Communications equipment is primarily fitted on ships to facilitate safety of life at sea (SOLAS) and ensure efficient search and rescue (SAR) co-ordination. Obviously, the communications systems are also used for general business purposes. Every modern vessel now boasts a communications hub that rivals that of the most modern office onshore. Historically, communications were carried out using Morse code, an excellent reliable system that was used at sea for nearly 100 years (the use of Morse was discontinued in 1999). Initially, communications were on medium range (405-525 kHz, with ranges of 500 miles) and high frequency/short wave (4, 6, 8, 12, 16, 22 and 25 MHz bands), which provided worldwide communications using ionispheric propagation. The use of these telegraphic systems required the services of a skilled radio officer, who was also responsible for maintaining the radio equipment. In the 1960s, VHF communications (short range on 156-171 MHz) came into general use and also around that time, double sideband (DSB) was superseded by the much more efficient single sideband (SSB) telephony. Telex over radio (TOR) came into general use in the 1980s; this was the advent of automated communications. It is worth mentioning that for approximately 90 years, the emphasis on vessels in distress was to contact nearby ships for assistance. Between 1992 and 1999, a new system of communications was introduced; this is called the Global Maritime Distress and Safety System (GMDSS). Under GMDSS, ships in distress contact shore-based search and rescue facilities that co-ordinate the SAR. [caption id="attachment_15978" align="alignright" width="902"] Marine communications infrastructure (click to enlarge)[/caption] GMDSS, as a hybrid system, uses both satellite and terrestrial communications. This combination meets SOLAS requirements and also satisfies the general communication needs of modern ships. Fully integrated communications systems are fitted, which require the services of skilled engineers to install, configure, commission, update and carry out routine/preventive maintenance and breakdown maintenance. As one would expect, these systems are complex and the engineers fitting and servicing this equipment need to be qualified, highly skilled and capable of working to very tight deadlines (considering the very fast turn-around time of modern container ships and passenger/ferries vessels). COMMUNICATIONS INSTALLATION A typical communications installation on SOLAS-compliant ship will now contain, at least, the following:

  • Very High Frequency (VHF) Transceiver (156-171 Mhz) + Digital Selective Call (DSC) to initiate distress alerts and provide general communications (range line-of-sight / 30-60 miles);
  • Medium Wave (MF) transceiver + DSC (2 MHz) for alerts and general communications with range of about 600-800 miles;
  • High Frequency (HF) Transmitter + DSC (4 – 16 MHz) for worldwide distress alerting and for general communications;
  • Emergency Position Indicating Radio Beacon (EPIRB) (406 MHz) This automatically or manually deployed beacon, when used in conjunction with the low earth polar orbiting (LEO) satellites (CosPas/Sarsat), provides a distress positional fix and vessel identity to within 5km worldwide;
  • Search and Rescue Radar Transponder (SART) (X band, 9.3-9.5 GHz) is a homing device to enable ships and SAR aircraft to accurately pinpoint a distress position using X band radar;
  • Navtex (518 KHz) (range 800 miles) for the receipt of alerts, weather forecasts and maritime safety information relating to navigational hazards and obstacles that the vessel may encounter during transit;
  • Satcom C (Inmarsat) for distress alerting and transmission and reception of maritime safety information via enhanced group calling (EGC). Sat C may also be used for general communications and automated position polling;
  • Inmarsat Sat B, M and mini M are some of these systems support distress alerting and messaging using voice or telex. The systems also enable data transfer and even support slow scan TV.
