Navigating through challenges within the marine infrastructure construction environment
Source: Andrew Pirrie, Stefanutti Stocks Coastal contracts director. Contributor: Tim Milner, Stefanutti Stocks Coastal bid manager
In spite of major technological advances over the past few decades, it still remains a mammoth task to plan, manage and construct a marine infrastructure project. The process often requires a lot of prudence, even more patience, as well as a very healthy respect for the forces of nature. The marine environment is not only a challenging operational environment for a construction team, but also a very taxing environment for construction materials, making it critical to design and construct structures in such a way that it ensures their durability, whilst still offering a low-cost solution to the client. “Our track record of value engineering, quality production and safe operations often forms the basis of our being awarded projects, even when we are not the lowest on tenders,” says Stefanutti Stocks Coastal contracts director Andrew Pirrie.
Design & Construct
Stefanutti Stocks Coastal’s experience within the marine infrastructure sector includes the rich heritage of Civil & Coastal, a niche marine contractor that was established in 1994, and that had, by the time it was fully acquired by Stefanutti Stocks in 2009, become well known for its culture of optimising designs.
Early contractor participation in a project, right from project inception, allows for a design to be optimised to suit not only the operating environment, but also allows for the consideration of appropriate construction methodologies, taking the project location and resources into account. The design & construct project delivery model presents a desirable scenario, that can often result in time and cost saving.
Some of the company’s design and construct highlights date back to the 2004 Saldanha oil jetty berth fender support where an alternative design saw the construction of a “launched” cantilever fender support from an existing caisson on the Saldanha oil jetty berth. This methodology saved Portnet nearly 50% on the postulated scheme by minimising floating plant and employing launch-type construction and pre-cast systems.
In 2009 the design and construction of a new dock as an extension to the existing Malongo Dock in Angola was undertaken, whereby the chosen construction methodology entailed the driving of tubular structural piles (filled with reinforced concrete) followed by the installation of precast concrete trough beams and precast concrete deck slabs, with in-situ infill marine grade concrete between the deck slabs. “The reason for using precast was that the concrete quality in the region was not up to the required standard, therefore all precast work was done in South Africa, and then shipped to Malongo,” explains Pirrie. The in-situ infill concrete was cast using Dieci mini-concrete mixer trucks and using stone, cement and fly-ash shipped from South Africa.
In 2013 the installation of mooring and berthing dolphins for Base Titanium Limited in Kenya saw Stefanutti Stocks propose an alternative solution that entailed the use of prefabricated structural steel headstocks in lieu of reinforced concrete platforms. “The headstocks and structural steel headstocks were concluded simultaneously,” says Pirrie. “This methodology translated into savings on cost and time, effectively killing two birds with one stone.”
Since 2014 a joint venture consisting of Stefanutti Stocks Coastal and its enterprise development partner, Axsys Projects, has been undertaking an upgrade to berths 1-4, 13 and 14 of Maydon Wharf that has seen some technical innovations including the implementation of new techniques never used before in South Africa for the installation of anchor piles as well as the in-situ construction of the submerged fender panels for the cope structure. This project was named the winner of the Railway & Harbour category in the 2016 SAICE-SAFCEC Awards.
Construction fleet & mobilisation
In addition to its years of industry experience and seasoned marine experts, a further asset Stefanutti Stocks Coastal is able to offer its clients is the company-owned specialist marine construction fleet. This plant and equipment can be mobilised, even across the ocean, to where-ever it is required. Furthermore, the contractor’s global marine network, allows it to mobilise appropriate equipment from anywhere in the world to projects that are situated in extremely inaccessible locations.
More often than not the required infrastructure, in terms of specialized equipment, plant and expertise is not readily available in many of the developing countries where marine infrastructure construction projects are undertaken.
As a South African-based marine contractor, mobilising for a local site with supporting transport infrastructure that caters for 21st century traffic conditions is not without its challenges. Mobilising across the ocean, with the accompanying shipping logistics, import and export regulations, and bureaucracy, as well as the long transportation time frames involved, requires precise, long-term planning and a sound logistical strategy. Stefanutti Stocks Coastal has successfully mobilised to a number of countries, including to Kenya, Sierra Leone, Tanzania, Mozambique, and Angola.
“The marine infrastructure construction environment is an incredibly dynamic, constantly changing environment,” says Pirrie. “Even after 25 years in the industry, there is seldom a contract that we undertake that does not provide us with a new challenge, or a new opportunity to find an innovative engineering solution.”