engineering guidelinesengineering standards and guidelines for maritime structures

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NSW MARITIME

ENGINEERING STANDARDS AND GUIDELINES FOR MARITIME STRUCTURES

COPYRIGHT © NSW Maritime This Document is copyright. No part of this Document may be reproduced or copied in any form or by any means, electronic or mechanical, including photocopying, without the written permission of the Chief Executive, NSW Maritime. Published by NSW Maritime, Locked Bag 5100 Camperdown NSW 1450. All enquiries to be addressed to the Chief Executive, NSW Maritime.

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Engineering Standards & Guidelines NSW Maritime For Maritime Structures _____________________________________________________________________________________________

DISCLAIMER

Every effort has been made and all reasonable care taken to ensure the accuracy of the material contained within this Document. However, the Waterways Authority trading as NSW Maritime does not accept any liability or responsibility in any way whatsoever and expressly disclaims any liability or responsibility for any loss, damage or costs howsoever incurred by any person as a result of or in connection with reliance upon any part of this Document. Where required, independent advice from competent professional persons should be sought on matters covered in this Document.

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CONTENTS Page SECTION 1 SCOPE AND GENERAL 1.1 General 5 1.2 Reference Documents 5 1.3 Notations 5 1.4 Definitions 6 SECTION 2 SITE INVESTIGATION 2.1 General 11 2.2 Survey 11 2.3 Geotechnical 11 2.4 Existing Structures 12 2.5 Assessment 12 SECTION 3 DESIGN REQUIREMENTS 3.1 General 13 3.2 Australian Standards 13 3.3 Stability 14 3.4 Strength 14 3.5 Serviceability 14 3.6 Durability 14 3.7 Redundancy 15 3.8 Design Life 15 3.9 Scour and Siltation 15 3.10 Sea Level Rise 15 3.11 Disability Requirements 16 3.12 Risk 16 3.13 Health and Safety 16 SECTION 4 DESIGN ACTIONS 4.1 General 17 4.2 Imposed Actions 17 SECTION 5 TYPES OF CONSTRUCTION 5.1 General 21 5.2 Marinas 21 5.3 Wharves, Jetties and Boardwalks 21 5.4 Piles 21 5.5 Ramps 22 5.6 Handrails 22 5.7 Pontoons 21 5.8 Fenders 23 5.9 Boat Ramps 23 5.10 Boatsheds 24

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5.11 Seawalls 24 5.12 Ladders 24 5.13 Davits and Winches 24 5.14 Stormwater Drains 25 5.15 Slipways 25 5.16 Skids 25 5.17 Embankments 25 5.18 Stairs and Steps 26 5.19 Lifebuoys 26 5.20 Demolition 26 SECTION 6 MATERIALS 6.1 General 27 6.2 Concrete 27 6.3 Steel 29 6.4 Timber 30 SECTION 7 MAINTENANCE 7.1 General 32 7.2 Inspections 32

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Engineering Standards & Guidelines NSW MaritimeFor Maritime Structures _____________________________________________________________________________________________

SECTION 1 SCOPE AND GENERAL

1.1 GENERAL

This Document sets out minimum engineering standards for maritime structures proposed to be constructed on the NSW Maritime Authority’s land.

1.2 REFERENCE DOCUMENTS

The following are recommended as useful reference documents.

1.2.1 Design Guidelines for Wharves and Jetties – NSW Public Works 1990

Advice is provided for the planning, investigation, assessment, design, construction and maintenance of public wharves and jetties. Guidance is given on pile design and calculating berthing forces.

1.2.2 Marina Guidelines – NSW Public Works 1987

Guidance is given on approval processes, site investigation, design loads, planning, design, materials, safety aspects, services, boat launching ramps and maintenance of marinas.

1.2.3 Boat Launching Ramps – Guidelines – NSW Public Works Department 1985

Advice is provided for the design and construction of trailer-boat launching facilities. Guidance is given on planning, geometry, materials and design of boat ramps.

1.2.4 British Standard Code of Practice for Maritime Structures – BS6349

Advice and guidance are given on the planning, design, construction and maintenance of maritime structures.

1.3 NOTATIONS

CDChart Datum.

DWT

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Dead Weight Tonnage.

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GRT Gross Registered Tonnage. H1

Wave height used for the design of structures. Hs

Significant wave height. HAT Highest Astronomical Tide. ISLW Indian Spring Low Water. LAT Lowest Astronomical Tide. LOA Length overall of a vessel. MHWM Mean High Water Mark. MSL Mean Sea Level. ZFDTG Zero Fort Denison Tide Gauge.

1.4 DEFINITIONS

For the purpose of this Document the definitions below apply. Accretion The growth of sand banks and other marine deposits by the movement and settlement of waterborne particles.

