International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 1

Number1

March 2007

Analysis of Ships Turn Manoeuvres in Port

Water Area

J. Kornacki & W. Galor

Szczecin Maritime University, Szczecin, Poland

ABSTRACT: The turning basin is a special part of port water area described by dimensions in horizontal and

vertical directions. Such area should be insuring the proper level of safety due to ship manoeuvres. The paper

presents the analysis of ships turn manoeuvres on aspect of turning basin designing. The examples of such

basins in polish port are showed.

1 INTRODUCTION

1.1 What this is the turning basin

The turning basin is understood as the maneuvering

reservoir or also the hydro technical building

artificial or natural about suitable horizontal and

vertical dimensions, where the considerable

alterations of the course of the ship are done.

Because the ray of the circulation of the ship in the

movement, even near small speeds, he is

considerable, so the ship practices the turning over

„in the place”. This should be understand as the

change of the course of the ship whose linear speeds

are zero in relation to water during the maneuver or

are close to zero. Turning over the ship is done on

the turning basin as a result of the planned tactics of

maneuvering and can be done on itself or in co-

operation with tugs or use of anchors or spring.

Turning basins are both reservoirs appointed and the

reservoirs not appointed on which the turn of the

ship is done with the considerable value of the

course and they make up the part of channels or port

basins. Turning basin as the hydro technical

building, from the safety of considerations, it always

has to be larger than the turning basin understood as

the maneuver reservoir to avoid the collision with

bottom or bank.

1.2 The definition of turning basin in polish law

The polish law defines the turning basin of ships as

the limited navigational reservoir, situated on the

point of contact of basins and port channels or on the

water track, designed to safe executing

the maneuvers of ships in the aim of the entry to port

basins or the altering course or mooring of the ships

in the harbor, with the use of own engine or with the

help of tugs (Dz.U.98.101.645).

In the thought of the law, the dimensions and

location of turning basins are determined in the

support of the navigational analysis. During projecting

the turning basins or reconstruction already existing,

the smallest diameter of the turning basin can not be

smaller than values passed in table 1.

On reservoirs, where the current of water with

measured speeds and the directions of the

occurrence, has influence on reliable floatable

objects, location and dimensions of the turning

basins are projected in the approximate shape to the

ellipse, which the large axis definite dimensions in

the table 1. The depth of water on the turning basins

is defined in dependence from loading status of

turned over ships (Dz.U.98.101.645).

Table 1. The dimensions of the diameter of turning basins

(Dz.U.98.101.645)

The way of the ships

turning

The building

of new turning

basins

The reconstruction

of existing turning

basins

The turn on spring

fixed to bollard on

the sea building

1.5 * L

1.3 * L

Turn for the help of the

tugs of tankers, gas

carriers or chemical

tankers

(2.0-2.5) * L

2.0 * L

The turn for the help of

the tugs of ships

different than the

tankers, gas carriers

and chemical tankers

2.0 * L

1.6 * L

where L

= the total length of the hull.

2 SHIPS MANOEUVERS ON TURNING BASIN

Many ways of the realization of the turn of ship exist

in dependence on accessible reservoir, reigning

hydro meteorologically conditions and the accessible

kinds of steering the ship. Special influence on this

maneuver has the kind of the used propulsion, use of

tugs, the use of the anchor or spring.

The presentations, in the following points, of the

realizations of maneuvers were used application of

simulation of maneuvering the ship – SMART

(Artyszuk 2005).

2.1 The turning of the ship using the own drive

The turning of the ship using the only own

propulsion complies on small ships the most often.

This consists in executing “kick ahead” maneuvers

ahead on transformations with the work astern to

keep the rotation of ship till the setting of the ship on

the desirable course (Fig. 1).

Fig. 1. Turning the ship of to use of the main engine (ship’s

positions every 60 seconds)

Mostly the turn of the ship complies consistent

with the tendency to the alteration of the course

through ship during the work of propulsion astern

(consistent with turning effect of propeller). It

happens that in case of wind conditions the

realization of turning maneuver in the opposite

direction of turning effect of propeller is easier then

turning consistent with it.

