Rolls-Royce invested US$58M in a new thruster factory, Schottel has modified its Rudderpropeller combi drives and Veth was acquired by Twin Disc, writes Ed Martin
With work nearing completion on Rolls-Royce’s £44M (US$58M) expansion of its thruster facilities at Rauma in Finland, Rolls-Royce customer director for propulsion and engines Gary Nutter and site manager Olli Rantanen spoke to Tug Technology and Business about what the investment has brought to the site.
Rolls-Royce has a strong heritage of providing thrusters for tugs, with the 10,000th of the azimuthing US-series thrusters brought into service. These are available in 12 sizes with a power range of up to 5,000 kW per unit. The company is planning to add an L-drive version of the US thruster to the range, and is also developing larger versions of the AZ PM permanent magnet azimuthing thruster range for the tug sector.
One of the main aims of the Rauma Transformation project was to consolidate all Rolls-Royce operations at Rauma onto one site, said Mr Nutter. The project includes refurbishing the existing facilities, a newbuild area for thruster assembly and testing parts, with component manufacturing completely outsourced, said Mr Rantanen.
“The scope [of the project] is mainly the building infrastructure and capital investment for equipment. That will be finalised by the end of this year,” he said, adding “when it is consolidated to one site, production is streamlined so we will get shorter lead times and better productivity.”
“We will get shorter lead times and better productivity”
Azimuth thrusters have been built at Rauma since 1965, with the first model made partly from tractor parts. This is a far cry from the current output of the plant’s three assembly lines. Mr Nutter outlined each line’s production.
The 40-tonne line is used to produce the US thrusters range, which are generally fitted to workboats and tugs and used for high-bollard pull activities, Mr Nutter said, citing examples of contracts with Damen and Sanmar.
The 80-tonne line will manufacture UUC thrusters, for use on larger vessels such as drilling rigs, semi-submersibles and thruster-powered floating production, storage and offloading units. Mr Nutter noted that UUC thrusters are used “in some of the harshest environments in the North Sea.”
The third assembly line is for large, retractable thrusters, used in harsh ice environments such as the Arctic. This line will have a height of 35 m and a hook height of 30 m to allow the largest thrusters to be tested, said Mr Nutter.
Orders and acquisition
Since the interview took place, it has been announced that Kongsberg will acquire Rolls-Royce’s commercial marine business, which includes the thruster division. When questioned on the possibility of a takeover during this interview, Mr Nutter said the thruster business had largely been unaffected by the possibility of the marine division being sold.
Damen Shipyards installs Rolls-Royce thrusters on the majority of tugs it builds for its own stock and those for owners. Rolls-Royce supplied thrusters for Damen’s new design for a harbour tug, reverse stern drive Innovation and supplied Kotug Smit’s Buffalo azimuth tractor tug (Tug Technology & Business, Q2 2018).
Turkish shipbuilder Sanmar Shipyards chose Rolls-Royce to supply propulsion and deck equipment for 21 tugboats being built for a range of customers. Rolls-Royce will supply 42 US205/255 azimuth thrusters with bollard pulls of 60, 70 and 80 tonnes, along with high-pressure hydraulic towing winches for the 80-tonne models.
Sanmar’s framework agreement means standard-specification products will be supplied for all of the vessels across a two- to three-year period, rather than being delivered on a project-by-project basis.
“The current orderbook for Sanmar tugs lends itself to this new procurement arrangement,” said Sanmar’s projects director Ali Gurun. “Rather than having to create a new supply agreement for each newbuild project, this new arrangement allows us to have a constant supply of Rolls-Royce equipment that we can adapt to meet our customers’ requirements.
“This means we can potentially reduce build time and streamline the building process,” he said. Rolls-Royce has delivered 150 azimuth thrusters to Sanmar in a relationship that spans 15 years.
Schottel has modified the nozzle design for its range of SRP Rudderpropeller combi drives (SCD). These are electric-drive azimuthing thrusters that increase efficiency of propulsion while reducing fuel consumption.
It has added ProAnodes on the outside of the nozzle to improve the amount of thrust these L-drives can generate, said Schottel senior sales manager Uwe Neddermeyer. “We put the anodes on the edge to improve flow from the propeller,” he explained to Tug Technology & Business. “There is then less disturbance in the flow and more efficiency of the nozzle.”
ProAnode's position improves corrosion protection and the lifecycle of the thruster. By moving the anodes from the outside surface of the nozzle into the cross-section of the nozzle tail lowers flow interference, saving fuel costs for tug operators.
This also reduces the risk of these anodes being knocked off by flotsam, such as ice or plastic, protects the anodes from any grounding and prevents loss of anodes, which could increase the nozzle's risk of corrosion. Anodes provide cathodic protection against corrosion for up to five years and their loss is often not discovered until a tug has its class survey.
SCD thrusters come in the power spectrum from 1,850 kW to 4,200 kW, with propeller diameters ranging 2,600-3,600 mm. They are based on Schottel’s Rudderpropeller azimuthing thruster design for tugs and other workboats, with limited space for propulsion.
Many commercially available thrusters house the electric motor in an underwater pod, but the SCD vertically integrates its motor into the support tube of the thruster inside the vessel.
