200 Years On: Sir Humphry Davy and Cathodic Protection

200 Years On: Sir Humphry Davy and Cathodic Protection

Technical Articles

Meet The Authors

Dr Bruce Ackland obtained a Bachelor of Science with Honours in Physics in 1979 and a Doctor of Philosophy in 1984 from Monash University, in the Department of Materials Engineering. Bruce has worked in the corrosion and cathodic protection industry since 1982, forming Bruce Ackland and Associates in 1985. Cathodic protection projects have involved work throughout Australia, New Zealand, Asia, SE Asia, the Middle East, North Africa and the USA. Bruce maintains an active role as a member and chairman in Australian Standards committees, participates in relevant ISO standards working groups, is the current chairman of the Australian Electrolysis Committee and is an accredited ACA Corrosion Technologist.

Dr Kathryn Dylejko is a corrosion engineer based in Australia at the Defence Science and Technology Group, specialising in minimising and controlling corrosion on Navy platforms. With roots as a mechanical engineer in armoured vehicles since 2006, she transitioned to corrosion 12 years ago, leveraging computational modelling to optimise cathodic protection systems for Navy vessels. Kate’s expertise spans various facets of corrosion, with a keen focus on cathodic protection systems for maritime platforms. Her research includes electrochemical studies on calcareous deposits and corrosion potential monitoring across Navy vessels and wharves. Actively contributing to the Victorian branch of the Australasian Corrosion Association, Kate recently achieved certification as an AMPP CP2 Cathodic Protection Technician, reinforcing her commitment to advancing the practice of corrosion control technologies.

Dr Markus Büchler FICorr, is Director of the Swiss Society for Corrosion Protection, President of the European Committee for the Study of Corrosion and Protection of Pipes and Pipelines Systems (CEOCOR), and convenor of ISO TC 156 WG10 on cathodic protection of buried and immersed metallic structures.

 

 

Introduction

The year 2024 marks the 200th anniversary of the first two of three remarkable papers [1-3] by Sir Humphry Davy describing the earliest scientific investigations into what we now call cathodic protection (CP). Although the word “cathode” was not in use until proposed by Michael Faraday in 1834 [4], this paper will keep using the modern abbreviation “CP” for convenience. Similarly, Faraday also proposed using the word “anode” in his 1834 paper and we will call the anodic metals used by Davy as anodes, rather than “protectors”. 

Davy presented three seminal papers to the Royal Society in London, beginning with his first on January 22, 1824 [1] giving the scientific reasons, background and laboratory research results for the application of CP to prevent corrosion of copper sheeting on timber ships in seawater. His second paper describing additional experiments and observations for copper sheeting on vessels in Chatham and Portsmouth Navy dockyards was presented on June 17, 1824 [2] and his third paper detailing full scale research and results for ships on the high seas was read on June 9, 1825 [3].

There was controversy then, as there is now, about some aspects of Davy’s work  [5, 6]. This paper discusses some of these issues and demonstrates that Davy was well aware of any shortcomings but importantly, he also suggested possible solutions to overcome the occasional problem of an increase in fouling of the copper sheet under specific circumstances [3, 7]. Notably, the application worked unambiguously to prevent corrosion of the copper in all cases, with fouling only occurring on some vessels and Davy was in the process of understanding the differences in operational circumstances. It will be shown that it was primarily a loss in funding and a wish by the British Admiralty (after pressure from some ship’s captains and the media) for quick solutions that cut short further investigatory work after just two years (i.e. 1823 to 1825). It was left to future scientists and engineers to show how CP could be used effectively and efficiently to protect any metal or alloy immersed in an electrolyte, including even reinforced concrete [8]. When reviewing his work, it must be seen in the context of the scientific understanding of electrochemical processes at the time. For instance, Davy was able to formulate the principles and application of CP decades before the electron was discovered by J.J. Thomson in 1897 and long before chemical and electrochemical reactions were written in the format used today. Judging his discoveries against modern principles is unfair at best and anyway, he was spot-on about plenty of technical points, as will be seen.

Previous Discoveries Leading to Davy’s Understanding of Electrochemical Processes and “Cathodic Protection”

Humphry Davy quickly adopted and contributed to the electrochemical technology developed by luminaries such as Luigi Galvani [9],  Alessandro Volta [10], Nicholson and Carlisle [11] and others. An example of the terrific electrical power he was able to produce can be seen in Figure 1 which shows the battery banks below a lecture theatre where he was demonstrating electric arc lighting. The portrait of Davy in Figure 2 includes a typical Voltaic pile (typically consisting of alternating stacks of brine-soaked cards sandwiched between pieces of copper and zinc or other combinations of dissimilar metals), a common feature in portraits of electrochemical scientists.

This background placed Davy in a perfect position to investigate a costly corrosion issue for the British Navy. In 1822, Davy was first approached by the British Navy Board to provide advice regarding the corrosion of copper sheeting on the Royal Navy’s timber ships [5]. The copper sheeting was effective at protecting the ships’ timber from worms and preventing the growth of “weeds” which otherwise had the effect of slowing the ships movement through the water. Davy read the board’s letter to the Council of the Royal Society of which Davy was President. The Council formed a committee (with Davy as President) to investigate the matter and decided to test copper specimens supplied by the Navy. Davy eventually dispensed with the committee and began working personally on the problem in 1823, reported directly to the Admiralty on 17th January 1824 and then read a groundbreaking paper to the Royal Society on 22th January 1824.

Davy’s Paper of January 22nd, 1824

This, Davy’s first paper on CP, proves the ability of CP to prevent corrosion. There may well be other consequences, but the beneficial effect upon corrosion was unambiguously proven and is not in dispute.

Let’s look at some of the key issues raised in this first paper:

Davy, along with his assistant Michael Faraday, proved incorrect the general supposition at the time that the “rapid decay” (i.e. corrosion) of copper was due to impurities, surmising that “pure” copper was acted upon more rapidly than the specimens which contained alloy (although the type of alloying was not provided) and that “changes” (corrosion) in various specimens of ships copper collected by the Navy Board “… must have depended upon other causes than the absolute quality of the metal”. The quality of the metal is important but other factors were also believed by Davy to play a critical role including “temperature, the relative saltness (sic.) of the sea, and perhaps the rapidity of the motion of the ship; circumstances in relation to which I am about to make decisive experiments” [2].

Davy described “the nature of chemical changes taking place in the constituents of sea water by the agency of copper” and especially the importance of oxygen in the process.

Davy repeats his hypothesis from 1807 [12] (read 20 November 1806) “that chemical and electrical changes may be identical”; a feature clarified and enumerated by his assistant Michael Faraday [4] several decades later with what is now popularly called Faraday’s Law of electrochemical equivalence [4]. Davy then describes how, by this hypothesis, “that chemical attractions may be exalted, modified or destroyed, by changes in the electrical states of bodies”. In other words, change the electrical state from its natural positive or negative state (i.e. change the potential, another word not yet in electrochemical use) and you will cause the chemistry to change. Davy then notes that it was the “application of this principle that, in 1807, I separated the bases of the alkalies from the oxygene with which they are combined and preserved them for examination; and decomposed other bodies formerly supposed to be simple”.

