2019 is a year for outstanding tug design and propulsion innovation, driven by owners’ need to reduce emissions
There has been a major evolution in tug design and innovation in 2019 with key drivers being hybrid propulsion and ice-breaking tugs. Environmental concerns are propelling designers and shipyards producing harbour tugs to go beyond IMO Tier III and US Environmental Protection Agency (EPA) Tier 3 emissions requirements.
They are combining electric motors and batteries with low-emissions propulsion for all-weather and cold-climate operations worldwide. Here is a round-up of the most innovative and technically advanced tugs delivered to owners in 2019. They represent the main categories of innovative design and construction. Tug Technology & Business was assisted in selecting these Tugs of the Year by industry organisations and leaders.
Powerful hybrid icebreaker
Port of Luleå took the tug industry by storm with the world’s most powerful ice-breaking tug in Q3 2019. Vilja will make a considerable impact to year-round harbour operations in Sweden. It was built by Gondan Shipbuilders at its shipyard in Spain as a 36-m hybrid icebreaker tug.
Vilja is employed for ship assistance and provides coastal towage, ice management, fire-fighting and navigation duties in the northern sector of the Gulf of Bothnia.
“Vilja represents the most technologically advanced tug currently in operation,” says Port of Luleå chief executive Henrik Vuorinen. “The hybrid power module will ensure a drastic reduction in emissions, setting new, higher standards for our service, and for the quality of life in the Luleå region.”
Vilja was built to Robert Allan’s TundRA 3600-H design and is certified by Lloyd’s Register. It has a hull structure that exceeds Finnish-Swedish ice-class rules and has high environmental standards. It has a moulded breadth of 13 m and navigational draught of 7 m.
It can break 1 m of ice at up to 3 knots with low emissions.
For this, Vilja is equipped with an innovative Wärtsilä HYTug hybrid power system that includes two Wärtsilä 26 diesel main engines, shaft generators, motors and batteries for energy storage, which will be automatically recharged by the onboard energy management system. Wärtsilä also supplied the power distribution train and the integrated automation and alarm system.
Vilja has a bollard pull of around 55 tonnes when operating on electrical battery power alone or using a single main engine. This is increased to around 90 tonnes of bollard pull on two engines and 100 tonnes, as tested during sea trials, when battery boost capacity is included.
Vilja’s total propulsion power is around 6,200 kW in hybrid boost mode, when it produces 20% less emissions than a conventional tug of this type and size.
Type: Ice-breaking harbour tug
Owner: Port of Luleå, Sweden
Builder: Gondan Shipbuilders
Designer: Robert Allan
Class: Lloyd’s Register
Ice: Finnish-Swedish ice class rules
Performance: Break 1 m of ice at 3 knots
Bollard pull: 100 tonnes (diesel-mechanical mode)
Length, oa: 36 m
Breadth, moulded: 13 m
Draught: 7 m
Main engines: 2 x Wärtsilä 26
Hybrid system: Wärtsilä HYTug
Tier III reversed stern drive
Innovator Multraship Towage & Salvage purchased a reversed stern drive (RSD) tug, the first in Europe to be IMO Tier III-compliant.
Multratug 6 was named in Terneuzen, the Netherlands, on 28 June after completion by Damen Shipyards. This RSD 2513 design tug is low in emissions and vibration which, according to Multraship managing director Leendert Muller, are operational and environmental benefits.
“The purchase of Multratug 6 was a response and desire to reduce our exhaust emissions,” says Mr Muller. “We take responsibility for the environment and this is why we have chosen an IMO Tier III-compliant vessel, the first of its kind in Europe.”
“[Tier III] is in tune with the increasing demand from local port authorities for clean operations,” says Mr Muller, who also considers seafarers’ working environments. “The reduced noise and vibration levels exhibited by the RSD 2513 was another deciding factor,” he says.
Damen included hull design innovation in this 25-m tug. Its twin fin skeg adds to the effectiveness of the hull, giving Multratug 6 excellent course-keeping and predictable sailing characteristics. The either-end bow concept has been adapted to provide this RSD 2513 tug with bollard pull of 75 tonnes ahead for pushing and 71 tonnes astern for pulling.
Multratug 6 has a wide range of additional features including Damen’s new human-machine interfaces, safety glass in the wheelhouse and Damen’s remote monitoring system. This shatterproof glass is similar to that used in the automotive sector and represents a huge step forward in crew protection. In addition, the superstructure is glued to counter noise and vibration.
Multratug 6 particulars
Type: Two-way harbour tug
Design: RSD 2513
Bollard pull ahead: 75 tonnes
Bollard pull astern: 71 tonnes
Length, oa: 25 m
Breadth, 13 m
Intelligent ice-breaking and pilotage
Chinese tug construction took an evolutionary leap in 2019 when the first intelligent ice-class tug, Jin Gang Lun 31, was delivered. This ASD combined towage and pilotage vessel was built by Zhenjiang Shipyard in Jiangsu Province, China, for Tianjin Port Tug & Barge Co. Its sister tug, Jin Gang Lun 32, was also delivered to the owner in May 2019.
Both were built to Robert Allan’s ASD 40-35 design for pilot transfer and towage. They are also the first in the world to have China Classification Society CCS’ Intelligence notation with systems on board to monitor fuel and engineroom systems’ performance and condition and have ice-breaking capabilities with Ice Class B hulls.
Jin Gang Lun 31 and Jin Gang Lun 32 were awarded the CCS class notation i-Ship, with sub-notations of N-intelligent navigation; M-intelligent machinery space, E-intelligent energy management and I- intelligent for the integral platform.
