Red and White Fleet present the successes and considerations of operating a hybrid-electric propelled sightseeing vessel – and how this is a first step towards a fully electric fleet
Sightseeing passenger ferry owner Red and White Fleet revealed its recently delivered vessel has achieved fuel savings of around 35% compared to a steel ship with conventional propulsion by using an aluminium-hulled, hybrid-electric vessel.
The savings were the biggest highlight from a year’s operation of newbuild passenger vessel Enhydra in San Francisco harbour, California. The 39-m vessel carries up to 600 passengers on an hour-long voyage around San Francisco several times a day. And its Cummins generators and Corvus 160-kWh energy storage system give Enhydra nearly 600 kW of power for the trips.
Red and White Fleet president Captain Joe Burgard said the company wanted to build an inspirational vessel with forward-looking technology, and the end product had to be more economical than typical vessels performing similar services.
“The hybrid-electric propulsion represents around 10% of the capital; we needed to see a return on that investment,” Captain Burghard said at Riviera Maritime Media’s Maritime Hybrid & Electric Conference in Bergen, Norway on 5 September.
“Our primary saving is in the fuel costs and we are seeing 30-35% fuel savings” versus a conventional steel-hulled vessel, he said.
“A lot of the fuel savings is from the aluminium hull design as it is a light material," Captain Burghard said. Aluminium displaces only a third of the water volume of steel.
The battery system made up the rest of the savings, he explained. "During operating hours, the vessel’s internal combustion engine only works around 50% of the time,” based on the vessel’s operational profile.
Enhydra’s batteries are charged from a shore facility overnight and during idle periods by the diesel generators throughout the day. “Enhydra can do an all-electric cruise for one hour,” said Captain Burgard. The generators use diesel sourced from renewables to minimise the emissions and environmental footprint of vessel operations.
Captain Burgard said another benefit of electric propulsion was how quiet the onboard systems are, adding to passenger comfort. Quiet operations generate challenges for crew, however.
"On the rest of our vessels, operators use auditory input for the engine controls, but Enhydra is quiet, so they need to have indication from the motion and instruments," he explained.
Training and operation
The low-volume engine operations mean telemetric information is particularly useful for crew operating this electric-hybrid vessel, informing sailing decisions that assist the vessel in operating on optimal battery power consumption.
Captain Burgard said crew retraining was needed when the vessel launched as operations and failure-mode processes are different with hybrid-electric compared with conventional propulsion.
“Crew needed to be trained on which sequences and processes to go through and on becoming familiar with the checklists,” said Captain Burgard.
“We worked with the US Coast Guard to ensure we did not need more crew and with the system integrator so the system was not too complex, and the crew could be trained on the system,” he said. Red and White Fleet selected BAE Systems as the system integrator and the shipyard for its willingness to work in partnership.
“We looked at the processes of the shipyard as they would be taking on something as new as we were,” said Captain Burgard.
“It was important the yard had a direct line with the US Coast Guard to resolve technical issues quickly. It was important the shipyard had a sense of ownership and was a partner.”
Construction of hybrid-electric Enhydra was a significant milestone in technical shipbuilding in the US, he said. “We all wanted this to be a success."
The 39-m LOA aluminum monohull vessel with a 9-m beam was designed by Nic de Waal of Teknicraft Design in Auckland, New Zealand. All American Marine (AAM), which built the vessel, partnered with BAE Systems to design and integrate the electric hybrid system.
BAE supplied its HybriDrive propulsion system that includes a generator, propulsion power converter, house load power supply and control system. The generator is mounted to a variable speed Cummins QSL9 410 mhp diesel engine. The system offers parallel hybrid powering of the AC traction motor from either the generator, the batteries or both. The motor is coupled to the propulsion shaft via a reduction gear for thrust and increased propeller efficiency.
AAM said with this configuration, torque is immediately available for the propeller, and the speed can be precisely controlled.
BAE Systems’ HybriGen system has lower engine operating hours and is more streamlined than a conventional drive, requiring fewer parts, thus resulting in savings in both fuel consumption and maintenance costs.
Inherent in Enhydra’s design, said AAM in a statement, is the ability to expand the size of the batteries to reach complete zero emissions operations in the future as charging infrastructure advances and battery technology improves. This current battery system can meet any power demands of Enhydra.
Simultaneously, the propulsion system provides a silent, emissions-free experience for recreational cruise excursions. The BAE HybridDrive system can automatically use full electric battery operation at slower speeds and when manoeuvring in and out of the harbour with Enhydra’s two Veem Star 4-blade props. At higher speeds, the generator will automatically engage and augment the additional power demands of the traction motor.
Founded in 1892 and one of the oldest businesses operating in the San
Francisco Bay area, Red and White Fleet is committed to environmental sustainability and community education.
The innovative design of Enhydra makes Red and White Fleet’s Captain Burgard hopeful for future possibilities. "We see the propulsion configuration on Enhydra as phase one in our move toward the full electrification of our fleet. Stay tuned for phase two."
This is not the only project Red and White Fleet is involved with using alternative power.
Red and White Fleet is also involved in a hydrogen fuel cell-powered ferry project. Water-Go-Round will be the first of its kind built in the US, and the first commercially operated hydrogen fuel cell ferry in the world.
Passenger Ship Technology reported in August 2019 that Water-Go-Round will undergo a three-month study period in service with Red and White Fleet in San Francisco Bay, with Sandia National Laboratories gathering and assessing performance data. California Air Resources Board (CARB) will use this data to assess the technology’s suitability for wider marine use. The Water-Go-Round project received a US$3M grant from CARB in June.
SW/TCH Maritime is the owner of the under-construction vessel, and the first customer of hydrogen fuel cell powertrain technology provider Golden Gate Zero Emission Marine.
Designed by Incat Crowther, Water-Go-Round’s keel was laid in November 2018 at Bay Ship & Yacht Co of Alameda.
Red and White Fleet says “An environmental consciousness is part of the company’s DNA, infiltrating every vertical of the business”. On top of Enhydra, Red and White Fleet implements daily practices to reduce the amount of energy consumed, and waste produced during its day-to-day operations, as well as education opportunities for their employees to garner environmental awareness and advocacy.
Red and White Fleet has a goal of zero pollutants by 2025.