All of these past works by Davy led him “to the discovery which is the subject of this Paper”.

It is a testament to Davy’s scientific method that he supported his hypothesis by past research results, created an understanding of the processes involved and then went on to test it in the laboratory and with full scale trials, collecting and analysing the data for comparison with the predictions of the hypothesis.

Once he had established the basis of his hypothesis, he went on to suppose that if copper “could be rendered slightly negative, the corroding action of sea water upon it would be null; (i.e. polarise the copper negative) and whatever might be the differences of the kinds of copper sheeting and their electrical action upon each other (i.e. galvanic effects), still every effect of chemical action must be prevented, if the whole surface were rendered negative” He then astoundingly says “But how was this to be effected? I first thought of using a Voltaic battery; but this could be hardly applicable in practice”. So, Davy first thought of using an impressed current CP system! He could hardly know that future DC power supplies would make impressed current an easy and common means of cathodically polarising a structure. Davy then says “I next thought of the contact of zinc, tin, or iron”; i.e. galvanic anode CP.

Davy, assisted by “Mr Faraday” then conducted a series of experiments using these three metals to mitigate corrosion on copper. He then reports that although tin was initially effective, “it was found that the defensive action of the tin was injured, a coating of sub-muriate (chloride compound of tin) having formed, which preserved the tin from the action of the liquid”; the tin chloride deposits reduced the effectiveness of tin as an anode. “ With zinc or iron, whether malleable or cast, no such diminution of effect was produced”. Davy now knew for certain that he had effective anodes for the galvanic CP of copper.

Davy and Faraday then proceeded to conduct numerous experiments using zinc and iron in various shapes and sizes attached to copper, including small pieces “as large as a pea”, wires, nails, sheets connected directly by wires, filaments, soldering etc, and always with areas of zinc or iron much smaller than the copper being protected.

Near the end of the paper Davy notes “…. that small pieces of zinc, or which is much cheaper, of malleable or cast iron, placed in contact with the copper sheeting of ships, which is all in electrical connection, will entirely prevent its corrosion”. It is an important note by Davy that the iron anodes were much cheaper, and we will return to this issue when discussing the next two papers presented to the Royal Society.

Finally, Davy says that in future communications he might describe other applications that the principle can be used “to the preservation of iron, steel, tin, brass, and various useful metals”. He was definitely aware that
the principle is widely applicable to any metal or alloy, a feature we enjoy today [13].

Davy’s Paper of June 17th 1824, Additional Experiments and Observations

Davy reports the results of sheets of copper connected to zinc, malleable and cast iron for many weeks in Portsmouth Harbour. He notes that cast iron, which is the cheapest and most easily procured of the materials tested “is likewise most fitted for the protection of copper” and lasts longer than malleable iron or zinc. Davy later however, after further research, recommends a preference to use zinc anodes rather than iron [3].

Davy anticipated and observed “the deposition of alkaline substances” on the copper being “carbonated lime and carbonate and hydrate of magnesia”. Nicholson and Carlisle had discovered the decomposition of water using a voltaic pile [11] (described by Davy as a “capital fact” [7]) and included a description of “the separation of alkali on the negative plates of the apparatus”, hence Davy’s anticipation. These now familiar calcareous deposits of calcium carbonate and magnesium hydroxide are crucial to
the efficiency of CP systems in seawater. Davy was clearly aware of the increase in alkalinity at the cathode and acidification at the anode.
(Note: Even though the concept of pH and the quantification of acidity
and alkalinity was not formulated until 1909 [14], Davy talks extensively about the alkalinity and acidity produced during galvanic coupling of different metals).

Davy also understood and documented that when the calcareous deposit completely covered the copper sheets, it could result in “weeds” and “insects” collecting on them. Davy then considers the amounts of calcareous deposits generated by various quantities of anode material. He found that using zinc and iron anode to copper area ratios from 1/35 to 1/80, the copper became coated with calcareous deposits but “weeds” eventually adhered to the surface as well. He then reports that when the ratio was reduced to 1/150 “… the surface, though it has undergone a slight degree of solution, has remained perfectly clean; a circumstance of great importance as it points out the limits of protection; and makes the application of a very small quantity of the oxidable metal, more advantageous in fact than that of a larger one”. So, Davy here cautions about the excessive application of anodes for the specific protection of copper in seawater when fouling is unwanted and illustrated that fouling could also be mitigated if careful selection of the anode quantities was made for the specific circumstances in which they were used.

Davy’s Paper of June 9th 1825, Further Research

Davy’s full-scale trials were generally very successful, certainly he prevented the copper corrosion, and he makes the comment that the fouling was usually not an issue if the vessel is on the move. He notes that mooring stationary in harbour allows calcareous deposits to form more readily (surface pH will rise more than when in motion) and weeds etc can adhere. He also mentions the quality of the copper may be important and that the proportion of the anode: cathode area ratio affects deposits.

He observed that the marine growths are often initiated on the iron oxides deposited near the anodes (“protectors’’); he recommends here a preference to use zinc anodes rather than iron, “Zinc, in consequence of its forming little or no insoluble compound in brine or seawater, will be preferable to iron …”

Davy defends his work from page 341 onwards in his 1825 paper where he says “A false and entirely unfounded statement respecting this vessel (the 28-gun “Sammarang”) was published in most of the newspapers, that the bottom was covered in weeds and barnacles. I was present at Portsmouth soon after she was brought into dock: there was not the smallest weed or shell-fish upon the whole of the bottom from a few feet round the stern protectors to the lead on her bow.” He goes on to describe other instances of fouling and non-fouling when protected and at least attempts to understand the various circumstances.It appears that cast iron anodes were used in most of the field trials on ocean-going copper sheathed ships. For instance, Davy states in the Bakerian Lecture of 1826 (p. 420) [7], when discussing the field trials and operations “… in the only experiment in which zinc has been employed for this purpose in actual service, the ship returned … perfectly clean”. Davy wanted to conduct further experiments on ships in service, because the mitigation of corrosion was proven and fouling only occasional for reasons he thought could have been elucidated by further work.

It seems reasonable to expect the vessel captains, wanting the most from the protection system, to add iron anodes at possibly excessive rates since they were relatively cheap, easily procured and then complain that fouling was unacceptable. This is corroborated by Davy’s observation [3] when discussing several ships returned from the West Indies that “The proportion of protecting metal in all of them has been beyond what I have recommended, 1/90 to 1/70; yet two of them have been found perfectly clean, and with the copper untouched after voyages to Demarara; and another nearly in the same state, after two voyages to the same place. Two others have had their bottoms more or less covered with barnacles; but the preservation of the copper has been in all cases judged complete”. Davy was therefore not reluctant to report fouling on some ships but balanced this with positive reports. Clearly it was possible to obtain both corrosion protection and no fouling; it would just require continued methodical research (and with ship owners/captains installing the recommended quantities of anodes rather than excessive amounts).

