Lessons from the Costa Concordia Collision
The tragedy of the luxury cruise liner Costa Concordia, which capsized on the rocks off the coast of the Italian Island of Giglio on January 13, should remind us that collisions at sea are not rare.
More than 30 groundings and in some cases sinkings of passenger ships have been reported since 2008. As recently as January 31, 2011 MV Polar Star, with 115 aboard, ran around in Antarctica with its outer hull breached, and even the famous cruise liner Queen Elizabeth 2 was grounded in August 1992 off the coast of Martha’s Vineyard and the state of Rhode Island by a 39-foot shoal at a depth of 30 feet.
Disappointingly, almost no questions have been raised about the failure of modern electronic collision prevention equipment to avoid these collisions.
Modern liners are routinely equipped with radar, which detects objects on and above the surface but not underwater. However, sonar equipment is readily available that will detect obstacles in the water, especially the type of rocks on which the Costa Concordia foundered.
100 years ago, the Titanic tragedy spurred the development of using sound waves to locate objects under water in a manner similar to the way bats use sound for navigation, and during WWI the system, which has been dubbed “Sonar,” short for Sound Navigation and Ranging, was used for detecting submarines.
Sonar uses sound waves as opposed to Radar (Radio Detection and Ranging), which was developed during WWII and uses electromagnetic waves.
The Sonar sound waves are produced by electrical devices like microphones and loudspeakers, known as transducers, that transform one form of energy into another. In an active sonar system, the sonar transducer generates pulses of sound waves into the water which bounce off objects in the vicinity as an echo. This echo is received by the equipment and the time taken for the forward and return journey of each pulse is measured. As the speed of travel of a sound wave in water is known, the instrument calculates the distance and the exact locality can be determined.
One of the leaders in the field of underwater acoustics, the US-based company FarSounder has developed a real-time 3D forward-looking sonar system for ship protection which, had it been in use on the Costa Concordia, would no doubt have averted the tragedy.
Although the captain may have been away from his post, it is more than likely that other bridge officers would have been alerted by the prominent appearance of the underwater rocks on the screen with flashing alarms. The equipment can be configured to provide an audio alarm when a dangerous object appears so as to make it unnecessary to constantly monitor a screen visually.
Cruise Lines International Association (CLIA) is the world’s largest cruise association, composed of 26 of the major cruise lines serving North America. Its mission is to promote policies and practices that foster a safe, secure and healthy cruise ship environment. An enquiry to CLIA’s director of public and media relations about the electronic obstacle recognition equipment carried on board its ships elicited the following reply:
“All cruise ships are equipped in accordance with the International Maritime Organization (IMO) rules and have the required bridge navigation equipment as found in SOLAS [International Convention for the Safety of Life at Sea] Chapter V.... The majority of cruise lines carry additional equipment beyond what is required. All ships have a compass, both magnetic and gyro-compass; radios and electronic means to receive weather forecasts & meteorological updates; charts, both paper and electronic; a global navigation satellite system; echo-sounding device (depth of water); radar with electronic plotting aid; speed and distance measuring device; Automatic Identification System (AIS) device and back-up devices as required by SOLAS for these systems, etc.”
Unfortunately, it appears that the IMO rules have not kept up with the availability of more advanced equipment. Radar is effective only above the water, charts may not show recent changes and depth sounders look down, not forward. It is only too obvious that in order to avoid obstacles in the path of travel, the detection equipment must look in that direction.
Yet the IMO rules do not appear to require even 2D forward-looking sonar, let alone the 3D equipment that is readily available today for measuring depth as well as range and bearing. The Costa Concordia tragedy should serve as a wake-up call to equip modern liners with the most advanced safety equipment available, including 3D forward-looking Sonar.