Bridge Equipment Flashcards
What does ECDIS stand for?
Electronic Chart Display and
Information System
What is the primary purpose of ECDIS?
To enhance the safety of navigation.
How can OOWs avoid becoming over-reliant on
ECDIS?
By regularly cross-checking the position given by the
ECDIS and by thoroughly understanding the limitations of the system.
What is datum shift?
Datum shift is when the datum used to derive the position doesn’t match the datum of the chart on which that position is plotted.
What is alarm fatigue?
Alarm fatigue is when users who are exposed to high-levels of spurious/false alarms begin to be desensitised and fail to respond to alarms appropriately.
What is an ECS?
An Electronic Charting System which does not meet the performance standards laid down by the IMO for it to be classed as an ECDIS.
Which vessels are required to be fitted with ECDIS?
All newly-built passenger ships of 500gt or more and all newly-built cargo ships (including tankers) of 3,000gt or more, on international a voyages.
Must a vessel carry two, independent ECDIS systems to meet the carriage requirements of SOLAS V R19?
No, it is also acceptable to carry an ‘appropriate folio’ of paper charts.
If a vessel does carry an additional ECDIS unit as a back-up, what are the additional requirements?
It must be an independent, type-approved ECDIS unit with a separate (normal and emergency) power supply and
GNSS input.
If an ‘appropriate folio’ of paper charts is carried as a back-up, what are the additional requirements?
The paper charts must be corrected and kept up-to-date at all times, be readily available and the passage plan must be indicated on the charts.
Which part of SOLAS states the carriage requirements for
ECDIS?
SOLAS Chapter V (Safety of Navigation), Regulation 19 (Carriage requirements for shipborne navigational systems and equipment).
What are the training requirements for the use of
ECDIS?
All Officers using ECDIS must have attended a Generic
ECDIS Course and have received type-specific ECDIS
Training.
Are Officers required to complete a type-specific
ECDIS training course?
No but the company must ensure that their Officers are appropriately trained and familiarised with the equipment. This may be through a course or a program of onboard training.
Where is the vessel’s approval to use ECDIS as the Primary
Means of Navigation recorded?
On the vessel’s Record of Equipment, which is part of the Cargo Ship Safety
Equipment Certificate (where it is known as Form E) or the
Passenger Ship Safety
Certificate (where it is known as Form Pl
What must the SMS contain regarding ECDIS?
It must include procedures for carriage and safe operation with ECDIS.
What is the primary source of position input for ECDIS?
Global Navigation Satellite
System (GNSS)
Which input enables the
ECDIS to generate a heading marker?
Gyrocompass
Which input creates the small triangles on the ECDIS screen which represent other vessels?
Automated Identification
System (AIS)
Which system input is used to display water depth and/or under keel clearance on the
ECDIS?
Echosounder
Which input provides the
ECDIS with STW data?
Speed log
Which system can be overlaid onto ECDIS and used for both position monitoring and assessing risk of collision?
Radar
Which two mandatory alerts relate to the vessel’s GNSS units?
Change in geodetic datum and positioning system failure.
How many mandatory alerts are there?
Five, although three additional ones may be raised either as an alert or an indication.
How many mandatory indications are there?
Twelve, although three additional ones may be raised either as an alert or an indication.
What is the difference between an alert and an indication?
An alert is audible (and most likely also visual), whereas an indication is solely visual.
What are the three priorities of alert on an ECDIS?
Alarm, warning and caution.
What are the five mandatory alerts on ECDIS?
- Pass closer than the set distance from the safety contour.
- Deviation from route.
- Positioning system failure.
- Approach to critical point.
- Different geodetic datum.
Which electronic chart type is preferable when navigating with an ECDIS unit?
An Electronic Navigational
Chart (ENC)
Does a small-scale chart represent more or less land/sea area?
More. A small-scale chart uses a smaller scale to represent more land/sea area on a single chart.
Which scale is an ENC at scale
6?
Berthing
What is an ECDIS called when it is being used to display
RNCs?
A Raster Chart Display System
(RCDS)
Which electronic chart type enables the interrogation of chart data?
ENCs
Which electronic chart type is a database of information which is then represented graphically to the user?
ENCs
Which electronic chart type can make it easier to find information on berth names/numbers?
RNCs, because this
information is often harder to find on ENCs and can be laid out less clearly.
Which set of ECDIS symbols looks more like those found on paper charts?
Traditional
Which UKHO publication provides information about the symbols used on electronic charts?
NP 5012 - Admiralty Guide to
ENC Symbols used in ECDIS
What are the four categories of symbols found on ENCs?
- General
- Navigational Aid and Services
- Topographical
- Hydrographical
Which category of symbols contains depth sounding?
Hydrographical
Which of the contours takes into account a ‘Minimum UKC value?
Safety Contour.
Which Chart Presentation
Mode contains the least chart information?
Base.
What is the Safety Depth value normally set to?
The same value as the Safety
Contour.