On the issue of fouling, F. James’ otherwise excellent article on Davy [5] claims that “Davy does not seem to have appreciated the side effect, and he was certainly unable to overcome it”. This is incorrect on two points; Davy did appreciate the issue if one refers to the scientific articles as we have above where Davy addresses this specific issue and he was in the throes of trying to better establish the conditions in which corrosion mitigation and acceptable amounts of fouling could be achieved. Unfortunately, ongoing pressure finally led the Admiralty to issue orders to the Navy Board on 19 July 1825 to discontinue the project [5], thus ending further research just two years after first being initiated. The historian S. Ruston, in an essay discussing Davy as the philosopher [6], seems to draw heavily on James’ article where Ruston writes “Unfortunately, what had worked in the laboratory did not work at sea …”. This is incorrect since there was no disputing that the corrosion was fully mitigated; it worked perfectly well and was the original aim of the Admiralty’s directions, with only fouling being a troublesome and sometimes unacceptable side effect. On this Ruston goes on to write “…the electro-plating (sic.) had a chemical side effect, which stopped the poisonous copper salts from going into the sea and resulted in ships’ bottoms being fouled thus slowing them considerably”. Although Ruston mistakes electrochemical protection used by Davy as “electro-plating”, the essay ignores the actual scientific words of Davy within his papers to the Royal Society where, as discussed above, he understood the effect of calcareous deposits, the effect on fouling and the need to strike a practical balance between corrosion protection and fouling.

There was a lot riding on Davy’s work and competition from other inventors tied with the newspapers [5]. Plenty of “fake news” and “alternative truths” – not much has changed! If we study these works with our scientific, objective eyes we can establish a good understanding of the success or otherwise of Davy’s work. Davy makes so many great and insightful statements about his observations, many of which are equally valid today. Also don’t forget that he had the greatest assistant one could imagine in Michael Faraday in these works. The veracity of Davy’s publications is not in doubt, especially with Faraday on board.

Today’s Navy

The world’s navies to this day use cathodic protection on virtually every ship, submarine and marine vessel on the oceans and waterways across the globe to mitigate corrosion, both external to the hull and within internal water filled spaces [15-17]. Ships hulls are of course now predominantly coated steel, but Davy would surely have been pleased to know that zinc anodes are still used extensively as shown in Figure 3, using the same basic principles [17]. Impressed current systems are used for larger current demand applications on bigger vessels but even these are often supplemented with zinc anodes around high current demand areas and shielded locations such as sea chests, ballast tanks, propellers or shafts. Aluminium alloy anodes also provide excellent, cost-effective performance in seawater, but zinc is especially versatile when vessels experience waters of varying salinity such as estuaries and harbours with freshwater inflow.

Conclusions

Although the intent of this paper is to focus on Davy’s work, it is important to note that in the decades and now centuries following Davy’s work extraordinary advances were made in the understanding of the science that underpins CP [13, 18, 19], amongst other fields of science and engineering, this included:

•Michael Faraday’s discovery and experimental proof about the electrochemical equivalence between electric current and corrosion already mentioned.

•Josiah Gibbs’ development of the thermodynamics that lets us determine whether an electrochemical reaction can occur.

•Julius Tafel’s investigations and descriptions during the 1890’s and early 1900’s about how changes in the metal potential can regulate the anodic and cathodic reaction rates and

•Walther Nernst who showed how the potential of a metal could be calculated if the concentrations of reactants and products were known and in doing so, the stability of chemical species could be predicted if the potential and pH were known.

•Marcel Pourbaix summarised all of these features into his first beautiful Pourbaix diagrams [20, 21].

•Mears and Brown [22] also provided a clear kinetic description of CP in 1938 that is still valid today.

•R. J. Kuhn [23, 24] first suggested the earliest criterion for CP of polarising to -0.85 VCSE or more negative, which was shown to be suitable for steel, not only in seawater [25] but also in soils [26].

The increase in pH at the metal surface [27] and the subsequent development of passive oxide films during cathodic polarisation and their role in mitigating corrosion for steel, when considering both the kinetics and thermodynamics, is now well established for iron and steel alloys [28-30] and our deeper understanding continues to evolve, as good science always does.

Role of Calcareous Deposits

•It was recognised very early on [31] that the primary protective action of the calcareous deposits is to; (i) act as a barrier to oxygen or other depolarisers, (ii) increase the internal resistance of the local corrosion cells and (iii) increase the pH of the water film in contact with the metal surface above that of normal seawater. The benefits to marine cathodic protection systems are now well known, particularly in reducing the current density requirement for corrosion mitigation [31-35], a feature reflected in various industry standards for marine structures [36-38].

•The formation of calcareous deposits anticipated and observed by Davy is also still of special interest today and the circumstances of their formation continue to be investigated [17, 39]. R. J. Kuhn [24] also noted the formation of calcareous deposits that varied from “… practically nothing in neutral areas to an inch in thickness in heavily drained areas”, and hence in the degree of the protective or beneficial efficiency.

•The calcareous deposits formed by CP can also have detrimental effects such as accelerated bearing wear in water-lubricated propeller shafts and seizing of hull valves due to clogging [17], or in non-seawater applications such as limiting heat transfer of pumps causing overheating. Means of avoiding these adverse effects continue to be investigated [17], along with understanding the effects of CP upon biofouling [40].

Davy achieved remarkable success even though after 200 years, issues with the protection of metals and alloys using CP are still the subject of ongoing research and refinement. The future remains bright, with vigorous research continuing worldwide into CP, advancing the science and range of applications to an ever-widening array of structures. Science never sleeps and no doubt each new generation of scientists and engineers will, bit by bit, keep adding to our knowledge and advance Davy’s legacy.

References

1. Davy, H. (1824) OVI. On the Corrosion of Copper Sheeting by Sea Water, and on Methods of Preventing This Effect; and on Their Application to Ships of War and Other Ships. Philosophical Transactions of the Royal Society of London 114 January 22, 1824 151-158

2. Davy, H. (1824) XII. Additional Experiments and Observations on the Application of Electrical Combinations to the Preservation of the Copper Sheathing of Ships, and to Other Purposes. Philosophical Transactions of the Royal Society of London 114 June 17, 1824 242-246

3. Davy, H. (1825) XV. Further Researches on the Preservation of Metals by Electrochemical Means. Philosophical Transactions of the Royal Society of London 115 June 9, 1825 328-346

4. Faraday, M. (1834) On Electro-chemical Decomposition, continued (part of Experimental Researches in Electricity – Seventh Series). Philisophical Transactions of the Royal Society of London 124 77-122

5. James, F. A. J. L. (1992) Davy in the dockyard: Humphry Davy, The Royal Society and the electrochemical protection of the copper sheeting of His Majesty’s ships in the mid 1820s. Physis 29 205-225