The use of thrusters is additional element helping

the process of the turning of the ship. The applying

thrusters on the forward as additional force applied

opposing with force produced by the propeller-

rudder arrangement seem to be sufficient for simpler

maneuvers of the turning. And the use of additional

thrusters on the aft allows to considerable facilitation

in the realization of the maneuver of the turning

(Fig. 2).

Such solutions with many thrusters not only on

the forward, but also on the aft, comply particularly

on large ships.

It should be remembered that thrusters have their

limited power. They in particularly unfavorable

conditions may be completely insufficient.

Fig. 2. Turning of the ship using the main engine and thruster

(ship’s positions every 60 seconds)

In case of using thrusters, while turning of the

ships, in the smaller degree can be take the turning

effect of propeller then in case of turning of the ships

without their use.

Using only the main engine while the turning of

the ship, she will also move along to the forward or

to the aft enlarging the maneuvering reservoir on the

turning basin. The use of thrusters will result in

smaller use of the main engine and simultaneously

decrease moves the ship along.

2.2 The turning of the ship using tugs

In the case of lack on the ship of thrusters, their

insufficient power, the large sizes of the ship or

unfavorable hydro meteorological conditions to

turning over the ship uses tugs. Different quantity

and the way of tugs work can depend from the scale

of the difficulty and the kind of the tugs which are at

one's disposal. The solution complies with one tug

fixed on the long tow on the forward or with two

fixed on long tows on the forward and on the stern

the most often. Such solution does not require

applying tug about more complicated and expensive

propulsion arrangements. It should be remembered

the maneuvering reservoir increase of the maneuvering

reservoir of tugs in this case. Tugs are place

perpendicularly to the axis of the symmetry of the

ship during the turning and they are pulling only

forward or both forward and stern according to the

direction of turn.

Second the solution, which does not cause the

increase the reservoir of maneuvering, is the uses of

tugs on the short tow. This requires, for the full

control, the tugs with expensive propulsions

solutions. Such method is applied in the USA and

Canada universally. Tugs while the turning thrust the

forward, the stern or they thrust and pull being on

same side or turn together with the ship (Nowicki

1992).

The shape of the maneuver reservoir can be still

more approximate to circular in the case of the

turning of the ship with the use of tugs. There is the

larger guarantee of the successful and failure-free

maneuver additionally. Port authority, in dependence

on the accessible fleet of tugs, the size of ship and

the degree of the difficulty, define the minimum

quantity of the tugs which has to participate from the

safety of considerations in port maneuvers.

2.3 The turning of the ship using the anchor

The turnings of ships with the use of anchors apply

more seldom. Such maneuver is executed through

the ship herself without the tows assist. The aim is

to limit the influence of the current on the size of

the maneuver reservoir and to improve the

maneuverability of the ship through the considerable

limitation of the possibility of acceleration using

“kick ahead” maneuvers. Maneuver this is prohibited

by port authority because of the danger of the port

reservoir bottom decay very often, and applied in

ports of small urbanization as the natural outlets of

rivers or open sea coasts. The shape of the maneuver

reservoir is bring nearer to the semicircle and the

pivot point of the ship turns is near a forward

(Fig. 3).

Fig. 3. The turning of the ship on the anchor (ship’s positions

every 60 seconds)

The executing of this maneuver can considerably

limit the frequency of setting propulsion astern.

The ship should be stopped or move with the very

small speed in relation to the bottom to lower

the anchor. Next the ship can be turned over using

the small settings of the propulsion ahead in the

monotonous way with rudder on same side as

the anchor was lowered.

2.4 The turning of the ship using spring

The maneuver of the turning of the ship on spring is

common on the berth, the most often during

departure or approach. It can be applied while

coming in to the locks or during the turning of the

ship around dolphin. He consists in the approach to

the hydro technical building and send a forward

spring or unmoor and keep the forward spring fast.