Bathymetry The depth of water in oceans, seas, rivers and lakes. Beam The greatest width of a vessel including all permanent attachments. Berth An area of water allocated for the wet storage of vessels attached to a fixed or floating facility and allowing for walk-on access to the vessels.

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Boardwalk A horizontal decked walkway on piered or piled footings, providing pedestrian access that extends over or beyond the intertidal zone, but not intended to provide direct access to a vessel. Boat ramp A structure designed primarily for the launching of trailer-borne recreational vessels and includes associated car parking facilities. Boatshed A building or other structure used for the storage and routine maintenance of a boat or boats and which is associated with a private residence and includes any skid or other structure or device used in connection with the building. Breakwater A fixed or floating barrier in the water to intercept waves and create a sheltered area to protect vessels and property from storm and wave damage. Capwale A horizontal structural member connecting two or more piles and providing support for superstructure decking, girders and joists. Channel An unobstructed waterway which allows the movement of vessel traffic. Chart Datum The datum used on Australian hydrographic charts and other hydrographic surveys for the specific region. This datum usually corresponds to the level of LAT. Chine The lower external line of any flotation component. Davit A mechanical device used for lifting or lowering a vessel out of or into the water. Dredging The removal of material from the sea or harbour bed or the bed of a river below MHWM. Fairway An unobstructed waterway between rows of berths which allows vessel movement between interior channels and individual berths. Fender A buffer, usually made or rubber or timber, to protect vessels and structures against damage during berthing.



Fetch The distance over open water across which wind waves can be generated. Freeboard The vertical distance between the still water level and the top of the flotation unit of a pontoon.

Gangway or Ramp A structure which provides pedestrian access between a walkway or shore and a floating structure or vessel. Girder or Joist A longitudinal structural member supporting the deck of a boardwalk, jetty or wharf. Headstock A horizontal structural member connecting two or more piles and providing support for girders or joists. A headstock is generally supported directly on the top of the piles. Indian Spring Low Water (ISLW) Obsolete estimate of LAT formerly used as Chart Datum. Equates to a reading of zero on the Fort Denison Tide Gauge. Jetty A horizontal decked walkway on piered or piled footings providing pedestrian access from the shore to the waterway. Landing steps A set of steps located at the end of a jetty or abutting a seawall or rock face used for providing access from vessels to the shore. Length overall The length of a vessel measured between extremities of fittings. Marina A group of pontoons, jetties, piers or similar structures designed or adapted to provide berthing for vessels used primarily for pleasure and recreation and may include ancillary works such as slipways, facilities for the repair and maintenance of vessels and the provision of fuel, provisions and accessories. Mean High Water Mark (MHWM) The position where the plane of the mean of all ordinary local high tides intersects the foreshore. This is presently 1.48 m above ZFDTG. Mean Low Water Mark (MLWM) The position where the plane of the mean of all ordinary local low tides intersects the foreshore. This is presently 0.415 m above ZFDTG.



Mean Sea Level The average of the sea surface over a long period, or the average level which would exist in the absence of tides. Mooring A detached or freestanding structure to which a vessel is moored. Pontoon A floating platform used for access to the water or a vessel. Reclamation An area of dry land that was previously submerged land but now is enclosed by seawalls that alter the natural line of the foreshore.

Revetment An inclined face of stone, concrete or synthetic material protecting an embankment from waves or currents. Seawall A structure separating land and sea. Significant wave height (H s) The average height of the highest one third of waves in any given time interval. Skid An inclined ramp used for the manual launching of small craft but does not include a slipway. Slipway A structure, usually in the form of two supported parallel rails on which a wheeled cradle is run to draw a vessel out of the water for maintenance and repair and includes any facility over which a vessel or object is hauled by means of a manually operated or power operated appliance such as a powered or manual winch, a block and tackle, etc. Sponson A rubbing strip, generally at the main deck level, to strengthen and protect a vessel from berthing impacts. Stub jetty A short jetty designed as support for a ramp or gangway to access a pontoon. Swimming enclosure A net or other structure placed in the waterway for the purpose of providing a protected swimming area. Vessel Any boat longer than 5.2 m excluding rowing boats, dinghies and other non-motorised craft.



Vessel displacement The total mass of a vessel and its contents. Wharf A structure on and parallel to the foreshore alongside which vessels may lie to load or unload cargo, passengers, etc. Zero Fort Denison Tide Gauge (ZFDTG) The hydrographic datum adopted by the NSW Maritime Authority in Sydney Harbour.



SECTION 2 SITE INVESTIGATION

2.1 GENERAL

Site investigations are an essential part of the planning and design of maritime structures. Consequently, site investigations should be undertaken to provide sufficient information for the design and construction of any maritime structure. It is anticipated that site investigations will be aimed at two levels. The first level, preliminary investigation, will be aimed at collecting information to assess whether the proposed facility is feasible. This assessment will usually be carried out based upon a site inspection and a review of existing data. The second level, detailed investigation, will generally proceed following development consent and will usually be based on detailed hydrographic surveys and geotechnical investigations.