6. Ruston, S. (2019) Humphry Davy: Analogy, Priority and the “true philosopher”. AMBIX 66 (2-3, May-August) 121-139

7. Davy, H. (1826) The Bakerian Lecture. On the relations of electrical and chemical changes. Philosophical Transactions of the Royal Society of London 116 383-422

8. Cherry, B. and Green, W. (2021) Corrosion and Protection of Reinforced Concrete, CRC Press

9. Galvani, L. (1791) De Viribus Electricitatis in Motu Musculari Commentarius (A Commentary on the Powers of Electricity in Muscular Motion). De bononiensi scientiarum et atrium instuto atque academia Commentarii 7 363-418

10. Volta, A. (1800) On the Electricity Excited by the Mere Contact of Conducting Substances of Different Kinds. Philosophical Transactions of the Royal Society of London 90 403-430

11. Nicholson, W. (1800) Account of the Electrical or Galvanic Apparatus of Sig. Alex.Volta and Experiments performed with the same. Nicholson’s Journal of Natural Philosophy, Chemistry and the Arts 4 (July) 179-191

12. Davy, H. (1807) The Bakerian Lecture, on some chemical agencies of electricity. Philisophical Transactions of the Royal Society of London 97 1-56

13. Ackland, B. G. (2012) Cathodic Protection – It Never Sleeps. In: Corrosion and Prevention 2012, Plenary no. 4, Melbourne: 11-14 November 2012, Australasian Corrosion Association

14. Sörensen, S. P. L. (1909) Enzymstudien. II. Mitteilung. Über die Messung und die Bedeutung der Wasserstoffionenkoncentration bei enzymatischen Prozessen [Enzyme studies. 2nd Report. On the measurement and the importance of hydrogen ion concentration during enzymatic processes]. Biochemische Zeitschrift (in German) 21 131-304

15. Morgan, J. (1987) Cathodic Protection. Second ed, National Association of Corrosion Engineers, Houston, Texas

16. von Baeckmann, W., Schwenk, W. and Prinz, W. (1997) Handbook of Cathodic Corrosion Protection, Gulf Professional Publishing

17. Dylejko, K., Neil, W. (2024) Plenary Lecture – Cathodic Protection and its Implications for Vessels in the Royal Australian Navy. In: Australasian Corrosion Association Conference 2024, Cairns, Australia

18. Ackland, B. G. (2005) P.F. Thomson Memorial Lecture – Cathodic Protection – Black Box Technology? In: Corrosion and Prevention 2005, paper no. 4, Brisbane, Australia, Australasian Corrosion Association

19. Martinelli-Orlando, F., Mundra, S. and Angst, U. M. (2024) Cathodic protection mechanism of iron and steel in porous media. Communications Materials 5 (1) 2024/02/16 15

20. Pourbaix, M. (1945) Thermodynamique des solutions aqueuses diluées. Représentation graphique du rôle du pH et du potentiel. Delft

21. Pourbaix, M. (1974) Atlas of Electrochemical Equilibria in Aqueous Solutions, National Association of Corrosion Engineers

22. Mears, R. B. and Brown, R. H. (1938) A Theory of Cathodic Protection. Transactions of The Electrochemical Society 74 (1) January 1, 1938 519-531

23. Kuhn, R. J. (1933) Cathodic Protection of Underground Pipe Lines from Soil Corrosion. API Proceedings 14 (Section 4) 153-167

24. Kuhn, R. J. (1928) Galvanic Current on Cast Iron Pipes – Their Causes and Effects – Methods of Measuring and Means of Prevention. In: Soil Corrosion Conference, Washington: December 10, Bureau of Standards

25. Schwerdtfeger, W. J. (1958) Current and Potential Relations for the Cathodic Protection of Steel in Salt Water. Journal of Research of the National Bureau of Standards 60 (3) March 1958 153-159

26. Schwerdtfeger, W. J. and McDorman, O. N. (1951) Potential and Current Requirements for the Cathodic Protection of Steel in Soils. Journal of Research of the National Bureau of Standards 47 (2) August 1951 104-112

27. Kobayashi, T. (1974) Effect of Environmental Factors on the Protective Potential of Steel. In: Proceedings of the 5th International Congress on Metallic Corrosion, Houston, Texas, NACE

28. Angst, U., et al. (2016) Cathodic Protection of Soil Buried Steel Pipelines – A Critical Discussion of Protection Criteria and Threshold Values. Werkstoffe und Korrosion 67 (11) 1135-1142

29. Angst, U. (2019) A Critical Review of the Science and Engineering of Cathodic Protection of Steel in Soil and Concrete. Corrosion 75 (12) 1420-1433

30. Freiman, L. I., Kuznetsova, E.G. (2001) Model Investigation of the Peculiarities of the Corrosion and Cathodic Protection of Steel in the Insulation Defects on Underground Steel Pipelines. Protection of Metals 37 (5) 484-490

31. Humble, R. A. (1948) Cathodic Protection of Steel in Sea Water With Magnesium Anodes. Corrosion 4 (July) 358-370

32. Wolfson, S. L. and Hartt, W. H. (1981) An Initial Investigation of Calcareous Depsoits Upon Cathodic Steel Surfaces in Sea Water. Corrosion 37 (2) 70-76

33. Ryan, L. T. (1954) Cathodic protection of steel-piled wharves. Journal of the Institute of Engineers, Australia 26 (7) 160-168

34. Humble, R. A. (1949) The Cathodic Protection of Steel Piling in Sea Water. Corrosion 5 (September) 292-302

35. Hartt, W. H., Culberson, C. H. and Smith, S. W. (1984) Calcareous Deposits on Metal Surfaces in Seawater – A Critical Review. Corrosion 40 (11) 609-618

36. ISO 15589-2 Oil and gas industries including lower carbon energy — Cathodic protection of pipeline transportation systems, Part 2: Offshore pipelines.  (2024).

37. DNV-RP-B401 Cathodic protection design.  (2021).

38. AS 2832.3 Cathodic Protection of Metals Part 3: Fixed Immersed Structures.  (2005).

39. Carre, C., Zanibellato, A., Jeannin, M., Sabot, R., Gunkel-Grillon. & Serres, A. (2020) Electrochemical calcareous deposition in seawater: A review. Environmental Chemistry Letters 18 1193-1208

40. Vuong, P., McKinley, A. & Kaur, P. (2023) Understanding biofouling and contaminant accretion on submerged marine structures. npj Materials Degradation 7 Article 50, https://doi.org/10.1038/s41529-023-00370-5

Fellow’s Corner

Fellow’s Corner

Fellows Corner

This series of articles is intended to highlight industry-wide engineering experience, guidance and focussed advice to practising technologists. It is written by ICorr Fellows  who have made significant contributions to the field of Corrosion Management.

B S Wyatt is an ICorr Past President, a member of the CP Governing Board (CPGB) and CEOCOR Immediate Past President. Brian is an independent Consulting Corrosion Engineer, a CP specialist in applications for steel in soils, waters and concrete. Experienced in design, performance assessment, detailed survey techniques and remedial work for:

• Onshore buried and offshore pipelines
• Offshore new build and retrofit CP for oil, gas and renewables structures
• Internal and external surfaces
• Coastal and port/harbour structures
• Steel in concrete for bridges, tunnels and buildings.

