Booming demand for expedition ships should not mean that good and safe shipbuilding practices for passenger vessels are compromised, according to naval architecture and engineering company Foreship.
The lack of consistency in the initial designs for vessels of around 10,000 GT may conflict with established safety and environmental values, the consultancy believes.
“Some designs we have seen do not meet the cruise ship Safe Return to Port (SRtP) provisions that were developed for a very good reason at the International Maritime Organization,” Markus Aarnio, Chairman of Foreship, commented. “These are smaller vessels, but they are still complex passenger ships; as such, they need to be envisaged as cruise ships from the outset,” he added.
As explained by Foreship, some proposed expedition ships designs are tailor-made to avoid SRtP requirements, as they have two overlength main vertical zones or one vertical zone which is “not counted”.
In January 2017, the Polar Code, a new regulation for ships operating in Arctic and Antarctic waters, entered into force. The regulation provides guidance to ensure that equipment operates at low temperatures, incorporates stability margins to deal with ice accretion on superstructures, and in some cases demands additional damage stability requirements.
“However, covering issues as diverse as design, construction, equipment, training, and search and rescue has not created a rule-set shrouded in mystery,” Aarnio said.
According to Aarnio, there are misconceptions as some confuse the Polar Code and Polar Class.
Aarnio also suggests that more consideration is given to the efficient use of space and energy on these smaller ships, and to meeting the new more stringent SOLAS2020 damage stability requirements in a clever way.
“There are projects where very little space has been reserved for technical areas and this can create extra cost and problems later, in operation; this might result in a ship not having an exhaust gas economizer, or not enough space for modern energy-efficient air handling units,” he further said.
The Foreship chairman adds that some designs seem to include tanks or voids at the ship’s sides more typical of offshore supply ships.
“These smaller expedition ships are not cargo vessels or boats; they must be designed to be fit for purpose, as passenger ships operating in remote areas. Smaller size does not mean that safety or energy efficiency should take a lower priority than is the case for bigger ships,” Aarnio concluded.