abs mooringspm guide

Spread MooringDescriptionTrelleborg Marine Systems designs and manufactures a range of mooring systems for offshore oil and gas F(P)SO & FSRU facilities.

This document provides information describing the main components that make up a Spread Mooring System installed onboard an F(P)SO.

The mooring system will generally include multiple chain stoppers positioned in the Bow and Stern quarters of the vessel, together with fairleads and chain

Spread Mooring Systems

Product Data Sheet / Reference no. OIM-VMS-04 Ver 1.0

Trelleborg Marine Systems|Takes the pressure off

©Trelleborg AB 2011

Design NoteThe basic design criteria for Spread Mooring hardware recommended by Oil Companies International Marine Forum (OCIMF) and Classification Societies is that the mooring chain should be considered the ”weak link”. Chain stoppers, fairleads and their foundations should be designed to withstand the Breaking Load of the mooring chain.

tensioning facilities.

Other enhancements include integrated Load Monitoring and high load warning systems with central monitoring.

FeaturesComplete system engineering including design and layout of equipment.•

Chain stoppers designed to minimize chain bending and wear.•

Safeguards and optional monitoring to ensure against accidental or inadvertent chain release.•

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©Trelleborg AB 2011Product Data Sheet / Reference no. OIM-VMS-04 Ver 1.0

1 DESIGN

1.1 Compliance with codes and guidelines

Oil Companies International Marine Forum - ”Mooring Equipment Guidelines Revision 3” (OCIMF MEG3).

Class design requirements, DNV, ABS, BV, Lloyds or RINA as applicable.

2 HAZARDOUS AREA COMPLIANCE

2.1 Area classification The equipment will be supplied with certificates for Hazardous Area Zone 1 or Zone 2 compliance as applicable.

3 CHAIN STOPPERS

3.1 Design Criteria

Based on OCIMF MEG3:

Chain stoppers are designed to withstand permanent deformation when loaded to the Minimum Breaking Load of the associated chain.

Maximum stress at the Design Load will not exceed 85% of the yield of the component material.

3.2 Stud Link Chain - Size and Grade Up to 127 mm and Grade R4.

3.3 Jaw Type Chain Stoppers

Vertical or horizontal chain lead with dual jaw and self locking.

This type of stopper is not releasable when under load. Refer to Section 7 for quick release stoppers.

3.4 Quick Release Chain Stoppers

Not covered in this Data Sheet -

Refer to Data Sheet OIM-CSH-02.

3.5 Load Monitoring Chain stoppers may incorporate a load cell for measuring the chain tension. Refer to Section 6 for details.

3.6 Construction Carbon Steel fabrication to ASTM A572 and high strength cast steel to ASTM A148.

3.7 Chain Locking Position Chain stoppers will lock any alternate common link.

3.8 Stopper Jaw Operation

The jaws of the chain stopper are self locking and may be opened manually or optionally hydraulically Jaw ”locked” or ”open” status can be monitored.

Jaws can only be opened when load is taken up by a tensioner unit.

3.9 Installation and Underdeck Stiffening

Bolt down or weld down installation.

The design of the foundation plate and underdeck structure is assumed provided by ”Others” unless specified otherwise.

4 CHAIN CHUTES AND SHEAVES

4.1 Design Criteria Designed in accordance to OCIMF MEG 3 and the relevant Class codes for design load and bending radius where applicable.

4.2 Chain Size Chain to 127 mm diamter.

4.3 Chain Chutes May be manufactured as an integral part of the chain stopper structure.

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4 CHAIN CHUTES AND SHEAVES

4.4 Chain Sheaves - for Chain Tensioning

May be a fixed unit located on the non loaded side of the chain stopper and used to align the chain with a common tensioning winch.

The chain sheave will be of 5 pocket design and may include a wire groove used in case of back up being required.

Unless otherwise specified the Design Load is based on the maximum tensioning capacity of the winch.

4.5 Chain Sheaves - for Mooring

The chain sheave is located on the loaded side of the chain stopper and may be fixed or swiveling type for above or below water application.

The Design Load is based on the Minimum Breaking Load of the chain.

The chain sheave wheel generally has a 7 pocket design with wire rope groove.

4.6 Sheave Lubrication All sheave units have a lubrication facility and those not accessible are provided with remote grease feed facility. Sheave shaft bearings are generally synthetic.

5 CHAIN TENSIONING

5.1 Chain Jacks and Tensioning winches

Chain tensioning for spread mooring applications require either chain jack or a winch to apply the tensioning of the mooring chain. After the chain is tensioned it is secured by the chain stopper.

5.2 Chain Tensioning Jack

Chain jacks may be either individual units mounted behind each chain stopper or a common unit shared between several chain stoppers.

Operational and handling considerations will generally dictate the suitability of using a transferable chain jack.

Features include:

Designed specifically for Trelleborg range of jaw and quick release chain • stoppers.

