ECDIS

links:
https://a/news/blogs/the-new-s-52-ecdis-standards
https://www.admiralty.co.uk/news/blogs/s-57-and-the-latest-iho-standards
http://www.shipsbusiness.com/ECDIS-voyage-planning-guide.html
https://www.iho.int/mtg_docs/com_wg/DIPWG/DIPWG4/TSMAD24-DIPWG4-09.9A_Safety_Depth_Contour_and_Safety_Depth.pdf






Passage planning on an ECDIS? 07931314688

SOLAS V R18
ECDIS should be type approved by the flag state administration.

type approval is the certification process that ecdis equipment must undergo before it can be considered as complying with the IMO performance standards for ecdis.
standard: iec 61174 the body testing it must issue a type examination certificate to the ecdis manufacturer.

How would you know it's type approved: the type approvla cert from the manufacturer, which you can check with the flag state to ensure it is in compliance.

Name and address of mna
detials of ecdis equip
conclusions of test
condtions of its validity
the necessary data for identyfiying the approved ecdis

the certs will state the imo performance standards against which the ecdis was approved:
beofre jan 2009 should conform to resolution: A.817 (19)

after 1 jan 2009 or on MSC.232 12

What is an ECDIS: electronic display and information system, it must comply with IMO and IEC performance standards.
IEC: the international electrotechnical commision.

The IMO ECDIS performance standards IMO resolution MSC 232 (82).

so an ecdis is defined as:

A navigation information system which, with adequate back up arrangements, can be accepted as complying with the up-to-date chart required by solas reg V/19 and V/27 by displaying selected information from a system ENC with positioned information from navigation sensors to assist the mariner in route planning and route monitoring, and if required display additional navigation related info.

So with this info how would a ship go about being paperless?

ECDIS under solas is capable of meeting the chart carriage requirements for international shipping therefore ecdis can be used as the primary source of navigational information, in place of paper charts.

In must comply with the IMO performance standard 1 jan 2009 MSC. 232 (82)

1. having approved hardware to carry and display the info.

2. approved software to manage the chart.

3. an official ENC.

This ecdis also requires a back-up the IMO performance standard for ecdis reuqires both a primary ecdis and an independent back-up arrangement.

1. a means to provide for safe navigation for the rest of the voyage in case the primary one fails.

2, facilities enabling a safe takeover of the ecdis functions in order to ensure that an ecdis failure doenst result in a critical sit.

so second ecdis needed connected to an independent power supply and a seperate gps pos input 

or corrected paper charts.

What is an ENC: An electronic database with all the official chart info.

standardised: content, structure and form. Issued by a HO for use with an ecdis.

ENC: chart infor, necessary for safe nav, it may contain supplementary info in addition to that contained in a chart such as sailing directions.

 IHO performance standards for ECDIS on display settings:

S.52

specifications for chart content and display aspects of ECDIS.

passage planning:

Appraisal: ENC coverage? is it adequate the corrrect scale and up to date.

currents and tides, pilot books/sailing directions is admiralty overlay information available?

appraise the ship's parameters and safety settings.

accuracy and source data of the ENC.

planning: when planning with an ENC consider: ENC display settings and use the best scale.

check and scan routes, first conduct automatic route checking, adjust the route to correct the alerts generated and the do a manual check of the route for hazards.

Also understand the limitations of the automated safety check facilities on ecdis.

plan a safe passage: add, delete, edit wp, change the order or plan an alt. route.

indicate if the plan crosses the safety contour or if it encroaches a special area.

limit of deviation from the planned route.

planning criteria: berth-berth a good plan so you can monitor your progress and control the situation.

important info for the plan:

UKC

NGA

MOS

Intended track

W/o and wp

speed alteration points

identify potential risks or hazards

advanced warning of navigational hazards, positions where accurate fixing is critical

contingency planning: aborting anchorage

note bridge notebook

tidal height, direction and speed.

tidal windows

time management speed and plan.

Features on an ecdis for planning the route:

Cross-track deviation limits.

coastal: use a planned cross track limit of deviation from the planned route to ensure safety.

In the plan of the ECDIS it will interrogate the width of the channel created by the ct limits for depths less than the safety contour. and hazards.

monitoring: an alarm will sounf when own ship reaches the cross track deviation limit. but the limit should not be too narrow and the ship should be confirmed to be there.

