Repository - Scientific Journals of the Maritime University of Szczecin - Ships’ ocean route programming

Scientific Journals

Zeszyty Naukowe

Maritime University of Szczecin

Akademia Morska w Szczecinie

2012, 29(101) pp. 164–173

2012, 29(101) s. 164–173

Ships’ ocean route programming

Programowanie tras statków na oceanach

Bernard Wiśniewski

Maritime University of Szczecin, Institute of Marine Navigation Akademia Morska w Szczecinie, Instytut Nawigacji Morskiej

70-500 Szczecin, ul. Wały Chrobrego 1–2, e-mail: b.wisniewski@am.szczecin.pl

Key words: ship’s ocean routes, programming, methods Abstract

The methodologies, planning procedures and integrated seas and ocean routes’ programming are presented. In programming of the most convenient route current and forecasted weather conditions, criteria and restrictions, speed and fuel characteristics of ships on waves and wind, computational methods and algo-rithms, navigation aids generating a route recommendation penetrate themselves. These elements when properly identified and adopted allow the master for effective ship’s course and speed decision making.

Słowa kluczowe: trasy oceaniczne statków, programowanie, metody Abstrakt

W artykule zaprezentowano metodologie i procedury planowania oraz zintegrowanego programowania tras statków na morzach i oceanach. W programowaniu najdogodniejszej trasy brane są pod uwagę takie czynniki, jak bieżące i prognozowane warunki pogodowe, kryteria i ograniczenia, charakterystyki prędkościowe i pali-wowe statków na fali i wietrze, metody obliczeniowe i algorytmy, systemy wspomagania nawigacji, wypra-cowujące rekomendację trasy. Te elementy, poprawnie określone i przyjęte, pozwalają kapitanowi statku na efektywne podejmowanie decyzji co do kursów i prędkości statku.

Introduction

For ship’s master some questions are

fundamen-tal: how in the most conveniently way reach the

destination, how to keep the ship’s-, cargo’s- and

people’ safety, how to transport the cargo without

any damage or loss, how to realize the most

effi-ciently sea voyage (fuel efficiency, voyage time

minimization, charter contract conditions’

ful-filling, etc.).

The problem of planning and forecasting of

ship’s sea voyage is still present due to changing

environmental conditions in which the ship sails as

a control object. It could say that the sailors and

ships’ navigators are always interested in choosing

the best shipping route beginning from historic

times, even mention the Phoenicians, the sailing

vessels’ and steam engines vessels’ routes, internal

combustion engine vessels’ routes, to the present.

The purpose

of this study

is to present in a

com-prehensive

way

the problem of ship’s sea route

planning and programming

in order to

integrate

the

interpenetration of

weather conditions’ issues,

ship’s

movement parameters

and ocean route’s

navigational

aspects

.

The methodology

and procedures

The sea voyage’s programming consists of two

stages:

A. Static

scheduling

based on all

available

naviga-tional aids

before the voyage

(route’s

plotting

on

operational

maps

, return points’ determination

,

KDd

taking into account

the

seasonal routes

’

variants);

B. Dynamic route’s programming

from departure

from the

quay

or from the pilot’s

disembar-kation

, taking into account

changing weather

conditions

, guidelines and

restrictions which

may

correct the

previously

planned route

.

Ship’s

route

planning and programming

schema

and

the procedures’ order

are

shown

in figure 1.

Ships’ ocean route programming

Current weather data – analyzes and

forecasts

Nowadays,

regardless of ship’s class,

the

weath-er

is still a

significant problem

, affecting the

voy-age’s

economic efficiency and in result

the

compa-ny’s financial results.

The increase

of

extreme

weather conditions

incidents

directly

affecting

the

navigation safety and

ship

each

individual is of

special concern

[1, 2

, 3].

In the last decade,

the

fleet captains

and

owners

are more interested in ocean routes’ improvement

of merchant ships,

what is done

by

taking into

ac-count

, inter alia,

changing weather conditions

.

A sign

of this interest

is a common

ships’ supply in

receiving

weather

maps equipment

, the use of

nomograms

to determine the

vessels’

safe

speed

,

carrying out

experiments with

terrestrial

weather

ship’s tracking

centers

and use of

software

on board

during the

exploitation

(e.g.

