How big things get done – modular construction in marine infrastructure

One of the best books on construction and project management was published on 7 February 2023, titled “How big things get done” a description of the book and its contents is available here .

Understanding what distinguishes the triumphs from the failures has been the life’s work of Oxford professor Bent Flyvbjerg, dubbed “the world’s leading megaproject expert.” In How Big Things Get Done, co-authored with Dan Gardner he identifies the errors in judgment and decision-making that lead projects, both big and small, to fail, and the research-based principles that will make you succeed with yours.

With a study of some 16,000 projects he looked at the project type and their cost and time overruns to find out why. Bent started his study with the Storeb?lt Link in his home country of Denmark which was built in the late 1980’s. I remember this project as it was the subject of a dredging claim with the company I joined in 1991.

An interesting table in the book summarises the projects and their fallout, see below

My background is in marine infrastructure so I was intrigued that Flyvbjerg’s Ports listing is roughly in the middle of the table with a mean cost overrun of 32% with a overrun percentage of 183%. So when port projects go bad the extra costs can really stack up which is confirmed in my own experience. By Ports I assume Bent means this to be marine structures such as jetties, port terminals, quay walls, harbour construction, sea defences revetment construction and shore protection as well as capital dredging through to maintenance dredging and land reclamation.

One of the main takeaways I got from Bent and the table is the importance of “Find your Lego” mention of lego seems quite apt coming from a Dane. The example of the Empire State Building and the importance of modular construction is key.

Then I thought how often have I seen this in marine infrastructure?

At first I thought dredging is not modular in nature as it is always dealing with ground conditions which are highly variable from one location to another but I gave it some further thought and considered my own contract risk profile, seen here below

It struck me that beach nourishment, maintenance dredging and land reclamation are all highly modular in nature. They all share the same characteristic that the same type of dredged material is being moved on a repetitive cycle basis. Claims on beach nourishment & maintenance dredging projects are generally quite rare as projects are repetitive and almost never are due to the type of material being different to that found previously. So Port maintenance dredging is usually annual and removed of accumulated sediments, so highly modular.

However, as we move up the risk curve to land reclamation this is where I have seen that contractor claims increase and significant cost blowouts occur. Yet land reclamation is in my experience also highly modular in nature, how come?.

Land reclamation usually involves sourcing sand from a marine borrow area some distance from the project site and transporting it to build a platform of land. A process of cycle trips usually made by a trailing suction hopper dredger, repetitive so very modular. The majority of claims in my experience were invariably due to poor assessment of the marine borrow area, usually by the Client.

Bent and Dan mention :

? Plan slow, act fast. Getting to the action quick feels right. But it’s wrong.

? Think right to left. Start with your goal, then identify the steps to get there.

The book then gives both good and bad examples of this. That lead me to think about the successful projects in my career which I could see all had this in common. My career started with the Chek Lap Kok Airport in Hong Kong back in 1991. It fits the Plan slow and act fast to a tee!

The Hong Kong Government had and still has a Marine Fill Committee , to manage its strategic sand reserves. These reserves had been extensively mapped and many thousands of samples taken. All this information was available to tendering contractors. So a key uncertainty was removed.

The Chek Lap Kok tender process took over a year (think slow). This gave the tender consortium time to number crunch and optimise the execution method which required the deployment of numerous dredging vessels, more than any one single dredging company had. The winning consortium not only brought the entire free market dredging fleet together (choose the best contractors who have experience) it had the top tier civil companies from both Hong Kong (local knowledge) and experienced Japanese and Australian mass earthwork companies to do the landside works. When the contract was awarded the act fast really came into force with 10 tons of soil removal every second! The dredging consortium further optimised the execution phase (rather like the Empire State Building example) and construction of the airport platform was finished ahead of time and on budget. Win-win for everyone.

Turning to the civil side of marine infrastructure I have seen many claims on jetties, port terminals and quay walls. Construction techniques can be both bespoke or modular. In my experience its when they are bespoke (site specific) that issues arise.

Again as Bent says “Find your Lego” is key.

The following picture shows cross sections of caissions, L-type wall and concrete blocks. All completely modular.

The majority of claims I see are on driven piles, see photo.

What is the known unknown? The ground conditions. The situation is completely bespoke and unique to the Site and depends on the quality and accuracy of the site information. Coupled with this is the fact that the execution method is highly bespoke and invariably influenced by site conditions. So often as far removed from modular as you can get.

That is not to say that care should not be taken with caissions, L-type wall and concrete blocks. Ideally they should be manufactured locally to avoid supply chain issues.

The Tuas Mega Port Project in Singapore did exactly this with 227 caissons, read here

So returning to Bent’s table look at your industry sector and assess how you can make your project as modular as possible.

If you are a Client you should be asking your tenderers to do so for your project, use Early Contractor Involvement to accelerate this. Get key components manufactured off site that can be delivered and bolted into place, delve into the supply chain and look to address supply chain constraints.

To finish on an end quote about ?How big things get done :

“A wise, vivid, and unforgettable combination of inspiring storytelling with decades of practical research and experience . . . Everyone who deals with large projects is already desperate to read this book. The rest of us will take great pleasure in learning from it anyway.”—Tim Harford, author of The Data Detective

#bigthings #bigthingscontest #dredging #earlycontractorinvolvement