International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 5
Number 2
June 2011
247
1 INTRODUCTION
Collisions, rammings and groundings, so called
CRG casualties, constitute large part of all casualties
at sea (approximately around 60 per cent) (Samu-
elides & Friese 1984). Therefore reducing risk of
CRG casualties contributes largely to the reduction
of overall risk of sea voyage.
Risk of CRG casualty depends on several factors,
one of which is human factor, i.e. operators skill.
Published analyses associated with commercial
shipping during recent years indicated that human
errors that occurred during handling operations were
responsible for approximately 62 per cent of the ma-
jor claims figure (Payer 1994). Other sources show,
that about 80 % of all CRG casualties are results of
human failure. Therefore attention is focused recent-
ly to the role of human factor in safety. (US Coast
Guard 1995).
As about two thirds of all CRG casualties are
caused by human error it is necessary to analyse fac-
tors which contribute to the efficiency of the opera-
tor. The author discussed this subject in the paper
presented to Nav 2009 (Kobylinski 2009) showing
that one of the most important factors contributing to
this is training.
2 SIMULATOR TRAINING
There are several factors contributing to the reduc-
tion of the number of CRG accidents, and experi-
ence is one of them. Experience is gained over years
of practice. Specialized training on simulators accel-
erates gaining experience, in particular gaining expe-
rience in handling dangerous situations that may be
rarely met during operation of real ships. Therefore
specialized training in ship handling is required by
the International Maritime Organisation. Seafarers'
Training, Certification and Watchkeeping (STCW)
Code, Part A, includes mandatory standards regard-
ing provisions of the Annex to the STCW Conven-
tion. Apart training onboard ships, approved simula-
tor training or training on manned reduced scale ship
models is mentioned there, as a method of demon-
strating competence in ship manoeuvring and han-
dling for officers in charge of navigational watch
and ship masters.
Also ship owners companies and pilots organiza-
tions attach recently great importance to training on
simulators and some pilots organizations require
repetition of such training every 5 years.
Obviously the best way to train ship officers and
pilots in shiphandling and manoeuvring is to per-
form training onboard real ships. Any use of simula-
Capabilities of Ship Handling Simulators to
Simulate Shallow Water, Bank and Canal
Effects
L.K. Kobylinski
Foundation for Safety of Navigation and Environment Protection Iława Poland
ABSTRACT: Safe operation of ships in restricted areas, in particular in canals and waterways of restricted
width and depth, often with presence of current. depends on operator skill. One way to influence operator skill
and hence to increase safety against collisions and groundings is proper training of operators in realistic envi-
ronment. Training could be accomplished on board ships, which takes, however, long time but also on simula-
tors. There are two types of simulators: full mission bridge simulators (FMBS) working in real time and phys-
ical simulators using large manned models in purposeful prepared training areas (MMS). Capabilities of both
type simulators are discussed in detail. Capability of FMBS depends on computer codes governing them. Few
examples of capability of FMBS to reproduce correctly ship handling situations are shown. There are few
MMS in the world, one of which is Ilawa Ship Handling Research and Training Centre. In the centre models
of several types of ships are available and training areas are developed representing different naviga-tional
situations. The main purpose of the training exercises is to show the trainees how to handle the ship in many
close proximity situations, in the presence of current, in very restricted water areas etc.
248
tors should be in addition to training onboard ships.
However, gaining skill "on job" watching experi-
enced practitioner working is a long and tedious
process. Moreover certain handling situations in-
cluding some critical ones may never occur during
the training period onboard ships and no experience
how to deal with such situations could be gained this
way. When serving on ships engaged in regular ser-
vice there is little or no possibility to learn about
handling in critical situations because such situations
must be avoided as far possible.
Simulator training is expensive, therefore the
simulator courses must utilize time available in the
most effective way. In order to achieve positive re-
sults simulators must be properly arranged and the
programme of simulator exercised should be proper-
ly planned in order to achieve prescribed goals.
In general, simulators may be either equipment or
situations. A simulator is defined as any system used
as a representation of real working conditions to en-
able trainees to acquire and practice skills,
knowledge and attitudes. A simulator is thus charac-
terised by the following:
− imitation of a real situation and/or equipment
which, however, may permit, for training purpos-
es, the deliberate omission of some aspects of the
equipment in operation being simulated, and
− user capability to control aspects of the operation
being simulated.
