Rules for Classification and Construction VI Additional Rules and...

Rules for Classification and Construction VI Additional Rules and Guidelines 11 Other Operations

8 Guidelines and Approval Procedure for "In Service Inclining Test Systems" (ISITS)

Edition 2000

The following Guidelines come into force on 1st June, 2000.

The respective latest edition of the "General Terms and Conditions" are applicable (see Rules for Classification and Construction, I – Ship Technology, Part 0 – Classification and Surveys)

Reproduction by printing or photostatic means is only permissible with the consent of Germanischer Lloyd.

Germanischer Lloyd Head Office

Vorsetzen 32, D-20459 Hamburg

Telephone: 0 40/36 14 9-0, Telefax: 0 40/36 14 92 00 Telex: 21 28 28 glhh d, Cables: klassenlloyd hamburg

e-mail: [email protected]

Published by: Germanischer Lloyd Printed by: Gebrüder Braasch, Hamburg

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Table of Contents

Section 1 In Service Inclining Test Systems (ISITS)

A. Application ................................................................................................................................. 1- 1 B. General ....................................................................................................................................... 1- 1 C. Software ..................................................................................................................................... 1- 3 D. Hardware and component parts .................................................................................................. 1- 3 E. User manual ............................................................................................................................... 1- 3 F. Tests ........................................................................................................................................... 1- 4 G. Documents to be Submitted ....................................................................................................... 1- 5

Annex A Log Data Sheet

Annex B Log Initial Test

VI - Part 11 GL

Table of Contents Chapter 8

Section 1

In Service Inclining Test Systems (ISITS)

A. Application

ISITS are computer based ship facilities consisting of a computer (hardware), a computer program (soft-ware) and measuring devices (components), control devices and protocol devices (files, printers) (see Fig. 1.1).

An ISITS serves as an aid in determining the actual G’M at the time the test is carried out.

1. These guidelines are applicable to all ships equipped with an 'In Service Inclining Test System' (ISITS) and classed by Germanischer Lloyd.

2. In conjunction with these guidelines the current editions of the following Rules for Construc-tions and Regulations of Germanischer Lloyd should be complied with:

– Rules for Classification and Construction

– Regulations for the Performance of Type Tests

– Regulations for the Electromagnetic Compati-bility of Electrical Equipment

– Regulations for the Use of Computer and Com-puter Systems

3. Provisions

3.1 The ISITS is a ship specific equipment and the test results are applicable to the ship for which it has been approved, only.

3.2 In case of any modifications implying changes in the used data of the ship and/or changes in any of the parts mentioned in Fig. 1.1, the approval is no longer valid. The ISITS is to be modified in ac-

cordance with these requirements and to be approved accordingly.

3.3 The rules for Heel-Compensating Systems are to be observed. Manual emergency OFF switches and automatic OFF switches of the Heel Compensat-ing System must be working independently of the ISITS in all operating modes.

3.4 A log must be kept (see Annex A) contain-ing the result- printouts and test conditions of the In Service Inclining Tests carried out. The log should be available and is to be presented to the surveyor on request.

3.5 A periodical recalibration test shall be car-ried out to verify the results of the ISITS. These peri-odical intervals shall not exceed five years. The re-port is to be submitted to Germanischer Lloyd Head Office for approval.

B. General

In the present context, the measurement covers the period from starting of the system until output of the protocol.

1. Determination of G'M

1.1 The determined G’M describes the vessel’s actual situation, including all free surface effects. It is calculated on the basis of an inclining experiment procedure, using ship specific input- and measured data.

Fig. 1.1

Computer Hard- & Software

Control Panel

Measuring Devices

Protocol Devices

Control Devices

VI - Part 11 GL 2000

Section 1 In Service Inclining Test Systems (ISITS) Chapter 8Page 1–1

B

1.2 The displacement and the KM value are to be determined on the basis of the draughts measured, taking into account the vessel’s trim as well as hog-ging and sagging.

1.3 Based on the data mentioned under B.1.2 the G’M is to be calculated, using the formula:

G' Mmass [t] distance [m]

tan(angle ) displacement [t]=

⋅° ⋅

where:

mass a defined heeling mass, shifted from one side of the ship to the other,

distance the shifting distance of the mass,

displacement determined on the basis of design data and draughts to be measured,

angle the inclining angle due to shifting of the mass.

