Dredging Aberdeen HarbourA Presentation to the Scottish branch of the

Hydrographic SocietyBy Eddie Aitken

Hydrographic SurveyorAberdeen Harbour Board

Synopsis

Heading Sub-heading DescriptionOverview Need Deepening New Berths - Siltation

Types Capital - MaintenancePlant Examples

Preparation Surveying Hydrographic Surveying at Aberdeen Harbour (short presentation)Survey Data - Volumes

Schedule Plan of working areas - Schedule of work - MethodConsents SOAEFD - Crown Estates - DETR

Controls Contract ICE 7th EditionPre-Contract Documentation and Info

Management Supervision Bathy-Survey updates - Routine inspections - FRS samples - Logs - Forward planning

Quality Control Survey and Logs Bar Sweeps - Side Scan Sonar Surveys - Post Dredge - Correlation with Nav. Control Logs

Considerations Environment Vessel Traffic - Noise - Local Fishermen - Water Framework Directive

Dredging Aberdeen Harbour (Presentation to the Scottish branch of the Hydrographic Society)

Why do we dredge ?

1. To deepen areas following new quay construction or strengthening to accommodate deeper drafted vessels

2. To remove siltation and debris thus maintain the working depth

3. To create catchment areas to aid future dredging

Types of Dredging

1. Capital Dredging – New work, following a quay construction or to create a catchment. Usually carried out by a more powerful dredger such as a Backhoe, Bucket or Cutter Suction Dredger

2. Maintenance Dredging – To remove build up over a previously established level. Usually carried out by a Trailing Suction Hopper Dredger in cooperation with a Bed Levelling Tug or alternatively in confined areas by a Grab Hopper Dredger.

Dredging PlantTrailing Suction Hopper Dredger

Bed Levelling and Raking Tug

Grab Hopper Dredger

Spud Pontoon Mounted, backhoe Dredger

Trailing Suction Hopper

Dredgers

Trailing Suction Hopper

Dredgers

Bed Levelling

Tugs

Bed Levelling and Raking Boxes

Backhoe Dredgers

Bucket Dredgers

Grab Hopper Dredgers

Grab Hopper Dredgers

al

in

the

192

Rock Removal in the 1920’s

Blasting

ing

And

Blast

Rock DrillingAnd Blasting

Planning

• Tender/Pre Dredge Survey• Volumes Calculated Above the Designed

Bed Levels• Plan Showing Dredge Areas• Schedule Detailing Volumes and loads• Method Statement Detailing the Order of

Work• Disposal Licences and Consents

Hydrographic Survey Work

• Bathymetry• Side Scan Sonar• Lead Line Profiles• Bar Sweeps

Volumes Shown In 3D Pre, Post Dredge and the

Difference

Plan Showing Dredge Areas, Loads to be removed and the Schedule

Schedule Detailing Volumes and loads based on previous records

Pre Dredge Digital Terrain Model (TIN)

Method Statement• First areas to be dredged are the River Dee berths.• Second priority given to the deep water berths, Telford Dock

initially.• Third priority given to the remaining berths.

• Final areas to be the Navigation Channel, Tidal Harbour and approaches.

Disposal Licences and ConsentsFisheries Research Services (Agency for the SOAEFD)

Crown Estates Commissioners

Scottish Executive, Development Department, Transport Division 4

Annual Application (FEP1 form and BPEO Report) for a Licence to deposit dredge material at the established spoil ground under the ;FOOD AND ENVIRONMENT PROTECTION ACT 1985 PART II DEPOSITS AT SEA (AS AMENDED)

Decennial letter of application to deposit material on crown seabed

Application for 6 Yearly consent for Disposal of Dredgings from Aberdeen Harbour under Section 34 of the Coastal Protection Act 1949 as amended by the Merchant Shipping Act 1988.