SPOS – Ship

Perfor-mance

Optimisation

Sytem) [4

, 5].

In figure 2 an

example of SPOS weather

demon-stration

with marked routes’

variants

is illustrated.

The

presentation of

several elements

such as

weather

helps

the user to analyze

the impact of

these

conditions on the

proposed

ship’s voyage

route

.

Ship’s speed characteristics

In addition to data from analyzes and weather

forecasts an important value needed for the

calcula-tion of ship’s route dynamic programming is

to adopt a ship’s speed

characteristics on wave

Seasonal route determined before the voyage, based on navigational publications

Dynamic voyage‘s programming during the voyage

Ships’ speed and fuel characteristics on

wind and waves

Navigation Support Systems (ECDIS, SPOS,

OPTY, “Cyclone”) Current weather data

(analysis and forecast)

Algorithms and computational methods due to criteria

The ongoing voyage

Current route’s verification

Decision-making by the master

Phase B

Voyage’s data input:

– port of departure and arriving – the estimated time of departure – ship’s characteristic

Static route’s planning before the voyage

Navigation publications Seasonal weather Ship’s owner recommendations and restrictions Navigation Support Systems (ECDIS)

Phase A

Fig. 1. Ship’s sea voyage planning and programming – schema Rys. 1. Planowanie i programowanie trasy morskiej statku – schemat

Bernard Wiśniewski

Fig. 2. Current weather conditions – example [own work with the use of SPOS]

Rys. 2. Bieżące warunki pogodowe – przykład [opracowanie własne z wykorzystaniem systemu SPOS]

Wave’s height h [m]

Wave’s angle on the bow Wave’s height h [m]

Wave’s angle on the bow 0º = 13.9961 – 0.1969h – 0.1514h2 ₊ +0.0072h3 _{+ 0.000038116h}4 45º = 13.9878 – 0.0927h – 0.1149h2 ₊ + 0.0009h3 _{+ 0.0003h}4 90º = 13.9967 – 0.1236h – 0.0171h2 _– + 0.0128h3 _{+ 0.0008h}4 135º = 13.9983 – 0.0633h + 0.0332h2 _– + 0.0196h3 _{+ 0.0011h}4 180º = 14.0078 + 0.0045h + 0.0629h2 _– + 0.0223h3 _{+ 0.0011h}4 180º 135º 90º 45º 0º 180º 135º 90º 45º 0º 0 14.0 14.0 14.0 14.0 14.0 7 12.1 11.1 9.8 8.7 7.8 1 14.1 13.9 13.8 13.8 13.7 8 11.2 10.1 8.6 7.6 6.6 2 14.1 13.9 13.6 13.4 13.1 9 10.1 9.0 7.4 6.5 5.5 3 14.1 13.7 13.2 12.7 12.2 10 9.0 8.1 6.3 5.5 4.5 4 13.9 13.3 12.6 11.9 11.3 11 8.1 7.3 5.2 4.7 3.7 5 13.5 12.7 11.9 11.0 10.2 12 7.4 7.0 4.5 4.1 3.1 6 12.9 12.0 10.9 9.9 9.0

Fig. 3. Ship’s speed characteristic (example) – speed curves in knots and numerical data

Rys. 3. Charakterystyka prędkościowa statku (przykład) – krzywe prędkości w węzłach i dane liczbowe

Wykres rozrzutu wiele zmiennych względem hf

0º 45º 90º 135º 180º -2 0 2 4 6 8 10 12 14 hf 2 4 6 8 10 12 14 16 [kt]

[kn]

Ships’ ocean route programming

and wind and vessel’s fuel ratios

[

1, 5, 6,

7].

The

combined

effect of

wind and

waves on

ship

comes

down to

change

its speed

in relation

to that

which

ship has by the given

propeller rotation on the

calm

water

(

V

).

Wind pressure

on the

floatage (vessel’s

surface over water) generates

additional

forces

act-ing on ship, which depend on wind’s speed and

wind angle on the bow.

Waving

gives formation to

wave

resistance especially wave’s height and its

angle on the bow

.

In addition,

the cumulative

im-pact

of wind and

wave

is dependent on

the vessel’s

design characteristics,

hull’s form

, the load

condi-tion and

displacement

[2,

3, 8

].