Wp-plan-ecdis:

edits: the default rot and radius of turn.

WOP: this is automatic on the approach to the wp.

you can also enter a planned speed, this can assist, as the calc. are done automatically. for each leg and this helps with ETA, DTG, TTG and wo adn wp times etc.

Planned route safety check: on completion. To run a safety check for hazards to surfaces nav.

visual inspection in vis/all dsiplay mode.

Execution: The plan is to be programmed and stored on to the ECDIS.

safety settings should be considered and adjusted. vectors, cross-track, guardzone etc. and safety contours and depths.

monitoring: following each fix a DR should be run up.

integrity: On the Ecdis you must check in coastal waters as to the integrity of the displayed position your your ship: As if the ECDIS display is a DGNSS pos the displayed pos. may not coincide with the ship's actual position in relation to the chart or charted hazards.

1. comparison of arpa (auto radar plotting aid) overlay of a fixed marked with the charted pos.

2.use the radar overlay and compare with conspicuous land or fixed target.

3. use a pi on the radar to monitor and compare with the planned track.

echo sounder.

issues associated with ecdis and passage planning: dangers of over-reliance and its back-up

The vulnerability of GPS.

jamming, solar flares, man-made interference transmitter and malfunctioning: The royal majesty the antenna for gps was seperated from it's cable.

solution: using LOP's

visual bearings, radar ranges and bearings

clearing rnages and transit bearings and the echosounder.

over-reliance on the ecdis:

Over-reliance on a single means of navigation has always been wrong – this remains true with electronic systems, including ECDIS. What are some of the perils of relying solely on ECDIS? Some issues to consider:

1. Screen fixation - tendency to become absorbed in an electronic display rather than looking out of the window.
2. Failure to cross check – tendency to assume that the displayed position is correct without verifying position integrity by some other means.

Dependency on Traditional Navigation Techniques include following:

• Radar overlay
• parallel indexing
• position fixing, including radar ranges, visual and clearing bearings
• track history
• dead reckoning
• knowledge of chart symbols

Safety contour: is the most important parameter of all the safety settings. for the display of unsafe water areas. detecting isloated dangers, and triggering anti-grounding alarms.

safety contour: an outline that marks the division between safe and unsafe waters.

The colour blue is used to indicate the unsafe areas while white or grey for safe areas

SAFETY CONTOUR = SHIP’S DRAFT + SQUAT + UKC – HEIGHT OF TIDE

Contours are present in the values of 5, 10, 15, 20, and 30 and so on. If the value set by the mariner is not available among the available depth contours, ECDIS selects the next deepest available contour in the ENC.

If within a specified time set by the user, the ship is about to cross the safety contour, an alarm will sound. 

safety depth:  https://www.marineinsight.com/marine-navigation/proper-use-of-ecdis-safety-settings/

How do you update an ECDIS?

So the ENC comes from the hydrographic office and it sends the ENC to whichever RENC it likes. a local RENC will vailidate the ENC data, ensure it meets the international standards, who them make the data available to value added resellers, data can be exchanged between RENC.

AVCS: uses data from nho. contains more directly relevant enc data than any other  service.

installing and updating ARCS and AVCS:

ARCS: 

 ARCS? supplied on cd-roms they are exact digital copies of BA paper charts (brit. adm.)

how to update a raster chart, the update disks are issued weekly, this matches the latest notices to mariners.

updates are cumulative: the latest updates includes all new editions and replacement charts, and both T and P notices.

T and P notices: temp and prel notices:

instead of a disk you an use software on a dongle: via email etc, dongle and a license.

a new arcs customer to arcs is automatically provided with a complete set of base cd's with every chart in the service.

coverage: licensed on a chart by chart basis.

AVC: AVCS:

updating: RENC: coordiantes the collection and dist of ENC.

licneces for 12 months.

updates are supplied weekly on cd or by remote updating software.

updates cumulative.

immediate updates over the internet or email.

S.63: updates are on a secure server protected adn digitally signed so that they are authentic and uncorrupted.

adc: admiralty digital catalogue.

incldues all

https://www.warsashacademy.co.uk/news-events/resources/article-ecdis-display-safety-settings-and-alarm-mgt.pdf

What are the mandatory alarms of an ECDIS

 1. crossing safety contour.

