An analysis in efficiency and operability in the medium-speed, medium-sized ferry sector.

This article was written based on the research conducted by Dr. Alf Baird, former Professor of Maritime Business at Edinburgh Napier University.

In the small to medium-size ferry industry, controversy continues about which hull type is greater in efficiency and operability: the monohull or the multi-hull. Much of the debate centres around the long-held belief that multi-hull ferries have an operational weakness in comparison to their single-hull competitor.

But today, this belief isn’t necessarily the case, considering the increasing number of medium-speed RO-PAX catamarans that have been built in the past few decades.

So which hull-type is best for ferry operations?

Let’s look at the one-on-one comparison study conducted by Dr. Alf Baird between a medium-speed monohull and a multi-hull catamaran RO-PAX ferry. Both ferries have similar vehicle deck space, speed and operate within fairly short island routes that occasionally experience severe weather and rough seas.

The considerations in the comparison study were:

1. Efficiency:
   Each ferry’s design aims to minimise a vessel’s block coefficient, its resist­ance, and its displacement, while striving to increase the revenue earning deadweight.
2. Motion Sickness Incidence:
   ‘MSI’ or Motion Sickness Incidence is a function of motion and extent of time. Catamarans have a different motion to monohulls; however, this doesn’t necessarily mean the MSI is greater for a catamaran than a monohull.
3. Manoeuvrability
   Catamarans are known for having the ability to manoeuvre in confined port areas even during strong winds due to their widely spaced hulls. Monohulls tend to experience more cancellations due to unfavourable weather and are much more difficult to handle in confined port spaces.
4. Sea Keeping
   ‘Seakeeping’ refers to a vessel’s ability to withstand and maintain speed during poor weather conditions and high waves.
5. Other Factors:
   Each ferry’s overall level of safety, the quality of evacuation procedures and cost to operate are considered.

The conclusions found in Baird’s study were that:

1. Efficiency:
   The catamaran was found to have a smaller block coefficient1 and, due to significantly lower resistance, the catamaran requires less power to perform at the same speed and carrying capacity of a monohull.
2. Motion Sickness Incidence:
   The catamaran was found to have an advantage over motion sickness thanks to its specifically designed shape which reduces the likelihood of slamming and rolling.
3. Manoeuvrability and Seakeeping:
   The catamaran’s specific design features, such as its slender bow form and its widely spaced hulls result in a vessel that can operate both in tight areas and in adverse weather conditions. The monohull was found to have a much higher rate of cancellation due to weather and port size.
4. Safety:
   The catamaran was found to have an advantage over the monohull with regards to its superior safety and evacuation features and its lower environmental impact.
5. Cost:
   The comparison shows that the catamaran has a considerably reduced operating costs that its monohull competitor and is far less likely to experience cancellations due to environmental factors.

Dr. Baird’s comparison study concludes that medium-speed RO-PAX catamarans offer very good seakeeping, a greater manoeuvrability in port and overall lower operating costs than comparable monohull vessels, making them the ideal choice for operations in the medium-speed, medium-sized ferry sector.
 
1 the ratio of the volume of the displacement of a ship to that of a rectangular block having the same length, breadth, and draft.
 

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At Sea Transport our team of ferry operation consultants are experts in finding ferry solutions through our bankable feasibility studies and operations management services no matter the transport task and size.

For more information on our ferry operation services, please click here.

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Sea Transport Solutions is pleased to announce that the brand-new STS-Designed RORO passenger and cargo ferry dubbed ‘The Galleons Passage’ will be operating the sea route between Trinidad and Tobago after its purchase this past January.

This 74-metre catamaran has an aluminium superstructure comprising a steel hull design, a capacity of 700 people and up to 100 vehicles, a maximum speed of 22 knots and, due to its 2.75 metre draft, it can berth anywhere at the Port of Spain harbour including the ferry terminal without dredging.

The Galleons Passage, whose name was inspired by the route it is set to run of the same name, is expected to arrive from China sometime in mid May, 2018.

Imbert also stated that the new vessel is intended to assist with the sea bridge while the other passenger vessels are drydocked for repairs but did add that the vessel is ‘perfect’ for the Toco-to-Tobago route as that journey will take only one hour.

The naval architects and ship designers at Sea Transport are confident that The Galleons Passage will meet the high expectations held by both the T&T Government and the route’s future passengers.

Fore more information on Sea Transport’s ferry designs, please click here or get in touch with our head office.

Sea Transport Solutions is proud of be part of the collaborative team that is raising the safety standards for Archipelago Philippine Ferries Corporation’s passenger ferry services. The new motto for APFC, “Ferry safe, ferry fast and ferry convenient”, is based on the firm goal to provide safer, more comfortable and more reliable ferry services to the Philippines.

The APFC has ferry transportation routes that seamlessly connect the 7, 107 islands of the Philippines including the country’s very first new Catamaran RORO (Roll on, Roll Off) ferries.

The focus to improve passenger safety, comfort and welfare prompted APFC to contact Sea Transport Solutions in order to bring the Philippines its first fleet of 10 RO-PAX (Roll on Roll Off Passenger Ship) vessels that were fully compliant with international standards for damage stability, firefighting and lifesaving.

Within the first 2 years of re-fleeting with these new vessels, APFC has run successful operations on both the eastern and western corridors of the country. The key to the success of APFC is centered on time, safety, reliability and positive feedback from passengers, as well as the fact that APFC was bold enough to look at a new and innovative ferry design.

“So far, we have made significant impact on safety and the travel time of people and cargo within the islands because the ferries used are far faster than the second hand-tonnage operating in the country.” Chet Pastrana, Chairman of the APFC.  Sea Transport Solutions has worked as part of the collaborative team to raise safety standards and awareness for the country’s ferry services which was in need of new systems and practices.

“The Philippines has the worst maritime record in the world for a single incident and I would really like to change that stigma that the Philippines does not adhere to safety standards. We’ve initiated a modernisation  program and other ship-owners will follow, and we can be proud that the Philippines is genuinely trying to get away from the perception that we are not responsible ship-owners.”

– Chet Pastrana, APFC Chairman

The system put in place by APFC is similar to that of airlines. Through investing in systems such as seat allocation, strict boarding controls and new technology, the company now has complete control over their passenger numbers and aware of the operations on their vessels at all times and in real time. “We want to be able to raise the standard of service and to provide a safer and more comfortable means of transportation,” explains Mr. Pastrana. “We hope Archipelago’s initiatives will encourage other owners to follow its example of safe, modern tonnage.”

“What we are offering is the convenience of daily departures, not having to wait for a container to be filled and not having to wait for it at the port,” says Mr. Pastrana. “Essentially the company is offering a point-to-point delivery of goods and people and there is no multiple handling. It’s a door-to-door service.”

Sea Transport Solutions is proud to be affiliated with assisting companies to improve their systems, their safety, their operations and ultimately their company’s reputation.

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