Southwinds - August 2000

Southwinds Local News for Southern Sailors - August 2000 Next Story

Electronic safety at sea -
a recent rescue
By Jim Johnston

A few months agoI happened to tune my radio across a distress situation where a sailing vessel had activated its EPIRB. The conversation I heard was being conducted between a U.S. Coast Guard Rescue Coordination Center (RCC) and three merchant ships.
     It all started as I heard the RCC provide latitude and longitude coordinates of the beaconing EPIRB. The merchant vessel responded that it had changed course and was proceeding to the designated location with an ETA of four hours. The merchant vessel requested confirmation of any other vessels that were in the same area and could assist. The RCC acknowledged that it was contacting two other vessels.
     Within a few minutes I heard the worbling sound of a Digital Select Call. After the next burst of DSC, a second merchant vessel answered. This time I heard the entire conversation between the RCC and the vessel. The RCC radio operator provided a quick rundown of the emergency situation. The EPIRB was registered to a 42-foot sailing vessel. No communications had been made with the vessel in distress, and a C-130 was en route to the area. The RCC requested the merchant vessel to divert to the area and provide an en route ETA. Within a few minutes the vessel reported it was on course to the designated area and anticipated arrival in 3 1/2 hours.
     A short time later the RCC contacted a third merchant vessel. Again, all the particulars of the emergency situation were passed. This vessel also diverted to the scene and was estimating a 4 1/2 hour ETA.
     I was dumbfounded. How in the world did the Coast Guard center know those three vessels were in the vicinity of the vessel in trouble? How did the operator know their DSC? Of course, time moves much more slowly in real life dramas as compared to TV stories. So it was almost an hour later when the RCC contacted the three vessels en route with the information that the C-130 had located the vessel and had talked with the crew via marine VHF.
     It turned out that the sailing vessel had been dismasted, and during the dismasting one of the crew members received a serious head injury.
     At this point the RCC asked if any of the vessels had a doctor on board. The second vessel, a Norwegian container ship, did have a doctor. The other two ships were then released to proceed to their respective destinations while the Norwegian ship proceeded at full speed to the distressed sailboat.
     A detailed discussion began, which dealt with recovery of the injured sailor. If the rescue ship was not equipped to handle the transfer, the Coast Guard would launch a pararescue team to assist in the transfer. After further discussions, it was determined the team could be at the scene within four hours. The Norwegian vessel passed weather and sea state information and explained they could launch an inflatable and perform the transfer by themselves.
     As I listened to the events unfold I was constantly amazed and kept wondering, "How'd they DO that?" All I knew for sure was that this operation had to be guided by the Automated Mutual-assistance Vessel Rescue system (AMVER). With my curiosity piqued, I contacted Richard Kenney, the AMVER maritime relations officer, and I received quite a bit of information.
     The technical aspects of the program are enormous. The AMVER system is a computerized ship reporting system used to assist in the search and rescue of ships or downed aircraft in distress at sea.
     Only merchant vessels participate. There are no naval or Coast Guard ships of any country on the computer plot for obvious security reasons. The participation is totally voluntary, and all message handling is free to the ships and their companies. The participating ships incur no additional obligation to assist in an emergency than would be required under the International Law of the Sea. They can be released from their legal obligation to respond if the RCC dispatches other ships in the area.
     All shipping and loading sail plans reported to AMVER are considered confidential and protected as "proprietary" to the shipping line. The information is available only to search and rescue agencies around the world and only in case of an emergency. Foreign RCCs contact the nearest U.S. Coast Guard RCC unless they are equipped with an AMVER computer terminal.
     At the present time there are 12,000 ships voluntarily participating in supplying AMVER with their sail plans. An average of 2,700 ships are on the AMVER plot each day. Last year alone they tracked over 100,000 voyages.
     The heart of the system is a modern mainframe computer located in Martinsburg, West Virginia. All AMVER enrolled vessels' sail plans are delivered to the programmers at this facility. These programmers receive more than 2,100 new sail plans a day. In addition, they update ships' positions and reported speeds due to weather, sea state, and any en route changes directed by the ship's owners. They validate approximately 100 sail plans per hour. Generally the ships send their sail plans before leaving port, indicating the ports of departure and destination, course, speed, navigational method, and significant navigational turn points projected for the voyage.

     Ships send a position after the first 24 hours to confirm departure and conformance to the sail plan, then every 48 hours thereafter to provide a control check on the computer projection.
     Ships send a deviation report to maintain plot accuracy in the event of a change in course or speed due to weather conditions.
     And, finally, ships send an arrival report from the sea buoy or harbor entrance at the sail plan destination. This removes the ship from the AMVER plot while the ship is in port. These sail plans are received by a number of methods including: electronic mail via the Internet, originating from the ship via satellite or HF radio; Inmarsat-C via COMSAT; Telex using either satellite of HF radio; and finally, Morse code (CW) although the number of coast stations supplying CW is declining.
     Now comes the interesting aspect of all this data input. I'm sure many of you have used or seen the many popular electronic navigation programs that can overlay your position, either by dead reckoning or GPS, on an electronic chart. This is precisely what the mainframe computer at AMVER headquarters performs. At any instant in time the mainframe has 2,700 ships moving across a world electronic chart.
     To be of any practical use, an operator has to key in a LAT/LON of a specific point. Instantly a Windows screen called a surface picture (SURPIC) is displayed. The default screen contains two rings, the first at 100 nautical miles and the second at 200 nm from the selected point. Contained on the screen are all the vessels within that 200-mile radius. Directly above each freighter icon is a small window, which displays the vessel's call sign. By using a mouse and selecting the vessel nearest to the point and clicking, another window appears with the vessel data.
     Also included is a second window that displays the Lloyd's data. This contains the basic ship specification length, width, DWT, gross tonnage, hull ID, year built, hull speed, draft, and of course, the flag the vessel sails under. This also includes the MARSAT number and DSC.
     So how is all this data utilized by a search and rescue (SAR) effort? Regardless of how the emergency is initialized--whether by EPIRB, marine SSB MAYDAY or satellite--the alert is sent to the nearest worldwide RCC. The RCC then connects with the AMVER computer, keying in the coordinate of the suspected emergency. The RCC receives the SURPIC on its monitor screen. It selects the ship closest to the known coordinates, which then provides the radio watch with vessel data.
     When the vessel responds, the RCC operator can update the present position of the vessel, which in turn is relayed to the mainframe computer. The RCC makes a decision based on the information from the vessels in the area to determine which ship to send to cover the emergency. Once the watch officer selects a particular vessel, at that instant, the AMVER computer displays another window that provides hours to intercept and distance to intercept.
     Obviously this is all based on dead reckoning, but the astounding aspect of this software is its ability to calculate the vessel's speed based on the design characteristics taken from the Lloyd's register, condition of wind and sea state, and information supplied in the sail plan that describes the load weight and fuel aboard the vessel at its last port of call. In effect, the dead reckoning position of the ship is calculated from all the available data resulting in a highly accurate vessel speed.
     We are frequently reminded of the safety features and importance of our EPIRBs. It is indeed a comforting thought to know that many ships are available to answer a call for help. 73, Jim, WB4GQK

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