1.4 Measurements are to be carried out to both sides; as a result, at least four G’M values are to be obtained.

e.g.: initial/starting position → port side G’M1

port side → starting position G’M2

starting position → starboard side G’M3

starboard side → starting position G’M4

The values obtained are processed automatically; as a matter of principle, the lowest individual G’M-value measured has to be taken for further calculations.

2. Mode of operation

2.1 Tests with such a system have to be auto-mated on a high level. That means without any man-ual interference.

2.2 For the purpose of determine the angle of inclination by separate means during an initial-/re-calibration test, the user should have the possibility to increase the stopping time between the pump phases manually. The minimum stopping time should not be influenced by the user.

2.3 The computer program should stop the test procedure automatically if the inclination of the ves-sel exceeds 5° (PS and SB are to be considered).

3. Operational requirements

3.1 In order to obtain reliable information on the actual G’M, the system is to be designed such that the

vessel can be inclined by an angle of not less than 2° in both directions under the assumptions outlined in B.3.4.

3.2 During the incline, several measurements should be conducted in order to calculate each G’M value.

3.3 The measurement results plus the input data have to be recorded in a protocol (see Annex A).

3.4 The arrangement and installation of the ISITS Control Unit should ensure that the person conducting the measurement, apart from checking the measurements, will be able to observe permanently the vessel’s condition as far as of relevance for the measurements, e.g. her unobstructed mooring at the pier, no loading activities, no tank operations unless required for the measurements.

3.5 The system is to be designed in a way that the automated measurement is carried out within a period of 20 minutes. The G’M to be assumed in order to calculate the time is G’Mreq. + 0,4 m 1 and the displacement is to be assumed according to a draught of 80 % of the draught corresponding to the summer freeboard at level trim.

3.6 The maximum initial heel shall not exceed 0,5°.

4. Accuracy of the measurements

4.1 The measurement of the heeling angle should be performed by at least two independent inclinometers. The measurement error should not exceed ± 0,02° i.e. 1 % of the required heeling angle of 2°.

4.2 The maximum allowed measurement error of automatic draught measurement systems is ± 0,02 m.

4.3 The measurement devices for the heeling moment should guarantee that the total measurement error does not exceed ± 2 % of the heeling moment.

4.4 If the water density is measured automati-cally the accuracy should be of ± 0,0025 t/m3.

C. Software

The software executed for the realisation of an auto-matic In Service Inclining Test is to be type approved according to GL "Regulations for the Use of Com-puter and Computer Systems", Requirement Class 3.

–––––––––––––– 1 G’Mreq taken from the G’M limit curve of the approved

stability booklet.

Chapter 8 Page 1–2

Section 1 In Service Inclining Test Systems (ISITS) VI - Part 11GL 2000

C

1. General

1.1 No other than ship specific, technical or organisational software shall be used on the ISITS hardware.

1.2 The system should be protected against unintentional or unauthorised modification of pro-grams and data.

1.3 Data protection shall include virus protec-tion, if applicable.

1.4 The system should be monitored for correct operation and an audible and visual alarm should be given for any abnormal condition.

2. Error detection and obstruction of the measurement process

2.1 The ISITS should be capable of detecting failure or breakdown of individual components. With a view to this, it may be necessary to ensure redun-dancy of some of the components, such as a.o. incli-nometers.

2.2 Plausibility checks should be run during the whole measurement checking the validity and detect-ing input and calculation errors, e.g.:

– verify plausibility of input data

– total sum of water constant during the run

– check excessive / negative values

– comparing results of redundant components

2.3 On dependence of the kind of error detected, the system should stop the measurement, release a relevant alarm or ask for new data.

D. Hardware and component parts

1. The hardware Type Approval is intended to ensure that the computer or e.g. a SPS- Unit on board is type approved in accordance with GL "Regulations for the Performance of Type Tests" Part 0 and Part 1.

2. In case of ISITS, which control units are generally installed in dry control rooms outside of the machinery spaces, modifications to the above regula-tions as stated in Part 1, Application Category E may be accepted.