Controls

• ICE Conditions of Contract 7th Edition with additional Special Conditions

• Pre-Contract Documentation• Work Permit

Additional Clauses to ICE Contract ConditionsClause 73 Variation of Price No variation over contract term

Clause 74 Harbour Regulations Adherence to Bye-laws and Pilotage Act 1997

Clause 75 Weather and Tide Delays At the Contractor's expense

Clause 76 Dumping Ground Location and Ref. To Admiralty Chart

Clause 77 Dredging Returns Direction to have them completed and submitted

Clause 78 Demurrage Advise as to expected delays and use of stand-by rate

Clause 79 Disturbance Dredging - Spillage Directions to minimise spillage

Clause 80 Measurement for purposes of Payment Description of the measurement method

Clause 81 Contractor's Staff and Equipment Full time agent and if necessary a hydrographic surveyor

Clause 82 Access to Dredging Plant Access provision for spot checks

Clause 83 Dumping Licence Advise on adherence to the disposal licence

Clause 84 Income Tax Prior to commencement of the works the Sub-Contractors Tax Exemption Certificate CIS 5 or 6 must be issued

Clause 85 VAT Receipt Prompt return of VAT receipt on payment

Clause 86 Performance Details of expected standard of performance

Pre-Contract DocumentationIssued by Contractor Issued by Client

•Copies of disposal license

•Paper Chart copies

•Emergency contact list

•Copy of Aberdeen tide tables

•Fisheries Research Services (FEP6) disposal log form

•Latest Port handbook

•Copy of Hopper Ullage Tables

•Letter Covering CIS5,6 Income Tax Clause 84

•Company Safety Policy

•Contract Safety Plan and Risk Assessment

•Copy of Insurances

•Copy of Master's Documentation

Other considerationsVehicle details from contractor for security clearance

FRS sample jars issued for sampling throughout the works

Organise debris skip to Mearns Quay East

Draw the contractor’s attention to the Vessel Transportation Plan and Marine Mammal Recording Form at the rear of the disposal licence

Inform local fishermen that the dredger is to commence as they often lay creels or nets around the spoil ground

International Ship and Port Facility Security (ISPS) Code must be faxed or emailed to Port Control before dredger enters port if arriving from outside the UK.

Aberdeen Harbour Work Permit

•Gives emergency contact telephone number.•Gives recommended standards for health and safety.•Serves as a security pass for access to working areas.•Gives brief details on safe working procedures.•Only issued when all other documents relative to the works have been exchanged

Supervision•Survey updates

•Routine inspections

•Logs

•FRS Samples

•Forward planning

•Spot Checks and log correlation

Survey UpdatesSurvey Updates

Routine Inspections

Routine Inspections

ABERDEEN HARBOUR BOARD

DAILY DREDGING RETURNTo be completed daily by the Contractor's Superintendent and returned to theHarbour Engineer before 9:30am on the second day following the 24 Hourperiod that this form describes

Date 12/05/2005 TSHD Amazone

Working Area's of Dredger Telford TelfordTelfordTelford

Measured Quantities (Hopper M3)1405 8541077983

Total = 4319

Total Time Dredging: 245In Minutes Sailing: 235

Dumping: 20DelaysStop Time Start Time Total Time Description of Delay

16:25 16:35 1017:10 17:15 518:00 18:10 1018:50 19:05 1519:30 19:40 1020:40 21:00 2021:25 21:30 521:50 22:00 1022:10 22:15 523:20 23:30 1023:55 00:00 5

Total of Delays and operational 605hours should equal 24hours(1440Mins)

Signed ............................................................................…(Contractor's Superintendent)

NB: If the contractor should encounter any obstructions to dredging he should notify the Engineer's Representative immediatly.

Cleaning draghead

Cleaning dragheadWaiting for outgoing shipCleaning dragheadCleaning draghead

Cleaning dragheadWaiting for outgoing ship Malyvia 19Waiting for outgoing ship HascosayCleaning draghead

Waiting for outgoing fishing vesselAll fast alongside Clipper Quay for repairs bowthruster.

