Rev No. Issue Description Prepared Reviewed Approved Date 5 Re-issued for use RGM SS RB 17 Aug 15 4 Changes made to procedure AFI JAL JAL 12 Sep 11 3 Re-issued for use RGM RAM MAJ 19 May 11 2 Re-issued for use RGM RAM MAJ 7 May 10 1 Re-issued for use GKS RGM RGM 25 Aug 09 0 Issued for use GKS RGM RGM 17 Jun 09 File Reference: X:\QHSE\private\F.Marin\Ranald Blair\SOP-003 Gyro Calibration and Verification Procedure.docx Copyright UTEC International Limited, 2014 Unless explicitly stated otherwise, all rights including those in copyright in the content of this document are owned or controlled by UTEC International Limited. Except as otherwise expressly permitted under copyright law or by UTEC International Limited, the content of this document may not be copied, reproduced, republished, downloaded, posted, broadcast or transmitted in any way without the written permission of UTEC International Limited. SOP-003 Rev 5 Page 1 of 13
REVISION HISTORY Rev. Section Revision Description Date 1 Front cover Copyright statement amended and reissued for use 25 Aug 09 2 All Procedure template revised & procedure number changed 7 May 10 2 All Procedure sections reorganised 7 May 10 2 2 Section on responsibilities added 7 May 10 2 3 Section on health and safety added 7 May 10 3 All Document rebranded, no change to content 19 May 11 4 5.8 New section dedicated to the Sun Shot Observation 09 Sep 11 5 All Reviewed as Part of Gap Analysis, Geophysical review and UTEC NCS Merger 17 Aug 15 SOP-003 Rev 5 Page 2 of 13
TABLE OF CONTENTS Page No. 1 INTRODUCTION 4 1.1 Purpose 4 1.2 Scope 4 1.3 Definitions and Abbreviations 4 2 RESPONSIBILITIES 5 2.1 Chief Surveyor 5 2.2 QHSE Manager 5 2.3 Project Manager 5 2.4 Party Chief or UTEC Senior Site Representative 5 2.5 Survey Engineer/ Online Surveyor 6 2.6 Survey Team 6 3 HEALTH AND SAFETY 7 4 GYRO COMPASS BACKGROUND 8 5 INSTALLATION AND CALIBRATION 9 5.1 Installation 9 5.2 Gyro Calibration and Verification Schedule 9 5.3 Gyro Calibration by Taped Offset Measurement 9 5.4 Gyro Calibration by Comparison with a GNSS Compass 10 5.5 Gyro Calibration by Total Station to Vessel Centre Line 10 5.6 Calibration for Structures by Dimensional Control 10 5.7 Gyro Calibration by Sun Shot Observation with a Theodolite 10 6 FIELD OPERATIONS 12 7 REPORTING 13 SOP-003 Rev 5 Page 3 of 13
1 INTRODUCTION 1.1 Purpose The purpose of this procedure is to detail the processes and responsibilities for the calibration and verification of various types of Gyro so as ensure they are operating correctly and to manufacturer specification. It is intended to ensure UTEC employ industry best practice and meet customer expectations. 1.2 Scope The procedure is to be followed by all UTEC personnel. It includes the types of Gyros used by UTEC, their accuracies, the approved calbration and verification methods, and the required records and reports. 1.3 Definitions and Abbreviations Azimuth : a direction on the ellipsoid Bearing : a direction on a grid or map projection C-O : Calculated minus Observed CM : Central Meridian CRP : Common Reference Point GNSS : Global Navigation Satellite System DGNSS : Differential Global Navigation Satellite System FOG : Fiber Optic Gyro G : Grid Bearing GPS : Global Positioning System QC : Quality Control RLG : Ring Laser Gyro RO : Reference Object ROV : Remotely Operated Vehicle T : True Bearing UPS : Uninterrupted Power Supply VRF : Vessel Reference Frame SOP-003 Rev 5 Page 4 of 13
2 RESPONSIBILITIES 2.1 Chief Surveyor The Chief Surveyor is responsible for: Ensuring the Gyro Procedure is based on industry best practice and that the content of the procedure is regularly reviewed and revised where necessary, when improvements in technology or practice are identified; and, 2.2 QHSE Manager The QHSE Manager is responsible for: Ensuring that the Gyro Procedure is adequately controlled with regards to review, revision and approval, and that the relevant version is available at the point of use. 2.3 Project Manager The Project Manager is responsible for: Ensuring that the Survey Team includes personnel competent to carry out the tasks involved in using gyro compasses. Ensuring that all project personnel are aware of their responsibilities with regards to the Gyro Procedure; Ensure that valid suppliers calibration certificates exist for all survey grade gyros and measurement equipment used to determine navigation system C-O corrections; Ensure that calibration certificates will remain in effect for the duration of the project, or until a scheduled system performance re-verification is called for by the schedule; and, Ensuring that any hazards associated with the tasks involved are adequately risk assessed and that project personnel are made aware of these hazards. 