2.2 SURVEY

Hydrographic surveys are required in order to determine the available depth of water and in particular to determine whether any dredging will be necessary in order to accommodate the proposed structure. Reference is made to the NSW Maritime Authority’s Guidance Note GN 03 – Depths in Berths and Fairways. Hydrographic surveys shall be undertaken in accordance with the NSW Maritime Authority’s Guidance Note GN 01 – Provision of Hydrographic and Geotechnical Data.

2.3 GEOTECHNICAL

Geotechnical investigations are required in order to determine the properties and constituents of the seabed and underlying rock strata and the depths of the various layers comprising the seabed. Information required from an investigation might include some or all of the following: (a) soil, sediment and rock classification; (b) grain size distributions and shape; (c) in-situ soil density; (d) stratigraphy; (e) soil strength parameters; (f) soil deformation parameters and; (g) chemical composition of any sediments to be dredged.

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Geotechnical investigations are generally performed under the direction of specialist geotechnical engineers and geologists. Geotechnical data shall be collected in accordance with the NSW Maritime Authority’s Guidance Note GN 01 – Provision of Hydrographic and Geotechnical Data.

2.4 EXISTING STRUCTURES

Any existing structures on the site need to be considered during the planning and design of proposed new structures. In particular, site investigations should consider the following aspects: (a) whether any part of an existing structure is suitable to be

incorporated into the new structure; and (b) where any part of an existing structure will become redundant,

demolition of same.

2.5 ASSESSMENT

Together with the above, site investigations should also include assessment of the following aspects: (a) wind climate; (b) wave climate; (c) currents; (d) water levels (tidal range, storm surge, flood levels, seiching); (e) coastal processes (accretion, erosion); and (f) services. For further guidance on these aspects, reference is made to the British Standard Code of Practice for Maritime Structures – BS6349 and Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

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SECTION 3 DESIGN REQUIREMENTS

3.1 GENERAL

The design of maritime structures proposed on the NSW Maritime Authority’s land shall take into account, as appropriate, stability, strength, serviceability, durability and redundancy.

The design shall be carried out in accordance with appropriate Australian Standards together with the requirements of this Document. Where thisdocument and the appropriate Australian Standards conflict, the requirementsof the Australian Standards will prevail to the extent of the conflict.

3.2 AUSTRALIAN STANDARDS

Commonly used Australian Standards for the design of elements of maritime structures include the following.

AS/NZS1170.0 Structural design actions – General principles

AS/NZS1170.1 Structural design actions – Permanent, imposed and other actions

AS/NZS1170.2 Structural design actions – Wind actions

AS/NZS1170.4 Minimum design loads on structures – Earthquake loads

AS1428 Design for access and mobility

AS/NZS1664.1 Aluminium structures – Limit state design

AS/NZS1664.2 Aluminium structures – Working stress design

AS1657 Fixed platforms, walkways, stairways and ladders – Design, construction and installation

AS1684.1 Residential timber framed construction – Design criteria

AS1720.1 Timber structures - Design methods

AS2159 Piling – Design and installation

AS3600 Concrete structures

AS3962 Guidelines for design of marinas

AS4100 Steel structures

DR02536 Guidelines for design of maritime structures

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Generally these Standards are strength limit state or ultimate limit state design though some are working stress design.

3.3 STABILITY

The structure and its elements shall be designed for static stability under overturning, uplift and sliding and for dynamic stability. Appropriate combinations of design actions shall be considered so that stability loads and other actions exceed the destabilising loads and other actions.

3.4 STRENGTH

The structure and its elements shall be designed for strength in accordance with appropriate Australian Standards together with the requirements of this Document as follows: (a) Determine the appropriate loads and other actions; (b) Combine and factor the loads to determine design loads for

strength; (c) Determine the design action effects for the structure and its

elements for each load case; and (d) Determine the design strength. The effects of fatigue from wind, wave and current action under normal conditions shall also be considered.

3.5 SERVICEABILITY

The structure and its elements shall be designed for serviceability by controlling or limiting settlement, horizontal displacement and cracking. Under the appropriate load combinations for serviceability design, vertical deflection shall be limited in accordance with the requirements of the appropriate materials Standards. Horizontal deflection and acceleration limits for trafficable structures shall be limited to a maximum deflection of l /150, where l is the distance between underside of the deck structure to the level of the support in the seabed, and a maximum acceleration of 0.1 g.

3.6 DURABILITY

The structure and its elements shall be designed for durability in accordance with this Document.

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3.7 REDUNDANCY

Consideration should be given in the design of the structure and its elements to allow for redundancies to prevent failure of the structure in the event of the loss of a critical element. For example, when designing a timber capwale supported by timber piles, consideration should be given to specifying at least one additional bolt than that required for strength purposes at the capwale/pile connection and/or notching the capwale into the pile.

