Ships and marine technology -- Measurement of changes in hull and propeller performance

ISO 19030-1:2016 outlines general principles for the measurement of changes in hull and propeller performance and defines a set of performance indicators for hull and propeller maintenance, repair and retrofit activities. The general principles outlined and performance indicators defined are applicable to all ship types driven by conventional fixed pitch propellers, where the objective is to compare the hull and propeller performance of the same ship to itself over time. NOTE Support for additional configurations (e.g. variable pitch propellers) will, if justified, be included in later revisions of this document.

Navires et technologie maritime -- Mesurage de la variation de performance de la coque et de l'hélice

General Information

Status
Published
Publication Date
15-Nov-2016
Current Stage
9020 - International Standard under periodical review
Start Date
15-Oct-2021
Ref Project

Buy Standard

Standard
ISO 19030-1:2016 - Ships and marine technology -- Measurement of changes in hull and propeller performance
English language
30 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 19030-1
First edition
2016-11-15
Ships and marine technology —
Measurement of changes in hull and
propeller performance —
Part 1:
General principles
Navires et technologie maritime — Mesurage de la variation de
performance de la coque et de l’hélice —
Partie 1: Principes généraux
Reference number
ISO 19030-1:2016(E)
ISO 2016
---------------------- Page: 1 ----------------------
ISO 19030-1:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 19030-1:2016(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 General principles ............................................................................................................................................................................................... 2

4.1 Hull and propeller performance .............................................................................................................................................. 2

4.2 Ship propulsion efficiency and total resistance .......................................................................................................... 3

4.3 Primary parameters when measuring changes in hull and propeller performance .................. 4

4.4 Secondary parameters ..................................................................................................................................................................... 5

4.5 Measurement procedures.............................................................................................................................................................. 5

4.5.1 General...................................................................................................................................................................................... 5

4.5.2 Data acquisition ................................................................................................................................................................ 6

4.5.3 Data storage ......................................................................................................................................................................... 6

4.5.4 Data preparation .............................................................................................................................................................. 6

5 Performance indicators ................................................................................................................................................................................ 6

5.1 Dry-docking performance: Change in hull and propeller performance following

present out-docking as compared with the average from previous out-dockings ....................... 7

5.2 In-service performance: The average change in hull and propeller performance

over the period following out-docking to the end of the dry-docking interval ............................... 8

5.3 Maintenance trigger: Change in hull and propeller performance from the start of

the dry-docking interval to a moving average at any chosen time ............................................................. 9

5.4 Maintenance effect: Change in hull and propeller performance measured before

and after a maintenance event ...............................................................................................................................................10

6 Measurement uncertainties and the accuracy of the performance indicators ................................11

Annex A (informative) Method and assumptions for estimating the uncertainty of a

performance analyses process ............................................................................................................................................................13

Bibliography .............................................................................................................................................................................................................................30

© ISO 2016 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 19030-1:2016(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,

as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the

Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.

The committee responsible for this document is ISO/TC 8, Ships and marine technology, Subcommittee

SC 2, Marine environment protection.
A list of all parts in the ISO 19030 series can be found on the ISO website.
iv © ISO 2016 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 19030-1:2016(E)
Introduction

Hull and propeller performance refers to the relationship between the condition of a ship’s underwater

hull and propeller and the power required to move the ship through water at a given speed. Measurement

of changes in ship specific hull and propeller performance over time makes it possible to indicate the

impact of hull and propeller maintenance, repair and retrofit activities on the overall energy efficiency

of the ship in question.

The aim of the ISO 19030 series is to prescribe practical methods for measuring changes in ship specific

hull and propeller performance and to define a set of relevant performance indicators for hull and

propeller maintenance, repair and retrofit activities. The methods are not intended for comparing the

performance of ships of different types and sizes (including sister ships) nor to be used in a regulatory

framework.
The ISO 19030 series consists of three parts.

— ISO 19030-1 outlines general principles for how to measure changes in hull and propeller performance

and defines a set of performance indicators for hull and propeller maintenance, repair and retrofit

activities.