Which contour is intended to indicate to the OOW that the vessel is entering an area where they may start to experience squat?
Deep Contour
What does a spot sounding which is deeper than the Safety Depth look like?
A light grey number.
What happens when the look-ahead sector touches the safety contour?
An alarm will sound on the
ECDIS. This is one of the mandatory alarms.
What’s the difference
between the Safety Depth and
Safety Contour?
Although they use the same value, the Safety Contour acts as the ECDIS’s no-go area, broadly dividing areas of safe and unsafe water in a way that’s very obvious and also works with the alarm features of ECDIS. Safety Depths give further context by highlighting depths shallower than the value set in bold, whereas safe depths are in a less-noticeable grey.
In the context of ECDIS, what does ‘interrogating’ mean?
Clicking on an ENC object to see more information about it
What is SCAMIN?
SCAMIN means Scale
Minimum. It is a filter, based on scale, which is used to manage the amount of information displayed on the ECDIS screen.
Which scale/zoom level should we navigate on?
In general, we should always navigate on the largest-scale cell available for the area in which the vessel is navigating and display that cell at its compilation scale.
How should the position be monitored when using ECDIS?
The GNSS feed into the ECDIS will provide it with continuous position updates but the OOW must also cross-check this position at appropriate intervals using other means, such as visual and radar fixes.
Which ENC standard ensures the consistency of presentation across ECDIS systems?
S-52
Which is the current version of the Presentation Library?
Version 4 - 2017
What are the four ENCs standards?
5-52, S-57, S-63 and S-100
What is the difference between S-57 and S- 100?
S-57 is a single standard which defines the procedures to construct an ENC, whereas S-100 is a Universal Hydrographic Data Model which will enable a variety of S-100-based products (such as S-102 - Bathymetric Surface, i.e. depth information) to be overlaid on top of S-101, the new S-100-series standard for ESPCs.
We have a vessel that is 336m in length, anchored with 8 shackles on deck. What radius should the swinging circle be set toß
0.3 nm (3 cables)
What are VDRs used for?
To record data from various systems during a voyage so that this information can be accessed in case of an accident, much like the black box on a plane. S
How many metres are there in a shackle?
27.5m
How many GPS satellites must be in sight of the receiver unit in order to provide a 3D fix?
4
Under SOLAS, which vessels are required to carry a GNSS unit?
All vessels on international voyages, regardless of size.
Which was the original GNSS system?
The American NAVSTAR
Global Positioning System
(GPS).
What is an advantage of
GLONASS over GPS?
GLONASS’s constellation provides better accuracy at high latitudes.
What type of course data will be provided by a GNSS?
Course Over Ground (COG).
How does a GNSS present position data?
In latitude & longitude.
What does a GNSS give speed in reference to?
GNSS speed is always Speed
Over Ground.
Is a more accurate position fix indicated by a smaller or larger
DOP value?
Smaller
How does RAIM work?
For receivers using the
NAVSTAR GPS constellation, it uses additional satellites that are within range to cross-check the integrity of the position data.
What is SBAS?
Space Based Augmentation
System.
What is the current status of dGPS in the UK?
dGPS was the primary form of Ground Based Augmentation
System in the UK but the service was terminated in 2022.
According to MGN 379, what is the approximate accuracy of GNSS-derived positions?
5-25m, 95% of the time.
However, high-quality receivers may achieve better results and augmentation systems may increase accuracy to 1m or less.
Which source of interference is the deliberate substitution of a genuine position signal with a fake one?
Spoofing.
Which error can occur when the GNSS signal bounces off of a vessel’s funnel before being received by the antenna?
Multipath error.
How does the radar understand the bearing of detected objects?
By reference to the vessel’s heading.
What size vessels are required to carry an X band radar?
Over 300gt.
Why must the first radar carried by a vessel be an X band?
Because only X band radars are able to detect SARTs.
What size vessels are required to carry an additional X band or an S band radar?
Vessels over 3000gt are required to carry either two X band radars or one of each.
Why do most large vessels carry an X band and an S band radar?
Because each has its
advantages, so it’s best to have one of each.
A radar must ensure that targets can be detected while the vessel encounters a roll of up to how many degrees?
10 degrees
A radar must ensure that targets can be detected while the vessel encounters a roll of up to how many degrees?
Within 1 degree.
What are the requirements for range discrimination of a radar?
In calm conditions, on a range scale of 1.5m or less, the radar must be capable of displaying two point targets on the same bearing, separated by 40 m in range, as two distinct objects
What are the requirements for bearing discrimination of a radar?
In calm conditions, on a range scale of 1.5m or less, the radar must be capable of displaying two point targets at the same range, separated by 2.5° in bearing, as two distinct objects.
When should you conduct a performance monitor on your radar?
On start up & once per watch.
Which type of clutter control reduces the amplification of the returning pulse in the vicinity of the vessel?
Sea clutter.
What is the correct order in which to set-up a radar?
B - R - G- T - Rain then Sea Clutter