WAVEWALKER 1: STEPPING INTO THE FUTURE

At the Neptune Shipyards in Hardinxveld-Giessendam on 21 September of 2012 a new generation of vessel had her naming ceremony. Sonja Jonkman, wife of André Jonkman, Chief Financial Officer and member of the Board of Management of Fugro NV, performed the ceremony. WaveWalker 1, as she is to be known, is the very latest idea in working platforms. Her keel was laid on 4 April at a ceremony performed by WaveWalker BV business managers Jelle Mens and Les Lugg and she was operational by the end of 2012.

WaveWalker 1 is the product of collaboration between Neptune Shipyards, Van Oord and Fugro Seacore. Van Oord is an internationally recognised contractor specialising in dredging, marine engineering and offshore projects (oil, gas and wind energy), whilst Fugro Seacore is a specialist overwater drilling, coring and geotechnical contractor in the marine world. WaveWalker 1 has been built to and classed by Germanischer Lloyd. Her owners are WaveWalker BV, which in turn is an equal part collaboration between Van Oord and Fugro Seacore, and the vessel will be available for rental or charter to the offshore industry. The first of these charters is for Wicks, which are the international contractors for ground treatment, marine drilling and blasting of Van Oord.

Neptune Shipyards BU

Neptune Shipyards BV is a maritime service provider, specialised in working vessels for the offshore and dredging markets. Their services consist of new building, repair, refit, maintenance and charter. High quality, flexibility, short delivery times and innovation are qualities the company are proud of.

They offer a broad range of products and services in the shipbuilding and ship-trading sector. These include tugboats, workboats, multipurpose pusher tugs, crew boats, survey boats, pontoons, and others. Moreover they boast a long track record of satisfied customers worldwide.

In addition Neptune Shipyards can manufacture and supply all the necessary components for the shipping industry. As a result of many years of experience, their standard of quality has developed with the demands of the market place. Their hulls are built in the Netherlands under the company’s control, allowing them to deliver a ship within a very short time frame, which is nonetheless based on a design developed in full collaboration with the client.

Builder
Neptune Shipyards BV, Hardinxveld-Giessendam,
the Netherlands
Owner
WaveWalker BV, the Netherlands
Principal particulars
Length, platform 32 m
Breadth, platform 32 m
Length, moonpool 17 m
Breadth, moonpool 9 m
Depth 4.50 m
Dredging depth, max 20 m
Walking speed 40 m/hr
Parameters
Installed power 2 x 180 kW
Capacities
Displacement, max 2400 tons
Payload, 4-leg mode 850 tons
Payload, 8-leg mode 400 ton
Deck load, max 8 tons/m2
Accommodation, day 24 persons
Crane particulars
Lagendijk LWC900 –
Offshore Wire Crane 100 t at 6 m
Lagendijk LKB
13.0/20.0-10.0 Knuckle Boom Crane 10 t at 4 m

WaveWalker 1 in action

Fugro Seacore and Van Oord have developed WaveWalker 1 jointly to move around and operate in rough shallow waters, surf zones, beaches and other intertidal locations. Fugro Seacore has been working with different forms of jack-up concept barges for about 14 years in these conditions and has brought this wealth of experience to the partnership. In these locations WaveWalker 1 has the advantage that it is less dependent of the prevailing weather conditions as it can continue to work from its vantage point high above the wave zone. Conducting geotechnical site investigations, drilling operations and other underwater actions take place from a stable platform without having to refloat to move to the next location is a big advantage and allows long time periods of activity with less interruptions.

On her first charter WaveWalker 1 is employed conducting drilling and blasting works for the new Brazilian Suape Outer Channel, a contract recently awarded to Van Oord. It is anticipated that some five million cubic metres of material will need to be removed in this evolution. Approximately one million cubic metres of which consists of rock for which WaveWalker 1 will conduct the blasting activities. Van Oord will remove the other four million cubic metres of material with a large trailing suction hopper dredger. Deepening the access channel from 15 metres to 20 metres is a key objective in the port’s growth plans.

Reduced impact of sea conditions
on the operational hours

In this instance WaveWalker 1 will move to a designated position where they will drill into the seabed and place charges. Once the charges are set WaveWalker 1 will walk away to a safe distance before the charges are detonated. Once completed it will move to the next location and repeat the process.

WaveWalker 1 versus the competitors

Most pontoons or barges, as they are also known, are either self-propelled employing thrusters or have no propulsion of their own requiring to be towed wherever they are to work. WaveWalker 1 as her name suggests is capable of walking around and to achieve this has taken some innovative thinking and design. Unlike other jack-up platforms or barges, which traditionally have four legs, WaveWalker 1 has eight. These can be used either as a set of four or all eight at the same time subject to the direction of movement required. This is what stands her apart from other ‘walking’ platforms, of which there are about ten, not only is WaveWalker 1 larger, but the others can only walk in one direction. WaveWalkers legs are 1.80 metres in diameter and 40 metres tall and are raised by a total of 32 hydraulic rams and moved by eight ‘walking’ hydraulic rams.

