A round-up of the most innovative and technically advanced tugs delivered since the beginning of this year demonstrates the technology jumps by designers and builders
This year has seen the biggest leaps in tugboat technology deployment for a generation. Some of these developments have been in reaction to a growing trend to improve the environmental footprint of tugs in harbours worldwide.
Other technology advances have come from a drive to improve crew safety during towage operations, or to enhance the stability of tugboats at higher bollard pulls. There has also been a reaction to the rising costs of building more advanced and powerful tugs with at least one unit built for low-cost harbour operations.
Here is a round-up of the most innovative and technically advanced tugs that have entered service in 2018. They are in no particular order, but represent the main categories of innovative design and construction.
Novatug revolutionised towage technology this year when its first Carrousel RAVE tugs came into service. Multratug 32 and Multratug 33 are operated by Multraship Towage & Salvage in Antwerp, Belgium and Bremerhaven, Germany each with a carrousel towing system that revolves around the wheelhouse.
They have Voith Turbo inline propulsion for manoeuvrability and for dynamic towage to escort oncoming ships into harbours and terminals instead of just static towage. “Capsizing should be impossible when towing with the carrousel system,” said Novatug managing director Julian Oggel. “This allows for the safe execution of manoeuvres that would be a higher risk with traditional tugs.”
Multratug 32 started trials in January this year and Multratug 33 joined the Multraship fleet in April. These have an overall length of about 32 m and 77 tonnes of bollard pull.
They are designed by Robert Allan and classed by Bureau Veritas. Their hulls were built at the Theodor Buschmann shipyard in Hamburg in 2017, and the tugs were completed at Damen Maaskant in Stellendam, the Netherlands.
They each have two Voith Schneider propellers arranged in-line, which means they can have a slender hull without affecting stability. These Voith 32RV5 EC/250 propellers have precise thrust control, quick response and insensitivity to variations in inflow direction. They enable the towline force to be continuously controlled safely and precisely via Voith electronic joystick controls in the wheelhouse. These Voith Schneider units are driven by two ABC 12VDZC engines that each deliver 2,650 kW at 1,000 rpm.
At the heart of these tugs are a patented carrousel system, which is a towing winch on a steel ring. Machinefabriek Luyt delivered the carrousel unit, which consists of a base structure surrounded by a ring that can rotate freely 360˚ in the horizontal plane around the tug’s deckhouse. This carries a towing winch that can tilt vertically 45˚ so that the winch can always be aligned with the towing line, providing optimal control.
Mr Oggel said these tugs have demonstrated improved safety in towage for escort and harbour operations. “There are advantages in less fuel and emissions as these tugs use the kinetic energy from ship motion for manoeuvring,” he said. “They increase capacity at existing ports for handling ships with more control and without affecting the safety margins.”
Since introducing the large 32-m Carrousel RAVE tugs, Robert Allan and Novatug have developed a medium-sized design that has an overall length of 28 m and bollard pull of about 50 tonnes.
Multratug 32 particulars
Design: Carrousel RAVE
Built: January 2018
Builder: Damen Shipyards
Owner: Novatug (Multraship)
Class: Bureau Veritas
Length, oa: 32 m
Beam, oa: 13.2 m
Draught: 6.3 m
Displacement: 494 tonnes
Bollard pull: 77 tonnes
Maximum speed: 14 knots
Main engines: 2 x ABC 12VDZC
Propulsion: 2 x Voith 32RV5 EC/250
Damen Shipyards unveiled a new design of tug for harbour towage and ship manoeuvring in tight areas in Q2 2018 when tug Innovation was put through its trials. It is Damen’s first reversed stern drive (RSD) tug and Tug Technology & Business witnessed its capabilities during a demonstration in Southampton, UK, in June.
This design combines elements of azimuth stern drive (ASD) and tractor tugs. It has a patented twin-fin skeg and the ability to tow ships ahead or astern. Innovation was built by Damen to an RSD Tug 2513 design.
The 25-m tug has a bollard pull of 75 tonnes ahead and 71 tonnes astern. Its 13-m beam is wider than other tugs of this size, while its 5.5-m draught enables it to assist ships in most harbours.
A spokeswoman for Damen said Innovation, which has a maximum speed ahead of 13 knots, was operating in Rotterdam, the Netherlands for a tug owner. Damen has built a second RSD 2513 design tug with propulsion compliant with IMO Tier III requirements. Bis Viridis is operating for a test period for the Port of Antwerp in Belgium.
Damen can also build a version with hybrid propulsion and has a fully-engineered and class-approved design for an RSD 2513 tug that could be fuelled by compressed natural gas.
Innovation has a higher freeboard than is usual on a tugboat of this size, which enhances safety and stability. It is propelled by a pair of Rolls-Royce MTU 4000 series M63L main engines that each produce 2,240 kW of power at 1,800 rpm. These drive Rolls-Royce US255 thrusters with 2.7-m diameter propellers. Additional power comes from two Caterpillar C4.4TA generator sets that produce 81 kVA at 50 Hz frequency.
