owned by Van Buitendijk, but recently acquired by Kooiman Group as part of their expansion programme. Kooiman has been involved in the construction of ships since 1884 and this experience has been put to good use on this project.

Shipyard Kooiman’s latest projects

Ongoing projects at the Shipyard Kooiman include the Veerhaven 3 which is a replacement for the old Veerhaven 3. Kooiman’s has built a succession of these vessels.

However, the exciting new project for the yard is the new build of a 6,000 cubic metre hopper dredger to be named Reimerswaal. This will be the largest project to date for Kooiman. The hull has been built abroad and recently launched for transport to the Netherlands. Kooiman expects to start working on the outfitting of this vessel in the beginning of 2012. In the meantime the design and engineering team in Zwijdrecht are feverishly completing the final details on their drawing boards.

Zwerver III

Zwerver III is 35 metres in length, an increase of seven metres over her predecessor, and is built to DP1 standard. Furthermore Zwerver III weighs in with an extremely shallow draft of three metres maximum. The vessel was delivered to the client HvS Dredging Support BV in Harlingen in December 2011 after a successful series of sea trials. Though exciting as ever, Zwerver III passed all tests with flying colours. After the sea trials only a few small adjustments to the DP system and some minor finishing jobs on the interior were required.

The design of Zwerver III is another example of a successful collaboration between a ship constructor and their client. On this occasion Shipyard Kooiman has taken a design, initially produced by the owners, and developed it in the light of their and the client operational experiences. In doing so, they have arrived at a successful result that appeals to, and pleases both parties of the collaboration.

The result is a Multi Purpose DP Offshore Support vessel that is probably one of the largest and most powerful of its class given that it measures less than 500 GT (in fact exactly 499 GT!). It is a Bureau Veritas I m HULL • MACH Tug Unrestricted Navigation • AUT-UMS • Dynapos 1 AM/AT – Ice Class 1C registered vessel aimed at both the ‘renewable energy’ and the offshore markets. As such she is capable of general support and anchor handling, dive support, supply work, Single Point Mooring (SPM) buoy installation, hose and cable handling, and survey and ROV operations.

Carefully balanced design

Considerable thought and planning has been given to her through life use and this manifests itself in many features that have not been seen on this type of vessel before. Unlike her predecessor, which had a half deck in the superstructure, Zwerver III has three full height accommodation decks. The superstructure is to the port side of the vessel and the vessels tanks on the starboard side counteract its mass. The tanks can hold 260 cubic metres of fuel and 50 cubic metres of fresh water. On the starboard side, outboard of the tanks is a passageway that houses a sophisticated transfer system for remotely controlling the fuel and fresh water transfer pump of 60 m3/hr each. Fresh water tanks can be filled by fresh water makers with a capacity of five m3/24hr.

Engine room

Zwerver III is powered by three Mitsubishi S12R-MPTK main engines, two of which drive conventional shafts and fixed pitch propellers, each with double rudders and independent steering. The third Mitsubishi engine powers a 360-degree azimuthing HRP thruster. Whilst at the forward end, in the underwater section of the push bow bracket, two HRP bow thruster units are located. Boasting a total of 2,820 kW of power, such an arrangement makes her a highly controllable and very accurately maneuverable vessel. Power is generated by two Mitsubishi 6D16T for 120 kVA – 230/400V – 50 Hz (one set is silenced) whilst at the same time hydraulic power is produced by two Mitsubishi S6R-MPTA power packs at 570 kW each. Compressed air for working tools and the vessels requirements is produced by an Atlas Copco GA30 capable of producing 500 litre/minute. Outlets are positioned on deck, in the workshops and in the engine room.