3.8 DESIGN LIFE

Design life is the period of time for which a structure or an element of the structure remains fit for use for its intended purpose with appropriate maintenance. The design life of maritime structures will depend on the type of facility, the intended function and the applicant’s requirements. Design life should be based on consideration of capital and maintenance expenditure. The designer, in consultation with the applicant, should determine an appropriate maintenance regime consistent with the adopted design and materials that will achieve the design life. Particular care should be taken when considering design life and maintenance regimes for inaccessible elements of the structure. Such elements should have a design life (with no maintenance) equal to the design life of the structure. At the end of its design life, the structure should have adequate strength to resist ultimate loads and be serviceable, but may have reached a stage where further deterioration will result in inadequate structural capacity. Guidance on design life is given in Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures. It is recommended that a minimum design life of 25 years be adopted for maritime structures.

3.9 SCOUR AND SILTATION

The structure and its elements shall be designed to remain stable, of sufficient strength and not become over-stressed in the event of temporary or permanent changes in the level of the seabed due to scour or siltation.

3.10 SEA LEVEL RISE

Structures shall be designed to allow for future sea level rise caused by global warming.



Guidance on the amount of sea level rise to be considered is given in Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

3.11 DISABILITY REQUIREMENTS

Structures which will be utilised by the public shall be designed to provide access for disabled persons in accordance with AS1428 and the Commonwealth Government’s - Disability Standards for Accessible Public Transport Guidelines 2001 and this Document. Aspects that are to be considered and addressed in the design include, but are not limited to the following: (a) Ramp slope; (b) Lighting; (c) Obstructions; (d) Tactile surfaces; and (e) Rest points.

3.12 RISK

Consideration shall be given in the design of the structure and its elements to firstly identify, then minimise or remove risks to future users of the structure. Examples of potential risks to users include, but are not limited to the following: (a) Tripping; (b) Slipping; (c) Falling; (d) Pinch spots; (e) Inadequate lighting; (f) Inadequate safety and rescue equipment; and (g) Inadequate egress points from the water.

3.13 HEALTH AND SAFETY

The design of all structures to be used by the public or to be used in a workplace shall take into consideration occupational health and safety requirements in accordance with the Occupational Health & Safety Act 2000 and Workcover NSW.



SECTION 4 DESIGN ACTIONS

4.1 GENERAL

The design for ultimate strength, serviceability, stability and other relevant limit states shall take into account appropriate design actions in accordance with AS/NZS1170 and Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures except as modified by this Document. In particular, the following design actions shall be considered, where appropriate: (a) permanent actions (dead loads); (b) imposed actions (live loads); (c) wind actions; (d) current and debris actions; (e) hydrostatic actions; (f) wave actions; (g) construction and maintenance actions; (h) lateral earth actions; (i) boat wash; and (j) earthquake actions. Combinations of design actions shall be considered generally in accordance with AS/NZS1170 and Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

4.2 IMPOSED ACTIONS

4.2.1 Marinas

Minimum live loads for marinas shall generally comply with AS3962. Fixed structures, other than gangways, shall be designed for a minimum uniformly distributed live load of 5.0 kPa or a minimum concentrated live load of 4.5 kN whichever produces the more adverse effect. Gangways shall be designed for a minimum uniformly distributed live load of 4.0 kPa or a minimum concentrated live load of 4.5 kN whichever produces the more adverse effect. Floating structures shall be designed for a minimum flotation load of 3.0 kPa or a minimum stability load of 2.0 kPa.

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4.2.2 Wharves, jetties and boardwalks

Minimum live loads for wharves, jetties and boardwalks shall generally comply with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures. Wharves, jetties and boardwalks subject to pedestrian traffic only shall be designed for a minimum uniformly distributed live load of 5.0 kPa or a minimum concentrated live load of 4.5 kN whichever produces the more adverse effect. Where wharves, jetties and boardwalks are subject to access by emergency and service vehicles such structures shall be designed for a minimum uniformly distributed live load of 10.0 kPa or a minimum concentrated live load of 45.0 kN whichever produces the more adverse effect.

4.2.3 Ramps

Ramps leading from wharves, jetties, boardwalks or the like shall be designed for a minimum uniformly distributed live load of 4.0 kPa or a minimum concentrated live load of 4.5 kN whichever produces the more adverse effect.

4.2.4 Handrails

Minimum live loads for handrails, including handrails associated with gangways and ramps, shall generally comply with those given for guardrails in accordance with AS1657 Clause 2.1.2.2.

4.2.5 Pontoons

Pontoons shall be designed for the minimum flotation and stability loads as shown in the following table. CATEGORY FLOTATION LOAD * (kPa) STABILITY LOAD ** (kPa) Private 1.5 1.5 Home Units 2.0 2.0 School/Club 2.0 2.0 Marina 3.0 2.0 Public 3.0 3.0 * Flotation load to be applied over the whole of the pontoon deck area and ramp

where applicable. For pontoons that will support shelters or building structures, the



flotation load shall also be applied to the whole of the roof area of such shelters or structures.

