Marine Link
Monday, August 8, 2022


The recent Estonia disaster in the Baltic Seaβ€”the worst in European ferry and maritime operation β€” has again highlighted the problems of RoRo passenger/car ferries. The development of RoRo ferries has taken a very short time since the requirement for the transport of cars and trucks across fairly short sea distances began to expand during the 1960s.

The extensive loss of life when a RoRo disaster occurs is mainly due to the speed at which the vessel sinks. In the case of the Estonia only 15 minutes elapsed between initial rolling over and sinking. This tragedy, occurring in heavy weather and at night, adds to the reasons why so many lives were lost.

The main design fault of such ships is clear β€” designed like a large box, the main car deck, if penetrated by seawater, will swiftly fill up and cause the ship first to roll over and then sink. All the stages in the sinking of a RoRo once water has entered the car deck involve very little time. The aims of the RoRo industry must be: β€’ To prevent seawater from entering the car deck β€’ To stop the seawater from flooding the car deck and making the vessel unstable β€’ To prevent the ship from rolling over β€’ To increase the time the ship takes to sink Although the safety of passengers and crew onboard RoRo ferries must be of the utmost importance to the shipowner/operator, competition between ferry operators and other fixed methods of crossings, such as the Channel Tunnel, have forced owners to cut costs.

However, despite the extensive media coverage of disasters such as the Herald of Free Enteprise and the Estonia, ferry operations are still much safer than other forms of transport, such as the aircraft industry, and losses have been much less, in terms of numbers of ships, than other forms of seaborne transport. A great deal of design work, since the Herald disaster during 1987, has gone along the road of preventing water from entering the car deck. In theHerald case the bow door was left open as she sailed from Zeebrugge, with no indication on the main bridge that this was the case. Almost immediately after the disaster, in which over 150 people lost their lives, video cameras and indication equipment were installed onboard the majority of European ferries to combat this type of incident. In the case of the Estonia, in which more than 900 passengers and crew were lost, heavy weather caused the bow visor to be ripped off and subsequently the inside bow door was damaged so leakage occurred, resulting in seawater entering the car deck. Water on the car deck caused the vessel to sink very rapidly.

In both the Herald and Estonia cases, although the design of the ship will inevitably be questioned as part of an overall RoRo design feasibility debate, it was operational procedures that caused the disasters.

In the case of the Herald the operational reason is obvious β€” a ferry should not be at sea with its bow doors open. In the case of the Estonia many believe that the ship should have altered course and steered away from the weather and not directly into it, especially following the loss of the visor.

So there are two roads open to inquirers into RoRo safety: first design, and second operations. On the question of design, the need for a single open car deck is obvious and therefore very little can be achieved by altering that basic scenario. Ideas have been initiated to find a way by which water can be contained in certain areas of the car deck and/or ways by which the ship can be prevented from rolling over and thus increasing the time it takes the ship to sink.

The operational factors can be simply dealt with by the various r e g u l a t o r y bodies, which supervise the operation of such vessels.

However, much design work has already begun to make RoRo ferries even safer.

The initial reaction to the Estonia incident is that ferries operated t h r o u g h o u t Scandinavia have had their bow doors sealed, which could be an answer, although RoRo pundits will recall the Princess Victoria disaster in the Irish Sea during the bad storms of 1953, when the sea entered the car deck through the stern door, her only means of access. The U.K. and near continent decided on a different approach, leaving the bow doors operational but limiting the sailings of RoRo ferries to weather conditions of below a wave height of 13 ft. (4 m) and a wind speed of 131 ft./sec. (40 m/sec.), although the latter restriction has now been dropped. Some ferries operating out of the U.K. had to adopt the Scandinavian regulations due to being classed and registered in Nordic countries.

One interesting fact has since occurred whereby the Stena Felicity, which operates across the Irish Sea and, because of her Scandinavian connections, had to have the bow door sealed, has, during the latter part of last year (1994), been released from this restriction due to her integrity.

Safety By Design There are two design factors that are now being considered: first, the installation of flood prevention doors, which would limit any seawater on the car deck to certain compartments, inhibiting a free flow of water all the way along the car deck. Second, the installation of sponsons and/or buoyancy tanks along the ships' sides, which would lessen the possibility of the ship rolling over even if seawater had managed to get to the car deck. This second factor would give more chance for the life-saving equipment to be used and increase the time available for crew and passengers to leave the ship.

Although this second factor would inevitably have helped the Herald to stay upright in what was fairly calm and shallow water, it is doubtful that current sponson designs would have had any effect upon the sinking of The world's largest ferry Silja Europa has been fitted with the prototype Kvaerner Ships Equipment flood prevention door. The door will go through a trial on the Turku-Stockholm run, prior to Silja Line deciding to retrofit the entire vessel the Estonia, which occurred in very bad weather.

Installing flood prevention doors is obviously a road many of the regulatory bodies may go down, and some designs have already been offered to ferry owners. However, until it is proven that such compartmentalizing methods are beneficial to the integrity of the vessel, there is very little chance of the majority of ferry operators fitting such equipment until it becomes law, which could take a number of years.

The cost of installing either sponsons or flood prevention doors would be fairly minuscule compared with the outlay for a newbuilding. Either option, at retrofit stage, would be in the region of $600,000. It is difficult to speculate on the cost at newbuilding stage but it is expected to be above $1 million for either system.

Meanwhile, some ferry operators are looking at this type of equipment as an answer to the problem of flooding on the car deck.

Immediately after the Herald disaster, Belgium operator RMT installed two hinged doors onboard its newbuilding Prins Filip, which now operates on the Cross Channel service between Belgium and Dover, and th eSpirit ofTasmaniahad similar equipment installed during a refit prior entering service on the Australia/ Tasmania service in the early 1990s.

The latest ferry operator to look at this method of reducing flooding on the car decks is Effjohn International, owners and operators of the Silja Europa (see related story, next page), which runs between Stockholm (Sweden) and Turku (Finland). Flood prevention doors of the Kvaerner Ship's Equipment (KSE) design from Gothenburg (Sweden) are to be installed on this vessel as part of a trial period for the owner to ascertain the effectiveness of the system. Only one door will be installed initially, another three doors are required to make the system fully operational.

Also involved in this trial are the Nordic Maritime Authorities, which, if the system is accepted and therefore becomes mandatory, might require a possible 50 Baltic ferries to have such systems.

Apart from KSE, other ships' equipment companies such as the MacGregor Group have designed similar systems. While the various regulatory bodies throughout the world continue to grapple with the problems of RoRo safety, the main operators throughout northern Europe and the Mediterranean have made little changes to the design of their vessels. It is inevitable that no design changes will be made, apart from those mentioned above, until it becomes law to do so.

Despite the maritime industries having a reputation of taking a great deal of time to alter or append existing safety rules, the International Maritime Organization (IMO) moved uncharacteristically quickly following the Estonia disaster by committing a panel of marine experts as early as October β€” a mere month after the disaster β€” to recommend changes.

This panel is still sitting, an initial report into safety standards onboard RoRo ferries due during the first half of this year, when IMO's Marine Safety Committee meets in May. Meanwhile, the International Association of Classification Societies (IACS) has announced that it will wait for the outcome of the IMO panel before making any rule changes to existing ferries or newbuildings.

Maritime Security History

Subscribe for
Maritime Reporter E-News

Maritime Reporter E-News is the maritime industry's largest circulation and most authoritative ENews Service, delivered to your Email five times per week