Tension forces to 200t.•

Stroke length (typically) 2.5 chain links.•

Stroke rate (typically) 0.75m/min.•

Operation by pushbutton or pendant.•

Incorporates load monitoring via a pressure sensor with local readout.•

HPU can be integrally mounted to the chain jack.•

Suitable for Zone 1 or 2 hazardous area where applicable.•

A jack handling system can be provided to suit the deck layout.•

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5 CHAIN TENSIONING

5.3 Chain Tensioning Winch

A tensioning winch may be considered where:

One common winch mounted to the Bow and Stern deck is used to • accommodate Port and Starboard side chains.

Adequate deck space and a clear route is available to run the winch wire to • each stopper.

A common wire rope deflector Sheave (or snatch block) in conjunction with • fixed deck sheaves can be installed to lead the wire to each chain.

Features:

Chain tensioning winches range in capacities to 200t pulling force.•

Fitted with a wire rope spooling system.•

Winch speed (typically) 6m/min.•

Operation by local flow control lever.•

Incorporates load monitoring via a pressure sensor with local readout.•

Suitable for Zone 1 or 2 hazardous area where applicable.•

Hydraulic consumption (typical) 100kW; 60 litres/min; 200 Bar. It may be • a dedicated HPU or hydraulics supplied from vessel’s own system where available.

5.4 Winch SheavesFixed, deflector or snatch block sheaves used to direct the winch wire to the chain have a design load based on the maximum static load capacity of the winch.

6 LOAD MONITORING SYSTEM (OPTIONAL)

6.1 Load Cells

Trelleborg manufactured load cells may be fitted to dual jaw chain stoppers.

Features include:

Redundantly strain gauged load cell.•

Stainless steel construction.•

Calibrated from zero to rated Safe Working Load (SWL).•

Accuracy +/-2% BSL.•

Ingress IP rating 66/68.•

6.2 Local Load Display Unit

Panel mounted display of loads and alarms for multiple chain stoppers.

Refer to Data Sheet LMS-LSMH-03.

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6 LOAD MONITORING SYSTEM

6.3 Central Monitoring System

The Remote Display Unit is generally located within the Cargo Control Room (CCR) to monitor, display and record load and alarm history for each stopper. Unless otherwise specified CCR is assumed a non hazardous area and an air conditioned room.

The Remote Display Unit consists of a 15 inch LCD touch screen workstation suitable for mounting to a 19 inch rack cabinet. Cabinet assumed by ”Others” unless otherwise specified.

Functionality:

Setting load alarm levels High and Very High for each chain stopper.•

Load display and warning.•

Load history and alarm trail recording for each stopper.•

6.4 Load Alarm Station Is an optional deck mounted visible and audible alarm station mounted adjacent to each group of stoppers to provide High and Very High load warnings.

6.5 Hand Held MonitorIs an optional pager sized portable monitor used to receive and display load and alarm information.

Refer Data Sheet DAS-IHDU-04.

6.6 Distributed Control System - Interface

The DCS interface allows transfer of data such as loads and alarms from the Load Monitoring System to the vessel based Distributed Control System (DCS) and is offered as an option.

7 POWER AND CABLE REQUIREMENTS

7.1 Voltage SupplyElectro Hydraulic Power Units require three phase 380 - 440 V 60 Hz.

Local and Remote Display panels require 110 V or 220 60 Hz.

7.2 Ship Wiring - Control Cable

All ship deck run cable are assumed to be supplied by ”Others” unless otherwise specified.

8 TESTING

8.1 Chain Stoppers Each Chain Stopper is load tested to 100% Safe Working Load (SWL).

8.2 Load Cells Each load cell is calibration tested from 0 to 100% SWL. Testing performed under witness of an independent third party or Class representative.

8.3 Chain Chutes and Fairleads

Unless otherwise noted load testing is not performed on chain chutes and fairleads. The verification of structural capacity is by Class approval of the structural calculations.

8.4 Instrumentation The Factory Acceptance Test (FAT) covers the end to end testing of the instrumentation package, system interfaces and software.

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Trelleborg Marine Systems’ commitment to continuous product improvement means that we reserve the right to upgrade and modify equipment and systems without notice as technological and operational parameters demand.

9 QUALITY

9.1 Accreditation Trelleborg Marine Systems Melbourne ISO 9001 2008 by Lloyds Register.

9.2 Material Traceability Structural materials are Class approved and material certificates are supplied with final documentation.

9.3 Inspection and Test Plan (ITP)

Provided with Vendor Post Award documentation package and submitted for client approval.

10 DOCUMENTATION

10.1 Post Award Vendor Technical Package Submitted for Client approval following contract award.

10.2 Manufacturing Data Record (MDR)

Manufacturing Data Record (MDR) provided at completion of the project covering fabrication, mechanical, materials, electrical certifications, NDT and testing.

10.3Installation Operation and Maintenance Manuals

A full set of manuals are provided.

For Further information, please contact:Trelleborg Marine Systems Melbourne Pty LtdVirginia Park, 9 South Drive, 236-262 East Boundary RoadEast Bentleigh, Victoria 3165AustraliaTel: +61 (0) 3 9575 9999, Fax: +61 (0) 3 9575 9900Website: www.trelleborg.com/marineEmail: [email protected]

abs mooringspm guide

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