Bridge contract breeds versatile crane vessel

The Rambiz is a heavy lift vessel — devised primarily to raise 2,200 ton bridge sections into position, 177 ft. (54 m) above the River Tagus in Portugal ~ developed by a joint venture of Belgian and Dutch companies.

Built in Rotterdam, the purpose-built Rambiz nonetheless incorporates a number of innovative elements to provide considerable versatility, rendering it capable of undertaking a uniquely broad spectrum of salvage and construction tasks following the completion of the 17-month Portuguese bridge building contract. The catamaran-type vessel uses two identical, existing 250.7 x 65.3-ft. (76.4 x 19.9-m) heavy lift pontoons, Ram and Bizon, for the twin hulls. These are joined amidships by a newly constructed link module, leaving a clearance between the hulls of approximately 90 ft.

(27.5 m). This module is a pontoon vessel in its own right, which not only enhances stability but provides the wheelhouse/control room and crew accommodation. Mounted on each end of the link are two new Huisman cranes with a 269-ft. (82-m) main boom and a 177-ft. (54-m) back boom. Fly-jibs may be fitted to extend the maximum reach to 787 ft. (240 m).

Flexibility is the essence of the vessel's originality. The two cranes can be removed and used for heavy lift tasks ashore, and the twin hulls can be separated to create a pair of heavy lift/transport platforms, each with a 2,000-ton capacity and capable of fully independent operation. All the constituent parts of Rambiz can be deployed for a variety of tasks simultaneously. For example, one hull could be used as a heavy lift pontoon for wreck removal, while the other is employed on a transport task and the link module utilized as a floating accommodation unit and command center.

The cranes break down into easily transportable sections, and the winches and power packs adapt to fit comfortably into containers. To provide exceptional strength at low weight, special steels have been used in the construction of the cranes.

Rambiz is fully certified for ocean passage with the cranes fully erected. For local operation it is propelled by four 750-hp, deck-mounted Schottel thruster propulsion units. Located at either end of each hull, this package provides a cruising speed of six knots and a maximum speed of 8.5 knots. For long ocean voyages the vessel would be towed. Tests carried out by the Marin Marine Institute, Wageningen, Holland, show that the design is able to withstand 26-ft. (8-m) wave heights.

The spacious wheelhouse (see picture,page 62) contains a special command panel for the four thrusters which may be controlled collectively or individually. In addition to the standard navigational aids — Sercel DGPS, Raytheon R82 Radar and JRC echosounder - precise positioning is achieved by a computerbased system which uses both satellite and radio beacon information to pinpoint the exact location to within 18 in. (0.5 m). The monitor 52 also displays water depth on a continuous basis. Crane and winch operation is also controlled from the wheelhouse. Rambiz is jointly owned by Scaldis Salvage and Marine Contractors based in Antwerp Belgium, and Dutch heavy lift specialist Van Seumeren. Scaldis, itself, is a consortium of four Belgian marine contractors with a track record of successful assignments, including the salvage of the vessel Mount Louis and its hazardous cargo, the refloating of Herald of Free Enterprise and the clearance of the wreck of jack-up rig West Gamma.

The company is led by former ISU President Klaas Reinegert. With subsidiaries worldwide, Van Seumeren has more than 200 large cranes and will take delivery in September this year of the world's largest crawler crane. Thetwo companies formed their joint venture specifically to bid for the Tagus bridge project marine services contract from the main contractor consortium, Agruamento Complementor de Empreses. The joint owners are already looking at the future of Rambiz beyond the initial contract. Frans van Seumeren said: "This highly flexible heavy lift system will find many applications in a wide variety of markets worldwide. There are obvious opportunities in the offshore industry with its growing requirement for cost-effective dismantling of oil and gas platforms.

The 88.6-ft. (27-m) spacing between the catamaran's floaters allows the Rambiz to position itself to lift heavy topsides with relative ease. In addition, the maximum lifting height of 787.4-ft. (240-m) should be of interest to those responsible for new construction projects around the world." Construction of Rambiz commenced by Dutch turnkey lift system specialists Huisman-Itrec in June 1995, and the vessel was officially named, following successful sea trials, in February 1996. Circle 244 on Reader Service Card 62 Maritime Reporter/Engineering News Belgium, and Dutch heavy lift specialist Van Seumeren. Scaldis, itself, is a consortium of four Belgian marine contractors with a track record of successful assignments, including the salvage of the vessel Mount Louis and its hazardous cargo, the refloating of Herald of Free Enterprise and the clearance of the wreck of jack-up rig West Gamma.

The company is led by former ISU President Klaas Reinegert. With subsidiaries worldwide, Van Seumeren has more than 200 large cranes and will take delivery in September this year of the world's largest crawler crane. The Building the Tagus bridge The Vasco de Gama Bridge is reportedly the largest transport related civil engineering project in Europe after the Channel Tunnel, and comprises an eight-mile concrete box girder bridge across the River Tagus near Lisbon, Portugal's capital. Almost the entire length will cross water - opening up a route to ease the city's traffic congestion, and forming a new link with the site of EXPO '98 which is being hosted by Lisbon.

The lifting program calls for the positioning of 150 girders each 262 x 52.5-ft. (80 x 16-m) and weighing up to 2,200 tons. Rambiz will also place eight 1,200-ton hammerhead pier top sections and perform a variety of other heavy lifts. Each 262-ft. (80-m) span consists of two girders placed side by side to create a 111.5-ft. (34-m) wide bridge deck. On completion, the Vasco de Gama Bridge will soar 177-ft. (54- m) over the busy navigation channel of the Tagus.

When the lifting devices are attached, the beam is raised sufficiently to clear the jetty support structure and the vessel winched into the channel. The beam is lowered onto a support system fitted to the foredeck before the vessel moves off into the Canal de Barreiro, under thruster power, to begin its journey to the bridge site. An hour long passage through the canal will bring it to one of three designated holding points to await the next opportunity to enter the river's dredged navigation channel which must be entered on a rising tide.