3. The certificate, issued by GL after Type Approval, will be valid for 5 years and will be en-tered in GL’s list of "Type Tested Products and Ap-proved Products, Procedures and Manufacturers".

4. In case the Type Approval has already been carried out by another IACS Classification Society the Type Approval tests already successfully per-formed may be accepted by GL, provided that all relevant GL requirements have been considered. This has to be documented.

E. User manual

1. General

1.1 A simple and straightforward instruction manual written in the same language as the stability booklet should be provided. If this language is not English, a translation into English has to be included.

1.2 The user manual is to be submitted to GL.

2. Contents

2.1 Structure, function and dealing of all com-ponents of the ISITS should be outlined in detail.

2.2 The hardware specification.

2.3 Certificates issued for any component.

2.4 Mounting positions of measurement devices.

2.5 Error messages, their meanings and respec-tive measures to be performed.

2.6 Instructions for maintenance.

2.7 Information about components to be recali-brated or replaced periodically.

2.8 Instructions to the master emphasising the need of plausibility checks to be performed.

2.9 Formulas and calculation samples for the guidance of checking the plausibility of the results.

2.10 Detailed guidance for the preparation and performance of a recalibration test and separate means to be used.

2.11 Forms for the ISITS-log and recalibration (samples see Annex A and B).

F. Tests

1. Initial test

1.1 Upon installation of an ISITS and/or upon completion of the vessel the proper working of the



F

global system and its components is to be demon-strated during an initial test in presence of a GL surveyor.

1.2 If an inclining experiment is carried out at the shipyard, this test of the ISITS should be carried out directly before, or directly after the inclining experiment.

1.3 At any rate, the same external conditions as required for an inclining test are required for the initial test.

1.4 During the test the inclining angles, draughts and displaced masses (tank levels) are to be measured by means of additional equipment independent of the stability measurement system (e.g. pendulum, u-tube, inclinometer, etc.).

1.5 The analysis and results of the measure-ments are to be presented in a detailed report to GL for approval.

2. Recalibration test

2.1 The installed components of the measuring system are to be recalibrated at regular intervals in accordance with the respective chapter of the operat-

ing manual and documented in the ISTIS-initial-/re-calibration log (see Annex B). These intervals must not exceed five years. The recalibration test has to be carried out in presence of a GL surveyor

2.2 During the test the inclining angles, draughts and displaced masses are to be measured by means of additional equipment independent of the ISITS.

2.3 If the recalibration test shows that a recali-bration or replacement of single components or the whole system is necessary the instructions of the operation manual are to be followed.

3. In Service Inclining Test

3.1 All In Service Inclining Tests carried out and their results should be documented in an ISITS- log (see Annex A).

3.2 Supplementary thereto, by regular reference readings, the crew has to check the draught gauges for perfect working.

3.3 Plausibility checks should be carried out in accordance to the user manual.



F

G. Documents to be Submitted

Table 1.1

Referring to Chapter

Required documents

Initi

al te

st

Rec

alib

ratio

n

For

the

use

on b

oard

Typ

e A

ppro

val

(har

d- a

nd so

ftw

are)

Protocol according to "In Service Inclining Test System" initial-/ recalibration – log (see Annex B) signed by a GL Surveyor 4 × 4 ×

Exact location were the independent tank measurements were taken. 1 × 1 × Exact location of the measuring devices for tank volumes. 1 × 1 ×

B

Sounding tables for the inclining tanks 1 × 1 ×

Specification of the system (hardware and software) 1 × Software quality assurance plan 1 × Power supply concept 1 × Description of functions, mode of operations, interfaces with other systems

1 ×

List of components 1 ×

D

Test reports with relevant certificates 1 ×

E User manual 1 × 1 × 1 ×

F All stability tests carried out and their results should be documented in an ISITS- log (see Annex A).

1 ×



G



G

Annex A

Log Data Sheet


Annex A Log Data Sheet Chapter 8Page A–1

Chapter 8 Page A–2

Annex A Log Data Sheet VI - Part 11GL 2000

Annex B

Log Initial Test


Annex B Log Initial Test Chapter 8Page B–1

Chapter 8 Page B–2

Annex B Log Initial Test VI - Part 11GL 2000

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