“Man overboard!” is an exclamation given aboard a vessel to indicate that someone has fallen off of the ship and is in need of rescue. Traditionally when a man overboard event occurs, the person who sees the fall shouts, “Man overboard!” and the call is then repeated by everyone within earshot, even if they have not seen the event. This is intended to be repeated until everyone on deck has heard the man overboard (MOB) call.
Until recently, this same process continues to be utilized with only a few advancements through the use of ship-wide alarms. However, recent technology advancements have enabled the development and deployment of man overboard detection systems which can instantly detect an MOB event, provide supporting evidence to the crew, facilitate a ship-wide notification and provide information valuable for rescue efforts. Such systems are a revolutionary jump in the detection and response to an MOB event, but how exactly does one go about testing such a system to ensure they actually work? Do these technology companies hire Acapulco cliff divers to jump from ships? Let’s take a closer look at how man overboard detection systems are tested.
Who is OSCAR?
Crazy enough, people have jumped off cruise ships in order to facilitate the testing of man overboard detection systems. However, from a practicality standpoint, using real humans is not the safest or most efficient approach, especially when testing the range of potential conditions in which an MOB may occur. So how does one simulate a real fall from a cruise ship or other maritime vessel? Meet OSCAR.
OSCAR is 6 feet tall, weighs about 180 pounds, and although he may have a somewhat odd appearance, he is very effective at his job. OSCAR is a man overboard rescue dummy used for simulating man overboard events and performing open water rescue training. OSCAR is designed and built to simulate a realistic look and feel of a typical adult human. To achieve his 180-pound physique, Oscar is filled with water, which can also be heated to truly mimic the core temperature of a real human. After testing, the water is removed, and OSCAR becomes very manageable for transport and storage at 35 pounds.
Another unique aspect of OSCAR is his ability to change form. Removing some of his appendages is possible by merely unscrewing a bolt, allowing OSCAR to reduce his height and weight to simulate a small child or even an infant. As cruise lines continue to expand their marketing strategies to make cruising a desired activity for the entire family, the ability for man overboard detection systems to be effective for a range of body sizes becomes more important.
Man Overboard Testing with OSCAR
Luckily, man overboard events are not a common occurrence; however, when they do happen, detection systems must be very accurate to not only detect the event, but also avoid false alarms. To ensure this level of performance, MOB systems subject themselves to extensive testing scenarios. These scenarios typically fall into several testing categories:
Environmental Testing – Cruise lines try to operate in ideal conditions, but they still experience a wide range of air temperatures, water temperatures, weather (rain, fog), lighting situations (day, night, cloudy) and sea conditions (sea states).
Fall Characteristic Testing – Ships come in many different sizes and configurations and falls may occur from a few meters above the water line to over 200 feet in height, at the stern, the bow or anywhere along the sides of the vessel. The victims may range from young children to adults.
Operational Avoidance Testing – Ships have a variety of operational procedures that occur on the sides of the ship. These include cleaning, maintenance operations and crew changes. As such, detecting an MOB event is more complex than just identifying activity that is occurring outside of the ship’s deck rails. To ensure timely response to events, these operational procedures must be understood and tested to ensure they are not the cause of an unwanted MOB alarm.
The result is an extensive matrix of potential testing scenarios, all of which are within OSCAR’s testing capabilities. Here is a typical MOB test using OSCAR.
- Prior to tossing OSCAR overboard, a heating blanket is often used to heat OSCAR to the approximate temperature of a real human. This characteristic is often exploited by MOB systems utilizing thermal cameras. In some cases, OSCAR may even wear clothing to further mimic an actual human.
- One end of a climber quality rope is securely fastened to the railing on the deck at intended test height. The other end of the rope will be attached to OSCAR. (You don’t want to lose OSCAR at sea!)
- The rope should be long enough so OSCAR can fall the full distance, but not enter the water. Entering the water when the ship is in motion can cause excessive force on the rope, the point of attachment and OSCAR himself.
- Prior to tossing OSCAR overboard, the rope should be neatly spooled on the deck, clear of all personnel and other obstacles. It’s also a good idea to use a knot that is easily released.
- All personnel need to stand clear of the dummy and the rope before tossing him overboard, as a 180-pound object falling from a considerable height carries with it a large amount of force.
- At 180-pounds, it is difficult to actually “throw” OSCAR overboard, but a simple drop or push is all that is required to simulate a typical fall.
- OSCAR is then retrieved by pulling the rope onto the deck.
- All pertinent data at the time of the test is then documented.
The test is then repeated, taking into account the various environment conditions, fall characteristics and operational events listed earlier.
How OSCAR got his name
At this point you may be asking how OSCAR got his name. Why didn’t we name him Fred or Bernie? Actually, the name dates back to the era when flags were used on the open seas to communicate between ships. The system evolved over centuries into a comprehensive, internationally-recognized flag signaling system functional for military and non-military purposes. Today, the International Code of Signals is an internationally-understood system comprised of 26 square code-letter flags for each letter of the alphabet (A-Z). There are also ten numeral pennants, one answering pennant, and three repeaters. Each letter of the flag alphabet is also assigned a phonetic codeword from the ICAO phonetic alphabet.
So, what does this have to do with OSCAR’s name? Part of the system includes single flag codes, whereby the use of an individual flag represents a message or condition. Over the years, the flag representing the letter “O,” or “OSCAR”, was reserved for the communication of a man overboard event. Hence, the origin of our rescue dummy’s name.
If you’d like to learn more about man overboard detection systems, including the technology behind their detection capability, you can find more in our white paper on man overboard detection.