passage sheep approaches port
uh... offices in crude must prepare for a morning
went bust
the ship's morning system must help insure the ship safety
and enable cargo operations to proceed smoothly
the purpose of mourning
is to ensure that the ship lie securely in the correct position of the birth
relative to the loading arms for cargo handling facilities
no matter how the wind
waves for parents may affect her
in this video
we should look at the various forces the morning ski must withstand
good morning employees will not to be considered
the forces that act on the ship's holla to both
combi considered as having to components
transverse forces
trying to move the ship away from or towards the birth
and don't get chewed no forces
trying to move the ship along the birth
oft
these forces may be caused by wind
will buy the movement of water
such as underwater currents
wave motion
and swell from pa sink ships
wherever possible
both the designed to minimize the transverse forces
in practice however
changing winds
time agency conditions mean that such forces may present a mood on the ship's
hull from any direction
effectively reinforcing or counteracting each other
there are of course political forces acting and we will deal with these nato
any morning system employed
must be designed to withstand most predictable changes in the forces acting
on the ship
the most frequently used morning scheme is made up of
spring lines foreign tufts to counteract the longer to admiral forces acting on
the ship
breasts lines for adopt to counteract the transverse forces acting on the ship
lines run into more acute angle to the birth than breast lines often cold head
doesn't stand lines
helped to counteract any turning force on the ship
hope all the forces acting on a ship scholars above
the wind and current forces of the most severe
but to design a morning system able to resist the most extreme conditions will
be very complex and costly
instead the design criteria
uh... based on the system being able to counter the longer to blow
and transverse components of the forces associated with wind at sixty knots
all both for force eleven
possibly in current of nor point seven five knots
or wind of sixty knots
possum and from ahead or stone
of three knots
remember
but the wind and current forces a proportional to the square of this speed
so
the force of a sixty north wind
is four times that of a fatty not went
three not current
would exert a force nine times that of the one not current
the higher ships free bold the larger the area on which the wind force will
act and the greater the force will be
but the wind speed increases with heights above sea level
this is because the wind is slow down at the surface by friction with the land or
sea
solange a high free board ships
a more susceptible to strong winds for two reasons
first because the wind acts on a larger area
and second
because the winds average speed is higher
when the ship is addressed
the vertical forces acting on its displacement downwards and buoyancy
uploads
are imbalance
during condo operations asked the displacement changes
so will the draft of the free board
this may have a significant impact on the morning scheme
as we have seen if the ship rises in the water the force exerted by the wind on
the ship's hull will increase
the false exerted by the currents will decrease as less of the hull is in the
water
it is the change in wind force it is more critical for the morning system
as this is much morita
than the change in force calls by the current
for example
a false eleven the transverse wind forces may range from a hundred tons
to three hundred and seventy times also
depending on the type and size of bezel
longer should really these forces could range from twenty seven to seventy five
times
single lines would be unlikely to withstand the forces associated with
very high winds
the basic patton of spring lines breast lines heads and stern lines
and nobody doubled up or even traveled to achieve the required morning strength
it is inevitable that the lines employed each position will be of different
lengths
and perhaps placed at different angles
different lengths of line will stretch by different amounts on the load
the longer the line the greater the stretch or elastic effect
this means that different lengths lines will take different portions of the
total load
the situation is even worse if you have to makes why lines
crime on june the synthetic groups and other types of wrote
wire lines and prime modular synthetic groups
have much less the less to succeed in polyimide all polyester robes
why arent high modular synthetic fiber ropes
will stretch only by about twenty twenty five percent of the length
whereas the conventional synthetic ropes might stretch by thirty percent
the while rawhide modular slide would take a much greater proportion of the
loan
it it was paired with a conventional five the road
possibly as much as ninety percent
wherever possible you should avoid mixing lines made of different materials
this will result in uneven load distribution between the lines
this can lead to lines carrying extremely heavy loads
