Navigation standards slammed - Tanker Operator

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p26-29.qxd 09/05/2006 11:15 Page 1 TECHNOLOGY ELECTRONIC CHARTS Convergence of radar and ECDIS Is there anything that distinguishes a radar display showing a chart underlay from an ECDIS showing a radar overlay, asks Dr Andy Norris*? IMO performance standards allow both configurations. If such displays have the same capability are they not effectively interchangeable? In fact there are important differences. These arise because of the different tasks that are implied when using an ECDIS or a radar. Despite these differences, ships will increasingly have multifunction displays (MFDs) on the bridge that can be configured as a radar or as an ECDIS, depending upon the immediate use by the bridge team. At the moment, MFDs are associated with integrated bridge systems but they are increasingly likely to be found on standard bridges and perhaps even as retrofit systems. The main advantage of MFDs is their configurability. The bridge team can decide on their use according to their specific needs, whether some are left semi-permanently in a single configuration or to allow certain displays to be used as more general navigation workstations. In particular, if displays fail, functionality can be taken on by other MFDs, continuing to allow the bridge configuration to be dynamically optimised to any particular situation, albeit with fewer displays. On a standard bridge if, say, a radar display fails you have no other alternative but to operate with less radar displays. MFDs give redundancy and therefore provide a valuable 'soft' failure mechanism. The display and processing requirements for radar and ECDIS require very similar hardware. The differences arise in their software requirements. This makes the design of MFDs covering these two functions - as well as others - relatively straightforward. In the more distant future we may find that displays cease being known as radar or ECDIS but will be simply called navigation displays. This is not surprising as even a basic radar being installed from 1 July 2008 needs comprehensive AIS display facilities, which is not a radar function at all. Calling it a radar display starts becoming a misnomer. In fact, a radar has two major but unrelated tasks. The first is as an aid to collision avoidance and the second is to aid own-ship position fixing. Dr Andy Norris Task-oriented displays Perhaps it is best to think in terms of what are the main tasks of a ship's navigation system, rather than in terms of the basic technology. These tasks are route planning, route monitoring (including position fixing) and collision avoidance. Therefore, specifically designed screens and functions - that is task-oriented displays - should be available to assist the execution of these tasks. Task-oriented thinking can go further. For instance, special displays to assist anchor watch and personoverboard can also be envisaged, rather than relying on general purpose displays for such specific tasks. When an MFD is in a specific 'mode' it is an IMO requirement that the mode in The MARIS NEMESIS S-VDR with optional ECDIS900 has been extremely well received in the tanker market since its release during Nor- Shipping in 2005, the company claimed. It is claimed to be a very innovative product in that it is the world's first type approved S-VDR offering an optional electronic chart display and information system (ECDIS). It has been independently type approved by DNV and the US Coast Guard (USCG) in addition to the Chinese and Ukraine shipping registries. This additional capability, which can be installed at the same time as the S-VDR, or at any time after - requiring only a monitor, keyboard and additional ECDIS software - should be of particular interest to a shipowner facing the US 108 Port and Waterways Safety Act, which calls for vessels over 20 m long operating in US waters to use official electronic navigation charts (ENC's) from January 2007. Perhaps of greater interest is the TankerOperator May/June 2006 page 26 use is properly indicated. For now and into the foreseeable future, MFDs with radar and ECDIS capability will have to use the specific terms, 'Radar' and 'ECDIS' for their main modes, as these are the functions defined by IMO, rather than the navigational tasks. Perhaps future IMO equipment performance standards will change to become task-oriented standards, rather than specifying the requirements for items of equipment. Unfortunately, this change is very difficult to implement in a practical manner, however desirable, and therefore the conventional terms 'radar display' and 'ECDIS display' are likely to be used for some time. IMO already has a number of requirements that are applicable to the design of navigational MFDs. These are contained within its performance standards for navigational displays, integrated navigation systems and integrated bridge systems. SOLAS What is not clear is how multifunction displays fit into the carriage requirements of SOLAS Chapter V. unique standard software feature of the MARIS S-VDR for record and playback of S-VDR data, which far exceeds the requirements of IMO's SN/Circ/245 issued on 17th June 2005. Data is recorded to a standard DVD and may be replayed on any multimedia PC. When combined with the optional ECDIS900 the complete ECDIS logbook data, including actual charts used during the voyage and their update status are also recorded along with all ECDIS alarms. Instant 'event' recording to DVD or USB memory stick for