The game changers of the dredging industry

JDN's backhoe Il Principe. Credit: Tony Slinn

From DPC’s inception over 52 years ago to this the final issue, the magazine has kept readers up to date with every aspect of dredging. Past editor, Tony Slinn, gives a personal overview of what he sees as the most influential legislation, technological developments, and pioneering marine engineering projects that have changed the industry over the last half century

Dredging is an often misunderstood sector of the maritime world, whose enterprise and world-class engineering abilities continues to play a major role in all our lives. The valuable role it plays in the supply chain makes it susceptible to changing trade patterns and shifting economic landscapes.

Over the past 50 years, the industry has been strongly shaped by legislation, especially in the US, and by technological advancements that has opened the door to advanced computerisation and, quite possibly, artificial intelligence (AI). At the same time, major industry companies have undertaken dredging campaigns that have made a global impact.
Despite being independent, DPC has always been viewed as the ‘house magazine’ of the Central Dredging Association (CEDA) and one of the first things I did as the new editor was to visit general manager Anna Csiti at the secretariat and core company members in the Netherlands and Belgium to find out what was expected.

I was able to expand my contact base at events such as Europort and CEDA Dredging Days, and during that time met then-Eastern Dredging Association (EADA) chairman John Dobson and then-secretary captain David Padman, who later became chairman. EADA did not have an official magazine in my early days, and a deal was struck with DPC taking on the role.

In the years that followed, one EADA major member, the China Dredging Association (CHIDA) became increasingly important – hosting the World Dredging Conference, for example. For a while, there was actually a Chinese-language edition of DPC that I did my best to edit. So what about the Western Dredging Association (WEDA), I thought? It did not have an official magazine, although two US dredging publications were closely allied to it. At this point, I learnt about the Jones Act.

Protected market

Dredgers working in the US must comply with a variety of acts, including the 1920 Merchant Marine Act. Better known as the Jones Act and named after Senator Wesley Jones who introduced it, the legislation regulates all maritime activities in US waters. Essentially, ships have to be built in the US, mostly crewed and owned by US nationals, and sail under the US flag. Apart from emergency waivers, the Jones Act bans all foreign dredging companies from working in the country.

It remains one of the most controversial pieces of legislation still extant and still affecting the dredging industry, as well as the US in general. While attending a WEDA conference in the US, I found myself immersed in an ongoing battle over the 8,460 m3 trailing suction hopper dredger (TSHD) Stuyvesant. The TSHD, though built in the US in 1982, operated under a 50–50 joint venture (JV) between New Orleans company Bean Dredging and Stuyvesant Dredging, which was owned by Dutch giant Royal Boskalis Westminster. Stuyvesant enjoyed ‘grandfather rights’ under the 1992 Oceans Act, allowing it to continue dredging in the country, but competitors accused the JV of stretching those rights … and it all wound up in the courts.

TSHD Stuyvesant working on a beach restoration. Credit: Bean Stuyvesant

DPC ran a story about the controversy, pointing out that US port authorities felt that restricting the JV would reduce competition and force ports and the federal government to pay more for harbour dredging. The article did not go down well with US dredging contractors. To this day I think the Jones Act should be at least heavily amended, or repealed, and it remains very controversial in the country. I was interested to read, in the 6 September 2019 issue of the Houston Chronicle, an article by Chris Tomlinson – ‘Misguided patriotism is strangling US ports and hurting the American economy’.

He pointed out that the non-partisan US Congressional Research Service stated, “The US privately owned dredging fleet is much older and smaller – in terms of capacity, individual vessels, and the total fleet size – compared to the four leading European dredging firms.” Tomlinson also argued that “smaller and older ships, combined with a virtual monopoly, means US firms typically charge 40% more than foreign competitors to move the same amount of sand”.

I think the Jones Act also saps the drive and need to invest in the technology and vessels that have made European contractors so successful. I also found it sad that the great nation that built the Panama Canal in the early 1900s failed to win a single major dredging contract when it was expanded a century later – and the canal’s own two new dredgers were built in the Netherlands by Royal IHC. As Tomlinson summed it up, “Nothing distorts markets like protectionism.”

“A recipe for disaster”

Staying with controversy, and disrupting the normal two-man bridge team of watch officer and dredgemaster, perhaps the greatest technological advance during my editorship was the one-man-operated bridge pioneered by Belgian dredging major DEME and Royal IHC (then simply IHC). It sparked major rows, with one critic calling it “a recipe for disaster”.

The main arguments against the idea centred on the following:

  • Dredgers mostly worked in crowded areas that demanded the watch officer’s full attention
  • A one man-operated bridge placed far more dependence on automation and sensors that could become faulty
  • Data overload and stress could lead the operator to make grave, possibly fatal mistakes
  • It contravened the international requirement set out by the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers

However, DEME’s newbuilding department manager, Etienne Clymans, championed for the one-man-operated bridge system. His counter-argument was that safety, reliability, and efficiency were put under stress by misunderstood commands, wrongly executed actions, and many other concerns.

Discussions with Royal IHC, classification societies, and DEME crew members then began in earnest. Royal IHC had a commission from DEME to build Marieke and Reynaert, sister TSHDs based on the successful 5,400 m3 Pallieter, which was built in 2004. It was decided that both would have one-man-operated bridges. The stakes were high, with Royal IHC stating at the time, “Even the slightest bug could ruin the overall favourable opinion and set the idea back for decades.”