Similarly,

these

weather factors and

ship’s

features affect the

ship’s

fuel factors. In figures 3

and 4

some

examples of

dry bulk vessels’

speed

characteristics

are presented

[6, 7].

Route’s

selection criteria

and limitations

Voyage’s planning takes into account the

crite-ria for the selection of the best route and restrictions

[6, 8, 9, 10, 11, 12].

Criteria:

– Profit

Z = F – K

– K

(t) – K

(t, V

)

where: F – freight,

K

– loading and unloading

costs,

K

– overhead costs of the ship’s owner,

K

–cost of fuel;

– Security;

– The minimum time;

– Fuels

– Voyage’s comfort;

– Keeping the cargo in undamaged condition.

[kt]

Fig. 4. Load ship’s speed characteristic (44 thousand DWT) in V0 % – example

Rys. 4. Charakterystyka prędkościowa statku z ładunkiem (44 tys. DWT) w % prędkości od V0 – przykład

Wind’s angle on the bow Wave’s angle on the bow

Wind’s speed Wp [kn] 0º 45º 90º 135º 180º Wave’s height h [m] 0º 45º 90º 135º 180º 0 100 100 100 100 100 0 100 100 100 100 100 10 98 98 99 100 101 2 95 97 98 99 100 20 95 96 98 101 103 4 85 89 92 94 96 30 91 93 97 102 105 6 70 76 81 84 88 40 86 89 96 103 107 8 55 60 65 69 75 50 80 85 95 104 109 10 40 46 50 54 60 60 74 81 94 105 110 12 30 35 40 44 50 Wave’s height h [m] Wind’s speed Wp [kn] Wave’s height h [m] Wind’s speed Wp [kn] % V0 % V0 % V0

Cumulative wind’s and wave’s coefficients

Wp [kn] h [m] 0º 45º 90º 135º 180º 0 0 100.0 100.0 100.0 100.0 100.0 10 2 93.1 95.1 97.0 99.0 101.0 20 4 80.8 85.4 90.2 94.9 98.9 30 6 63.7 70.7 78.6 85.7 92.4 40 8 47.3 53.4 62.4 71.7 80.3 50 10 32.0 39.1 47.5 56.2 65.4 60 12 22.2 28.4 37.6 46.2 55.0

Bernard Wiśniewski

Limitations:

– separation zones, restricted waters, military

op-erations’zone, piracy, and other.

For company the most important criterion,

which affects the cost of fuel and voyage time, is

the profit’s criterion [6]. For master the most

im-portant criterion is to preserve the safety of the

vessel, cargo and people, which should be included

in the vessel’s speed characteristics. Next, the

master may take into account other criteria.

For the voyage”s planning there is always a

problem how to identify constraints and their

im-portance [8, 9, 11, 12]. An example of such

con-straints may be, e.g. waters threatened by piracy

and terrorism (Fig. 5).

Starting the calculations and determining the

best navigation route an exemplary quality

indica-tor is very often time of transition, which for

opti-mal route reaches a minimum value, i.e.:

T = min {T}

u





where: u – control’s variables;



– collection of

admissible controls set by the control’s limits, and

indirectly by reducing the state’s variables.

Limitations:

N = N

(φ, λ, u, t)

(φ, λ, u, t), the

variables φ, λ, t can be regarded as state’s variables,

and course u as control’s variable.

State’s limitations: land, prohibited waters, areas

of intense wave action, etc.

O

(φ, λ, t) ≤ 0 for i = 1,2,3,…,i

Control’s limits:

O

(φ, λ, t, u) ≤ 0 for j = 1,2,3,…,j

Understanding

O

as the function describing the

j-th constrains of control’s variable.

They depend on the state’s variables and

deter-mine the permissible courses depending, e.g. on

deck flooding, degraded stability’s conditions.

Computational methods

and

instance

of the algorithm

For the calculation and selection of the most

convenient route algorithms using the directed

graph method, isochrone method, and evolutionary

algorithms discussed extensively in the literature

[5, 6, 8, 13, 14, 15, 16, 17, 18] are applied and

pre-sented in the paper in figures 6, 7, 8.