2. area with special condtions (or an indication).

3. deviation from route.

4. positioning system failure.

5. approach to critical point.

6. different geodetic datum.

7. or indication: malfunction of ECDIS.

 What are the three different display settings for ECDIS? (Basic, full, user) How do they differ?

display settings:

The system ENC and it's display, the chart objects and information available for display: the three settings:

1. base display: it's the minimum and can't be reduced.

useful for an initial appraisal in the planning stage, and for when moving the chart display and it allows for a faster refresh rate. It is not intended for safe navigation.

2. standard display: the ECDIS should present the standard display at any time by a single operator action.

it doesn't necessarily display all the chart objects necessary for safe navigation under all circumstances.

spot soundings: display may be preferred to assist monitoring integrity of position.

underwater obs: useful to know if it is intended to anchor.

'all other information'

it's more of a user display.

dpends on man, each man provides differnet facilities for managing the display of the cart objects nad info.

info: spot soundings, tidal diamonds, place names etc.

comes down to experience: the choice of selection of certain layers or objects for display will become better.

it's up to the mariner to consider what selection constitutes an efficient navigational display, everythign displayed, is not good seamanship.

What do you understand by “limitations of an ECDIS”? (GIGO, situational awareness, overreliance. Managed to tie this to a case study, which seemed to impress)

http://www.ainegypt.org/event/papers/presentation%20-%20Revised%20Zakirul%20Bhuiyan%20-%20Presentation.pdf

https://www.warsashacademy.co.uk/news-events/resources/article-ecdis-display-safety-settings-and-alarm-mgt.pdf

https://www.marineinsight.com/marine-navigation/pros-and-cons-of-ecdis-or-paperless-navigation-of-ships/

limtiations:

over-reliance:royal-majesty.

if you don't cross check it with a radar overlay how accurate is it really?

GIGO: agian over-reliance gps input? dr mode?

Other inputs such as the GYRO, Anemometer, Echo Sounder, Navtex, etc should be frequently verified independently to ensure smooth operation.

wrong settings, user input and bad seamanship?

Feeding in wrong parameters for safety critical settings such as the Safety Depths, Safety Contours etc can give a false sense of safety.

can you password protect?

 Alarms should not be deactivated without strong reason and never just for the sake of avoiding frequent alarms. All the alarms in use should be properly documented and their switching on and off should be controlled by a defined procedure.

 4. Alarm Deafness: If alarms start going off too frequently, 4. Alarm Deafness: If alarms start going off too frequently,

ence, alarms should be carefully chosen which are appropriate to the prevailing conditions. Every single alarm should be checked and investigated prior acknowledging.

System Lag: Modern ECDIS software can have a lot of data to display. And with various equipment interfaced with the ECDIS, the system can slow down very easily leading to system lag. The hardware needs to keep up with the software and frequent upgrades are necessary. A higher RAM and a higher graphics card is a must.

look at the case studies.

pride of canterbury?

ecdis assisted grounding.

chrted wreck. no formal passage plan formulated or marked on any chart. Knew the shoal was there but was not aware that, there was a charted wreck on that shoal, and the wreck was not displayed because of the user settings then in place on the electronic chart, with the paper chart being sporadically used.

safety settings: The importance of the safety contour settings and the division between safe and unsafe waters as well as the display of underwater obstructions or isolated danger symbol can change in the chart according to the settings of the safety contour.

see 76 for exmaples.

Limitation of ECDIS

There are some limitations of the ECDIS as followings:

1.      Chart Accuracy

ECDIS provides the navigator with a tactical tool which incorporates a high accuracy positioning device.  The navigator can "zoom" in on an ECDIS chart to a scale beyond the intended accuracy of the charted information.

1. Technical limitation of other devices

The accuracy is also depends on the technical limitation of other devices linked to the ECDIS, such as GPS, radar, etc.  The mariner must be attentive to the source and accuracy of the position fixing device utilized by the ECDIS.

                                          

3.  Information Overload

The mariner is cautioned to be wary of information overload and a very cluttered display screen. Information overload and a cluttered screen seriously degrade navigation safety for the mariner and could result in a "technology-assisted incident".