Editing Roll-on/roll-off (section)

=== Seaworthiness ===
{{Further|List of RORO vessel accidents}}
The seagoing RORO car ferry, with large external doors close to the waterline and open vehicle decks with few internal [[Bulkhead (partition)|bulkheads]], has a reputation for being a high-risk design, to the point where the acronym is sometimes derisively expanded to "roll on/roll over".<ref>{{cite book |last=Bryson |first=Bill |author-link=Bill Bryson |year=1995 |title=Notes from a Small Island |publisher=Doubleday |location=London |isbn=978-0-385-40534-8 |url-access=registration |url=https://archive.org/details/notesfromsmallis00bill_0 }}</ref> An improperly secured loading door can cause a ship to take on water and sink, as happened in 1987 with {{MS|Herald of Free Enterprise}}. Water sloshing on the vehicle deck can set up a [[free surface effect]], making the ship unstable and causing it to [[Capsizing|capsize]]. Free surface water on the vehicle deck was determined by the court of inquiry to be the immediate cause of the 1968 capsize of the {{ship|TEV|Wahine}} in New Zealand.<ref>{{cite book |first=Emmanuel |last=Makarios |title=The Wahine Disaster: a tragedy remembered |page=50 |year=2003 |publisher=Grantham House |location=Wellington |isbn=1-86934-079-5}}</ref> It also contributed to the wreck of {{MS|Estonia}}.

Despite these inherent risks, the very high [[Freeboard (nautical)|freeboard]] raises the seaworthiness of these vessels. For example, the car carrier {{MV|Cougar Ace}} listed 60 degrees to its port side in 2006, but did not sink, since its high enclosed sides prevented water from entering.

In late January 2016 {{MV|Modern Express}} was listing off [[France]] after cargo shifted on the ship. Salvage crews secured the vessel and it was hauled into the port of Bilbao, Spain.<ref>Wright, Paul (2016 February 4) [http://www.ibtimes.co.uk/abandoned-cargo-ship-modern-express-successfully-dragged-into-port-after-rescue-operation-1541939 "Abandoned cargo ship Modern Express successfully dragged into port after rescue operation"]. ''International Business Times''.</ref>