Schottel’s Singapore subsidiary, Schottel Far East, has relocated to new facilities in southwest Singapore. Incorporating a workshop with a 90-tonne lifting capacity, two 40-tonne cranes that can lift loads up to 9 m in height, and a crane with a lifting capacity of six tonnes, the facilities will be capable of servicing rudder propeller thrusters of up to 3,500 kW.
Schottel has received multiple orders for its SRP series and supplied thrusters for new deliveries this year. It has supplied two SRP 4000 fixed propeller units for two tugs – Rosemary McAllister and Capt Brian A McAllister – for McAllister Towing’s US east coast operations. These 30.5 m tugs meet US Environmental Protection Agency’s Tier 4 and IMO Tier III requirements for emissions.
This propulsion system manufacturer delivered SRP 1515 controllable pitch azimuth-drives for four tugs built by Triyards in Vietnam for Star Marine. The 34-m escort tugs were designed to operate in the Red Sea along the Saudi Arabia coast.
Schottel also supplied fixed pitch nozzled Rudderpropellers for a series of six tugs built by Shipyard De Hoop this year for a consortium of companies manoeuvring barges across the Caspian Sea. They are transporting modules to the Tengiz oilfield in Kazakhstan.
In another order, Schottel provided thrusters for a new harbour tug at the largest port in New Zealand’s South Island. Lyttelton Port Co has commissioned a Robert Allan RApport 2500 design tug from ASL Marine Shipyard Singapore to take over from an older vessel. This new tug will be equipped with two Schottel type SRP460 azimuth Rudderpropellers, each of which will have an input power of 2,240 kW.
Peruvian tug operator Tramarsa chose Schottel in January to provide thrusters for a new escort and harbour tug, Lima, under construction at the Jiangsu Wuxi Shipyard in China. Lima will be fitted with two Schottel type SRO 490 FP azimuth Rudderpropellers, each of which has an input power of 2,240 kW and a bollard pull of around 78 tonnes.
The tug will be a RAmparts 2400-W series model equipped with a FiFi1 fire-fighting system and will be classed by ABS for unrestricted navigation and towage. It is set for delivery in Q4 2018 and will be the third tug in Tramarsa’s Peruvian fleet, which operates at the port of Callao.
Veth acquired by Twin Disc
Racine, Wisconsin-based power transmission firm Twin Disc has agreed to acquire Veth Propulsion for approximately US$58.6M plus net cash and potential adjustments based on Veth Propulsion’s working capital and performance. Twin Disc said it would finance this acquisition through a combination of cash and creating new debt facilities.
There would be add-ons of up to US$3.9M, to be paid in Twin Disc common stock, if certain earn-out provisions are met. Twin Disc expects to complete this purchase in July 2018.
Twin Disc chief executive officer and president John Batten said the acquisition will “strategically expand our global market and increases our size, scale, and scope within the marine industry”. He added that Veth Propulsion’s hybrid drive and integrated L-drive technology “will open new markets and opportunities for growth”. This year, Veth Propulsion is expected to achieve sales of US$60M.
The two companies have worked together since December 2015, when Veth Propulsion selected Twin Disc as its distributor for selected Asian markets. This relationship was expanded in 2016 with a North American distribution partnership.
Meanwhile, De Boer Remorquage SARL’s tug Papillon, delivered in January, is the first Damen-constructed tug to be fitted with Veth propulsion’s Z-drive thrusters.
The tug, built to Damen’s ASD 2310 design, is fitted with two Veth VZ-1100A thrusters with a propeller diameter of 1,800 mm, fitted with a VOB50 nozzle. It is powered by a Mitsubishi S12R-MPTAW and has a bollard pull of 33.5 tonnes full ahead and 29.6 tonnes full astern.
While Damen has looked to Veth since the 1980s to supply Z-drives, tunnel bow thrusters and generator sets for a range of vessel types, this is the first time a Z-drive has been delivered for an ASD tug, according to Veth general sales manager Martin van der Jagt.
Mr van der Jagt added that Veth has received an order for two VZ-1250A-VHD hybrid drives and a 200 kW tunnel bow thruster for a multipurpose tug/dredger, also being constructed by Damen for De Boer Remorquage.
Veth is also supplying VZ-900 azimuthing stern thrusters for Abu Dhabi Marine Services (Safeen) in the UAE. Safeen purchased three tugs from Sanmar shipyard in Turkey in September 2017, and has so far taken delivery of two.
At 18.7 m by 9.2 m these Yenicay-class tugs are compact and designed to provide high performance line and ship handling capabilities typical in smaller ports and harbours. They are based on Robert Allan’s RAscal 1800 design. Propulsion comes from two caterpillar C32 main engines, each generating 969 kW at 1,800 rpm.
Voith thrusters in RAVE
Voith Turbo worked with naval architects at Robert Allan and Novatug to develop the Carrousel RAVE tug concept. Two of these have been constructed and brought into service for port operations in northern Europe. These are 32-m tugs with a rotating towing system combined with inline Voith Schneider propulsion for 360˚ manoeuvring.
The inline propulsion allows the vessel to have a slender hull without affecting its stability. It also enables the towline force to be continuously controlled safely and precisely via Voith electronic controls in the wheelhouse. This propulsion generates up to 77 tonnes of bollard pull on Multratug 32 and Multratug 33. These were built by Damen Shipyards and classed by Bureau Veritas.
Additional reporting by Martyn Wingrove