Turn this way

An innovative new Wärtsilä thruster offers captains manoeuvrability and, thanks to its lean and compact design, is easy to integrate and install by the shipyard.

Three-point turns; the challenge everyone hopes the instructor will accidentally forget as you try to pass your driving test. There are over 161,000 hits on “three-point turns” on YouTube, but imagine having to navigate not your dad’s battered Beetle, but an entire barge loaded with cargo worth hundreds of thousands of dollars.

That’s a daily reality for the captains who ensure much of our natural resources get to where they need to go. On narrow waterways manoeuvrability can be a game breaker, which means that technology such as Wärtsilä’s new WST-14 steerable thruster – with cutting-edge azimuthing propeller technology – not only saves time, but can cut costs.

Wärtsilä’s thruster portfolio – with 9 sizes available to cover a 1100-3200 kW range – has been developed mainly with tugs in mind, but with this latest thruster offering Wärtsilä also aims to serve the designers and builders of cargo vessels, with a focus on the Russian, US and Latin American inland waterway markets.

“The WST-14 is designed for cargo vessels for inland waterways, and there are design features that specifically address that market,” says Joost van Eijnatten, Manager, Application Engineering, Propulsion, Wärtsilä Marine Solutions. “On a tug boat, which is a relatively short vessel, you can turn it on the spot with a thruster, which you can’t do with a rudder. The same applies to larger vessels, but of course more space is needed to turn and navigate the vessel.”

The compact design offers shipyards as well as owners and operators considerable advantages. The space-saving aspect also aids installation.

“We have done our utmost to make this thruster as compact as possible, that means that everything that is needed to operate the thruster is on the thruster itself,” van Eijnatten explains. “For example, you need a steering system to turn it around but also a lubrication system which doubles as a cooling mechanism, for the bearings and the gears.”

The new thruster has integrated all these components.

“It is installed as one unit on the vessel,” van Eijnatten says. “The whole idea is that the shipyard puts it in, and then only has to realise the mechanical connection to the engine and the necessary connections for cooling water, electric power and data-buses to complete the installation.”

The compact design also means more space for cargo when compared to a conventional shaftline propulsion system.

“We have calculated a 10% increase in cargo space,” says van Eijnatten. “A considerable gain for an operator.”

Ice class notation

There are further solutions sewn into the design: An integrated slipping clutch that provides a cost competitive solution for manoeuvring when combined with a fixed pitch (FP) propeller. Another feature is the possibility to have an ice class notation, enabling operation in ice-covered waters and lending the strength to withstand impacts from floating debris.

The design has also made maintenance easier – bringing down the total cost of ownership – because it is possible to service the propeller shaft and steering seals without a complete overhaul of the thruster.

The importance of the vessels to be served cannot be understated. In many markets, inland waterways and rivers are equally, if not more, important than rail and roads.

“In Russia, these vessels transport anything from refined oil products to other kinds of liquid cargo,” van Eijnatten points out. “In the US and Brazil, virtually everything can be transported on barges including ore and timber.”

To simplify the selection and integration of the propulsion drive line, the thruster can be combined with a Wärtsilä engine – offering an all-in-one package. The 6-cylinder in-line Wärtsilä 20 engine and the WST-14 thruster make a noteworthy duo, not just on rivers and canals, but also in harbours and during ice conditions.

”This introduction fills a particular need in the inland waterway vessel sector, and it is already attracting interest from owners and yards in Asia, Europe and America,” says Arto Lehtinen, Vice President, Propulsion, Wärtsilä Marine Solutions.

  • The DNV-GL classification society approved the design of Wärtsilä WST-14 in 2014.
  • Getting type approal early in the design phase cuts development costs and reduces manufacturing time of new products.
  • The WST-14 thruster is part of the Wärtsilä Steerable Thruster series, aimed primarily at tugs, anchor handling vessels, and coastal and inland waterway cargo vessels. Other sizes include WST-11, -16, -18, -21, -24, -28 and -32, the number being an approximate indication of the maximum power level in kW/100.
  • Key benefits for the WST-series are high-end performance, ease of installation, a high level of integration, high-speed engine and ice class compatibility. It also complies with the latest environmental regulations, e.g. EPA VGP 2013.
  • The WST-14 prototype was manufactured in Wuxi, China, and tested and validated in Tuusula, Finland. 


© 2018 Wärtsilä