2.4 Party Chief or UTEC Senior Site Representative The Party Chief or UTEC Senior Site Representative is responsible for: Ensuring that the Survey Team follow the requirements of the Gyro Procedure during operations; Advising the Project Manager when any deviations from the procedure is felt necessary due to changes in operational method, procedural inadequacy or change in project specific requirements; Review, verification and approval of the Gyro data and calibrations; and, Ensuring that any hazards associated with the tasks involved are adequately risk assessed and that project personnel are made aware of these hazards. SOP-003 Rev 5 Page 5 of 13
2.5 Survey Engineer/ Online Surveyor The Survey Engineer is responsible for: Ensuring that equipment is installed, tested and maintained in accordance with this procedure; Installation and set-up of gyro compasses; Acquisition and processing of data to carry out calibrations, provide heading information and ensure its correct application within the navigation software; and, Recording installation checks and results from operations in the appropriate logs. 2.6 Survey Team All members of the Survey Team are responsible for: Ensuring that they follow the requirements of the Gyro Procedure during operations; and, Ensuring that they comply with all controls in place to protect the health and safety of themselves and others. SOP-003 Rev 5 Page 6 of 13
3 HEALTH AND SAFETY Installation, testing, maintenance and operation of Gyro equipment are potentially hazardous activities. Prior to commencement of these activities a risk assessment shall have taken place to ensure that all hazards have been identified, the associated risk assessed and that all personnel are aware of the necessary control measures. SOP-003 Rev 5 Page 7 of 13
4 GYRO COMPASS BACKGROUND A gyrocompass system provides the means for determining the heading of a vessel, ROV or structure referenced to True north. Before a gyrocompass can be used operationally it is necessary to carry out a calibration of the system to ensure that it is operating within manufacturer s specifications. The calibration of a gyrocompass is required when a new system is installed on a vessel/rov so as to align the gyrocompass reference to the centreline of the vessel. These procedures are also required periodically to determine any long-term drift of the heading reference or alterations to the physical alignment of the gyrocompass. The types of heading determination equipment which may be used on offshore projects include: Mechanical Gyrocompass Systems; GPS Gyrocompass Systems; Fibre Optic Gyrocompass Systems; and, Ring Laser Gyro Systems. The table below details the nominal accuracy of different types of gyro and the accuracy of the standard against which each type is to be checked. Heading Reference System System Accuracy Accuracy of Standard Gyrocompass Systems +/-0.1 secant lat 0.1 Fibre Optic Gyrocompass +/- 0.7 secant lat 0.1 GNSS Compass +/- 0.1 0.02 Ring Laser Gyro <0.05 secant lat <0.005 Table 1 Heading Reference System Accuracies With the exception of GPS Gyros, gyros output bearings relative to True North. To obtain bearings relative to Grid North convergence must be applied. True Bearing = Grid Bearing+ Convergence SOP-003 Rev 5 Page 8 of 13
5 INSTALLATION AND CALIBRATION 5.1 Installation A Gyro must be installed by suitably trained and qualified personnel as per the manufacturer s recommendations and in accordance with UTEC work instruction Gyro Installation. 5.2 Gyro Calibration and Verification Schedule The typical instances and time schedules when calibration or verification is required for the various heading reference systems is given below in Error! Reference source not found.. Heading Reference System New Installation New Project Ongoing Projects Magnetic Fluxgate Compass Always Always Client Specified Gyrocompass Systems (e.g. TSS Meridian) Fibre Optic Gyrocompass (e.g. Octans) GPS Gyrocompass RLG Table 2 Always Always Quarterly Always Always Quarterly Always Always Not required unless specified by client Not required unless specified by client Calibration Schedule Annually Annually Where more than one heading reference is available, the two should be continuously compared and monitored within the navigation software. Differences larger than the quoted accuracy of the instruments should be investigated and resolved. If necessary operations must be halted until the difference is satisfactorily resolved. 