** Stability load to be applied in the most adverse locations over the pontoon deck

area and ramp where applicable with consideration being given to pattern loading. For pontoons that will support shelters or building structures, the stability load shall also be applied to the roof area of such shelters or structures.

4.2.6 Fenders

Fenders shall be designed so that the deceleration of the vessel/acceleration of the berthing structure does not exceed 0.1 g. In deriving the berthing energy of a vessel, the eccentricity factor Ce shall be taken as 1.0.

4.2.7 Boat ramps

Boat ramps shall be designed for a minimum uniformly distributed live load of 10.0 kPa or a minimum concentrated live load of 45.0 kN whichever produces the more adverse effect.

4.2.8 Boatsheds

Minimum live loads for boatsheds shall generally comply with the Building Code of Australia.

4.2.9 Seawalls

Subject to recreational use only of the land behind the seawall, seawalls shall be designed for a minimum uniformly distributed surcharge live load of 5.0 kPa.

4.2.10 Ladders

Minimum live loads for ladders shall generally comply with AS1657 Clause 2.1.2.5.

4.2.11 Skids

Skids shall be designed for a minimum uniformly distributed live load of 4.0 kPa or a minimum concentrated live load of 4.5 kN whichever produces the more adverse effect.

4.2.12 Stairs and steps

Steps shall be designed for a minimum uniformly distributed live load of 4.0 kPa or a minimum concentrated live load of 4.5 kN whichever produces the more adverse effect. Minimum live loads for stairs shall generally comply with AS1657 Clause 2.1.2.4.



4.2.13 Marine growth

It is recommended that in stability calculations for concrete pontoons allowance is made for marine growth with a minimum buoyant weight on all submerged surfaces of 15 kg/m2. Fibreglass pontoons are generally not affected by marine growth.



SECTION 5 TYPES OF CONSTRUCTION

5.1 GENERAL

Requirements are given below in relation to various types of construction for which the NSW Maritime Authority’s approval is sought.

These requirements are not exhaustive and designers shall investigate and determine the requirements relevant to the type of construction for which approval is being sought.

5.2 MARINAS

Marinas shall be generally designed in accordance with AS3962 .

Marina berths and fairways shall comply with the NSW Maritime Authority’s - Guidance Note GN 03 - Depths in Berths and Fairways.

5.3 WHARVES, JETTIES AND BOARDWALKS

Wharves, jetties and boardwalks shall generally be designed in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

Wharves, jetties and boardwalks shall be designed so as not to impose lateral loads on existing seawalls.

Wharves, jetties and boardwalks providing for disabled access shall be designed in accordance with AS1428 and the Commonwealth Government’s - Disability Standards for Accessible Public TransportGuidelines 2001.

Wharves, jetties and boardwalks shall have a minimum clear width of 1.8 m.

5.4 PILES

Piles shall generally be designed and installed in accordance with AS2159.

Consideration shall be given to achievable tolerances when installing piles over water when designing elements of structures to later be connected to such piles.

Consideration shall be given to marine growth when designing piles.

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Where timber piles are used they shall have a minimum toe diameter of 300 mm.

5.5 RAMPS

Ramps leading from wharves, jetties, boardwalks or the like shall generally be designed in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures. Attention shall be given to the design of connections and appropriate bracing where lateral loads from the end of the ramp are being transferred to the jetty. Ramps for facilities providing for disabled access shall be designed in accordance with AS1428 and the Commonwealth Government’s -Disability Standards for Accessible Public Transport Guidelines 2001. Ramps shall have a minimum clear width of 1.2 m.

5.6 HANDRAILS

Handrails shall generally be designed in accordance with AS1657. Handrails for facilities providing for disabled access shall be designed in accordance with AS1428 and the Commonwealth Government’s - Disability Standards for Accessible Public Transport Guidelines 2001.

5.7 PONTOONS

Pontoons shall be stable under the most adverse combination of dead and live loads applied to the pontoon deck. Under such loads, unless permitted otherwise, the following requirements shall be met: (a) For pontoons with a rectilinear flotation system, the minimum

freeboard shall be the greater of 50 mm or 5% of the moulded depth of the pontoon, measured from the top of the flotation unit;

(b) For pontoons with a horizontal cylindrical flotation system, the minimum freeboard shall be the greater of 50 mm or 25% of the diameter of the cylindrical float, measured from the top of the flotation system;

(c) The pontoon chine shall not emerge; and (d) The angle of tilt shall not exceed 15 degrees. Consideration shall be given to marine growth when designing pontoons. Pontoon stability shall be calculated in accordance with the metacentric height method.