Then use small power of propulsion ahead with

rudder on the side according to the direction of the

turn. As soon as the ship aligns perpendicularly to

the quay the propulsion should be set astern to avoid

hull or bulb damages and to tighten forward spring

to continue ships turning (Fig. 4).

Fig. 4. The turning of the ship on spring (ship’s positions every

60 seconds)

In the case of unmooring suffice to let go forward

spring on the end of the maneuver of turning and to

go away from berth. When mooring is the aim next

ropes should be passed from the mooring side and

the spring on which the turning took place should be

let go.

3 THE METHOD OF DESIGNING

THE TURNING BASINS

Two methods of designing the turning basins:

analytic method and simulating method are comply

(Gucma 2001).

3.1 The analytic method of designing the turning

basins

The sizes of the maneuvering reservoir while making

the turning of the ship depend on so many factors.

So in practice these are applying the very simplified

analytic method. It consists in dividing turning

basins on two kinds: turning basins on reservoirs

without currents and turning basins on current

reservoirs. This takes the root that the turning basin

has the shape of the wheel on reservoirs without

current and the elliptic shape has on current

reservoirs, for simplification, the contained surface

in shape between two circles, like without current,

shifted about the distance, which the ship will pass

under the influence of the current. The dimension of

the turning basin on the reservoir without current

defines the example Equation1 (Gucma & Jagniszczak

1997; Gucma 2001; Gucma & Jagniszczak 2006):

5.1=

(1)

where d

= the diameter of the turning basin; L = the

length of the ship.

This is introduced on figure 5:

Fig. 5. Parameters of turning basin on reservoirs without

currents (McCartney 2005)

The dimensions of the turning basin on the

current reservoir define the examples Equations 2, 3:

oco

tvLl += 5.1

(2)

5.1=

(3)

where l

= the length of the turning basin; b

= the

width of the turning basin; L = the length of the

ship; v

= the speed of the current; t

= the time of the

turning.

This is introduced on figure 6:

Fig. 6. Parameters of turning basins on current reservoir

(McCartney 2005)

3.2 The simulating method of designing the turning

basins

The simulating method of designing the parameters

of turning basins depend execution of series of tests

in comparable conditions on prepared model of

reservoir and the model of the ship planned to use

the turning basin. The results of tests are subjected

the statistical processing. This is the characteristic

feature of the simulating method, that simulating

models of the ship maneuvering are especially

designed to the solved problem. Effect of that kind

of research is delimitation of the reservoirs of

maneuvering on the turning basin according to the

various foundations of hydro meteorological

conditions, various parameters of ships and various

levels of the trust.

Below, shown reservoirs of harbors: Świnoujście

(Fig. 7, 8), Kołobrzeg (Fig. 9) and Police (Fig. 10),

were introduced designed turning basins in:

Fig. 7. Parameters of the turning basin near the embankment

Górników in Świnoujście (the collective work 2000)

Fig. 8. Parameters the turning basin near the base smooth fuels

in Świnoujście (the collective work 1995a)

Fig. 9. Parameters of the turning basin in the harbor Kołobrzeg

(the collective work 1995b)

Fig. 10. Parameters of turning basin in harbor Police

(the collective work 1998)

You can see that the shape of turning basin

dependence from accessible reservoir and hydro

meteorological conditions is different and very

irregular.

3.3 The real investigations method of designing the

turning basins

These investigations are leaning about real

observations consisting in the measurements of the

position of the ship and concurrent tugs during the

maneuver of the turning. This method can not be

used to marking parameters of designed or

modernized turning basins from obvious regards.

However, this method finds the use to the

verification of analytic and simulating methods on

the basis which they already became built turning

basins.