— ISO 19030-2 defines the default method for measuring changes in hull and propeller performance

and for calculating the performance indicators. It also provides guidance on the expected accuracy

of each performance indicator.

— ISO 19030-3 outlines alternatives to the default method. Some will result in lower overall accuracy

but increase applicability of the standard. Others may result in same or higher overall accuracy but

include elements which are not yet broadly used in commercial shipping.

The general principles outlined, and methods defined, in the ISO 19030 series are based on

measurement equipment, information, procedures and methodologies which are generally available

and internationally recognized.
© ISO 2016 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 19030-1:2016(E)
Ships and marine technology — Measurement of changes
in hull and propeller performance —
Part 1:
General principles
1 Scope

This document outlines general principles for the measurement of changes in hull and propeller

performance and defines a set of performance indicators for hull and propeller maintenance, repair and

retrofit activities.

The general principles outlined and performance indicators defined are applicable to all ship types

driven by conventional fixed pitch propellers, where the objective is to compare the hull and propeller

performance of the same ship to itself over time.

NOTE Support for additional configurations (e.g. variable pitch propellers) will, if justified, be included in

later revisions of this document.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
hull and propeller performance

relationship between the condition of a ship’s underwater hull and propeller and the power required to

move the ship through water at a given speed
3.2
delivered power
power delivered to the propeller (propeller power)
3.3
speed through the water

ship’s speed through water for a given set of service (environmental) and loading (displacement/trim)

conditions
© ISO 2016 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 19030-1:2016(E)
3.4
accuracy

described by trueness and precision, where trueness refers to the closeness of the mean of the

measurement results to the actual (true) value and precision refers to the closeness of agreement

within individual results
Note 1 to entry: See ISO 5725-1:1994, 3.6 and Introduction 0.1.
3.5
uncertainty

probability that the measurement of a quantity is within the specified accuracy to that quantity’s actual

(true) value
3.6
filtering
method of removing unwanted data
3.7
normalization

refers to the creation of shifted and scaled versions of statistics, where the intention is that these

normalized values allow the comparison of corresponding normalized values in a way that eliminates

the effects of specific influences
3.8
performance indicators
PIs
used to evaluate the effectiveness of, or to trigger, a particular activity
3.9
dry-docking

bringing the ship onto dry land to maintain, repair and/or retrofit the parts of the hull that are

submerged while the ship is in service
3.10
out-docking
period immediately following a dry-docking
3.11
dry-docking interval
period between two consecutive dry-dockings
4 General principles
4.1 Hull and propeller performance

Hull and propeller performance refers to the relationship between the condition of a ship’s underwater

hull and propeller and the power required to move the ship through water at a given speed. Hull and

propeller performance is related to variations in power, because ship hull resistance and propeller

efficiency are not directly measurable quantities.
2 © ISO 2016 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 19030-1:2016(E)
4.2 Ship propulsion efficiency and total resistance

Hull and propeller performance is closely linked to the concepts of ship propulsion efficiency and ship

resistance. The performance model is based on the relation between the delivered power and the total

resistance where delivered power, P , can be expressed as Formula (1):
RV×
P = (1)
where
R is the total in-service resistance (N);
V is the ship speed through water (m/s);
η is the quasi-propulsive efficiency (-).

The total resistance consists of several resistance parts and can be written as Formula (2):

RR=+ RR++ R (2)
TSWAAAWAH
where
R is the still-water resistance (N);
R is the added resistance due to wind (N);
R is the added resistance due to waves (N);

R is the added resistance due to changes in hull condition (fouling, mechanical damages, bulging,

paint film blistering, paint detachment, etc.), (N).

Likewise, the quasi-propulsive efficiency consists of different efficiency components expressed as

Formula (3):
ηη= ηη (3)
Q0 HR
where
η is the open-water propeller efficiency;
η is the hull efficiency;
η is the relative rotative efficiency.