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Any restraint from adjacent piles or moored vessels shall not be taken into account in calculations for pontoon stability. Pontoons composed of a number of compartments shall be designed so that the stability requirements above are met with a single compartment flooded. All compartments should be accessible from hatches in the pontoon deck and consideration should be given to ventilation of all compartments. Pontoon decks shall be designed to have a positive fixing to the flotation unit. Such fixings shall be capable of supporting the deck in the event the pontoon turns over. Consideration should be given to the “ride” of the pontoon together with its suitability for the proposed wave and wind climate. Factors such as weight, freeboard and form of restraint shall be considered in the pontoon design. For certain types of pontoons involving a stepped or sloped deck the NSW Maritime Authority may give consideration to varying the above stability requirements and may permit part of the deck to become submerged. Such pontoons will be considered on a case by case basis. The minimum depth of water required to accommodate a pontoon shall generally comply with Clause 3.3 of the NSW Maritime Authority’s - Guidance Note GN 03 - Depths in Berths and Fairways. This depth of water shall be provided under the pontoon and for a minimum distance of 500 mm measured in plan around the pontoon perimeter.

5.8 FENDERS

Fenders shall generally be designed in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures. Proprietary fenders are recommended to be used and in these instances manufacturer’s catalogues will assist in the selection of an appropriate fender. Absorption of a proportion of the berthing energy through deflection of the vessel hull is not recommended. Consideration should be given to not exceed the vessel hull pressure when berthing.

5.9 BOAT RAMPS

Boat ramps shall generally be designed in accordance with the Public Works Department’s - Boat Launching Ramps Guidelines.



5.10 BOATSHEDS

Boatsheds shall generally be designed in accordance with AS1684 and the Building Code of Australia. Attention shall be given to the design of connections and in particular bracing and tie-down details to resist wind loads.

5.11 SEAWALLS

Seawalls shall generally be designed in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures and AS4678. Where applicable, seawalls shall be designed taking into account the recommendations made in the NSW Maritime Authority’s – Guidelines for Waterside Works Subject to Rivercat and Harbourcat Wash. Allowance shall be made in the design for the loss of at least 600 mm of material from the seaward face of the seawall unless the seawall is founded on rock. Seawalls shall be designed to incorporate drainage holes together with a suitable filter layer to relieve water pressure behind the seawall.

5.12 LADDERS

Ladders shall be installed to permit access to and from the water where suitable alternate access is not possible in close proximity to a maritime structure. Ladders shall generally be designed in accordance with AS1657 as step-through ladders. The maximum spacing between ladders shall not exceed 50 m unless there are objects located between ladders that a person in the water can hold on to as they attempt to make their way to a ladder. In such situations the maximum spacing between such objects and between such an object and a ladder shall not exceed 10 m. The ladders rungs shall extend from deck level down to below low water level with the bottom rung 300 mm below LAT.

5.13 DAVITS AND WINCHES

Davits and winches shall generally be designed in accordance with AS1418.

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Davits and winches shall comply with the requirements of the WorkCover Authority’s - Construction Safety Branch - Requirements for Shore Mounted Cranes and Hoists .

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Proprietary davits and winches are recommended to be used. In these instances, applicants should ensure that the manufacturer is prepared to supply a certificate indicating that the davit or winch has been designed in accordance with the above requirements.

5.14 STORMWATER DRAINS

Stormwater drains shall generally be designed in accordance with the NSW Maritime Authority’s - Guidance Note GN 100 – Stormwater Discharge.

5.15 SLIPWAYS

Slipways shall generally be designed in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures. A minimum horizontal clearance of 600 mm over a vertically projected height of 2 m shall be provided each side of the slipway between the vessel cradle and any other object during slipway operations. Vessel cradle track wheels shall be guarded to prevent persons becoming trapped between the leading face of the track wheel and the slipway rail. Winch controls shall be located so that the vessel cradle remains in full view of the operator during slipway operations.

5.16 SKIDS

Skids shall generally be designed in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures. Skids shall be designed to provide a safe foothold. This can be achieved by means of spaced decking or the use of cleats. Where cleats are used they shall comply with AS1657 Clause 3.1.2.

5.17 EMBANKMENTS

Embankments shall generally be designed in accordance with the US Army’s Shore Protection Manual. Where applicable, embankments shall be designed taking into account the recommendations made in the NSW Maritime Authority’s – Guidelines for Waterside Works Subject to Rivercat and Harbourcat Wash.



5.18 STAIRS AND STEPS

Stairs and steps shall generally be designed in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures and AS1657. Steps shall have a minimum clear width of 1.8 m. Stairs shall have a minimum clear width of 1.2 m. Steps in the tidal zone shall be provided with an antiskid treatment.