Deck equipment on Innovation includes a hydraulic towage winch that has a split drum and can deliver a pull of 31 tonnes at up to 11 m/min or a reduced pull at up to 38 m/min. It has a 175-tonne brake. There is also an electrically driven anchor winch that operates up to 10 m/min and a 360-kg anchor.
In the wheelhouse, Furuno Electric supplied radar, echosounder, speedlog, Navtex and automatic identification system equipment. Simrad provided the autopilot and GPS, while Jotron supplied an emergency position indicating radio beacon and a search and rescue transponder.
Innovation’s communications is relatively unique for tugs as it has a 60-cm diameter very small aperture terminal supplied by Intellian that operates over Inmarsat’s Global Xpress network. Cobham Satcom supplied two Sailor 6222 VHF radios and Jotron supplied hand-held VHF.
Design: RSD 2513
Built: April 2018
Builder: Damen Shipyards
Class: Bureau Veritas
Length, oa: 25 m
Beam, oa: 13 m
Draught: 5.5 m
Displacement: 525 tonnes
Bollard pull ahead: 75 tonnes
Bollard pull astern: 71 tonnes
Speed ahead: 13 knots
Speed astern: 12.8 knots
Main engines: 2 x MTU 4000 series M63L
Propulsion: Rolls-Royce US255 thrusters
Sanmar constructed the first of its Gökçay class of tugs in May to an adapted Robert Allan design for a cost-effective harbour tug. Gökçay was constructed as the first RApport 1600-SX tug with conventional twin screw propulsion and a bollard pull of 21 tonnes.
This 16.3-m and Bureau Veritas-classed tug has a top speed of 11.5 knots. It was designed with stability, manoeuvrability and affordability in mind in recognition that many harbour operators do not require the high bollard pulls of more expensive tugs.
Since May, more of these RApport 1600-SX tugs have been built and sold to owners in the Mediterranean and Black Sea region. Gökçay has two Caterpillar C18 engines, which each develop 650 kW of power and turn two five-bladed propellers of 145 cm diameter, through Reintjes 5.5:1 reverse and reduction gears. There are twin high aspect ratio rudders fitted behind each nozzle.
To maintain stability, Gökçay’s fuel is stored in two wing tanks on port and starboard, which are centrally located to minimise the effect on trim. On the aft deck there is a 25-tonne towhook with an electric-driven winch.
The wheelhouse has extra-large windows facing the aft and funnels have a low profile, meaning most of the aft deck is visible to the operator.
Designer: Robert Allan
Design: RApport 1600-SX
Class: Bureau Veritas
Length, oa: 16.3 m
Breadth, moulded: 7.4 m
Depth, moulded: 3.3 m
Draught: 2.7 m
Speed: 11.5 knots
Bollard pull: 21 tonnes
Fuel oil: 15 m3
Crew: 3 people
Main engines: 2 x Cat C18, 650 kW
In May, the first of two Singapore-built and based LNG-fuelled harbour tugs was brought into service, starting a trend in dual-fuel towage vessels. Keppel Singmarine completed KST Liberty, a 32-m ASD tug for Keppel Smit Towage. A second tug, Maju Loyalty, was delivered in August.
KST Liberty was built to Keppel’s own design and to ABS class as a towing and fire-fighting vessel. It has a 12.5-m moulded beam, draught of 5.5 m and capacity to store 140 m3 of fuel oil.
Its propulsion provides a top speed of 13 knots and up to 73 tonnes of bollard pull. KST Liberty has two Niigata 6L28AHZ dual-fuel engines that each develop 1,920 kW of power at 800 rpm. These drive two fixed pitch propellers with steerable azimuthing thrusters. This tug’s electrical power comes from two Cummins-supplied generator sets that produce 116 kW of power at 415 V and 50Hz.
Its fire-fighting system is to FiFi1 class. It includes an engine driven pump with a capacity of 2,900 m3/hr and feeds two remotely controlled monitors, each able to throw 1,200 m³/hr of water up to 120 m in length and 50 m in height. There is also a self-drenching water spray system.
KST Liberty’s deck machinery includes a towing winch and windlass on the foredeck. This is a twin drum unit with 200 m of 114-mm diameter rope and brake holding of 163 tonnes.
Design and construction of this tug was partially funded up to S$2M (US$1.46M) by the Maritime and Port Authority of Singapore under its LNG bunkering pilot programme. KST Liberty is equipped with containerised, type-C ISO-certified LNG tanks on the main deck. It also has a patented and compact LNG vaporiser.
The LNG tanks can be refuelled by truck-to-ship operations or by replacing the empty tanks with replenished ones by FueLNG, a joint venture between Keppel and Shell Eastern Petroleum, at Jurong Port.
KST Liberty particulars:
Owner: Keppel Smit
Builder: Keppel Singmarine
Length, oa: 32 m
Breadth, moulded: 12.5 m
Depth, moulded: 5.3 m
Draught: 5.5 m
Speed: 13 knots
Bollard pull: 73 tonnes
Fuel oil: 140 m3
Crew: 8 people
Main engines: 2 x Niigata 6L28AHZ-DF
Rosemary McAllister was a major addition to McAllister Towing’s fleet and a jump in environmental tractor tug operations. It surpasses the stringent US Environmental Protection Agency’s Tier 4 and IMO Tier III emission regulations.