The added resistance due to changes in hull condition can be expressed as Formula (4):

P ×η
R = −+()RR +R (4)
AH SW AA AW
© ISO 2016 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO 19030-1:2016(E)
where
V is the ship speed through water, can be measured directly;

P is the delivered power, must be approximated – for example based on calculations of shaft

power;

P is from measurements of shaft torque and shaft revolutions or, alternatively, from calculations

of brake power;

P is from SFOC reference curves, measurements of fuel flow and temperature and data on calo-

rific value, density and density change rate for the fuel being consumed.

Variations in the delivered power required to move the ship through water at a given speed, and the

same environmental conditions and operational profile, are due to changes in the underwater hull

resistance and/or propeller efficiency. Changes in underwater hull resistance are due to alterations in

the condition of the hull. Changes in the propeller efficiency are due to both alterations in the condition

of the propeller and to modifications to the flow of water to the propeller (the hull wake) as consequence

of alterations to the hull condition.

For a vessel in service, both environmental conditions and operational profile (e.g. speed, loading, trim)

vary. In order to measure changes in the speed-power relationship for a vessel in service, it is necessary

to compare two periods (a reference period and an evaluation period) where the environmental

conditions and the operational profile are adequately comparable (filter the observed data) and/or

apply corrections (normalize the observed data).

There are a number of alternative procedures for filtering and normalizing observed data. These

procedures each have advantages and disadvantages in terms of the resulting accuracy of the

measurements. This document prescribes a practical blend of filtering and normalization procedures

found to yield sufficient accuracy.

NOTE The relative importance of the different resistance components varies to certain degree with

the operational and environmental condition the vessel is exposed to. Also, the accuracy of the models to

correct/normalize for such variations depends on the operational and environmental conditions. These

dependencies impact the accuracy of the hull and propeller performance indicators as described in the current

standard. Therefore, in the estimation of the accuracy of the performance indicators and for the intended use

comparable operational and environmental conditions over the reference and evaluation period (see Annex A)

are assumed. Future revisions of this document will re-evaluate if more accurate correction formulae are

available that take the above mentioned dependencies into consideration.

Hull and propeller maintenance, repair and retrofit activities have an effect on the energy efficiency

of a ship in service. An indication of these effects can be obtained by measurement of changes in the

delivered power required to move the ship through water at a given speed between two periods for

which the environmental conditions and operational profiles have been made adequately comparable

through filtering and/or normalization of the observed data.
4.3 Primary parameters when measuring changes in hull and propeller performance

The above definition gives ship’s speed through the water and delivered power as the two primary

parameters when measuring changes in hull and propeller performance.

NOTE If hull performance is to be separated from propeller efficiency, propeller thrust would also have to be

measured.

For these parameters, different measurement approaches, and for each approach, different sensors with

different signal qualities are available. In ISO 19030-2, default measurement approaches and associated

“minimum required” signal quality values are specified.

If sensors with the minimum required signal quality are not available, alternative measurement

approaches can be used, but they introduce additional uncertainty. In ISO 19030-3, alternative

4 © ISO 2016 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 19030-1:2016(E)

measurement procedures are described. For each alternative, the minimum required signal quality is

specified together with an estimation of the additional uncertainty introduced.
4.4 Secondary parameters

In order to apply the filtering and normalization procedures necessary to make the reference period

and evaluation period adequately comparable, measurements of both the environmental conditions

and the ship’s operational profile are required. Relevant environmental factors are as follows:

— wind speed and direction;
— significant wave height, direction and spectrum;
— swell height, direction and spectrum;
— water depth;
— water temperature and density.
Relevant operational factors are as follows:
— speed;
— loading conditions (static draught, static trim, heel);
— dynamic floating conditions (motions, dynamic draught, dynamic trim);
— rudder angle / frequency of rudder movements.

If reliable sensor signals are not available for all parameters, either signals from alternative sensors can

be used to approximate and/or for practical purposes one must assume their effects “average out over

time”. Using alternative sensors or relying on an equal distribution assumption introduces additional

uncertainty.