Deck layout

The deck layout and equipment also reflect this thoughtful approach. Starting at the very first step the deck plating is 20 millimetres at the aft of the vessel and 25 millimetres in the forward deck. The larger middle area of the main deck is covered with a thick layer of tropical hardwood to protect the deck from undue wear in the same way that her sister vessel Zwerver I has. A 1,000 millimetre diameter moon pool is fitted, that can be used for seabed research and exploration, and other diving tasks. An interesting feature of this is the fact that a truck can be driven over or a container located on top of the moon pool so that equipment or instrumentation can be deployed straight from it through the moon pool. The work deck has been reinforced throughout to withstand a load of ten ton per square metre. At the same time fixing and lashing points for 24 20ft containers have been let into the deck in such an arrangement that several different configurations can be used subject to the vessels operations at the time. The vessel is even built for the use of spud poles by means of several reinforced holes ready to accept the spud carriage with poles if required.

In-house designed deck equipment

Kooiman’s in-house designed retractable towing cleats are fitted both aft and forward on the work deck. These are normally recessed into the deck and pop up only when needed; the obvious advantage of this is a larger clear unobstructed deck space. The work deck space totals a 300 square metres of area, this is impressive considering the length of the vessel.

Superstructure, accommodation and wheelhouse

The superstructure and portside hull contain comfortable accommodation for twelve persons divided over seven cabins and all required workspaces. All cabins, galley, office and wheelhouse are heated and air conditioned by an installation supplied and installed by Breman.

The same company also supplied and installed all sanitary equipment. The vessels navigation and communications package, including the dynamic positioning system was supplied Alphatron. The dynamic positioning installed on Zwerver III is their well-known Navis NAV DP-4000 system. The mast, on the top deck of the superstructure, has been made hinged so that it can be hydraulically lowered to allow the vessel to pass or work under platforms or dredger structures. As if to emphasize the common drive to reduce energy usage and heat production, all searchlights and light beams are LED-types.

Offshore support features

For anchor handling purposes, two large rollers are fitted; the one at the aft end of the working deck is four metres wide and 1.3 metres in diameter, whilst the bow roller is eight metres wide and two metres in diameter. Both rollers have safe working load rated at 250 ton. Zwerver III boasts a truly unique feature, a hydraulic bow door to prevent deck ‘flushing’ whilst the vessel is in transit. In the raised position (one metre above deck level) it prevents water coming onto the fore deck, whilst for anchor handling it can be lowered to increase deck space so that the top of the bow roller and the main deck are flush.

The anchor handling winch, towing/bollard winch and crane are all located centrally on a common seating and framework. This is different from the Zwerver I which had them laid out separately each on their own foundation and seating. There are several advantages of this new layout; the combination saves on deck space, because the three seatings are located together their strength compliments each other making for a stronger seating. Locating the units close together permits a level of flexibility in operation allowing interchangeability of the winches and thus a level of redundancy. Finallythe combined unit requires only one area of additional reinforcement on the lower deck. In addition to all mentioned above, this centrally located and integrated unit of Zwerver III is also suitable to accept the Ampelmann® personnel transfer system.

Zwerver III has two main winches: the first is an offshore anchor handling winch with a bollard pull of 200 tons and a holding power of 250. This drum has a wire capacity of 1,000 metres for 64 millimetre diameter wire. The second is a towing winch with a bollard pull of 100 tons and holding power of 200 tons, capable of taking 1,000 metres of 48 millimetre diameter wire. Furthermore, she has three tugger winches, manufactured by Brevini, each with a capacity of 15 tons pull and these drums allow for 100 metres wire with a diameter of 22 millimetre each. In addition to the centrally mounted crane, a second one is located on the port bow area. Both cranes are remote controlled knuckle boom type, supplied by Promac and have a capacity of ten tons at 20 metres each.

At the forefront of offshore support

HvS Dredging Support can count all the major dredging companies amongst its clients. With
names such as Boskalis, DEME, Jan De Nul and Saipem on their books. Zwerver III seems to have very busy life ahead of her. For which she looks to be more than capable thanks to Shipyard Kooiman.

Tom Oomkens