This method requires the study of investigative

firing ground and measuring methods. They can be

base about measurements on the maneuvering ship

or for the help of external measurements. First way

requires the installation on the maneuvering ship (if

she does not possess them) the system of positioning

about the suitable level of the exactitude of defining

the position. It should be remembered that the ship is

not the punctual object here and the measurements

of the position of the ship should be bring back to

the water plane of the ship. The qualification of the

position of tugs (even to four) is difficult here.

Near the way of external measurements to find

distance of the ship can be applied laser rangefinders

at list of two points (on forward and stern) and the

distance to tugs. The different method is the

fotogrametric method. The use of the digital

autograph is the best way.

The methods of real investigations are time- -

consuming and expensive. The results of investi-

gations, similarly as near the simulating method,

should be subjected the statistical processing.

4 THE OPTIMIZATION OF TURNING BASINS

The minimization of the costs of building or the

modernization of the reservoir of the turning basins

is the aim of the optimization. The safety of

navigation of the executed the turning maneuver is

the condition restrictive determined the navigational

risk.

Criterion function for the method of the

optimization can be introduced of the parameters of

the turning basin as follows:

bVaK −∗=

(4)

where a

= the isolated cost of getting out the 1m

the output; V = the quantity of the output which was

not obtained in the consequence of the minimum

dimensions of the turning basin; b = losses of

the bank collision.

Following figure 11 represents the pattern of the

optimization of the dimensions of the turning basin.

100

Profit

Loss

Turning basin

size

Criterion function

Fig. 11. Pattern of the optimization of the turning basin

5 CONCLUSIONS

The existing analytic methods of marking and

the optimization of turning basin are exact little.

The turning basin on the reservoir with the

stepping out current of water is the special type of

the turning basin. The analytic method takes into

account the time of the turn of the ship and the speed

of the current, while it is definite for the help of the

circular shape in many cases.

Simulating methods, although they are more

labor-consuming, they give large exactitude.

However this did not become so far in the sufficient

way definite.

According to existing experiences in projecting

and making of turning basins on reservoirs ports of

Świnoujście, Police, Szczecin and Kołobrzeg, their

shape runs away from the wheel considerably. This

results of investigations leanings about simulating

methods concerns.

The study of the methods of the optimization of

the size of turning basins will let lower the costs

of their building or modernization near the behavior

of the suitable level of the safety.

ACKNOWLEDGEMENTS

We would like to thank Jarosław Artyszuk for the

facility of the application of the simulation of

maneuvering the ship to scientific of aims.

REFERENCES

Artyszuk, J. 2005. Methodical guide of the ships maneuvering

simulation with application. Naval University of Szczecin.

Dz.U.98.101.645 Minister Transportation and Sea Economy

decree „w sprawie warunków technicznych, jakim powinny

odpowiadać morskie budowle hydrotechniczne i ich

usytuowanie”.

Gucma, S. 2001. Inżynieria ruchu morskiego. Gdańsk: Okręto-

wnictwo i Żegluga.

Gucma, S. & Jagniszczak, I. 2006. Nawigacja dla kapitanów.

Gdańsk: Fundacja Promocji Przemysłu Okrętowego i Gos-

podarki Morskiej.

McCartney B. 2005. Ship Channel Design and Operation.

American Society of Civil Engineers No. 107.

The unpublished report 1995a. Badania symulacyjne ruchu stat-

ków w bazie paliw płynnych w Świnoujściu. Naval

University of Szczecin.

The unpublished report 1995b. Określenie optymalnego wa-

riantu przebudowy wejścia do portu Kołobrzeg w oparciu

o badania symulacyjnego ruchu statków. Naval University

of Szczecin.

The unpublished report 1998. Badanie możliwości optymalnej

lokalizacji przeładowni kwasu fosforowego w Porcie

Police. Naval University of Szczecin.

The unpublished report 2000. Analiza nawigacyjna dla przebu-

dowanego Nabrzeża Górników w porcie handlowym

Świnoujście. Naval University of Szczecin.