In ISO 19030-2, a “minimum set” of sensor signals and the “minimum required” signal quality for each

sensor are specified for the default method for measuring changes in hull and propeller performance.

In ISO 19030-3, alternative sets of sensor signals and “minimum required” signal quality are defined,

together with estimations of their effect on the expected accuracy of the performance indicators.

4.5 Measurement procedures
4.5.1 General

There are three basic procedural steps involved when measuring changes in hull and propeller

performance. Figure 1 summarizes these three steps.

Figure 1 — Procedural steps when measuring changes in hull and propeller performance

© ISO 2016 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO 19030-1:2016(E)

The accuracy of a measurement is determined by both its trueness and its precision (see ISO 5725).

Trueness refers to the closeness of the mean of the measurement results to the actual (true) value.

Precision refers to the closeness of agreement within individual results and is a function of both

repeatability and reproducibility. Reproducibility refers to the variation arising using the same

measurement process among different instruments and operators, and over longer time periods.

Measurement procedures have a considerable impact on the reproducibility of, and therefore on the

accuracy of, the performance indicators.

NOTE The procedural steps do not have to be conducted in the above sequence. For example, some

preparation of the data can be done as a part of data acquisition.
4.5.2 Data acquisition

Data acquisition refers to the systematic process of recording (manually and/or automatically)

signals/data from the relevant sensors, equipment installed on the vessel and external information

providers. Manual data collection is typically performed once every day (noon data). Generally,

automated data collection occurs at a much higher frequency.
4.5.3 Data storage

Data storage refers to the saving and retention of collected data in a suitable format. This process

should allow previously stored data to be kept together with new data, and ordering it in a sequence so

that it is easy to retrieve when required.
4.5.4 Data preparation

Data preparation includes extracting, compiling, screening and validating the data to give it a structure,

format and quality suitable for further processing. A set of non-dimensional performance values,

that reflect the changes in the hull and propeller performance over the given period of time, are then

calculated. Different sub-sets of the performance values are used to calculate the various performance

indicators. Data preparation can be partially or fully automated.

Practical approaches to data acquisition, data storage and data preparation that yields a high expected

accuracy is defined in ISO 19030-2, the default method for measuring changes in hull and propeller

performance.

In ISO 19030-3, alternatives to the measurement procedures are defined and the impacts on the

expected accuracy of the performance indicators are described.
5 Performance indicators

Measurements of ship specific changes in hull and propeller performance can be used in a number of

relevant performance indicators to determine the effectiveness of hull and propeller maintenance,

repair and retrofit activities. Table 1 outlines four basic hull and propeller performance indicators.

6 © ISO 2016 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 19030-1:2016(E)
Table 1 — Basic hull and propeller performance indicators (PIs)
Performance indicator Definition
Dry-docking performance: Change in hull and propeller performance following
present out-docking (evaluation period) as compared
Determining the effectiveness of the dry-docking (re-
with the average from previous out-dockings (refer-
pair and/or retrofit activities)
ence periods).
In-service performance: The average change in hull and propeller performance
from a period following out-docking (Reference peri-
Determine the effectiveness of the underwater hull
od) to the end of the dry-docking interval (evaluation
and propeller solution (including any maintenance
period).
activities that have occurred over the course of the full
dry-docking interval)
Maintenance trigger: Change in hull and propeller performance from the
start of the dry-docking interval (Reference period)
Trigger underwater hull and propeller maintenance,
to a moving average at any chosen time (evaluation
including propeller and/or hull inspection
period).
Maintenance effect: Change in hull and propeller performance measured
before (Reference period) and after (evaluation peri-
Determine the effectiveness of a specific maintenance
od) a maintenance event.
event, including any propeller and/or hull cleaning
5.1 Dry-docking performance: Change in hull and propeller performance following
present out-docking as compared with the average from previous out-dockings