The effectiveness of a simulator in training mari-
ners depends on the simulator capabilities to simu-
late the reality. Sorensen (2006) stressed the point
that simulators must be realistic and accurate in sim-
ulating the reality. Therefore simulators should,
apart from simulating properly the main manoeu-
vring characteristics of a given ship, i.e.
− Turning characteristics
− Yaw control characteristics
− Course keeping characteristics and
− Stopping characteristics
be capable to simulate different factors influencing
ship behaviour, e.g: at least:
− Shallow water effect
− Bank effect
− Effect of proximity of quay or pier
− Effect of limitation of dimensions of harbour ba-
sin
− Surface and submerged channel effect
− Ship-to-ship interaction
− Effect of current
− Effect of special rudder installations, including
thrusters
− Effect of soft bottom and mud
− Ship-tug cooperation in harbour (low speed tow-
ing) and.
− Escorting operations using tugs
− Anchoring operations.
3 FULL MISSION BRIDGE AND MANNED
MODELS SIMULATORS
Simulators used in training in ship handling and
manoeuvring are basically of two types : Full Mis-
sion Bridge Simulators (FMBS) and Manned Mod-
els Simulators (MMS).
FMBS computer controlled simulators are widely
used for training of ship officers, pilots and students
of marine schools and also for studying various
manoeuvring problems, first of all problems associ-
ated with the design of ports and harbours.
There is at present a considerable number of such
simulators of different types operating throughout
the world, starting from desk simulators to sophisti-
cated FMBS where the trainee is placed inside a
bridge mock-up with actual bridge equipment, real-
istic visual scene of the environment, and sometimes
rolling and pitching motions and engine noise.
FBMS are working in the real time and are con-
trolled by computers programmed to simulate ship
motion controlled by rudder and engine (and thrust-
ers or tugs) in different environmental conditions
MMS use large models for training purposes in
specially arranged water areas, ponds or lakes. Mod-
els are sufficiently large in order to accommodate 2-
4 people (students and instructors) and are con-
structed according to laws of similitude. Models are
controlled by the helmsman and are manoeuvring in
the areas where mock-up of ports and harbours,
locks, canals, bridges piers and quays, shallow water
areas and other facilities are constructed and where
also routes marked by leading marks or lights (for
night exercises) are laid out all in the same reduced
scale as the models. Also in certain areas current is
generated. As a rule, monitoring system allowing to
monitor track of the model is available.
Important feature of manned model exercises is
that all manoeuvres are performed not in real time,
but in model time which is accelerated by the factor
λ
-1
. This may pose some difficulties for trainees at
the beginning who must adjust to the accelerated
time scale.
Currently there are only few training centres us-
ing manned models in the world, however, accord-
ing to the recent information, few others are planned
or even in the development stage.
249
4 CAPABILITIES OF FBM SIMULATORS
In FMBS because there is a mathematical model of
ship motion on which computer codes are based it is
important that this mathematical model represents
properly behaviour of the real ship. In spite of great
progress in the development of the theoretical basis
of ship manoeuvrability not only in unrestricted wa-
ter areas (turning, course-keeping and stopping char-
acteristics), but also in the proximity of other objects
(bank, shallow water effects and the effect of other
ships), the last effects are still investigated not suffi-
ciently enough. Sophisticated computer programmes
that include calculations of hydrodynamic coeffi-
cients using advanced methods requiring powerful
computers and extreme large memory. simulating
the close proximity effects cannot be used in FBMS
because they must work "on line" therefore rather
simplified methods must be developed for this pur-
pose.
Practically all modern FMBS are capable to simu-
late manoeuvring and ship handling characteristics
in open water properly. Usually they are also capa-
ble to simulate the close proximity effects based on
simplified theory. But in many cases even simple
manoeuvres such as turning circle manoeuvre or zig-
zag manoeuvre are often simulated not accurately
enough. Gofman & Manin (1999, 2000) showed
several cases where results of simulation on Norcon-
trol SH simulator differed considerably from results
obtained during tests of full-scale ships. One may
however argue that results shown by Gofman were
obtained in nineties of the last century and modern
simulators are much more effective.
There is little information available on the valida-
tion of the effectiveness of FBMS. Some data on
comparison of simulated and measured at full scale
trials of few ships were collated by Ankudinov
(2010) and one example of simulation of turning
circle test on TRANSAS simulator is shown in Ta-
ble 1.
Fig 1 shows results of comparison of simulated
and measured characteristics of stopping manoeuvre
of the ship ARKONA. Simulator in this case was
ANS 5000 developed by Rheinmetall Defence Elec-
tronics GmbH (de Mello Petey 2008). In both cases
it is seen that the simulation is quite reliable.