Fig. 6. Exemplary routes’ course set out with the use of directed graphs in OPTY system

Rys. 6. Przykładowy przebieg dróg wytyczonych z zastosowa-niem grafów skierowanych w systemie OPTY [6]

Fig. 5. Recommended shipping corridors in the Gulf of Aden due to threat of piracy and terrorism [Source: BA6609 chart – Anti-piracy planning chart – Red Sea, Gulf of Aden and Arabian Sea, www.icc-ccs.org] [9]

Rys. 5. Zalecane korytarze żeglugowe na Zatoce Adeńskiej z uwagi na zagrożenie aktami piractwa i terroryzmu [źródło: mapa BA6609 – Antipiracy planning chart – Red Sea, Gulf of Aden and Arabian Sea; www.icc-ccs.org] [9]

Ships’ ocean route programming

Fig. 7. Block diagram of searching the minimum-time based on evolutionary algorithms in OPTY system [17]

Rys. 7. Schemat blokowy programu poszukiwania drogi mini-malno-czasowej oparty na algorytmach ewolucyjnych w sys-temie OPTY [17]

Navigation

support systems

on the

example of

SPOS

and

“

Cyclone” program

SPOS

has two functions:

– provides

current

weather information

by

pre-senting

them to the user

in the form of

analyzes

and forecasts

charts

to 216

hours;

– allows ship’s route programming

taking into

account weather data

and

vessel’s

speed

charac-teristic [

4, 5, 7].

CALM SEA SPEED (KNOTS): 13.0 Currents: yes Data files: 990910q.000; 990911q.000; 990912q.000;

990913q.000; 990914q.000 Valid time (h): 11

COEFFICIENT OF FUEL CONSUMPTION: Ko = 0.200 HOURLY FUEL CONSUMPTION FOR AUXILIARIES

(kg/h) = 100

Calculated data for: GRC LOX REC Route [Mm] 3490.50 3565.42 3539.70

Time [h] 278.48 274.18 274.11

Av. Sp. [knots] 12.53 13.00 12.91

Diff. Co. 1. 0.53 0.26 0.34

Great circle fuel consumption: 150.2 tons Loxodromic fuel consumption: 147.9 tons Optimal route fuel consumption: 147.9 tons

Fig. 8. Exemplary calculations’ results with the use of iso-chrone method in OPTY system [6]

Rys. 8. Przykładowe wyniki obliczeń z zastosowaniem metody izochron w systemie OPTY [6]

On

example of the voyage

from Gibraltar

to the

United States

(15–25

September 2010)

on

the

fol-lowing

charts projected weather

situations

on

se-lected

days and

considered ship’s route courses on

Atlantic Ocean are presented (

Figs 9–11).

The

analysis of the

following three

charts

shows that

ship’s route

will be

influenced by

wind and

waves

from two

cyclones

, “Julia”

and

“

Igor” [

5].

In this

situation,

the vessel

uses

recommended

SPOS’s

route

only

to 17

September 2011

and then

uses

another program

associated with

navigation

support

(“Cyclone”) [

19, 20, 21].

“Cyclone” recommends

ship’s route change

from September, 17

_{to the}

more

southern

with passing

“Igor”

cyclone

from the

back quarters (Fig. 12).

Another example of use of the navigation

sup-port system presented in figure 13. is the testing’s

result for voyage from New York to Brazil with

secure cyclone passing with ship’s route and

cy-clone’s path.

START Data entry:

– digital weather data – ship’s speed characteristics

– water’s parameters including prohibited areas – coordinates of the origin and destination

– program’s operating parameters (number of individuals, number of generations, number of individuals subject to crossover, mutation rate)

Create an initial route’s population Shipping time’s calculation on particular routes

i = 1

Crossover operation application on the routes’ population Mutation operations application

on routes’ population

Shipping time’s calculation on particular routes (individual parental) Routes’s selection to new population

i = i + 1 i < number of generations Results’ presentation STOP Yes

Bernard Wiśniewski

Fig. 9. The weather situation in the Atlantic on 15 IX 2010, ship’s position in Gibraltar and the considered routes’ scheme [own work with the use of SPOS]

Rys.9. Sytuacja pogodowa na Atlantyku w dniu 15 IX 2010 r., pozycja statku w Gibraltarze i schemat rozważanych tras [opracowa-nie własne z wykorzysta[opracowa-niem systemu SPOS]