The change in hull and propeller performance following present out-docking as compared with the

average from previous out-dockings (where data/measurements are available) is useful for determining

the effectiveness of the dry-docking.
Key
H hull and propeller performance
t time
DDn present dry-docking
DDn+1 next dry-docking
DDI dry-docking interval

R reference period: average hull and propeller performance following previous out-dockings

E evaluation period: hull and propeller performance following present out-docking

PI-1 performance indicator 1: dry-docking performance
Figure 2 — Dry docking performance
© ISO 2016 – All rights reserved 7
---------------------- Page: 12 ----------------------
ISO 19030-1:2016(E)

During a dry-docking, the propeller(s) are typically cleaned, polished and/or repaired and the

underwater hull is typically cleaned, spot or fully blasted, repaired and re-coated. In addition, retrofits

may be undertaken to improve the performance of the hull, propeller or both.

It is not possible to accurately isolate individual effects (for example impact of differences in level or

quality of pre-treatment, quality of application or surface characteristics of paint). But, if only a sub-

set of effects are expected to differ between the dry-dockings and everything else can reasonably be

assumed to be the same, the performance indicator can serve as an indicator for this sub-set of effects.

The procedures for calculating this performance indicator are provided in ISO 19030-2 and ISO 19030-3.

NOTE Damage to, and deformation of, the hull occurring during the dry-docking, for example, bulging

caused by improper placement of supporting blocks, will affect measured hull and propeller performance and,

unless accounted for, is a source of uncertainty in this performance indicator.
5.2 In-service performance: The average change in hull and propeller performance
over the period following out-docking to the end of the dry-docking interval

The average change in measured hull and propeller performance over the period from the out-docking

to the end of the dry docking interval can be used to determine the effectiveness of the underwater hull

and propeller solutions including hull coatings used and any maintenance activities that have occurred

over the course of the dry-docking interval.
8 © ISO 2016 – All rights reserved
---------------------- Page: 13 ----------------------
ISO 19030-1:2016(E)
Key
H hull and propeller performance
t time

DDn present dry-docking (or in the case of a new ship, date of entry into service)

DDn+1 next dry-docking
DDI dry-docking interval
R reference period: hull and propeller performance following present out-docking

E evaluation period: avg. hull and propeller performance over remainder of dry-docking interval

PI-2 performance indicator 2: in-service performance
Figure 3 — In-service performance

The procedures for calculating this performance indicator are provided in ISO 19030-2 and ISO 19030-3.

NOTE 1 Damage to, and deformation of, the hull occurring during the dry-docking, for example bulging caused

by improper placement of supporting blocks, will affect measured hull and propeller performance and, unless

accounted for, is a source of uncertainty in this performance indicator.

NOTE 2 Fouling of the propeller(s) (and / or tip damage) can have a significant influence on hull and propeller

performance. If an indication of the change in hull performance is required in isolation, it is necessary that the

propeller(s) be clean and un-damaged during both reference and evaluation periods.

5.3 Maintenance trigger: Change in hull and propeller performance from the start of

the dry-docking interval to a moving average at any chosen time

The measured change in hull and propeller performance from the start of the dry-docking interval to a

moving average at a chosen time during the same interval can be used as a trigger for underwater hull

and propeller maintenance, including propeller and/or hull cleaning.
© ISO 2016 – All rights reserved 9
---------------------- Page: 14 ----------------------
ISO 19030-1:2016(E)
Key
H hull and propeller performance
t time

DDn present dry-docking (or in the case of a new ship, date of entry into service)

DDn+1 next dry-docking
DDI dry-docking interval
R reference period: hull and propeller performance following present out-docking

E evaluation period: moving average hull and propeller performance at any chosen time

PI-3 performance indicator 3: maintenance trigger
Figure 4 — Maintenance trigger

The procedures for calculating this performance indicator are provided in ISO 19030-2 and ISO 19030-3.

5.4 Maintenance effect: Change in hull and propeller performance measured before
and after a maintenance event

The change in hull and propeller performance measured before and after a maintenance event can

be used to dete
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.