Results of simulation of manoeuvring capabilities
of POD driven ships on this simulator are also avail-
able (de Mello Petey 2008) and by Heinke(2004).
The code used in this simulator takes into account
the following:
− Propeller thrust
− Transverse propeller force
− Lift and drag forces of the POD body
− Interaction effects between different POD units
− Interaction effects between POD and hull, and
− Shallow water effects.
Table 1 Turning circle tests with both pods at an angle 35
0
(EUROPA)
Manoeuvre to
port
Manoeuvre to
starboard
lated
Actual
Simu-
lated
Actual
Starting speed [knots] 21.40 11.40
Engine[%]
100
60
Rudder angle [deg] 35.0 -35.0
Adcance [m]
379.6
333.0
364.0
Transfer [m] 165.0 159.1 167.0 164.3
Tactical diameter [m]
392.1
382.5
398.7
Turning circle diame-
ter [m]
320.0 313.7 323.5 320.3
Steady speed at turn
[knots]
6.59
3.90
4.38
t90 [s] 56 54 91 96
t180 [s]
120
182
203
t270 [s] 192 314
t360 [s]
264
397
425
The high level of accuracy achieved by the simu-
lation module was proved by validation tests per-
formed with pollution control ship ARKONA (L=
69.2m). The example of comparison of simulated
and measured results of the stopping manoeuvre
where at full speed both POD were commanded to
zero RPM is shown in fig. 1 (de Mello Petey 2008).
Figure 1. Comparison of simulated and measured characteris-
tics of stopping manoeuvre ARKONA ship (Ref. 27 )
250
The technique used by TRANSAS in simulating
manoeuvring characteristics of ships in shallow wa-
ter and the bank effect is based on the generalized
flow pressure functional describing motion effects
and variable pressure field of maneuvering ship in
the restricted channel of variable bottom and banks
in the presence of other stationary or moving ships.
The developed technique is fairly complex and best
suited for solid unmovable objects in the channel
(walls, moored ships). The modeling of proximity of
other maneuvering ships of various types moving
with various heading angles and velocities needs
however further refinement (Ankudinov 2010).
Gronarz (2010) reported results of the simulation
of shallow water and bank effect in four most mod-
ern FBMS, marked A,B,C,D. The results of simula-
tion of speed loss in shallow water and increase of
turning diameter are shown in figs. 3 and 4.
Figure 2. Speed loss with reduced UKC
Fig 3 Increase of turning circle diameter with reduced UKC
In deep water a ship can reach the highest veloci-
ty using constant revolutions of the propeller. With
reduced UKC, i.e. increased T/h the speed loss will
increase. In general all simulators show loss of speed
with decreasing depth of the water as it can be seen
in fig. 2. However, for T/h=0.3 i.e. the case where
UKC is more than twice the draught of the ships gap
the speed loss should only be marginal. This is rep-
resented correct for simulators C and D, but simula-
tors A and B show significant loss of speed which is
not correct. On the other hand at very shallow water
(T/H~0.8) the speed loss shown by simulators A and
B is not great enough as it should be.
The simulated turning circle diameters in shallow
water are larger, as expected (Fig.3).
However simulator A shows increase of turning
diameter in rather deep water (T/H=0.3) which is not
correct. As it is seen from fig.3 the increase in diam-
eter in shallow water is significantly different. The
range of 35% (C) to 135% (D) increase seems unu-
sual. Also for simulators A, B and C the turning di-
ameters are nearly constant for T/h=0.80 and 0.85
which contradicts the theory. This means that simu-
lation of shallow water effects are not represented by
all simulators correctly and the computer codes used
have to be improved.
5 CAPABILITIES OF MMS SIMULATORS
In the case of manned models the governing law of
similitude is Froude's law and all quantities for mod-
els are calculated according to the requirements of
this law. However, as it is well known, the require-
ments of second law of similitude which is relevant
to ship motion, Reynolds law, cannot be met. This
means that the flow around the ship hull and ap-
pendages and in particular separation phenomena
might be not reproduced correctly in the model
scale. Fortunately those effects are important when
the models are small. With models 8 to 15 m long
the Reynolds number is sufficiently high to avoid
the majority of such effects.
One important difficulty with manned models is
impossibility to reproduce wind effect. Wind is a
natural phenomenon and according to laws of simili-
tude wind force should be reduced by factor λ
3
( λ -
model scale). Wind force is proportional to the
windage area and to the wind velocity squared.