Marine electrical and electronic equipment must operate in the most hostile of environments due to vibration, temperature fluctuations, humidity and salt atmosphere. Consideration must be given to the means of ensuring availability of equipment. The SOLAS convention specifies the options available to ensure availability of essential equipment; this can be done by a combination of duplication of equipment and with servicing being carried out by competent shore-based engineers who are compliant with the Standards of Training, Certification & Watchkeeping Convention or by at-sea maintenance engineers (electro technical officers). AUTOMATIC IDENTIFICATION SYSTEM [caption id="attachment_15987" align="alignright" width="1000"]Meskell 2 Example of a stand-alone AIS display[/caption] Automatic identification systems (AIS) are mandatory carriage requirement for all vessels above 300 GT and all passenger ships, regardless of size. AIS data is available to all other suitable equipped ships, vessel traffic systems (VTS) and coastguard tracking and participating shore-based services to clearly identify each vessel within range, together with the following details: the ship’s name, International Maritime Organization (IMO) number, call sign, Maritime Mobile Service Identity, position, speed, heading, rate-of-turn, next port, estimated time of arrival to next port, and persons on board. This information is displayed on dedicated AIS displays, radar displays and Electronic Chart Display and Information System (ECDIS). Transmission of this static and dynamic information is synchronised by GPS timing, with transmissions being carried out on VHF frequencies (161.975 MHz and 162.025 MHz, max TX power 12.5w). Example of a stand-alone AIS display Radar display with radar & AIS targets In 2007, the Irish Coastguard commissioned an AIS system that provided full AIS coverage for the Irish coastline. This consisted of 16 of strategically positioned base station sites, one server centre and three control centres (Malin Head, Valentia and Dublin Coast Guard). The system has many uses, including: • Aiding in SAR operations; • Protection of the marine environment; • ID of vessels, including high-risk targets for maritime security; • Powerful statistical tool VOYAGE DATA RECORDING [caption id="attachment_15989" align="alignright" width="901"]Meskell 3 Radar display with radar and AIS targets[/caption] The marine version of the ‘black box’ that is carried on aircraft is the voyage data recording (VDR) system, which became an enforced carriage requirement in July 2002, following IMO regulations for all passenger ships and other ships above 3,000 gross tonnage. While the primary purpose of the VDR is for accident investigation after the fact, there can be other uses of recorded data for preventive maintenance, performance efficiency monitoring, heavy-weather damage analysis, accident avoidance and training purposes to improve safety and reduce running costs. Systems include a protective storage capsule, which is either fixed retrievable or float free. All are mounted externally on the ship which, where fixed, can be retrieved by divers in the case of the ship sinking. Locating the capsule/ship is aided by a salt-water-activated acoustic beacon mounted on the capsule. The capsule contains 24 hours of recorded ship data including direct interface feeds from a variety of equipment and sensors, many mandatory and some optional. Examples of these would include engine/propeller and thruster information, automation data, rudders, hull openings, watertight and fire doors, VHF radio communications, bridge audio, radar, AIS and ECDIS, main alarms and sensors (depth, wind, speed, position, heading, et cetera). Like many marine systems, VDRs are surveyed annually by approved personnel to ensure they are compliant with the required standards laid down by the IMO. VESSEL TRAFFIC SYSTEMS Essentially, the vessel traffic systems (VTS) could be described as the marine equivalent version of air-traffic control. They operate as marine traffic monitoring and communications systems, providing navigational information and the tracking of vessel movements within the port limits. The size and complexity of these systems varies from port to port, depending on the geographical area of coverage required. [caption id="attachment_15991" align="aligncenter" width="1024"]Meskell 4 Example of a VTS operations centre[/caption] Systems comprise of many interfaces, from the implementation of single to multiple radars located at prime locations – often in extremely harsh climatic locations like headlands or lighthouses – for uninterrupted coverage. All remote radar, communications, meteorological and hydrographical information, combined with AIS targets data received from ships, is relayed to a more central hub or main VTS operation centre. These centres are generally fully manned but, in some situations, they are only temporarily manned. This is often done also by pilots who offer assistance to vessels for inward or outward journeys within the port limits. This acquired information is displayed on an ECDIS, along with a variety of other information that is vital to aid the safe movement of vessels around the port. Wind, tide, wave-height and visibility sensors, along with cameras, are all widely used, with updated information also communicated