5.3 Gyro Calibration by Taped Offset Measurement This is a standard calibration/verification procedure which may be used for gyros installed on a vessel or ROV. This calibration is carried out whilst the vessel is alongside a quay of known heading. This method provides a reference heading with a level of precision of the order of 0.2 to 0.3. A gyro calibration by taped offset measurement must be carried out by suitably trained and qualified personnel as per the manufacturer s recommendations and in accordance with UTEC work instruction Gyro Calibration by Taped Offset Measurement. SOP-003 Rev 5 Page 9 of 13
5.4 Gyro Calibration by Comparison with a GNSS Compass This is a standard calibration/verification procedure which may be used for gyros installed on a Vessel. This calibration may be carried out whilst the vessel is alongside or offshore. This method provides a reference heading with a high level of precision <0.1 the actual precision will depend on the system used and distance between the two GNSS antennae. A gyro calibration by comparison with a GNSS Compass must be carried out by suitably trained and qualified personnel as per the manufacturer s recommendations and in accordance with UTEC work instruction Gyro Calibration by Comparison with a GNSS Compass. 5.5 Gyro Calibration by Total Station to Vessel Centre Line This is a standard calibration /verification procedure which may be used for gyros installed on a Vessel. This calibration is carried out whilst the vessel is alongside. This method provides a reference heading with a high level of precision <0.1 the actual precision will depend on the stability of the platform A gyro calibration by total station to vessel centreline must be carried out by suitably trained and qualified personnel as per the manufacturer s recommendations and in accordance with UTEC work instruction Gyro Calibration by Total Station to Vessel Centre Line. 5.6 Calibration for Structures by Dimensional Control This is a standard calibration /verification procedure which may be used for gyros installed on a structure. It requires two points of known coordinate and a Total Station. This calibration is usually carried out in the yard prior to load out. This method provides a reference heading with a high level of precision <0.1. A gyro calibration for structures by dimensional control must be carried out by suitably trained and qualified personnel as per the manufacturer s recommendations and in accordance with UTEC work instruction Gyro Calibration for Structures by Dimensional Control. 5.7 Gyro Calibration by Sun Shot Observation with a Theodolite This is a standard calibration/verification procedure which may be used for gyros installed on a Vessel or fixed installations. This calibration maybe carried out whilst the vessel is alongside or offshore. This method provides a reference heading with a high level of precision <0.1 the actual precision will depend on the stability of the platform and the accuracy of the time standard used. SOP-003 Rev 5 Page 10 of 13
A gyro calibration by sun shot observation with a theodolite must be carried out by suitably trained and qualified personnel as per the manufacturer s recommendations and in accordance with UTEC work instruction Gyro Calibration by Sun Shot Observation with a Theodolite. SOP-003 Rev 5 Page 11 of 13
6 FIELD OPERATIONS All individual equipment operating work/safety instructions and manufacturer s equipment manuals are to be available. Prior to operations starting, personnel are to ensure that where applicable the correct speed and latitude is set for the work site. The appropriate corrections must be applied within the navigation software. Heading information must be monitored during operations to ensure continued quality of the data. Any logged data should clearly define whether the bearings are Grid (G) or True (T). The UTEC standard is to report Grid headings. SOP-003 Rev 5 Page 12 of 13
7 REPORTING Reporting requirements will typically be defined in the Project Plan. Specific reporting requirements can relate to: Mobilisation Procedure; For manual logging and calculations use MSF-049 Gyro Calibration Record; and, MSF-077 Final Report. SOP-003 Rev 5 Page 13 of 13