Brian is an expert witness in multiple sectors of CP, he has carried out technical consulting and project management of large and complex CP systems. He is a UK Nominated Expert by BSI for CEN/TC219 and ISO TC156/WG10. He is active in the ICorr Training, Examination and Certification of CP personnel in accordance with BS EN ISO 15257. Brian has competence Certification to ISO 15257 Level 4 in all 4 Sectors: Buried, Steel in Concrete, Marine and Internals and Certification to Level 5.

The Role of an Expert Witness

Introduction

I have been requested by the Editor to submit a paper on the role of an expert witness. For reasons I will explain below, this is quite a difficult task, but I will do my best within the necessary confidentiality of cases in which I have been appointed to this role.

There are several other Fellows of ICorr working as expert witnesses. Some, like me, only occasionally undertake such work, others have chosen this activity as a major part of their fee earning activities. One is resident in and very active in the USA.

I explain below, how I assess approaches from legal teams and determine if I think I am suitable for, and if I am prepared to act as an expert, in the case in which they are involved.

For those readers who have not experienced technical or construction disputes, and whose exposure to the actions of expert witnesses may be limited to newspaper reports of criticisms of expert witnesses, or the reported inadequate understanding of expert witness testimony by the courts, for example in UK medical negligence cases, or to fictional US cases in criminal cases, please be ready to be disabused.

General Rules

Firstly, the rules for expert witnesses are quite different in the UK and the USA. I have taken guidance in the summary below from the Global Arbitration Review1 and from Bond Salon2.

England and Wales have established the Civil Procedure Rules: Rules and Directions, Part 35 (CPR Part 35)3, which set out the requirements for expert evidence, specifically requiring that an expert witness has an overriding duty to the court to be independent and impartial. As a result, ‘experts should constantly remind themselves through the litigation process that they are not part of the Claimant’s or Defendant’s “team” with their role being the securing and maximising, or avoiding or minimising, a claim for damages. Although experts always owe a duty to exercise reasonable skill and care to those instructing them, and to comply with any relevant professional code, as CPR 35.3 expressly states, the experts have at all times, an overriding duty to help the court on matters within their expertise. That they have a particular expertise and the court and parties do not (save in some professional negligence claims) mean that significant reliance may be placed on their analysis, which must be objective and non-partisan if a just outcome is to be achieved in the litigation.4

From Ref 1 ‘The UK judiciary has made criticisms of expert evidence in, for example, ICI v. Merit,[15] Riva v. Fosters,[16] Energy Solutions v. NDA[17] and Russell and Anor v. Stone,[18] which highlighted that a ‘hired gun’ who pretends to be independent is of little help to a tribunal and may damage the position of the instructing party. It may cause the parties to incur higher expenses in the whole proceedings, prevent any settlements or render the expert evidence of little assistance to the tribunal. An expert must maintain objectivity and independence. The English courts have given many judgments regarding the bias of experts; for instance, in Jones v. Kaney,[19] the Supreme Court of the United Kingdom removed the immunity of an expert witness from lawsuits for negligence.’

Expert witness reports are required to contain a ‘statement of truth’ which would typically be in the following form:

‘I confirm that I have made clear which facts and matters referred to in this report are within my own knowledge and which are not. Those that are within my own knowledge I confirm to be true.

The opinions I have expressed represent my true and complete professional opinions on the matters to which they refer.

I understand that proceedings for contempt of court may be brought against anyone who makes, or causes to be made, a false statement in a document verified by a statement of truth without an honest belief in its truth.’

In one case in which I was involved, I was asked to attend chambers of the leading barrister who would be putting the case for the party who had appointed me. One of the expert witnesses for the other party had made claims that I considered to be spurious and that were directly contradicted by a published document that the expert had previously written; I had identified this in my opinion report. The barrister [many of whom can be quite robust] described the expert as a ‘man of straw’ and said that he would ‘enjoy picking the wings off this fly’. The case was settled before the hearing.

In the United States, Federal Rules of Evidence (US FRE) Article VII sets out the requirements governing the rules for opinion and expert testimony, which are less prescriptive. The conduct of expert witnesses, and their overriding duty to serve and assist the court, is not established under the US FRE. I am advised by my expert fellow colleague that there are differing rules in different states.

Corrosion expert witnesses in the USA and elsewhere, must be experienced and have specialized knowledge or skills to offer unbiased opinions to help attorneys, judges, mediators and juries understand complex corrosion issues.  The Daubert Standard5  is now the law in federal court and in other courts over half of the states.   Related to Daubert, attorneys may question expert witnesses if they are knowledgeable in the Scientific Principle6 7, which is intended to eliminate bias.

In the USA, a corrosion expert – before testifying – must stipulate that their scientific or engineering knowledge will assist the court or tribunal understand the facts in issue.  These responsibilities should ensure that expert witnesses are able to play a crucial role in ensuring fair and informed decision making in legal cases.

In international disputes the contract terms will normally have defined the rules and jurisdiction under which any dispute will be subject to arbitration or settlement, if the latter, often by an expert tribunal. In all in which I have been involved the CPR Part 35.3 rules have been applied either formally as these rules by name or by direct copying of their requirements. In large international construction contracts, the parties may have agreed to use a particular form of arbitration to address any disputes; one such is prepared by the United Nations Commission on International Trade Law (UNCITRAL).

With all this being said, the reality is that once appointed, all the information related to the case that the expert requires to properly execute his or her work comes from the instructing party’s legal team, and it is normal for there to be meetings with the legal team and with the instructing party’s personnel who have information on the matters in dispute. Eventually, some of these personnel with intimate knowledge of the matters in dispute will present their own witness statements. During the process there will be a need for legal advice for the expert in respect of procedures for the hearings in court or before a tribunal. Draft expert reports may be commented on by the instructing party’s legal team and barrister(s); however, at no time should the expert be prepared to receive or act on instruction to change his or her expressed opinion. During a long preparation for a hearing there is a risk that a ‘team spirit’ is developed, particularly if there are multiple experts with interlocking expertise; hence the emphasis in Ref. 4 above: ‘Experts should constantly remind themselves through the litigation process that they are not part of the claimant’s or defendant’s “team”, with their role being the securing and maximising, or avoiding or minimising, a claim for damages.’

In all of the expert witness cases in which I have been involved, before tribunals or an arbitration expert, the evidence and the outcome, where it has become known to me, have been strictly confidential. The details remain so. Therefore, my description of the process is necessarily restricted. In cases that are heard in the Technology and Construction Courts  , the CPR Part 35 rules apply, however, the judgements are published.

In my experience a typical process has been:

1. The Initial Contact

A phone call or e-mail, out of the blue, often from a legal professional, but occasionally from a technical or scientific professional with expertise in a related or unrelated field, typically asking guarded

questions regarding expertise, availability and, very soon, regarding conflicts of interests.