Daily Dredge Return

Load Number Ladingnummer 1 2 3 4 5 5

Dredge Area Baggervak Telford Telford Telford Telford

Hopper Soundings (M) HoppermetingenPort/Starboard Fore 880.00 900.00 890.00 865.00 865.00 870.00 860.00 870.00

Mid 885.00 855.00 875.00 880.00 870.00 850.00 865.00 855.00

Aft 800.00 880.00 870.00 875.00 860.00 870.00 825.00 870.00

Average 866.67 875.83 864.17 857.50

Sluice Level (M) Meting vloeistofoppervlak 155.00 170.00 145.00 140.00

Gross Hopper Volume (M3) Volume hopper totaal 2371 2321 2404 2420

Volume of Settled Solids (M3) Volume vaste stof 71 60 74 83

Volume of Liquid (M3) Volume vloeistof =(totaal - vast) 2300 2261 2330 2337

Measured % Solids in Suspension Percentage monster 58% 45% 39% 33%

Bulk Volume of Solids in Suspension (M3) Vaste stof in mengsel (% x Volume)Total Volume of Hopper Solids (M3) Totaal vaste stof (hopper + mengsel)Start Loading Time 13:55 16:00 18:30 21:15

Finish Loading Time GELE VLAKKEN NIET INVULLEN 14:55 17:10 19:55 22:40

Dump Start Time 15:30 17:45 20:25 23:05

Dump Finish Time 15:35 17:50 20:30 23:10

Co-ordinates at Dump StartCo-ordinates at Dump Finish

771

1077 983 8541405

1334 1017 909

Daily Dredge Load Sheet

Navigation Control logs all vessel movements

FRS Marine Mammal Recording Form

FRS Samples and Visits

FRS Samples and Visits

Forward PlanningForward Planning

Quality Control• Pre, interim and post-dredge bathymetry• Side Scan Sonar surveys• Bar sweeps• Leadline profiles at quaysides• Correlation with port control vessel movement logs• In-situ comparison against hopper volumes• Log of vessel track to spoil ground• Visual check of disposal vessel from shore of dumping location.• Inspection of samples, sluice adjustment, communication with AHB Port Control, independent hopper

dip measurement, positioning system accuracy, water jet and degassing use (suction dredger)• Post contract report

Form FEP4 Fisheries Research Services (FRS) Environmental Protection Section, Marine Laboratory, PO Box 101 Telephone No: 01224 295331 Victoria Road, Torry Switchboard: 01224 876544 Aberdeen AB11 9DB Facsimile: 01224 295524

FOOD AND ENVIRONMENT PROTECTION ACT 1985 PART II DEPOSITS AT SEA (AS AMENDED)

SECTION 14 AND SCHEDULE 4

LICENCE RETURN FORM FOR THE DEPOSIT OF SOLID WASTE (E.G. DREDGE SPOIL)

IN THE SEA NOTES: 1. This form must be completed as a condition of licence. 2. The form must be completed in full, detailing NIL returns if appropriate. 3. The completed form must be submitted to the above address. A copy should be retained for your own records. 4. The licence conditions detail the required frequency of licence returns. 1. FRS Reference Number: D26 2. Licence Number (including revisions) : 1881 (Rev 3) 3. Licence Validity Dates: 7 January 2003 to 7th January 2004 3.1 Commencement and Completion Dates of Operations: 4. Name of Licensee: Aberdeen Harbour Board 5. Name of Sea Disposal Contractor(s) 1. WD Medway II, Westminster Dredging and Vessel(s) 2. WD Medway II, Westminster Dredging 3. Cherry Sand, UK Dredging 4 Cherry Sand, UK Dredging 6. General Description of Waste: Silt, Sand, Clay, Gravel and Cobbles 7.Geographical Coordinates of Disposal Site(s) 57° 07’ N 02º 00’ W 8. Nature and Quantities of all Materials Deposited below Mean High Water Springs (in cubic metres and tonnes):* *Continue on a separate sheet if necessary Signed ................................................................... For and behalf of the licensee Date ......................................................................

1 19/01/2003- 23/01/2003 2 18/05/2003- 29/05/2003 3 29/08/2003- 27/09/2003 4 29/08/2003- 27/09/2003

1. 12,047 M³, 15,661T Maintenance 2. 122,876 M³,159,739T Maintenance 3. 4,738 M³, 9,476T Capital 4. 28,260 M³, 36,738T Maintenance Total Capital 4,738M³, 9,476T (insitu vol) Total Maintenance 163,183M³, 212,138T (bulked vol)

FRS FEP4 Return

Environment

• Vessel Traffic• Noise• Local Fishermen• Water Framework Directive

Questions?