5.19 LIFEBUOYS

Lifebuoys shall be provided on all public facilities. Lifebuoys shall be located in order to cover the water area a distance of 10 m measured in plan around the perimeter of the public facility. Lifebuoys shall generally comply with the Australian Maritime Safety Authority’s Marine Orders Part 25 Appendix 1.1. Lifebuoys shall be fitted with a buoyant lifeline which shall comply with the Australian Maritime Safety Authority’s Marine Orders Part 25 Appendix 1.4.

5.20 DEMOLITION

Demolition shall generally be carried out in accordance with AS2601.

All demolished materials shall be removed from site and disposed of in an approved manner in accordance with AS2601.



SECTION 6 MATERIALS

6.1 GENERAL

Maritime structures are usually located in very aggressive environments. Materials for maritime structures shall be chosen so that the structures are capable of withstanding this environment and achieving the required design life in conjunction with an appropriate preventative maintenance programme. Materials shall generally comply with the durability requirements specified in Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures and appropriate Australian Standards. Whilst this Section only deals with the use of typical materials, it does not preclude the use of other materials.

6.2 CONCRETE

6.2.1 General

The deterioration of concrete maritime structures is predominantly caused by the corrosion of steel reinforcement and prestressing tendons as a result of chlorides in the marine environment coming into contact with steel. Steel corrosion shall be minimised by designing durable concrete structures and limiting concrete crack widths. Common methods used to achieve the above include, but are not limited to the following: (a) use of plain concrete members; (b) use of high strength, low water to binder ratio concrete mixes; (c) use of chemical absorption agents in the concrete mix; (d) use of pore blockers in the form of admixtures to wet concrete or

surface applications to finished concrete; (e) painting of concrete members; (f) use of non corrosive reinforcement such as galvanised steel,

stainless steel, plastic filament and carbon fibre; (g) designing for low stresses in steel reinforcement; (h) minimising the use of thin sections particularly in the wetting and

drying zone; (i) encapsulating prestressing tendons in watertight plastic conduits; (j) use of epoxy coatings to reinforcement; (k) use of cathodic protection systems; and (l) careful attention to structural detailing particularly with respect to

constructability and maintainability. Care shall be taken by designers in specifying high strength concrete (concrete with a characteristic compressive strength above 50 MPa) in

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order to improve durability. Further advice regarding the use of high strength concrete is given in Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

6.2.2 Maintenance Considerations

If normal (carbon steel) reinforced concrete is used repairs would be expected after about 25 years and thereafter at about 5 to 10 year intervals. A higher grade of reinforcement and/or concrete may extend the life to the first repairs. Repairs will require the removal and replacement of deteriorated concrete and reinforcement. Consideration should be given to the following: (a) the ability to access the repair location including the need for any

scaffolding; (b) the ability to remove and contain waste materials during repairs;

and (c) the ability to apply and maintain an adequate curing regime to the

repairs. Saltwater washdown of concrete members should be avoided.

6.2.3 Structural Design

Concrete maritime structures and elements shall generally comply with the design and performance requirements of AS3600 together with the requirements of this Document.

6.2.4 Material Requirements

Requirements for concrete, reinforcement and prestressing steel shall generally comply with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

6.2.5 Exposure Classifications

Exposure classifications for concrete elements shall be determined generally in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

6.2.6 Cover to Reinforcement

Minimum requirements for cover to reinforcement shall generally comply with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

6.2.7 Crack Control

Crack widths shall be limited by designing structures with low stresses in the reinforcement. Maximum allowable reinforcement stresses shall



generally comply with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

6.3 STEEL

6.3.1 General

Whilst steel is a suitable material for use in the construction of maritime structures, particular where design loads are high, its vulnerability to corrosion after exposure to seawater should be considered when using carbon steel in the marine environment. In the design of steel members, designers shall consider appropriate protection systems to protect and maintain steel members. In addition, designers shall also consider methods for installation and connection of steel members to prevent damage to pre-applied protection systems. Consideration should be given to the selection of steel members to allow ease of application and maintenance of protection systems and not simply based on the most efficient size or shape with regard to strength. Further advice regarding the selection of steel members is given in Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.


Paint coatings can generally provide a service life of 10 to 20 years, before repair or recoating is necessary. In relation to any repairs or recoating, consideration should be given to the following: (a) the ability to access the repair/recoating location including the need

for any scaffolding; (b) the ability to remove and contain waste materials during

repairs/recoating; and (c) the ability to prepare and apply protective coatings in-situ to

achieve the required standard. The preparation and recoating of steel in the marine environment is difficult and standards reached in the manufacturing process are generally not achievable in this environment.


Steel maritime structures and elements shall generally comply with the design and performance requirements of AS4100 together with the requirements of this Document.




Minimum sizes of steel members and connections shall generally comply with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures. Requirements for stainless steel shall generally comply with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

6.3.5 Protection Systems

Protection systems for steel structures and elements shall generally be applied or installed in accordance with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.