to the ships to aid purposes such as safe docking. Communications also play an essential role in VTS. All ports will operate on marine VHF frequencies at a minimum, with specific channels (frequencies) dedicated as each port’s working channel, i.e. CH12 (156.6 MHz). As VHF communication operates on a line-of-sight basis (approximately 30+ NM), quite often ports have to set up highly complex remote systems to enable full communications coverage throughout the port, controllable from the main operations centre. One of the biggest challenges technically is ensuring that all this live data is available readily and reliably at the main operation centre. The increase in bandwidth availability on leased lines, together with developments in technology in UHF radios and microwave links (i.e. 5 GHz), allow increasing options here, with many combinations often used for back-up redundancy needs. The use of long distance, point-to-point microwave technology can generally pose problems. Many of these links used in VTS systems can be over tidal waters with swings of many meters, so there can be added headaches installing and commissioning a system. An understanding of ‘Fresnel zone’ theory and associated calculations relating to the links are necessary to ensure that a strong signal is maintained at all times, avoiding any downtime in data flow across the network. Current demands on the harbour master and port authorities mean that remote access to the VTS systems via laptop/pads using various software is now required. It is essential that service engineers also have remote access – by using the latest remote diagnostic software tools to check, test and often repair issues on the system from the car or office, system downtime is minimised and the engineer can better prepare for service of the systems in advance. This is a major advantage, given the remote location of many sites. Through associated software, VTS systems build and provide statistical information for the ports and are often linked to database management information systems. These can be custom built to compile information for many purposes, from ship invoicing to port analysis. THE MARINE ENVIRONMENT AND IRELAND’S MARITIME TRADITION [caption id="attachment_15994" align="alignright" width="450"]an Ireland's naval fleet[/caption] While transiting the world’s oceans, vessels encounter many hazards such as icebergs, sand storms, fog and high seas as a result of storms and typhoons. Floating objects such as lost containers, derelict vessels and even floating mines must also be avoided. All of these could be categorised as natural hazards. In addition, piracy is rampant in parts of the world such as the east coast of Africa (off Somalia), West Indian Ocean, Gulf of Aden and Gulf of Guinea, with ships, personnel and cargo being seized and held to ransom. Mechanisms and procedures have been developed to counteract terrorism and piracy and there has been a large combined effort from naval and other forces within these regions to help protect vessels. Along with radars for initial detection and the activation of the ship security alert systems via satellite, ships are utilising other means to protect themselves against modern-day pirates. Armed personnel are additionally employed for trips, coinciding with the availability of many other anti-piracy means such as long-range acoustic devices, lasers, stun grenades and high-pressure air and water cannons. However, as the development and implementation of these means for protection are introduced on ships, the pirates also continue to ply new and more aggressive methods to capture vessels. As is befitting for an island nation, naturally, Ireland can boast of a long and proud maritime tradition. Our geographical location on the Continental Shelf results in fertile fishing grounds, providing employment for personnel in the fishing and associated fish-processing industry. The Irish Naval Service can trace its origins to the foundation of the State, when it assumed responsibility for customs and fisheries protection in 1922. The Irish Naval Service came into being in 1946 and since then has safeguarded Irish strategic interests, carrying out fisheries protection, counteracting smuggling and assisting in SAR missions. The Irish Shipping Company was founded in 1941 to safeguard Ireland’s import and export trade during the Second World War. Unfortunately, the company was disbanded in 1984 (therein lies a tale!). However, Ireland still has a vibrant and successful shipping fleet – for example, the excellently managed Arklow Shipping Company continues to expand its fine fleet and gives great employment to Irish seafarers. The quality of training and education of Irish seafarers has always ensured that they easily found employment on vessels of all nationalities. Training of radio officers was carried out in Limerick, Dublin and Cork. Limerick and Cork have continued to train electro technical officers. The National Maritime College in Cork has an excellent reputation internationally and trains navigation officers, mechanical engineering officers and electro technical officers for the Irish marine industry and for many other international shipping companies. References: IMO; SOLAS; L3 SAM Electronics To contact John P. Meskell of John Meskell Marine Electronics, email or call +353 87 4172339.