Vancouver Proudly Welcomes its First Resident Battery Electric Tugs

[By: Robert Allan Ltd.]

Ceremonies and celebrations were recently held in Vancouver harbour for a pair of ElectRA 2300-SX battery electric tugs designed by Robert Allan Ltd. and built by Türkiye’s Sanmar Shipyards. Both tugs are owned and operated by SAAM Towage Canada and represent major milestones in the Port of Vancouver’s goal of becoming the world’s most sustainable, as well as SAAM Towage’s leadership in the drive to the decarbonization of harbour operations.

The close collaboration between Robert Allan Ltd, Sanmar Shipyards, and SAAM Towage was key to yielding a tug pair that are perfectly optimized for emissions-free ship-docking operations in their home port. With compact 23 metre lengths and outstanding manoeuvrability, they are perfectly suited for operations between the tight “finger piers” where many ships are docked in Vancouver. They are also ideal for ship-berthing and unberthing work at Neptune terminals in Vancouver where their environmental credentials were instrumental in winning them a contract to provide towage services.

Their exceptional manoeuvrability is a product of a concerted effort during the design to give them handling characteristics tuned to the preferences of SAAM Towage Canada’s crews. After surveying SAAM’s local Tug Masters, Robert Allan Ltd. embarked on a series of live trials to quantify handling characteristics that these captains identified as most favourable. Using a specialized sensor package, and by closely listening to what the Tug Masters said they could feel, it was possible to establish a quantified baseline for what the new design should ideally achieve.

Predictions of the performance of the new tugs were made using a proprietary CFD-based manoeuvring tool which was validated using the earlier trials. Using this tool, it was possible to establish that the new design, for which underwater features were customized to suit the desired performance, should indeed deliver the specific manoeuvring characteristics that SAAM’s crews had identified as being optimal. The tool was also used to check that directional stability would be on par with expectations. Part of the magic of these tugs is in how this is achieved while also yielding their tremendous manoeuvrability. Hull design is critical to the goal, and one of the other keys is a relatively minimalistic and strategically shaped single skeg that has low drag in all directions, and the benefit of reduced energy consumption in transit.

Sea trials proved that the efforts were a major success. Handling, performance, and manoeuvring characteristics were exactly what had been hoped for, and SAAM was delighted with the results. There is perhaps no greater endorsement of the how these tugs perform than SAAM’s decision very shortly thereafter to order a new ElectRA 2500-SX design (also from Sanmar Shipyards) to operate in Chile. The only caveat was that the existing 25 metre design be updated to have a geometrically similar underwater hull and appendages to the 23 metre tugs that they like so much! That work is underway, with delivery of the ElectRA 2500-SX expected in 2025.

The significance of this success transcends the project itself. A new benchmark has been achieved in the degree of customization that can be achieved in terms of a tug’s manoeuvrability and performance when working in close collaboration with an owner-client and its crews. This can be applied to future projects as well, where preferences may differ from one location to another.

Boosting the already impressive handling characteristics afforded by the custom hull and appendages is the phenomenal acceleration that arises from the electrical propulsion system, and which puts the tugs in a completely different class than mechanically driven tugs. This performance is delivered with vastly reduced vibrations, as well as noise both aboard and radiated underwater. As a proud member of both Green Marine and the Port of Vancouver’s ECHO program, SAAM Canada is dedicated to the reduction of underwater radiated noise and recognized the benefits of battery electric propulsion in selecting such a vessel for its operations.

The electrical system is powered by a very impressive battery installation, which itself sets a new standard for the total capacity that can be installed in a compact tug. Featuring 3,616 kWh of lithium-ion batteries, these tugs pack significant onboard energy storage. That capacity translates into the ability for these relatively high-usage harbour tugs to perform their missions on battery power alone. With charging from the local hydroelectric power grid in as little as one to two hours, these tugs can quickly get out to the next job and accommodate a busy schedule.

Each of these tugs are expected to reduce emissions by over 1,200 tonnes of CO2 per year from tank-to-wake (and even more from well-to-wake) compared to diesel counterparts. Emissions of NOX, SOX, CO, and particulate matter will all be zero as well when operating on their generous battery banks. The reductions for the tug pair are on par with removing over 600 cars off the road.

Impressive as these tugs’ maximum performances may be, they also perform their missions with exceptional finesse. The electrical propulsion system affords fine control of thrust including at very low speeds. This affords the Master additional control in feathering up against an assisted ship, with soft contact ensured by virtue of the extended cylindrical fendering system (with a custom durometer) to keep pressures below 20 tonnes/m2 even when applying the full bollard pull of 70 tonnes.

The rest of the crew, which can be as few as two or three persons in total depending on the operation, can appreciate the ergonomics of the clean and flush working deck, as well as the comfortable and exceptionally quiet accommodations which are entirely located above deck.

Just as pleased with the ElectRA 2300-SX as their own customer, Sanmar Shipyards is already nearing completion of a third tug for their own towing fleet. Featuring an FFV1 (2,400 m3/hour) off-ship fire-fighting system, yet another custom skeg for escort, and a battery capacity tuned to their individual needs, Dinamo 2023 as it is named, is only the next iteration in what stands to be a popular series of compact battery electric tugs.

Key Particulars

• Length, overall: 23.40 metres
• Beam, moulded: 11.85 metres
• Depth, least moulded: 4.94 metres
• Maximum draft (navigational): 5.50 metres
• Gross tonnage: 295 tons

Capacities

• Batteries: 3,616 kWh, split between two battery rooms
• Charging time: 1-2 hours (customizable)
• Complement: 2x crew (also available in configuration for 4x crew)

Class Notation

? A1, Towing Vessel, ? AMS, ? ABCU, BP (70.83 MT), QR, ESS-LiBattery, UWILD

Also available with optional fire fighting (FFV1), underwater radiated noise (URN), and escort notations.

Major Machinery

• Corvus Orca energy storage and battery management systems:
  • with customizable installed capacity plus option for alternative makes and types of lithium-ion batteries
• 2x Schottel SRP 460 LE FP L-drives with 2,100 kW electric motors and 2.7 metre diameter fixed pitch propellers in SDV45XPA high efficiency nozzles
• 2x CAT C32 backup power gensets, 940 ekW each, IMO Tier III with switchable SCRs
• Elkon E-drive system with 1000 VDC multi-drive switchboards and power management system
• DMT electric deck machinery featuring:
  • TW 021 E 250 kN hawser winch
  • AW 100 E16c anchor winch

Performance

• Bollard pull (ahead and astern): 70.8 tonnes
• Speed: 13 knots
• Side-stepping: 7+ knots