This might proceed to the exchange of limited documents regarding the dispute and the parties, under a confidentiality agreement. It is at this point where, historically, I have sometimes declined to be involved, either because I am not comfortable acting for the ‘instructing party’, or I think from the limited information available the instructing party’s case is likely ill-founded or indefensible, or I consider that my expertise is not appropriate for the scope of the case. Where I can, I have pointed the enquirer towards people, often also Fellows of ICorr, who I think are either more competent than I am in that field or more likely to wish to work on the particular case.

If I am interested and available and the key issues are within my expertise and still under confidentiality agreements, there are exchanges of more technical details, sometimes preliminary timetables and suggested fees. It is at this stage, before any appointment that I detail, that I describe, I hope honestly and self-critically, my relevant technical strengths and weaknesses.

2. The Appointment

Typically, quite quickly, a draft engagement letter will be sent by the instructing legal team, detailing who they act for, who are the parties to the dispute, and the jurisdiction which will hear the details of the dispute by way of the claims and counter claims, which may be an Arbitration Board, Tribunal or a Court. The engagement letter may also detail other experts already appointed, providing other expertise [e.g., coating, testing, etc.], and it may outline in more detail the provisional timetable. The legal team will have obtained approval from the court or tribunal for the appointment of experts and their anticipated costs.

The engagement letter will require confidentiality and ‘legal privilege’; likely all documents to and from the expert will be marked ‘Privileged and Confidential – prepared for use in XYZ proceedings. It will require disclosure of any conflicts of interest [which will likely exclude the expert from the proceedings] and either directly or indirectly, compliance with the CPR Part 35 rules. In all such cases, the workload and the attention to detail required are abnormal. I have had multiple boxes of small print A5 files of evidence arrive by courier on a Friday evening with a requirement for initial comments the following Monday morning. Every word on the page of an expert witness report, or ppt. presentation to be used in evidence should be 100% accurate and impossible to be misinterpreted.

In one of the largest cases in which I was involved, I gave evidence for a day and a half and ‘suffered interrogation’ from the most aggressive barrister I have ever met. My expert technical report, which I had worked on for many, many hours, was hardly addressed. I was advised afterwards that he could find nothing of substance in it to challenge, and his challenges were primarily of me and my expertise. Before this long tribunal hearing, I was grateful to have taken part in some expert training in how to deal with such questioning and how to react in front of the tribunal.

3. The Work Process

The overall Work scope typically falls into 4 stages:

• Outline and Scheduling

• Assessment

• Review and Final presentation

• Proceedings

Outline and Scheduling

Initially the expert will be presented with the claims and counter claims from the parties in the dispute, the claimant and the respondent.

At a relatively early stage in the process a draft timetable will be published advising when expert reports are to be submitted, if an ‘experts meeting’ is required, and when court or tribunal hearings are planned. At around the same time a list of experts will be exchanged between the claimant and respondent. This may result in an

assessment of particular areas of expertise being brought to bear on the evidence by one party and the need for the other party to strengthen the expert witness team in this area. It is critical at this time for any appointed experts to be realistic in respect of the limits of their expertise and experience. I have advised a legal team that a particular expert in the team for the other party had expertise beyond mine in what could be a relevant sector, and that the legal team should consider adding another expert in order to competently address matters within this sector.

Assessment

Then the real work begins, with a thorough review of all the available evidence, possibly requesting additional information if any is available, or suggesting additional testing in order to better inform if there is any ‘fault’ or to better determine the impact of any such fault on the required performance of the asset at the core of the dispute. All such requests and any additional data or site visits and their outcomes must be openly shared between all of the parties.

Depending upon the complexity of the dispute there may be many hundreds of relevant documents. Different legal firms have different methods of presenting these to experts, some largely in hard copy bound documents, some in well-constructed and easy to access electronic systems and some in less easy to use systems.

Review and Final presentation

I have been involved in a number of cases as an expert where I have been required to prepare power point presentations for the tribunal or arbitration board. The purpose is to present an accurate summary of the previously prepared expert opinion report which can be presented before the tribunal. Draft expert reports or opinions are presented, and questions can be submitted between claimant and respondent, in order to seek clarity.

It may also be required that experts appointed by both claimant and respondent meet, in what is termed an ‘experts meeting’ with the intention of determining what, if any, matters in dispute can be agreed between the experts, and thus to be removed from,  or closed off in, the later revisions of the expert opinion reports and the eventual proceedings. The intention is to simplify and reduce the costs of the process, whilst retaining the key issues in the dispute to be assessed by the court or tribunal without the distraction of matters that can be agreed. These meetings between experts are normally ‘without prejudice’ and the legal teams for the claimant and respondent may determine not to accept removing the agreed items from the dispute.

Proceedings

Experts should be prepared for the parties to a dispute to reach a compromise agreement in the weeks or even days before the planned court or tribunal hearing. This has happened to me in several cases.In one particularly complex overseas case I had been to the job site for some weeks, collecting more information and, in parallel, preparing the final version of my expert opinion report, along with a power point presentation to be used in the hearing. On the day before my planned time before the tribunal, for which I considered I was well prepared, I was phoned and told to go home; the matter had been settled. At the time I was disappointed, thinking that part of my work was incomplete; on reflection on this and other disputes settled before the planned court or tribunal hearing, the appropriate conclusion is that the expert has, to the best of his or her’s ability, clarified the matters in dispute for the parties and the court/tribunal in order to facilitate an agreed settlement. Job done.

Personal Experiences

Over the years I have been appointed as an expert in cases related to CP failures on sheet steel piles in seawater and saline infills, hot oil pipelines, to district heating schemes, to pipelines in swamps with disputed field joint coating quality, a buried pipeline with disputed field joint coating quality and disputed CP system adequacy, offshore wind farm monopile foundations, ship hull coatings and related CP performance and others. The Figures to the right are NOT from expert witness cases in which I have been appointed [due to confidentiality issues] but examples of some of the sectors in which I work.

External Corrosion on Buried Gas Transmission Pipeline:

The Thames Barrier London (not a dispute but a success where independent experts were assessing the corrosion protection performance)

A project on which I was involved for many hours alongside another Past President of ICorr, David Deacon. David was a respected coating expert, but not a believer in CP. He was persuaded of the efficacy of CP on this project, which was well designed by our mutual expert predecessors and we had the pleasure of assessing their success:

In my non-dispute related experience, often with colleagues, I have investigated and assisted in developing and executing remedies for failed corrosion protection schemes [CP, coatings and other related matters] or as independent technical expert(s) advising employers in complex CP related schemes being designed and executed by others. Much of the same rigour and obligations mandated to be applied in technical or construction dispute resolution outlined above are applicable to these activities. From my personal experience, expert witness work can be significantly disruptive to other professional activities and to personal life, but I have enjoyed the intellectual challenge of attempting to make the evidence to the court, or tribunal, complete, clear, detailed and as far as possible, difficult for a barrister whose role is to demolish my evidence or credibility to the benefit of his or her client, to misinterpret. In all of this, the evidence is not for the barristers, it is for the judge or tribunal panel and is intended to make what can be quite complex and subtle technical matters clear to all.

