Whitehorse | Bridge Equipment Flashcards
What does ECDIS Stand for?
Electronic chart display 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 the 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
Which vessels are required to be fitted with ECDIS?
All passenger ships of 500GRT or more, all tankers of 3000GRT or more and all cargo ships (other than tankers) of 10000GRT or more, on international voyages, are required to be fitted with ECDIS
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.
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 vessels approval to use the ECDIS as primary means of navigation recorded?
On the vessels record of equipment, which is part of the Cargo Ship Safety Equipment Certificate (where is is known as Form E) or the passenger ship safety certificate (where it is known as Form P)
What must the SMS contain regarding ECDIS?
It must include procedures for the carriage and safe operation with ECDIS
What is the primary source of position input for ECDIS?
Global Navigation Satellite System (GNSS)
Which input enables to generate a heading marker?
Gyrocompass
Which input creates the small triangles on the ECDIS screen which represents other vessels?
Automatic 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 alarms relate to the vessel’s GNSS units?
Change in geodetic datum and positioning system failure
How many mandatory alarms are there?
5
How many indications are there?
9
What is the difference between an alarm and an indication?
An alarm is audible (and most likely visual), whereas a indication is solely visual
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 RNC’s?
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 makes 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 of the contours takes into account a ‘Minimum UKC value’?
Safety contour
Which Chart presentation mode contains the least information?
Base
What is the safety depth value normally set to?
Same value as 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 a 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.
In the context of ECDIS, what does ‘interrogating’ mean?
Clicking on an ENC object to see more information about it.
What is SCAMIN?
SCAMIN is a filter, based on scale, which is used to manage the amount of information displayed on the ECDIS screen
Which scale chart should we navigate on?
In general, we should always navigate on the largest-scale chart available
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 presentation library?
Version 4.0 - 2017
What are the four ENCs standards?
S-52, S-57, S-63, & S-100
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.
How many metres are there in a shackle?
27.5m
How many GPS satellites must be in sight of a receiver unit in order to provide a 3D fix?
Four
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?
COG (course over ground)
How does a GNSS present position data?
In latitude and longitude
What does a GNSS give speed in reference to?
GNSS speed is always Speed Over Ground
Is a more accurate 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.
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 vessels funnel before being received by the antenna?
Multipath error
How does the radar understand the bearing of detected objects?
By reference to the vessels heading.
What size vessels are required to carry an X band radar?
Over 300GRT
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 S band radar?
Vessels over 3000GRT 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.
What is the wavelength and frequency of S Band?
W = 10cm, frequency = 3GHZ
What is the wavelength and frequency of an X Band radar?
W = 3cm, frequency = 9GHZ
What are the advantages of S Band radar?
Detects longer range, able to penetrate clouds, better tracking in poor weather
What are the advantages of X Band radar?
More detailed image, better at detecting small targets, it can detect SART
A radar must ensure that targets can be detected while the vessel encounters a roll of up to how many degrees?
10 degrees
What is the required radar bearing accuracy for detected objects?
Within 1 degree
Which error causes multiple targets at the same bearing but different ranges?
Multipath error
How much sea and rain clutter should be applied on our radar?
The minimum necessary to achieve a usable image. We should not attempt to have a ‘clean’ radar screen.
Which error results from additional, weaker radiation emanating from the radar scanner?
Side-lobe error