Minding the Helm Marine Navigation and Piloting (1994) / Chapter Skim
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6 NAVIGATION AND PILOTING TECHNOLOGY
6 NAVIGATION AND PILOTING TECHNOLOGY
Pages 217-270
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From page 217... ...
International technical and performance standards and criteria, and corresponding national standards and criteria are needed to guide the systematic introduction of new navigation technologies with capabilities and configurations that are well designed to enhance navigation safety. Technology is an important component of an overall approach for solving safety issues confronting marine transportation.
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From page 218... ...
Indeed, error-free performance of technical systems at sea can lead to premature confidence and trust in their capabilities for use in pilotage waters. The ever-expanding variety of navigation technologies multiplies the demands on marine pilots, who ideally would be l |
From page 219... ...
These and other advanced technologies could help masters, marine pilots, and ship's conning officers cope with a variety of long-standing navigation and piloting difficulties as well as certain factors that can affect visibility or maneuverability on large modern ships. These problems include impaired visibility from the bridge; large wind-catch areas; and the propensity to maintain momentum for long distances, particularly for loaded tankers.
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From page 220... ...
Indemnify from liability providers of electronic charts and manufacturers ot:^ electronic chart systems Review and if necessary revise laws x and regulations for bridge team operations Retain paper charts as a backup for ECDIS Improve accuracy of short range aids to navigation Improve positioning of buoys and fixed aids Expand distribution of racons and high-intensity lighted ranges Develop and install electronic ranges for poor visibility conditions Accelerate implementation of GPS and DGPS Accelerate development of electronic charts Accelerate schedule for harbor surveys Increase attention to human factors aspects of ECDIS Develop long-range plans for improving aids to navigation Review long-range plans for production of charts x x x x x x x x x x x x x x x x x
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From page 221... ...
. capabilities Review, revise international ARPA standards to permit use of alternative technologies for speed measurement Standardize data outputs from integrated systems Adapt low-light video and sound discrimination systems for marine use Increase use of advanced technologies such as automated dependent surveillance (ADS)
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From page 222... ...
and integrated ship control systems (ISCS) Develop expert systems for complex, busy waterways Conduct research and development to improve compatibility of expert systems with PCNS, IBS, and ISCS Dedicated radio frequencies for marine electronic data transmission Develop efficient and standard data protocols · Develop international standard for ADS Conduct risk assessments of integrated bridge operations and equipment Develop regulations allowing non traditional bridge team Review and amend manning laws and regulations .
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From page 223... ...
. poslhon ilxlng; communications; collision avoidance and surveillance; steering and track keeping; bridge team management and decision making; 223
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From page 224... ...
, the unavailability of government-provided electronic charts or chart data, and the fact that the hydrographic data that are available for many pilotage waters are not as accurate as is the capability to determine precise positions using differential GPS (DGPS) and electronic charting systems.
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From page 225... ...
Further, the hydrographic data need to be very accurate and reliable so that the mariner is not given a false sense of security, because the appearance of the high-technology display may be better than the data presented. Thus, even as electronic charting systems can offer unique additional support for navigation functions other than voyage planning, they also have the
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From page 226... ...
Only electronic charting systems that meet international performance standards including some minimal level of detail would carry the ECDIS designation and be considered to meet legal carriage requirements. Accuracy of Nautical Charts An electronic charting system, when combined with real-time position data conveys a convincing sense of reality.
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From page 227... ...
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From page 228... ...
Options for Incremental Improvements Accuracy and reliability are complicating factors in the effort to accord electronic charts the same legal status as paper charts. To help ensure the legal status of electronic charts systems in application, authorities could require that electronic charting systems meet international performance standards and recommended practices (referred to as SARPS by the International Civil Aviation Organization [ICAO]
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From page 229... ...
Electronic data transmission systems could be established for broadcasting forecast data on tides, currents, and weather as well as real-time observations of environmental conditions. This would be a value-added feature that is not integral or essential to an electronic charting system.
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From page 230... ...
This is fine at sea but inadequate in pilotage waters, where the timing of maneuvering can be just as critical as in aviation with respect to ensuring a safe transit. There is unusually high interest among ships' officers and marine pilots in the emerging real-time position-fixing technologies.
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From page 231... ...
Electronic charting systems would enable the master, pilot, and watch officer to visualize a vessel's position instantaneously relative to features displayed on the electronic chart. Available data can be taken from a sensor (such as DGPS)
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From page 232... ...
If an electronic charting system satisfied legal requirements for position fixing-the ECDIS concept it no longer would be necessary to manually collect and process navigation data, except as may be necessary to confirm that electronic systems are functioning correctly. Although electronic charting systems and DGPS can be used separately, it is in their combined use that maximum benefits are obtained, because the detail on the electronic chart can be immediately related to position data.
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From page 233... ...
Supporting Technologies and Resources An issue constraining the use of electronic charting systems and ECDIS is the availability of supporting technologies and resources, particularly the accuracy of radionavigation signals (Box 6-2~. Eight to 20 m accuracy 2 dRMS (distance/root mean square)
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From page 234... ...