Whilst the platform has enough buoyancy to float on unaided and (except from propulsion) can be fully self supporting, its shape (or hull form) is not been designed for moving through the water. This means that towing over long distances, which would be the normal procedure for a similar craft, and or walking at water level are not practical. So for the Brazilian contract, for example, it was placed on a large barge, which in turn was towed by a tug.

However here WaveWalkers innovative design provides benefits, because it is able to load itself onto a barge without having to ballast the barge down and then pump it out again. To achieve this WaveWalker 1 simply walks over the barge in its normal sea going ballasted position, so that it straddles the barge and then gently lowers itself onto the barge. The only ballasting necessary is that of maintaining the sea going trim of the barge. In doing so a considerable amount of time is saved making the relocation to another site much less onerous than a conventional barge.

Jelle Mens, who besides being the business manager for WaveWalker is also the general manager of Wicks, Van Oord’s business unit responsible for marine drilling and blasting, explains the advantages in the market: “WaveWalker 1 will boost the productivity of a variety of the traditional barge and jack-up operations as Wicks can now undertake drilling and blasting works from a stable platform with the added benefit of relocation without floating. This reduces the impact of sea conditions on the operational hours required for the anticipated drill and blast operations in Brazil.”

“One giant step”

WaveWalker can move in four directions and by combining the steps she can effectively move diagonally in a series of crab like movements. WaveWalker 1 uses four of its eight side mounted jacking legs, which can be conventionally raised or lowered, allowing the platform to jack-up and down. The other four raised legs are moved in the required direction by sliding them along the sides of the barge in the required direction of travel. These two pairs of legs are then lowered and pre-loaded to ensure the crafts continued stability. The other four ‘standing’ legs are raised and the entire platform, supported on its newly preloaded legs, slides forward through the side frames. The raised legs are then lowered again, preloaded to assume the weight again, and the walking cycle to be repeated. A single ‘step’ has a ‘stride’ (span) of four metres and WaveWalker 1 can complete ten moves per hour, one move every six minutes so she has a walking speed of 40 metres per hour. The sliding arrangements by which WaveWalker 1 moves is a patented process invented and developed by Fugro Seacore Limited called ‘FSCL Gripper’.

WaveWalker 1: truly capable of ‘dancing steps’

Once located in position with the legs firmly grounded the craft is levelled and jacked up clear of the waves ready for work to begin. The levelling process is manually conducted relying on the skill and knowhow of the operators.

At 2,400 tons displacement WaveWalker 1 has day accommodation only for 24 persons to operate shift work around the clock. This means that there is no accommodation for non-working staff to relax or sleep etc. The accommodation consists of a galley, offices, operational bridge, washing areas for the crew and stores. However there is room on the platform to install accommodation and additional generator capacity, should the need arise for another contract.

WaveWalker 1 is not only designed for blasting work, but is also a general purpose platform that can be used for many other offshore tasks. Equipment and gear can be shipped on board subject to the task the craft is contracted to undertake at the time. The vessel has a moonpool of 17 metres by nine metres, which can, if required, be covered over. The total deck space is 32 metres square and, with deck load of eight tons per metre square, is capable of carrying a payload of 400 tons whilst walking. For some contracts WaveWalker may not require all of the legs, when this happens four (two pairs) of the legs can be removed and the

Two electro/hydraulic cranes are installed on the vessel, all supplied by Lagendijk. They comprise a LKB13.0/20.0-10.00 offshore knuckle boom crane, capable of lifting ten tons at a radius of four metres, complete with hydraulic grab capable of working at 20 metre depth. The other is a newly designed LWC 900 offshore wire crane with a capacity of 100 tons at a radius of six metres or 76 tons at six metres in sea state 5. It is fitted with an operators cabin. Both cranes are fitted with constant tension winch arrangements and conform to GL classification, whilst the knuckle boom crane is also certified for man riding.

Two Caterpillar C9 driven diesel generator sets generating 180kW (225kVA) supply the electrical power. Hydraulic power is provided again by Caterpillar, in the form of two C18 hydraulic power packs of 470kW each. WaveWalker has all the tanks and pipework systems one would expect to find on a vessel of this type, including fuel, fresh water etc.

Neptune’s challenges

Construction of the craft was in itself a challenge, which was overcome by building it in two L shaped sections under cover, in one of the construction halls of Neptune Shipyards. The sections were then transported to the quayside at Hardinxveld where they were joined together and before being launched into the river Merwede. At the shipyard in Hardinxveld-Giessendam it was fitted out as much as possible, including trial fitting of the legs. However the height restrictions on the Merwede River, and the others that the craft needed to navigate to get to the sea, prevented WaveWalker from being completed at this location. This was overcome by moving the vessel to Dordrecht where the cranes were finally fitted.

With WaveWalker 1 the consortium is hoping to make great strides into the future and stay ahead of the competition.

Tom Oomkens & Andrew Rudgley