possibly beyond they're breaking strength
the ability of mooring lines to counteract the forces threatening to
move the ship
depends upon the angle between the direction of the forces and the morning
line itself
for maximum effectiveness
nine should not deviate from the horizontal
unfortunately
this is seldom achieved
the effectiveness of the line
is proportional to the cosine of the angle that it makes to the direction of
the force it is resisting
for example at thirty degrees
only about eighty seven percent of the mood in the line will be resolved
horizontally
at forty five degrees
the proportion reduces two seventy one percent
when mooring lines change direction around rollers fairly eads or panama
leads they can be a for the loss of effectiveness of up to twenty five
percent
this is because only a portion of the strands in the rogue takes the load
the rest of compressed round the bend
the tie to the band
the greater the compressive force will be
to minimize this loss of effectiveness
you should select the routes for the lines carefully to avoid severe changes
of directions
kindly apply these theoretical rules
in practice
basically
the strength of any morning scheme depends on the strength of each
individual line
a week line that parts could set up a sequential failure in the other mornings
as they would then be subject to additional loading
as a general principle
a good length of line should be employed to avoid the loss of affective miss
which would arise for example
in the case of a short and steep morning line
short lines have less capacity to stretch
and it sure time long lines a combined
the shorter line will reach its maximum extension and pop fest under excess load
the breaking strengths of all the ropes and wires on board unknown from the
manufacturers stated values
ops through wear and tear
they will suffer and element of loss
to allow for this
a safety factors introduced and typically
fifty five percent of the maximum rated load is used to assess the available
restraint
this factor also provides a margin to combat any additional dynamic loads
which may occur
lost the breaking strength of an individual nineties important assessing
the effectiveness of any morning patton depends more on the contribution that
each line makes to the overall morning arrangements
so
we can summarize the load factors affecting a morning scheme as follows
the effects of currents and winds are considered a static loading
these static loadings are calculated for maximum conditions of sixty knots wind
around force eleven as not point seven five knots transverse current
and three knocks
long get chewed no comment
the ship's mornings are designed to withstand these loads
the maximum rated load for a rope
must be adjusted by a general safety factor
and by factors relating to the orientation of the lines at any
particular burr
on occasion
there are additional forces of the dynamic nature
which can move the shit from her birth
these may come from waves
swell
all the interaction from passing ships
these can create powerful lateral and long beach you'd know forces
these dynamic loads could break the vessel after birth
unless restrained by a sufficient number of well tended in tights mooring lines
all the lines must be correctly orientated intentions to prevent the
ship from being able to range of her birth
causing damage both to the ship
and the birth
to ensure the mooring lines remain effective
they must be regularly moments into my watch keepers during every watch
the winch is of course of also a key element of the morning system
the brakes uh... generally designed to hold a minimum load of around sixty
percent of the minimum breaking the or envio of the line
ensuring that the break will render before the line cards
this value should be stenciled on peach winch
either the safe working alone
s w l
all the work load limits w l_l_
must be clearly mark some or morning equipment
to maintain the maximum holding power of a split drum winch brake
they should only be a single layer of while all wrote on the tensioning drama
this will provide the best use of the winch breaks holding power
a second layer would increase the radius at which the line would call against the
break
the increased leverage could result in the break being overcome
as an added bonus
the use of a tensioning drum avoids crushed layers of lying on the storage
drum
this is particularly important when using synthetic fiber ropes
all these theoretical knowledge has been applied to create a suitable morning
scheme foot each port and each terminal around the globe
mo ships will have on board such bogus as a recent copy off the
guide to port entry
which give all the basic information needed for morning requirements for each
participating port did to you
political wing level two please
like this information may also be available on c_d_
updates can be obtained on the internet which also provides the latest
information of the morning
watch this program again
lead the workbook the company's
wash the all the programs in this morning's series
you should also investigate all the information about the morning which will
find on the ocean