To overcome this performance limitation and to minimize other systemic signal errors, GPS can be augmented by differential corrections to its range measurements based on the precise location of a reference antenna, an approach referred to as differential GPS, or DGPS (Alsip et al., 1992; USCG, 19921. The present attainable 2 dRMS accuracy of DGPS is roughly 5 to 10 m (Alsip et al., 19923; accuracy may improve with the next generation of GPS receivers, as receiver errors (noise and multipath)
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From page 235... ...
As noted carUcr, no nadona1 standards bevy been sat for commercial systems,5 but several intemational inidatives arc under way many recrcatioDal bowers use low-cost systems that provide real-time, precision navigation in~on. Use systems calculi, Die vowing defies ~ p=Ci~oD, Me position of arc vessel Em Lor=, GPS.
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From page 236... ...
, the legal status of this position is uncertain. In view of the potential benefit of electronic charting systems to improved navigation safety, it is desirable that the resolution of legal issues proceed in parallel with the further development and introduction of the technology.
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From page 237... ...
A concept for an interactive, portable electronic charting system, the portable communications, navigation, and surveillance (PCNS) system, is described later in this chapter.
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From page 238... ...
The new surveys could be conducted using state-of-the-art technology to provide 100 percent bottom coverage in significant areas. And, to ensure that new technologies are used properly to reduce risk, it would be helpful to explore the human factors aspects of using electronic charts (such as boredom, fatigue, and human-machine interaction issues)
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From page 239... ...
Electronic data transmission capabilities are already available for naval uses and have appeared in prototype form in commer
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From page 240... ...
Such a system is being developed for private operation in the Port of Tampa based on a 2-year study by the Greater Tampa Bay Advisory Council in which a number of marine pilots participated (John C Timmel, Tampa Bay Vessel Information and Positioning System, personal communication, July 16, 1993~.
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From page 241... ...
Options for Long-Term Development Marine pilots responding to the committee's inquiry suggested that voice radio frequencies be established for the exclusive use of professional navigators and pilots (Ramaswamy and Grabowski, 1992J. To alleviate channel saturation, additional VHF channels could be made available for commercial marine voice communications.
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From page 242... ...
These integrated systems include electronic charting system display of ARPA targets or radar images; use of radio frequency data links to provide ADS information about other vessels (e.g., identity, location, speed, course) on the ARPA or electronic charting system ARPA radar in use "aboard" a full mission ship-bridge simulator.
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From page 243... ...
In addition, integrated navigation systems, also discussed in more detail later in this chapter, could be developed that include display of ARPA targets and radar video (along with functions included in the ECDIS display; Royal Institute of Navigation, 19931. Also, standardized outputs from ECDIS and other integrated systems could be used to support data transmission from ship to ship and to shore stations, such as a VTS.
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From page 244... ...
DSC would require multiple VHF radio channels would to accommodate high-density vessel traffic operating environments, necessitating allocation oi additional VHF frequencies for marine use. Such a requirement would appear to require regulatory changes.
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From page 245... ...
For the future, the Coast Guard is looking at other means for data communications, such as satellites and highly efficient data transmission schemes for VHF. A more modern system could transmit many more information bits than can DSC in the same radio bandwidth.
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From page 246... ...
Steering and Track Keeping Establishment of a marine traffic regulation system analogous to that employed in air traffic control would require, among other things, that vessels have the capability to precisely adhere to assigned paths (see Chapter 5~. Although precision navigation and adherence to planned tracks are technologically feasible, they seldom are practiced in commercial marine operations.
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From page 247... ...
Steering is controlled by an autopilot at sea and a crew member in confined waters. As most ships do not have electronic charting systems or other real-time systems to display the ship's progress along a planned trackline, a course typically is ordered by the watch officer or pilot as a compass heading, which is maintained by the helmsman or quartermaster or set in an autopilot.
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From page 248... ...
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From page 249... ...
law amended, to allow the use of high-performance autopilots in pilotage waters and under certain operating conditions if superior steering can be demonstrated. Track keeping also could be improved by use of ECDIS, which can provide real-time position fixing more accurately and consistently than can plots on a 8These systems are actually a combination of ECDIS and a piloting expert system.
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From page 250... ...
To facilitate the effective use of ECDIS, regulations could be issued to establish ECDIS and an electronic chart data base as equivalent to manual plotting, provided that suitable performance and operational objectives and standards are also developed and observed. Decision-Making Aids Integrated navigation systems have potential to enhance the immediacy and precision of information available on the bridge and, by consolidating displays, reduce the work load on the crew.
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From page 251... ...
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From page 252... ...
Rules also could be developedfor thefi~nctional layout and design of bridges of ISCS vessels, to ensure the crew's access, from a single control station, to all required controls and information, including visual and audible lookout posts. Taking a broader perspective, traditional maritime operating practices may have to change if the full benefits of integrated technologies are to be realized.
