At a time when many companies in the marine industry see mergers as the key to success, Brunvoll AS, the Norwegian thruster manufacturer continues to 'steer' its own course, resisting the temptation to enter into joint ventures or acquisitions in order to gain market share. In fact, as Knut Andresen, Brunvoll's Technical Director explained recently, acquiring a 'package' of systems from a large concern may not be the best solution for shipowners anyway, because of the temptation for some companies to 'hide' costs within the package.
Brunvoll has been designing and manufacturing thrusters for more than 37 years since it first introduced tunnel thrusters onto the Norwegian market. It continues to specialise in thrusters to this day, and has gained a worldwide reputation in that sector of the market, choosing to design and manufacture thrusters that are 'customised' to meet the demands of individual ships, rather than low cost, 'off the shelf' equipment that is poorly suited to individual shipowners' requirements.
As Andresen explained, thruster capacity on board all types of vessels is growing rapidly, in response to shipowners' requirements. In the cruise ship sector, the one of the main reasons for increased demand for thruster capacity is the growing requirement for better position keeping capability. Often this is because anchoring restrictions prevent the use of traditional means of maintaining a ship in position, leading to increased use of azimuthing propulsion units and larger bow thrusters.
Elsewhere, in other sectors of the shipping industry, such as the market for offshore supply vessels and other types of offshore ships such as cable layers, additional thruster capacity is seen as way of enhancing position keeping, providing a redundant propulsion capability, and reducing operating costs. He believes that if shipowners pay careful attention to the requirement for thrusters aboard their ships, they can make them more manoeuvrable, safer, and less expensive to operate, and says the best, most economical thruster to acquire may well not be the least expensive.
As Andresen explains, selection of a thruster may be based on a shipowners business strategy, or the shipbuilder's specification for a ship. This tends to result in a thruster 'solution' that is harmonised either with the expected lifetime of the ship, or the selection of the thruster(s) with the lowest unit cost or cost per kW. However, the latter tends to lead to the installation of over-rated units, and low cost design solutions in which the structure of the tunnel that houses the thruster is not properly integrated, structurally and hydrodynamically, with the hull structure of the ship in which it is installed.
Then there is the role of the classification societies. Some class societies don't have any requirements at all for auxiliary thrusters; others do. Where class societies do have requirements for thrusters - as is the case with thrusters for a Dynamic Positioning system (DP) - class requirements often differ significantly. "The basis for an approval or certification by a class society needs to be clarified, and carefully evaluated by shipowners", says Andresen. "When it comes to thrusters for DP systems, the lack of a harmonised approach among class societies is in itself a major cost for the thruster manufacturer. Moreover, at the moment, as a rule, class societies don't generally accept one another's certificates, so in many cases certification just adds to the cost of the thruster without also adding value".
Thrusters of all types should never be regarded as standardised or 'off the shelf' products, says Andresen, if an owner is to get maximum value from a thruster, not just in terms of initial cost, but overall performance, and through life costs.