References

1. https://globalarbitrationreview.com/guide/the-guide-construction-arbitration-archived/fifth-edition/article/expert-evidence-in-construction-disputes-expert-witness-perspective .

2. https://www.bondsolon.com/expert-witness/expert-witness-training/

3. https://www.justice.gov.uk/courts/procedure-rules/civil/rules/part35

Quotation from a Bond Salon briefing note regarding a 2022 dispute.

4. https://www.bailii.org/ew/cases/EWHC/KB/2022/2648.html

5. https://www.law.cornell.edu/wex/daubert_standard.

6. https://legalclarity.org/what-is-an-example-of-the-frye-standard-in-court/

7. Scientific principles give foundation to definitive expert opinions evaluating hypotheses for causation and feasibility for extraordinary claims.

8. https://www.judiciary.uk/courts-and-tribunals/high-court/technology-and-construction-court/

 

 

 

 

CED – Join the New CED Committee

CED – Join the New CED Committee

Institute News, Latest News

We’re rebuilding – and we want you with us

The ICorr Corrosion Engineering Division (CED) is undergoing a major refresh – and we’re looking for passionate corrosion professionals across the UK to help shape our next chapter.

Whether you’re working in energy, infrastructure, materials, asset integrity or beyond – if you care about corrosion and want to share your knowledge, build your profile, and contribute to a growing technical community… we’d love to hear from you.

We’re establishing a new committee to align with our refreshed structure and strategy. This is an exciting opportunity to join a supportive, cross-sector group with a shared vision:

Our Vision: To champion corrosion engineering through connection, collaboration, and contribution – bringing professionals together to share practical insights, tackle emerging challenges, and influence industry best practice.

Who We’re Looking For?

We welcome expressions of interest from individuals who are:

• Based in the UK

•Working in or passionate about corrosion engineering and science

• Keen to contribute their ideas, experience and time

•Interested in building their network, shaping strategy, or supporting technical activities

Whether you’re early in your career or a senior specialist, there’s a place for you.

Committee Opportunities

We’re currently seeking:

• Vice Chair (with possible progression to Chair)

•Working Party Leads – guiding topic-based technical communities

•Committee Members – supporting events, outreach, and growth

Working Parties – Lead or Get Involved

As part of our revitalised structure, we’re forming broad, strategic working parties designed to be more inclusive, collaborative, and aligned with industry challenges:

Each group will meet 2–3 times a year and contribute to events, discussions, and outputs.

What’s involved?

We’re a volunteer-led committee and aim to keep involvement flexible, rewarding, and well-supported. Typical contributions include:

• Bi-monthly online committee meetings (30–60 mins)

• Working Party involvement (2–3 short meetings per year)

• Helping shape or promote our events and outputs

• Supporting outreach, mentoring, or knowledge-sharing

Key Annual CED Events

•ICorr CED One-Day Technical Conference

    (April – aligned with Corrosion Awareness Day)

• Paul McIntyre Award Presentation & Celebration

• Technical Webinar (November/December)

• ICorr AGM Participation and Reporting

What’s Next for the CED?

Our priorities for 2025–2026

• Rebuild a diverse, cross-sector committee

• Launch working parties aligned to current challenges

• Enhance our online presence and resource hub

• Strengthen collaboration with the Corrosion Science Division

• Celebrate excellence through the Paul McIntyre Award

• Continue growing our flagship events and technical visibility

Interested in Joining?

If you’re motivated by collaboration, knowledge-sharing and professional growth – and want to help move corrosion engineering forward – we want to hear from you.

Get in touch: Danny Burkle, Chair, Corrosion Engineering Division, Email:  CEDchair@icorr.org

CEng Updates

Institute News, Latest News

New application are being processed and assessors are adjustinh to their new roles.  The website is being updated to provide the documentation and processes as per the ICorr direct licence.

Our much-valued assessors come from varied backgrounds to review and assess the applications from ICorr’s wide-ranging membership. These volunteers are contributing to ICorr to support our members to attain the registration status with the Engineering Council.

Anthony Setiadi: Anthony is a chartered engineer currently working for Wood Thilsted, an offshore renewable consultancy. He has more than 20 years in the industry covering various energy and infrastructure roles and studied materials science at the University of Sheffield. He works in materials selection, coating and cathodic protection. He is also supporting ICorr as vice president and has been leading the ICorr registration process for the past 3 years.

Greg Brown: Greg is a senior materials engineer at Mott MacDonald, and he is currently chair of the ICorr Northwest branch. He is highly experienced in destructive and non-destructive testing and is a chartered engineer. He has been part of the Registration committee for the past 2 years.

Jim Preston: Jim is Managing Director of Corrosion Prevention Limited. He has worked in the fields of structural concrete repair and cathodic protection for over 30 years, including 15 years working for contracting organisations and latterly 15 years as a consultant. He is a Chartered Engineer and a Fellow of ICorr. He is a certified Level 4 CP Specialist in accordance with ISO 15257.

Ashokan Gopal: Ashokan Gopal is an electrochemical engineer and an industry-recognised cathodic protection expert in the UK with over 18 years of experience in the field of corrosion mitigation and cathodic protection. He is a chartered engineer with a master’s in corrosion control engineering from the University of Manchester. He is currently the vice-chair for the London ICorr Branch and an active member of the ICorr CPGB, working closely with the industry’s best minds. He is a certified Level 4 CP Specialist in accordance with ISO 15257.

Emilya Abdullayeva: Emilya is a senior corrosion engineer in SLB with 20+ years of experience in corrosion engineering, integrity chemicals, and microbiological control across upstream oil and gas operations. She has a master’s degree in engineering oil and gas and a PhD in corrosion inhibitors and MIC control in the oil and gas industry. Chartered Chemist from the Royal Society of Chemistry and Chartered Engineer from ICorr.

Ibtesam Hasan: Ibtesam is a chartered metallurgy and materials engineer with over 20 years of experience in offshore oil and gas. He currently manages P&L for IMR operations for the Fugro Middle East office. He holds degrees in metallurgy and materials and a PgD in corrosion control engineering, complemented by NACE and API certifications.

Azri Aziz: Azri is a chartered engineer and currently works as a senior corrosion engineer at Aramco. He has 14 years of experience in corrosion engineering and integrity management within the oil and gas industry. He holds a degree in Materials Engineering and an MSc in Corrosion Control Engineering, complemented by professional certifications from the American Petroleum Institute (API) and AMPP. Azri has a strong track record of developing and implementing integrity management strategies, ensuring asset reliability and driving industry best practices in corrosion control in operating assets.

Lian Ling Beh: Lian is a chartered engineer and professional member of ICorr. She is a materials and corrosion engineer with nearly 20 years of experience in asset integrity and management in the North Sea. Currently supporting operations across BP’s NS assets, providing consultation to multidisciplinary teams, including pressure systems, pipelines, mechanical and rotating equipment, structural integrity and lifting equipment.

