Collision Avoidance Issue (Explanation); Collision Avoidance In Navigation; Marine Accidents And Collisions - JRC JMR-7230-S3 Instruction Manual

6.2 Collision Avoidance Issue
(Explanation)

6.2.1 Collision Avoidance in Navigation

Marine collision avoidance in navigation is one of the problems that have been recognized from of old.
This section contains a brief statement about the position of collision avoidance in navigation.
The navigation pattern of all mobile craft constitutes a system with some closed loops regardless of the
media through which the mobile craft travels, whether air, water, the boundary between air and water,
or space. This pattern consists of two closed loops in principle, one of which is a collision avoidance
with another mobile craft and the other is a loop of finding a right and safe way to reach a
predeterminate destination.
The following figure shows the conceptual diagram of navigation pattern by Mr. E.W. Anderson. The
closed loop of collision avoidance is shown on the left side and the closed loop of finding a safe route
on the right side.
Collision avoidance
Traffic rule
Vessel's spacing loop
Visual and radio
wave monitoring
Judgement

6.2.2 Marine Accidents and Collisions

Among marine accidents, collision accidents have been highlighted as the tonnages and speeds of
ships become higher along with the increase in traffic at sea.
If a tanker carrying dangerous articles such as crude oil collides with any other vessel, then not only
the vessels involved with the accident but other vessels in the vicinity, port facilities and inhabitants in
the coastal area as well as marine resources may also suffer immeasurable influence.
Collision accidents have a high percentage of the marine accidents that have occurred in recent years.
To cope with these problems, any effective measures are needed and some equipment to achieve
collision avoidance requirements has been developed at rapid strides.
Destination
Route
Cource and
speed
Collision
avoidance loop
Maneuver
Ship traveling in controlled condition
Navigation Pattern
6-3
Decision of route
Decided by radio wave,
visual and observation
Guide loop
Dead
Calculation
reckoning
Compass
and log
Instrument or
judgement
Control
loop
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