transmission to head For instance, if a ship is of a size that has to carry two radars and it also has a paperless chart system, consisting of an ECDIS and a second ECDIS for back-up, how many MFDs does that equate to? A possibly good answer is four but do the regulations imply that any two of these must be continuously used for radar and the other two for ECDIS functions? Is it acceptable for the bridge team to adopt different configurations according to their immediate needs, in the knowledge that an appropriate configuration - particularly the statutory configuration - can always be switched in instantaneously? If bridge teams are permitted to do this - as surely they should be - have they been trained to make the right decisions? Although SOLAS does not mention MFDs, Regulation 5 of Chapter 1 allows 'Equivalents' to the regulations, at the discretion of the flag state. This means that individual maritime administrations have to make their own judgements, perhaps on each specific installation. This is clearly unsatisfactory and could be a disincentive to use MFDs. MARIS makes a name for itself World’s first S-VDR, offering ECDIS as an option office via the vessel's communications channels is also a standard feature of the recording systems. MARIS' S-VDR is certified for simple annual remote survey by the crew in cooperation with the company, greatly reducing costs normally associated with annual survey and recertification of equipment. The S-VDR is based entirely on commercial off-the-shelf hardware, which ensures low life cycle costs and worldwide availability of spare parts. A worldwide network of certified service stations also supports this feature. Thorough on board crew training in the operation and capabilities of the S- VDR are included with each installation. Pre-installation equipment checklists are provided prior to installation and several installation options after training from full turnkey to crew installations, are available. Options are also available to meet individual shipowner requirements with respect to non-mandatory interfaces and extended data recording by means of higher capacity hard drives. Since its introduction in July 2005 more than 170 S-VDR systems with optional ECDIS have been ordered for installation on tankers of various type. The latest being Stolt Nielsen, which placed a fleet order for the NEMESIS S- VDR with optional ECDIS. (see TankerOperator, March, page 20)
p26-29.qxd 09/05/2006 11:26 Page 2 TANKER Operator So why cannot an ECDIS with a radar overlay be considered to be a radar with a chart underlay? On an ECDIS the charted information naturally takes precedence. Any radar data on top, be it 'raw' radar images or target tracking (ARPA) vectors, have to allow the chart symbols to remain visible. In effect the chart data acts as an opaque overlay onto a radar background. On a radar the opposite is true. If a chart underlay is being used the radar image always take precedence over the charted features. In addition there are numerous requirements that are particular to a radar or an ECDIS. For instance, range rings, an azimuth bearing scale and CPA calculation are required on a radar; route planning functions, look ahead hazard detection and voyage recording facilities are required on an ECDIS. These differences can be readily incorporated into an MFD, using a task-oriented display philosophy. At any one time the Mode Indicator will identify whether the selected display meets IMO ECDIS or radar requirements. Background processing and alarm monitoring will be maintained on non-displayed functions to enable rapid switch-over and alarming. approved chart radar, with an ENC underlay does not have many of the features of ECDIS that are considered essential within the design of a digital charting system. For instance, to ensure safe route monitoring and planning an ECDIS cannot show less charted detail than that defined within the Display Base. A chart radar is usefully allowed to display less detail than this to avoid confusing the assimilation of radar data. Also, chart radars do not have to include the route checking and hazard monitoring facilities provided on an ECDIS. In conclusion, we should look forward to the availability of MFD solutions embracing radar and ECDIS functionality but be careful to use standalone equipment for the type approved purpose to which it was designed. TO *This article was reproduced by kind permission of sister publication Digital Ship. Stand-alone equipment It is dangerous to assume that a stand-alone ECDIS can be used safely as a radar or vice versa, despite the apparent capability of modern designs. There are numerous reasons for this. For instance an ECDIS may be capable of displaying target tracks from an ARPA. However, during the type approval process it is only necessary for it to have been tested to ensure that radar images and target vectors appear in the correct positions and do not degrade the chart displayed information. Type approval would not necessarily include checks on other transferred data concerning tracked targets such as CPA, TCPA or track number. These may be inadequately displayed or even in error. Furthermore, it may not be possible to independently choose whether true or relative vectors are displayed. Also, the actual reference frame of the vectors may not be clearly displayed. Similarly, even a type TankerOperator May/June 2006 page 27
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Navigation standards slammed - Tanker Operator

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