Olubayo Latinwo: Olubayo is an asset integrity specialist with over 20 years’ experience across international oil and gas assets. He earned his PhD in Engineering Materials in 2012. Olubayo is a professional member of ICorr, IOM3 and IAM. He is also a Chartered Scientist and Chartered Engineer with the Science and Engineering Council, respectively, and also has multiple qualifications with AMPP and API. He has been part of the Aberdeen Branch of the Institute of Corrosion for 6 years in various roles, including Vice Chair. He has also been a formal PAC assessor for the MICorr grade for over 4 years with the Institute of Corrosion.

Syed Umair Niaz: Syed is a Chartered Scientist and Chartered Engineer with nearly 15 years of experience, having a degree in mechanical engineering with a strong focus on corrosion management, coating selection, and welding integrity. He has authored numerous publications in these fields and currently works with EDF France, based in the UK, leveraging his expertise to drive innovation and excellence. He is also serving ICorr as a member of the Professional Assessment Committee (PAC) and an assessor for CEng registrations.

For all Chartership enquiries, please contact Greg Brown at Ecreg@icorr.org

ISO 15257 Level 4 Cathodic Protection Examination dates for 2026

Institute News, Latest News

LEVEL 4 ENGINEER EXAMINATIONS TO BS EN ISO 15257

Level 4 Certification of Competence is a requirement for the design of Cathodic Protection (CP) systems in all the BS, EN and ISO Cathodic Protection Standards. See the attached brochure on the ICorr CP Scheme and the Standards for more details.

It is expected that Candidates will already have Certification for Level 3 in the Sector in which they are applying and the requisite experience (see Preliminaries item 8 below). They must have passed the L3 Examination in that Sector, there is no dispensation.

Examinations:

All Level 4 examinations are presently held in Northampton at the Institute of Corrosion HQ, Corrosion House; see https://www.icorr.org They will be held typically 4 times per year; the facility is spacious, complies with UK Governments rules and guidance related to C-19. It is a short walk from the station; there is a modern budget hotel and parking nearby. Candidates are required to book one of the dates below; no other dates will be available. If one date does not suit you, choose another from the list. If there is limited demand for a particular date, we may cancel that from the programme and allocate your booking to the next examination date, whilst advising you. We will strive to avoid delaying your examination by more than 3-4 months. The examination is closed book, desk based, handwritten, with no practical element (this is in the mandatory L3) and is expected to take some 6.5 Hours, in 3 sessions with breaks between. A simple calculator, a Casio FX-991EX) will be provided; you will not be permitted access to any other electronic device. IF you are sitting the examination for more than one Sector (Buried, Steel in Concrete, Marine, Internals) you will need to sit for more than one date of those below:

Thursdays: 2026: 26 February, 4 June, 10 September, 26 November     

Examination arrangements are:

Book and pay for the Examination at least 1 month before the date you plan to attend. Do not attend unless you have confirmation of your place from Corrosion House.

Start 0900 Hrs: Book in, identification (passport or driving licence with picture), remove mobiles, laptops, smart watches, calculators to locked facility. No access to these during the day. Tea or coffee.

Expect to start examination at 0930 Hrs

Core: Applies to all Sectors: 2.5 Hours, 0930 to 1200 Hrs If you have previously passed the Core Examination, you may, after notifying Corrosion House, plan to arrive no later than 1215 Hrs to book in as above and be ready to commence as below, or you can arrive during the morning and finish early:

Break for lunch (provided)

Design Sector Specific: 2 Hrs, 1245 to 1445 Hrs

Break for tea or coffee

Performance Assessment: Sector Specific: 2 Hrs, 1500 to 1700 Hrs

Collect mobiles, laptops, calculators etc and depart building 1715 Hrs

Preliminaries:

  1. It is expected that candidates will only be sitting the Level 4 ISO 12527 examination if they are planning to apply to ICorr for certification for Level 4. This is an entirely separate process. It requires a separate application form and a certification fee; it involves an independent assessment of the candidate’s work experience, a refereed Application and a Dossier detailing completed complex projects.
  2. All Candidates must be competent in all the key tasks and knowledge required at Level 3 in the CP Sector for which you are applying at Level 4. Accordingly, you must have a valid Level 3 Examination pass in all parts of the examination, the Core, the Sector Specific and the Sector Specific Practical Examination; there is no dispensation available to avoid this.
  3. If you do not already have Level 3 certification and your cv clearly shows that it is likely that you do meet the experience requirements for Level 4, you can sit the Level 3 examination without attending the Level 3 Course. This includes the Level 3 Practical examination in the Sector(s) applicable to your intended Level 4 application(s). If you pass the examinations, you may choose to obtain L3 certification, but need not delay your application for L4, but if you fail the certification for L3 you will fail for L4.
  4. At present there are no ICorr Level 4 Courses; you are expected to have learned the skills and gained the competence by working alongside CP Engineers or Specialists more experienced than you, preferably Certificated to Level 4, and by personal study and attending conferences and courses. This is expected to have taken some years of supervised design and other challenging CP work after your Level 3 certification.
  5. The main difference between L3 and L4 is that the latter requires the competence and the experience of undertaking, without guidance, complicated and detailed CP designs. The full requirements are summarised as being competent in the of design cathodic protection systems, to establish and validate cathodic protection criteria and testing procedures, to interpret standards, codes, specifications and procedures, to designate the particular cathodic protection test methods and procedures to be used, to interpret the reported results of cathodic protection testing and use them in performance verification, to determine any remedial actions and to carry out and supervise all Level 1,2 and 3 duties.
  6. Level 4 personnel shall have a detailed knowledge of corrosion theory, cathodic protection design, installation, commissioning, testing and performance evaluation including safety in at least one application sector, competence to undertake without supervision the design of complex cathodic protection systems in at least one application sector, sufficient theoretical knowledge and practical experience of cathodic protection to select cathodic protection testing methods, survey requirements and performance criteria. They shall have competence to evaluate and interpret results of cathodic protection performance in accordance with existing standards, codes and specifications, competence to assist in establishing testing and performance criteria where none are otherwise available and a general familiarity with cathodic protection in other application sectors.
  7. The examination is designed to test these abilities. It will be challenging; some candidates will fail.
  8. The separate certification procedure will more rigorously assess these by way of your experience and what you can document in terms of projects, including complex CP designs. Certification to L4 requires 3 to 8 years’ CP experience [dependent on qualifications] if progressing from full Certification at Level 3, or 5 to 12 years’ experience if applying directly for Level 4 after only passing the L3 examination. You may sit the L4 examination early, but the above experience requirements will be used in your certification assessment after you pass the examination. You will need to prepare a detailed dossier detailing more than one and ideally 3 detailed designs in each Sector. You will not achieve certification until your experience has been assessed and you are likely to be interviewed by the ICorr Professional Assessment Committee during this process.

Examination Booking Form