Windage area is reduced automatically by factor λ
2
but wind velocity apparently cannot be reduced.
However, actually windage area in models is usually
reduced more than by factor λ
2
, and wind velocity.
due to sheltered training area and low position of the
windage area in the model in comparison with the
full-scale ship is considerably reduced. Still usually
wind force is larger than it should be.
Final speed in straight run
75%
80%
85%
90%
95%
100%
0 0.2 0.4 0.6 0.8 1
T/h
V / V deep
A
B
C
D
Turning Circle: Diameter
100%
125%
150%
175%
200%
225%
250%
0 0.2 0.4 0.6 0.8 1
T/h
D / D deep
A
B
C
D
251
Capability of manned models to simulate shallow
water, bank, submerged and surface canal effects,
effect of current, close proximity of other stationary
or moving objects is automatically assured and is
practically unlimited, restricted only by local condi-
tions in the training area.
As there are only few manned model centres op-
erating in the world, facilities arranged in the Iława
Ship Handling Research and Training centre are
shown below as an example.
As safe handling of ships is much more difficult
in restricted areas and in presence of the current, in
Iława Ship Handling Centre there are artificially
prepared training areas that, apart of the standard
model routes marked by leading marks, leading
lights (at night) and buoys, comprise also routes par-
ticularly suitable for training ship handling in canals
and shallow and restricted areas. They include:
− restricted cross-section surface canal of the length
140m (corresponding to 3.3 km in reality), called
Pilot’s Canal. In this canal exercises comprising
passing the canal feeling bank and restricted cross
section effects, stopping ships in restricted width
of the fairway, meeting and overtaking with two
or three ships feeling interaction effects are per-
formed,
− wide (corresponding to about 360m width in real-
ity) shallow water canal of the length correspond-
ing to about 1.5 km, where current could be gen-
erated from both sides, called Chief’s Canal.
Passing the shoal, feeling slowing down and
squat, berthing in shallow water, turning the ship
in shallow water and in current and similar exer-
cises are performed.
− long (corresponding to about 2.5 km in reality),
narrow deep water waterway comprising several
bends, marked by buoys, simulating some routes
in fiords and similar areas called Captain’s Canal,
− narrow fairway restricted from one side by the
shore, called Bank Effect Route where ships are
supposed to feel bank effect,
− narrow passages, including narrow passage under
the bridge feeling the close proximity effect,
− river estuary area where several current genera-
tors installed create current. Several mooring
places are provided in the estuary, including shel-
tered dock. Current pattern and velocities could
be adjusted by activating particular current gener-
ators, the maximum current velocity correspond
to 4 knots in full scale.(fig.4). There is possibility
to arrange several exercises where ships make
manoeuvres in current.
− locks, deep and shallow water docks for docking
ships in different situations, harbour basins of dif-
ferent dimensions and configuration of the en-
trance
− mock-up harbour basins, locks, bridges, fairways
and other arrangements existing in different parts
of the world as the need arises.
6 CONCLUSIONS
It appears that simulator training in ship handling
becomes more and more popular and some pilots or-
ganizations require now refreshing such courses eve-
ry five years.
From the experience with FBMS and MMS simu-
lators it is now clear that they do not supersede but
rather they supplement each other, because the pur-
pose of training on each of them is different.
Figure 4. Arangement of the river estuary at Ilawa centre
Capability of FBMS depends on the reliability of
computer codes governing them, that are still far
from perfection, and the quality of visualization of
the situation around the ship simulated. They are
particularly suitable to simulate situations in some
ports, canals, approaches etc, and master and pilots
may learn how to maneuver in this particular situa-
252
tion. FBMS may be used also as a tool for harbour
design.
The capability of MMS depends on the possibil-
ity of making different arrangements such as de-
scribed above in the training area available. From
this point of view Ilawa training centre in compari-
son to the other centres (Port Revel and Warsash)
has the advantage of having to its disposal large wa-
ter area (Silm lake),where different arrangements
could be installed.
The purpose of training on manned models is
mainly to make the trainees aware of different hy-
drodynamic effects, in particular close proximity in-
teractions, which may be easily arranged. High real-
ism and automatically hydrodynamic correct
representation of close proximity situations is the
main advantage of MMS.
Tugs action, escort and anchoring and ship-to-
ship operations, simulation of which is attempted al-
so in FBMS are particularly realistic when using
manned models.
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