Foreship advises caution on expedition passenger ship rush

Naval architecture and engineering firm Foreship has warned that the increasing demand for expedition ships could compromise safe shipbuilding practices.

The consultancy believes that lack of consistency in the initial designs being rushed to market for vessels of around 10,000gt may conflict with established safety and environmental values.

“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 Organisation,” said Markus Aarnio, chairman at Foreship. “These are smaller vessels, but they are still complex passenger ships; as such, they need to be envisaged as cruise ships from the outset.”

Aarnio said he is particularly concerned that some proposed expedition ships designs are tailor-made to avoid SRtP requirements, as they feature two overlength main vertical zones or one vertical zone which is “not counted”.

“This is allowed in principle, if the alternative design analysis proves that two overlength main vertical zones without SRtP is at least as safe as three main vertical zones with SRtP,” he added. “But how could this kind of analysis be justified? Responsible owners would follow the SRtP main principles even for smaller explorations ships.”

The Polar Code centres on ship safety and environmental protection in polar waters. It 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, according to Aarnio, covering issues as diverse as design, construction, equipment, training, and search and rescue has not created a rule-set shrouded in mystery. “There are misconceptions: some confuse the Polar Code, the IMO regulation for ships accessing Polar Areas, and Polar Class which is the ice class regulation governing mainly the steel structures of ice-going vessels, for example,” he explains.

Polar Code ships fall into three categories: Category A ships are strengthened for at least medium first year ice; Category B ships are designed for at least thin first year ice; while Category C ships are designed to operate in open water of less severity.

“Unless they really are designed for breaking ice, cruise ships are typically in categories B or C,” said Aarnio. “Ice-breaking is another thing; if an owner really wants a ship that can break ice, a compromise is needed on fuel efficiency and passenger comfort in open water; this is not so in properly designed category B or C vessels.”