TSHD Marieke was the first to have a one man-operated bridge. Credit: DEME


Extensive simulation and factory acceptance tests resulted in a green light, and Marieke, built in 2006, was the first ship to have a one-man-operated bridge. Sea trials proved it worked and DEME commissioned two more larger TSHDs, the 11,000 m³+ Brabo and Breydel, with more advanced one-man-operated bridge systems. I remember my first impression on seeing the bridge layout: a dredger or the Starship Enterprise?

Palm Jumeirah

Land reclamation was nothing new to the dredging industry, but Palm Jumeirah in Dubai was in a different league altogether. Its shape, with a trunk and 17 fronds, was attributed to the Emirate’s then ruler, the late Sheikh Maktoum bin Rashid al-Maktoum. Creation of the 560-hectare (5.6 km2) project began in 2001.

A USD12 billion project, Jumeirah was the testbed for a controversial building technique. Belgian and Dutch mega contractors Jan De Nul (JDN) and Van Oord convinced the developer, Nakheel, that concrete and steel were not needed to build the foundations; instead rock and sand would do the job despite the size and complexity of the project. The dredged quantities were enormous, totalling around 120 million m3 of sand from borrow areas 6 nautical miles (11 km) off the coast.

The crescent-shaped breakwater was the first section built, to protect the subsequent trunk and fronds. Geotextile membranes held the sand and were themselves held held in place by more than 7 million tonnes of rocks, mostly from Dubai quarries and weighing up to 6 tonnes each. On either side, 100 m wide openings allowed access through the breakwater.

Palm Jumeirah in Dubai. Credit: Van Oord

Creating the fronds involved the dredgers using GPS to spray sand into place with pinpoint accuracy. Vibro-compaction techniques were then used to prepare Palm Jumeirah for its residents, the first moving in during 2007. Today, the 17 fronds are home to about 1,500 beachfront mansions, with another 6,000 apartments on the trunk. Major hotels that are based here include the Atlantis, Palm, and Waldorf Astoria.

Two further Palms were planned:

  • Jebel Ali: while land reclamation was completed, development work stalled due to the 2008 financial crisis
  • Deira: originally set to be eight times larger than Palm Jumeirah, but it was scaled back to a four-island project

The Palms and other reclamation projects in Dubai, such as the 300-island The World – which like Jebel Ali stalled in 2008 though work got under way again in 2018 – all have their detractors, especially for their environmental effects. Although nobody can deny that as dredging and engineering projects, they are world class.

Panama Canal expansion

Worth roughly USD5.25 billion, the Panama Canal expansion programme – also called the ‘Third Set of Locks’ project – was cheaper than Palm Jumeirah. But simply in terms of its global significance on shipping, as well as on Panama itself, it is my number one. It was also a very personal experience; I went to Panama twice during the project, and twice I interviewed Panama Canal Authority (ACP) administrator Alberto Alemán Zubieta. I also got to get on board a variety of dredgers.

Former president Martín Torrijos proposed the expansion project on 24 April 2006. A national referendum backed him with a 76.8% majority on 22 October, and the project formally began in 2007. It was initially announced that the expansion would be completed by August 2014, to coincide with the 100th anniversary of the canal’s opening. However, following various setbacks with construction consortiums and initial seepage from the new locks, the expansion was not opened until 26 June 2016.

It doubled the canal’s capacity by adding two new sets of locks, one each on the Atlantic and Pacific sides, and new channels to those locks. Existing channels were widened and deepened. It allowed New Panamax ships – at up to 12,000+ teu, well over double the previous Panamax limit – to use the canal. Commercial operation began on 26 June 2016, and in its first 20 months of operation the ACP reported that more than 3,000 New Panamax ships had used the new routes. DEME and JDN played huge roles in the project, while Boskalis expanded the Pacific-side of the Port of Balboa.

Suez Canal

In my final year as editor, another project with global impact was getting under way – the overall USD8 billion Suez Canal expansion. The most remarkable aspect of this mega project was its speed, as President Abdel Fattah al-Sisi wanted it completed in a year instead of the expected 3–5 years. And it was. It was also funded almost entirely by Egyptians themselves, taking pride in buying shares.

The expansion added an additional lane to the 193 km long canal, which links the Red and Mediterranean seas and is the shortest shipping route between Europe and Asia. It included 35 km of new waterway cut through the Sinai Desert to flow parallel to the existing canal, plus a further 37 km where existing stretches were dredged to accommodate larger ships.

CSDs expanding the Suez Canal. Credit: Boskalis

A JV consisting of Boskalis, JDN, Middle East-based National Marine Dredging Co, and Van Oord won the major USD1.5 billion contract for the new 24 m deep waterway. The JV dredged 180 million m3, working from both ends. A DEME and US contractor Great Lakes Dredge & Dock JV landed a USD540 million contract to widen and deepen 25 km of the canal, plus a 9.5 km long, 18.5 m deep access channel to the eastern part of the Port of Said.

A huge fleet of the world’s biggest and most advanced dredgers descended on Egypt, carrying out an intricate logistics operation involving thousands of people and that more than 1 million m3 of material had to be dredged every day. Throughout the project, ships continued to sail through the Suez Canal. For me, Boskalis dredging director Bas van Bemmelen summed it up, “Never before has so much equipment been deployed on a dredging project; never have the time pressures on a project been so enormous; and never has there been a project with such high daily production volumes.”

A fitting end to my story, I think you will agree.