Horizon Shipbuilding constructed this tug to ABS class for an escort, ship-docking and rescue tug with fire-fighting FiFi1 capabilities. Rosemary McAllister started serving ports in Virginia, US in May 2018. It has an overall length of 30.5 m and a bollard pull of 82.5 tonnes.
Rosemary McAllister has two Caterpillar 3516E Tier 4 engines that each have a selective catalytic reduction after-treatment system for removing nitrogen oxides. Combined, these engines generate 5,050 kW of power and drive two Schottel SRP 4000 fixed Rudderpropeller units.
Also in the engineroom there are CAT C7.1 Tier 3 gensets rated at 118 kW and two CAT C18 Tier 3 fire pump engines. On deck there is a Markey class III escort winch on the bow and a Markey 57-mm wire towing winch on the stern.
Rosemary McAllister particulars
Owner: McAllister Towing
Builder: Horizon Shipbuilding
Environmental: EPA Tier 4/IMO Tier III
Length: 30.5 m
Breadth: 12.2 m
Bollard pull: 82.5 tonnes
Main engines: 2 x Cat 3516E Tier IV
Propulsion: 2 x Schottel SRP 4000FP
Gensets: 2 x CAT C7.1 Tier 3
Kotug Smit Buffalo
Kotug Smit Towage introduced azimuth tractor drive (ATD) tug Buffalo to its operations in Southampton, UK in February 2018. This was designed and built by Damen Shipyards. It is a 24.7-m, ATD 2412 design tug with a twin-fin hull and 72 tonnes of bollard pull.
Buffalo was built to Lloyd’s Register class as a highly manoeuvrable harbour and escort tug. It has an overall beam of 12.6 m, hull depth of 4.6 m and draught of 5.85 m.
In the engineroom, there are two Caterpillar 3516C main engines with a total power of 4,200 kW at 1,600 rpm. These drive two Rolls-Royce, US 255 fixed pitch azimuthing thrusters with 270-cm diameter propellers and built-in slipping clutches. These provide Buffalo with a service speed of 12.5 knots ahead and 12.7 knots astern.
Its auxiliary equipment includes two Caterpillar C4.4 gensets that generate 86 kVA at 230/400 V and 50 Hz frequency. These feed an electrically driven anchor winch on the deck. There is also a hydraulically driven aft towing winch with a split drum and 31 tonnes of pulling power.
Pelabuhan Indonesia III (Pelindo III) completed its fleet modernisation in 2018 with the addition of the Jayanegara series of tugs. These 15 tugs are the first to be built to a Robert Allan design for ports in Indonesia.
They were built by PT Dumas Tanjung Perak and PT Daya Radar Utama shipyards in Tanjung Priok, Indonesia, to Lloyd’s Register class and RAzer ASD designs. They have a freeboard to ensure a high degree of stability while keeping the superstructure low and well aft to enhance safe working under the flared hulls of ships.
These tugs are 29 m in length and have a 12-m beam. They have a draught of 4.6 m and top speed of 12 knots. The most powerful of these has a bollard pull of 60 tonnes and accommodation for 10 seafarers. These were built to a RAzer 2960 design and with a pair of Caterpillar C280-6 main engines, each rated at 1,850 kW at 1,000 rpm. These drive two Schottel SRP 151 Z-drive units.
All of these tugs have a fire-fighting system, supplied by FFS. Deck machinery includes a bow-mounted ship-assist hawser winch and an aft tow hook.
Rimorchiatori Riuniti’s affiliate Finarge Armamento Genovese took delivery of a powerful 32.5-m escort tug in Q2 2018. Paraggi is a multipurpose ASD escort tug built by Turkish shipyard Bogazici to a design by Cintranaval Ship Design. It was built to a CND-15231 design and RINA class.
It has 70 tonnes of bollard pull and a top speed of 13 knots. In the engineroom there are two Caterpillar 3516C type main engines, each delivering 2,100 kW of power at 1,600 rpm. There are two Caterpillar C7.1 gensets that each generate 150 kW of electrical power at 1,500 rpm and 50 Hz, plus there is a smaller harbour genset.
Paraggi's ASD capabilities come from two Schottel SRP 1515 controllable pitch and azimuthing propellers, while there is also a 160-kW electric-driven bow thruster for extra manoeuvrability.
Paraggi is equipped with an escort-towing winch with a towing winch and towing hook on the aft deck. It has accommodation for up to 10 people and FiFi1 class fire-fighting system.
Vittoria Shipyard returned to tug construction and delivered its first harbour towage tug this year. Cap de Fer was built for €7M (US$8M) for the port authority of Skikda in Algeria. It is an ASD escort tug with an overall length of 26 m, a bollard pull of more than 40 tonnes and a top speed of 12 knots.
It has a width of 10 m, draught of 3.8 m and displacement of almost 500 tonnes. Cap de Fer is classified by Bureau Veritas and has two semi-fast diesel engines that can develop 2,460 kW of power.