6.4 TIMBER

6.4.1 General

Timber has many applications in maritime structures, particularly in small craft facilities such as jetties, ramps, skids and steps due to its ease of workability. Timber can be used on its own to construct complete structures (including piles, headstocks, bearers, joists and decking) or in conjunction with other materials to provide economical, and durable structures. The deterioration of timber is usually by rot or attack by living organisms. Timber durability is dependant predominantly upon the species chosen in the design. Further advice regarding the use of timber is given in Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures.


Individual timber members are relatively small, forming an assembly of members within a structure. Members can usually be replaced easily within a structure to maintain the structural capacity, without significant interruption to service operations. Timber members will generally have a shorter service life than concrete or steel members. For timber piles affected by marine organisms a service life of 5 to 10 years would be expected. For timber decking exposed to weathering a service life of 10 to 15 years would be expected. Natural shrinkage of drying timber will result in the need to tighten bolted connections during the early years of the structure’s life.



In relation to maintenance, consideration should be given to the following: (a) the availability of skilled carpenters, able to maintain the works over

the structure’s design life; (b) the future availability of suitable timber species and member sizes;

and (c) the detail and accessibility of bolted connections for ease of

replacement during maintenance.


Timber maritime structures and elements shall generally comply with the design and performance requirements of AS1720.1 together with the requirements of this Document.


Requirements for timber shall generally comply with Standard Australia’s - DR 02536 - Guidelines for Design of Maritime Structures. Hardwood timbers shall be either durability class 1 or class 2 in accordance with AS1720.1. Suitable species for timber members are shown below: (a) Piles:

Turpentine.

(b) Headstocks, wales, capwales, girders, joists and braces: Grey ironbark, grey gum, white mahogany, tallowwood, grey box, yellow stringybark, white stringybark, woollybutt, forest red gum, mountain grey gum and turpentine.

(c) Decking: Brushbox, blackbutt, grey gum, white mahogany, tallowwood, grey box, yellow stringybark, white stringybark, woollybutt, forest red gum and mountain grey gum.

(c) Kerbs: Blackbutt, grey gum, white mahogany, tallowwood, grey box, yellow stringybark, white stringybark, woollybutt, forest red gum and mountain grey gum.

(d) Handrails: Tallowwood, white mahogany and grey box.



SECTION 7 MAINTENANCE

7.1 GENERAL

During the design life of a maritime structure maintenance will need to be carried out in order to ensure that this design life is achieved. Costs associated with such maintenance can be greatly reduced by adopting an appropriate preventative maintenance programme. Essential features of such a programme include the following: (a) regular inspections; (b) timely repairs; (c) timely renewal of protection systems; (d) timely replacement of worn-out components; and (e) keeping records of inspections carried out and maintenance

performed.

7.2 INSPECTIONS

7.2.1 General

Inspections should be carried out by suitably qualified persons experienced in the design and construction of maritime structures. Typical inspections for various structures that should be performed are given below together with suggested inspection intervals. These inspections are not an exhaustive list and will vary from structure to structure. More frequent inspections may be required where structures are located in extreme environments or subject to severe loads.

7.2.2 Piles

The tidal zone of a pile should be inspected visually from the surface at low tide annually. Signs of excessive wear or evidence of marine borer attack or corrosion should be noted and remedial measures taken if necessary. Timber pile tops should be inspected for deterioration due to decay or dry rot annually. At intervals of 3 years or after major storms or other severe events, a detailed inspection of piles should be carried out. It is recommended that experienced divers be used to inspect the condition of piles below water level. Timber pile circumferences should be measured above and below low water, pile alignments measured, any corrosion noted and marine fouling removed.

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The intervals between inspections above should be reduced for old or partially damaged piles.

7.2.3 Pontoons

Pontoons and their mooring systems should be visually inspected above water at 6 monthly intervals. Such inspections should take note of any damage from boat impacts, mooring line chafing, chemical spillage, pontoon freeboards and levels, and the condition of pontoon connections. At intervals of 3 years, a detailed inspection should be carried out. This inspection should include an underwater investigation of marine fouling and pontoon connections not normally visible above water.

7.2.4 Timber Structures

Timber components above water should be inspected annually for decay and infestation. Major structures should have a detailed inspection at 5 yearly intervals. Such inspections should note the condition and alignment of the structure, fastenings and all associated hardware.

7.2.5 Steel Structures

Steel fittings and components should be inspected for wear and corrosion on an annual basis. Any damage to protective coatings should be noted for repair. Distortions due to overstress should be noted and remedial action taken. Attention should be paid to wear and corrosion in pile guide systems and pontoon connection hardware, where visible. Major structures should have a detailed inspection at 5 yearly intervals. Such inspections should consider corrosion, deterioration of protective coatings together with signs of fatigue and wear.

7.2.6 Concrete Structures

Inspections should be carried out to check for signs of deterioration usually evidenced by white salt encrustations, cracks, rust stains and spalling. Such inspections should be carried out at intervals of 5 years.

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