These tugs transport pilots in rough sea conditions in Tianjin Port, in China’s Bohai Bay which was one of the reasons for reducing noise and vibration on these vessels. To accommodate pilot transfer, Robert Allan included a boarding system in their design after receiving input from Tianjin Port and pilot station personnel.
For pilot transportation, Jin Gang Lun 31 and Jin Gang Lun 32 achieved free running speeds of 14.48 knots during sea trials. They both have bollard pull ahead of 36 tonnes for ship manoeuvring in the port.
Main propulsion comprises a pair of Wärtsilä 6L20 diesel engines, each rated 1,200 kW at 1,000 rpm driving Kongsberg US 155P14 controllable pitch Z-drive units with 180-cm diameter propellers. The electrical plant consists of three Cummins diesel generator sets that each produce 150 kW of power. Robert Allan says the cooling systems were improved over previous vessels based on Tianjin Port’s experience and input from Wärtsilä.
Jin Gang Lun 31 particulars:
Type: ASD towage/pilotage vessels
Owner: Tianjin Port Tug & Barge Co
Builder: Zhenjiang Shipyard
Designer: Robert Allan
Class: China Classification Society
Notations: intelligent ship (i-ship), Ice Class B
Length, oa: 40 m
Beam, moulded: 11 m
Hull depth, moulded: 5.1 m
Maximum draught: 4 m
Top speed: >14 knots
Main engines: 2 x Wärtsilä 6L20
LNG-fuelled Japanese tug
A major shipping group took LNG-fuelled harbour vessels to a new level when it commenced operations with Ishin. This is the first LNG-fuelled tug and first to conform to the IGF Code in Japan.
Mitsui OSK Lines (MOL) received tugboat Ishin in February and it bunkered its first LNG fuel from a lorry in Sakai Senboku Port in March. In September, this 250-gt tug bunkered its first LNG from Kobe Port.
This 43.6-m tugboat was built by Kanagawa Dockyard Co in Kobe and is operated by Nihon Tug-Boat Co in Osaka Bay, where it regularly refuels at a specialised facility in Sakai Senboku Port. It has a beam of 9.2 m, draught of 3.12 m and top speed of 16 knots.
Ishin is powered by two advanced Yanmar 6EY26DF dual-fuel main engines. It has a removable LNG fuel tank mounted on the aft deck for convenience in bunkering, maintenance and inspection.
MOL said Ishin emits 25% less CO2 in comparison to tugs that run on marine diesel and produces lower SOx and NOx emissions. The shipping group worked with Osaka Prefecture Port and Harbour Bureau and Osaka Gas to implement the Sakai Senboku Port bunkering facility.
Type: LNG-fuelled harbour tug
Owner: Nihon Tug-Boat Co
Builder: Kanagawa Dockyard
Class: Class NK
Length, oa: 43.6 m
Beam, moulded: 9.2 m
Maximum draught: 3.12 m
Top speed: 16 knots
Main engines: 2 x Yanmar 6EY26DF
Integrated hybrid propulsion
Harbor Docking & Towing was thinking innovatively when it ordered the first harbour tugs from Washburn & Doughty with an integrated hybrid propulsion system. Ralph and Capt Robb were the first harbour tugs to feature Caterpillar’s integrated propulsion including main engines that comply with EPA Tier 4 emissions requirements, auxiliary generators and Z-drives.
A pair of Cat 3512E main engines each develop 1,900 kW of power and drive MTA628 fixed-pitch azimuthing thrusters. Caterpillar also delivered two Cat C18 gensets that produce 565 kW of electrical power and one 200-kW Cat C7.1 genset.
These 28.3-m tugs have an advanced and well incorporated hybrid system comprising two ABB electric motors, each rated at 600 kW, on the drive units.
It means Ralph and Capt Robb have bollard pulls ahead of 84 tonnes and free running speeds of 14 knots. They have a beam of 11.5 m, hull depth of 4.7 m and accommodation for six crew.
Capt Robb particulars:
Type: Hybrid harbour tug
Owner: Harbor Docking & Towing
Builder: Washburn & Doughty
Length, oa: 28.3 m
Beam, moulded: 11.5 m
Hull depth: 4.7 m
Top speed: 14 knots
Main engines: 2 x Cat 3512E
Propulsion: 2 x MTA628 FP 03
Other notable deliveries
Delta Teresa – a hybrid-propulsion tug with electric motors on the Z-drives built by Nichols Brothers for Baydelta Maritime’s operations in western US. It has two C3516 C Tier 3 diesel engines driving two Kongsberg 255FP units. It can work on electric motors only to achieve 10 knots during transits.
Tsimshian Warrior – one of the first IMO Tier III escort tugs in Canada comes from Uzmar tug builders with additional protection for operations at an LNG export terminal. It has two Caterpillar Cat 3516E engines and Kongsberg US255 controlled-pitch drives.
Vittoriosa – a highly rated escort tug with safety systems for LNG terminal operations, including gas detection and ventilation shutdown with stored air. Built by Med Marine for Tug Malta with 80 tonnes of bollard pull from twin MTU 4000 series M65L engines driving two Kongsberg US 255 P30 thrusters.
PSA Aspen – a dual-fuel tug with integrated LNG storage. It has a Niigata propulsion system with two medium-speed 6L28AHX dual-fuel main engines and a pair of ZP-31 Z-Pellers.
Ohio – a compact ice-breaking tug with a Logan FlexaDrive hybrid power system, two MTU 8V4000 diesel engines that meet IMO Tier III emissions requirements for Great Lakes towage.
List of participants
The following organisations (in alphabetical order) were contacted for their opinion on tug innovation and design.