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From page 253... ...
Used in that manner, ADS shipborne equipment could reduce substantially the uncertainty and communications workload now facing the mariner in determining the intentions of approaching or passing ships. If integrated with ARPA or used as input to an integrated navigation system, ADS shipborne equipment could provide faster and more accurate solutions for collision avoidance than are available now.
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From page 254... ...
Because of the lack of standardization, the demands on pilots would not be relieved even if all ships were equipped only with advanced technologies. Possible approaches to alleviating this problem include enhanced pilot training, development of operational guidelines or standards for equipment use, pilot-ca~ried navigation equipment, and provision of a pilot specially trained in navigation technology to provide and ensure adequate support for the lead pilot.
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From page 255... ...
. marine pilots In some way.
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From page 256... ...
Monitoring and cross-checking practiced as a matter of good seamanship in traditional ship bridge settings must be accomplished through technological means to offset the potential for "single-person error." Options for Long-Term Development To improve the accuracy of onboard or shoreside systems for surveillance and collision avoidance, one or more international radio frequencies could be dedicated to transmission of data among ships and between sliips and shore stations, and a more efficient standard data protocol (compared with today's standards, could be developed for transmitting data regarding a ship's identity, position, speed, and course. And to ensure compatibility of integrated surveillance systems among ships of various flags and the port facilities of different nations, IMO could develop an international standard for ADS.
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From page 257... ...
Determining the appropriate role of marine pilots with respect to the pilotage of ships with an IBS is also an important consideration that merits attention (Box 6-7~. Meanwhile, regulations could be developed to allow nontraditional bridge team organization for ships with IBS meeting acceptable standards.
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From page 258... ...
At the same time, maritime academies could revise curricula to train for such a position. In devising such training programs, it is important to remember that new technology demands new skills but may not obviate the need for traditional skills such as those of the marine pilot, and,
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From page 259... ...
Weather and Environment Monitoring Information about the weather and the operating environment is essential for safe navigation. Mariners need accurate forecasts to avoid potentially damaging storms and to determine tides and currents that will allow a vessel to enter port safely.
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From page 260... ...
Constant tension winches are very useful during docking evolutions. They are designed to maintain constant tension on the wire ropes used to winch or hold a ship alongside a pier.
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From page 261... ...
Options for Long-Term Development No specific options for long-term development were identified. TECHNOLOGICAL CHANGE How Marine Navigation Technology is Adopted Historically, advances in marine navigation technology have been driven largely by military needs and considerations (such as radar in World War II)
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From page 262... ...
Marine pilots now consider VHF radio and radar fundamental to piloting practice and have been instrumental in establishing their near-universal application. This is a legal as well as a practical choice.
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From page 263... ...
Although some marine pilots have promoted the use of advanced navigation technology, for example, the use of bridge-to-bridge radiotelephone (USCG, 1972) , pilots in the past infrequently were brought in at the "proof of concept" stage of technology development, with the notable exceptions of computer-based marine simulation for channel design, and more recently, in developing some VTS systems (Maio et al., 1991; NRC, 1992aJ.
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From page 264... ...
Multiple Equipment Configurations and Regulatory Restrictions Two problems multiple configurations and regulatory restrictions are illustrated by ARPA. Marine pilots responding to a committee inquiry complained about the lack of standardized ARPA consoles, a frequent cause of pilot difficulty in using this equipment effectively (Ramaswamy and Grabowski, 19921.
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From page 265... ...
Regulations addressing technology application can either foster or impede research and development, depending on how they are written. For example, a 12-channel GPS receiver is required by the Coast Guard for the ADS/VTS system for tank vessels over 20,000 deadweight tons in Prince William Sound (33 CFR 161.376~.
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From page 266... ...
It is difficult if not impossible to stress a technology sufficiently to see if it works, in either a port-and-waterways operating environment or river system, without exposing the vessel serving as the testbed to some physical dangers. These dangers become more pronounced as the pilotage waters or traffic situation become more challenging.
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From page 267... ...
Field trials also appear to be needed for each individual installation, because of differences among vessels, even those of the same type or class (see Chapter 41. In select cases, it may be possible to obtain a broad base of experience with a new technology by applying it on regular routes, with regular bridgeteam personnel, over a wide range of operating conditions and for an extended period.
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From page 268... ...
Technology-Induced Changes to Pilotage The time-honored methods of piloting, recruitment, and on-thejob professional development may be challenged by inexorable technological changes. With the emergence of sophisticated technologies and new bridge configurations, marine pilots find themselves and their profession under increasing pressure to update their practices to make use of these new capabilities.
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From page 269... ...
Chances are that marine pilots will find it necessary to adapt to changing technologies to satisfy the professional expectations of operating companies, masters, and public authorities concerned with operational and environmental safety. How quickly this need will develop is not certain; given the swiftness of technological advances and the lack of universal, continuing professional development programs, it could be soon.
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