Centre for Research in Engineering and Surface Technology John Colreavy Enterprise Ireland Restoration of the Ha’penny Bridge Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Introduction  A little Irish History.  Paint specification and resultant issues.  Performance evaluation.  Surface preparation and soluble salts.  Harland & Wolff facilities.  Railings assembly.  Importance of supervision and inspection.  Summary. Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20 th to the 24 th of September 2004

Restoration of the Ha’penny Bridge History  Officially opened in 1816 and named Wellington Bridge (Iron Bridge after the Iron Duke).  Cast at Coalbrookdale in Shropshire.  Only pedestrian bridge up to  Erected by Alderman Beresford at a cost of £3,816.11s.6d.  Mr William Walsh ordered to replace his unworthy ferry fleet by Dublin Corporation. Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Performance expectations  ISO Paints and Varnishes – Corrosion Protection of Steel Structures by Protective Paint Systems. Part 1.General Introduction Part 2.Classification of Environments. Part 3. Design Considerations. Part 4.Types of Surface and surface preparation. Part 5.Protective Paint Systems. Part 6.Laboratory Performance Test Methods. Part 7.Execution and supervision of paint work. Part 8. Development of specifications for new work/ maintenance. C4 EnvironmentIndustrial Areas and coastal areas with moderate salinity. Chemical plants, swimming pools, coastal shipyards. Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge New steel sub-frames to walkway (Decks)/New ductile iron handrail/New steel bracing members Aluminium metal spray Zinc phosphate 2 pk. epoxy sealer12m 2 /litre High build MIO high build quick drying epoxy undercoatdft 125  m Acrylic Urethane finish.dft 50  m Performance No Maintenance up to 12 years Minor maintenance from 12 years Major maintenance after 20 years Existing cast iron bridge superstructure Zinc phosphate 2 pk. epoxy blast primer12m 2 /litre Zinc phosphate high build quick drying 2 pk. epoxy primer dft 100  m High build MIO high build quick drying epoxy undercoatdft 125  m Acrylic Urethane finish. dft 50  m Paint specification Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Specification issues.  Removal of aluminium metal spray advised.  Galvanising advised for walkway sub-frames/new steelwork.  Specification for sealers/stoppers and fillers.  Specification for in-fill bars and joint sealers.  SA2½ adequate.  Chilled iron grit to be avoided.  J-Blast/Garnet or alumina preferred (J-blast for lead removal)  Wet abrasive blast existing lead to reduce airborne hazard.  Penetrating blast primer to facilitate crevice protection.  Second finish specified as final operation..  Colour match flakes removed from existing paint system Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Performance Evaluation Type approvalDescriptionStandard Neutral salt sprayISO 7253>720 hours CondensationISO 6270>480 hours BlisteringISO RustingISO Ri0 CrackingISO FlakingISO hours without defects achieved in salt spray. Existing track record on Turner Curvilinear Greenhouse in Gardens. Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

42.8 metres 3.6 metres 6 sections 7.2 metres long. 12 deck panels. 20 railing panels. Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

End-caps Diaphragms Lead gaskets Cast porosity Fish-belly beams. Soluble salts Dublin Existing Trusses Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Soluble Salts Oxidation MM + + e(metal loss at anode). ReductionO 2 + 2H 2 O + 4e 4OH - (oxygen reduction at cathode) M + +Cl - +H 2 O = MOH +H + Cl - Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Soluble Salts K 3 FE(CN) 6 K 3 Fe(CN) 6 before hydroblasting after hydroblasting before hydroblasting after hydroblasting Rib section lug Rib section lug Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

End-cap sockets Cross-member joints End-caps Fish-belly beams Diaphragms Dublin Existing Trusses Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Harland & Wolff Paint Cell Environmental Cell Variable control for the most vulnerable component. Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Paint Cell Titanic Engine Room Decks Restoration of the Ha’penny Bridge Harland & Wolff Harland & Wolff Drydock Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Railings Disassembled railings at H&W Panel layout at GHC Dromore Railing restoration logistics Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Railings Assembly on-site Final fix with marine engine epoxy Final inspection Competing operations Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Inspection Consultation Advice on specification (ICorr network) Type approval. Compatability evaluation. Trouble-shooting(ICorr network) Inspection Compilation of project QA records. Monitoring Substrate cond. SA2½ etc. Environmental conditions Dew point, temperature etc. System dft’s eddy current. Paint QA/S.G. Approval system. Production versus inspection! Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge Trusses  Soluble salts and hydro-blasting  Complex structure requiring sealers and bedding compounds.  Treatment of porosity Decks  Aluminium metal spray not appropriate.  Box-sections flooded  Benefits of shipyard facilities.  Consult corrosion consultants at design stage Railings  Logistics  Soluble salts  Competing operations Advances in Corrosion Protection by Organic Coatings Christ’s College Cambridge 20th to the 24th of September 2004

Restoration of the Ha’penny Bridge The Final Product Thank You Nostrada Restoration Award September 8 th Lord Mayor Ryan