By Larry Pearson
In today's fast moving offshore service industry with vessels venturing deeper and deeper into the Gulf of Mexico
and to far off oilrigs around the world, communications is more important than ever. Today's offshore service vessels need far more ship-to-ship, ship to shore and even internal ship communications than ever before.
"System redundancy is the key to today's state-of-the-art marine communications system", said Karl Beier, president of Beier Radio
, Harvey, La. one of the leading suppliers of maritime communications equipment. "Communications backups not only make good sense but SOLAS rules mandate separate communications systems be in place to meet the Global Maritime Distress and Safety System (GMDSS)", Beier added.
That means that certain marine communications equipment has to be in place on the bridge in order to meet SOLAS as well as current Coast Guard regulations.
For example, vessels that travel in the Gulf of Mexico area
in what has been designated Sea Area 3. Sea Area 1 and Sea Area 2 are closer to shore. The farther from shore the vessel travels, the more equipment has to be carried. Sea Area 3 vessels, requires significantly more communications equipment duplication as well as separate types of equipment.
One of the key components of GMDSS systems and a major advancement in radio signal range is Digital Selective Calling (DSC). This allows for routine communications and for transmitting, acknowledging and relaying distress alerts. DSC allows a specific station to be contacted and indicates the method and channel on which to reply.
DSC sets an automated watch and users can set it to channel 70 VHF, 2187.5 kHz on the MF band and there are also DSC channels on the HF band.
A typical commercial vessel over 500 GRT in Sea Area 3 requires two complete VHF radio installations that include Digital Selective Calling (DSC), a complete Inmarsat C satellite communications system, a complete MF/HF DSC watchkeeping radio system, A NAVTEX receiver, a 406MHz EPIRB, two Search And Rescue Transponders (SART) and three portable VHF transceivers.
Power for the communications system must come from three sources of supply…ship's normal gensets, ship's emergency genset and a dedicated radio battery supply. The batteries are to be charged by an automatic charger that must be powered from the main and emergency gensets.
Prime examples of vessels equipped with the latest communication equipment are the 240-ft. and 260-ft. supply boats built for Hornbeck Offshore Services, Mandeville, La. In the last two years, LEEVAC Industries LLC, Jennings, La. has delivered two 240-ft. vessels and a pair of 260-ft. vessels. Alabama Shipyard, Mobile, Ala. is building two 260's for completion later this year.
Both of the 240-ft. OSVs (Innovator and Dominator ) were contracted to Sonsub, Inc., Houston, Tex. for ROV support. One of the 260-ft. vessels (BJ Blue Ray) was finished out as the first ABS approved well stimulation vessel for BJ Services Company, Houston, Tex, Inc.
The second 260-footer (HOS Brimstone) is under contract as a supply boat for a major oil company. This vessel was delivered in June, 2002.
The communications suite on board all of these vessels is essentially the same with most of the equipment manufactured by Japan Radio Ltd. and all supplied by Beier Radio. A pair of JRC JHS-32A VHF radiotelephones featuring digital selective calling for both distress and general routine communications is one of three prime methods of sending and receiving messages.
A second radio-based system is the JSS-800 for both medium frequency and high frequency transmission and reception. Featuring 250 watts of output power, the GSS-800 is a key to the GMDSS system. A printer and a keyboard give the system a telex option and the DSC function
and the DSC watchkeeping received are incorporated in the equipment package along with a built in battery charger and a dual power supply.
Satellite communications is the third separate communications system onboard the Hornbeck vessels to comply with GDMSS requirements under the latest SOLAS. The JRC JUE-75C Inmarsat-C mobile earth station provides two-way data/message communications anywhere in the world from 70 degrees north latitude to 70 degrees south latitude..
The satellite communications system easily transmits and receives data/messages. The messages can be stored and forwarded. The system is programmed to automatically respond to a polling command from a landline subscriber and send out pre-edited messages and various on-board data.
The satellite system also incorporates an Enhanced Group Call function so it can receive SAFETY NET (maritime safety) and FLEETNET (commercial one-way communications) service.
The other class of communications equipment onboard the new Hornbeck offshore vessels are Emergency Position Indicating Radio Beacon (EPIRB), Search And Rescue Transponder (SART) and portable VHF radios, all manufactured by ACR Electronics, Ravenswood, Fla.
The EPIRB is another essential component of the GMDSS system. It is a small device designed for automated transmission of distress alerts. It transmits on 406 MHz and is capable of transmitting a unique coded signal identifying the carrying vessel. The EPIRB is activated when it contacts water.
SARTS are another vital part of the GMDSS system .At least two SARTS are required on vessels of over 500 grt. A SART enhances radar returns with 12 intense blips for identification of survival craft and responds when interrogated by radar.
The last vital link in the GMDSS system is the portable VHF radio for use in survival craft. Three such radios are required on vessels larger than 500 grt.
Although not a part of the ship's communications system, a NAVTEX receiver is a part of the GMDSS system. A JRC NCR-330 NAVTEX receiver is included on the bridge of the Hornbeck OSVs. NAVTEX provides unattended reception and print out of current navigation and weather information.
Integrated into parts of the communication systems on the Hornbeck vessels is a Beier Integrated Vessel Control System (IVCS). This system is DP-2 compliant and is approved by ABS. The DP-2 system allows the operator to dock, maneuver, or hold position manually via a joystick or automatically via push buttons. The IVCS integrates the vessel's engines, controls, rudders, thrusters, gyrocompass, wind system, DGPS and other navigation systems.
The future of marine communications equipment will parallel developments in other areas of electronics.
"The one thing I can say with assurance," said Beier "is that marine electronics will continue get smaller and offer better performance." Beier noted that "flat screen monitors will continue to get larger, thinner and cost less."
Today's deepwater supply boats are not only equipped with state-of-the-art communications and navigation systems as noted in the accompanying story, they continue to get longer and wider with deeper hulls. Hornbeck's new HOS Brimstone is the latest example. At 265-ft. long with a 60-ft. beam and a 22-ft. deep hull, this vessel is specifically designed to haul large amounts of cargo, liquids and bulk products into the most demanding parts of the Gulf of Mexico or anywhere in the world.
Delivered by LEEVAC Industries LLC, Jennings, La., in June 2002, the supply boat is powered by a pair of Caterpillar 3608 diesel engines developing a total of 6,780 hp driving 118-in. Scana Volda controllable pitch propellers. The two main engines have shaft generators and each of those produce 2,000 kW of electricity.
Since the vessel is rated DP-2, it has two bow and two stern thrusters each rated at 600 hp driven by electric motors. One of the bow thrusters is of the drop down type and all thrusters are manufactured by Brunvoll.
The DP-2 rating of the vessel also led to the installation of four gensets…two 500 kW powered by Caterpillar 3412 engines and two 320 kw gensets powered by Caterpillar 3406C engines.
There is also a 170 kW emergency genset powered by a Caterpillar 3306 engine.
Tankage of the HOS Brimstone is impressive. It can hold 135,000 gallons of fuel oil, 332,500 gallons of rig water, 10,450 barrels of liquid mud and 10,800 cu. Ft. of dry bulk in centerline tanks. The vessel carries eight crew and 24 passengers and is rated at a speed of 15 knots.
The HOS Brimstone is practically identical to the BJ Blue Ray delivered by LEEVAC in October of 2001. This vessel was built as a dedicated well stimulation vessel. Without the well stim equipment, the entire rear deck of the HOS Brimstone is clear for cargo. Otherwise the two vessels are very similar.