Fig. 10. The weather situation in the Atlantic on 18 IX 2010, projected ship’s positions on the considered routes [own work with the use of SPOS]

Rys. 10. Sytuacja pogodowa na Atlantyku w dniu 18 IX 2010 r., przewidywane pozycje statku na rozważanych trasach [opracowanie własne z wykorzystaniem systemu SPOS]

Ships’ ocean route programming

Fig. 11. The weather situation in the Atlantic on 19 IX 2010, projected ship’s positions on the considered routes [own work with the use of SPOS]

Rys. 11. Sytuacja pogodowa na Atlantyku w dniu 19 IX 2010 r., przewidywane pozycje statku na rozważanych trasach [opracowanie własne z wykorzystaniem systemu SPOS]

Fig. 12. Graphical presentation of the corresponding at the same time projected ship’s – and cyclone’s position and the numerical data

Rys. 12. Graficzne przedstawienie odpowiadających sobie w tym samym czasie przewidywanych pozycji statku i cyklonu oraz dane liczbowe

Bernard Wiśniewski

Fig. 14. An example of the current voyage’s review performed from Europe to North America (Florida) by Pentland strait and a theoretical alternative route through the English Channel Rys. 14. Przykład bieżącej weryfikacji trasy statku realizowa-nej przez cieśninę Pentland z Europy do Ameryki Północrealizowa-nej (Floryda) oraz teoretyczna trasa alternatywna przez Kanał Angielski

Route’s verification and decision-making

Before captain comes to a decision, verifies the

route,

as

graphically

illustrated

in

figure 14

.

Ship

was on the route

from Europe

to North America

(Florida) by Pentland strait

, and captain compared

it

with theoretical

results,

if

pursued

the route

through

the English Channel.

On

the two

sketches

of

the wave’s height distribution in the North

At-lantic

the actual

ship’s

positions

and

alternative

positions

for the voyage’s given day

were plotted.

The final decision on the route’s selection

and implementation takes the master [6, 8, 22, 23].

He discusses four stages of solving the situation

of decision-making:

 defines and adopts the decision-making situation

(conditions in which he operates, measures used,

the factors’ structure, which factors can be

changed and modified and which are not

im-portant and have no value, what kind of

deci-sions is physically acceptable);

 sets out the optimal or quasi-optimal decision

(criteria, methods for models’ solving models:

deterministic or non-deterministic;

 carry out the model’s verification (confrontation

between the model and reality, confirmation,

change or modification of previously accepted

solution);

 works out a control system in the practical

plementation and collects data needed to

im-prove future decisions (solution for today may

not be optimal for tomorrow, e.g. change in

weather forecasting, criterion’s change,

learn-ing’s mechanism change).

Fig. 13. Graphic example of cyclone’s passing with the numerical data in stages to 72 hour

Ships’ ocean route programming

Conclusions

Today ocean voyage can not be carried out only

based on standard navigational aids. Topicality

of the problem is a result of rapid development

of many science’s fields and ocean sailing

require-ments. In recent years, the number of weather

information obtained from ocean areas greatly

increased and forecasting’s reliability is greater.

A rapid ship’s development and means of

commu-nication has made, there is the possibility of using

computer software. On the other hand, the ship

owners concerne about increasing losses caused by

storms, including a large percentage of the vessels’

total loss in excess of 0.2% per year globally. The

owners put their vessels with increasingly higher

performance requirements, such as voyage-time,

loading the boundary stability’s conditions, the

implementation of new navigation routes in the

difficult polar zones.

During the ship’s ocean voyage penetrate each

other navigational issues, weather conditions,

ves-sel’s characteristics as control object, developed

algorithms and methods for determining the most

favorable routes, the captain’s and crew’s

experi-ence and treating the route’s selection process as an

ships’ routes integrated programming system.

Planning and programming of the vessel during

the voyage depend on the used algorithms and

cal-culation’s method, the available data and

special-ized software for decision support systems, e.g.

presented SPOS and “Cyclone” program.

From the experiences of the analyzed ships’

routes comes out that by the full use of available

systems up to ten percent of the time needed to pass

the routes in relation to standard seasonal routes

can be saved.

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