PROJECT
INCORPORATING COLD CHAIN
Traditional refrigeration systems treat condenser heat rejection as an unavoidable by-product. In the Belcon plant, that same energy is recovered and redeployed through a heat reclaim loop, providing up to 350kW of usable heating capacity for hot water and sterilisation processes.
“ Once you start viewing heat as a resource rather than a loss, your system design philosophy changes completely. In a CO₂ system, the available discharge gas temperatures are perfect for reclaim – so instead of venting heat to atmosphere, we feed it back into the building’ s process services,” explains Hadfield.
This recovered heat is used for defrost cycles, hot water generation and space heating, dramatically cutting the facility’ s net energy consumption. The approach reflects a broader global trend: thermodynamic integration, where cooling and heating are co-optimised in a single plant.
ADIABATIC COOLING AND WATER REUSE
To complement its heat recovery system, Belcon employs a condensate recovery circuit that collects meltwater and defrost condensate into the 60 000l storage tank. This reclaimed water feeds the adiabatic gas coolers, reducing the need for fresh water and enhancing gas cooler performance during Cape Town’ s warmer months.
“ CO₂ transcritical plants are most efficient when you can manage discharge pressures effectively. The adiabatic system lets us lower gas cooler outlet temperatures, keeping the system in optimal operating
Mobile racking in part of the primary cold room has maximised floor space.
range even on hot days – and we’ re doing it with reclaimed water,” notes Carelson.
This dual focus on energy and water efficiency underscores the broader sustainability intent of the project, aligning with Maersk’ s global decarbonisation goals.
PROJECT OVERVIEW: DELIVERING THE MAERSK BELCON COLD STORE
When Maersk set out to build its Belcon Cold Store in Cape Town, the result became a facility that demonstrates how engineering innovation and teamwork can overcome immense project pressures.
According to MacDonald, the project tested every aspect of project management and technical skill.“ We were only appointed in April 2024 – four months after the project had already begun in December. By the time we came on board, the steel had been ordered and fabrication was already under way. It was one of those situations where you’ re running to catch a moving train.”
Despite the late start, the team pressed ahead under challenging conditions. The company was appointed under a direct contract with Maersk, working alongside FGN and main contractor Abbeydale. This structure, though efficient in theory, required HC Engineering Solutions to shoulder considerable responsibility for co-ordination, detailed design and site execution.
“ Because of our late entry, we had to take on more than the usual scope. We handled the shop drawings, detailed engineering and all the installation co-ordination ourselves – while simultaneously sourcing scarce components and keeping the project on schedule,” says MacDonald.
The Belcon Cold Store was built during a time of global component shortages, particularly in CO₂ refrigeration equipment and stainless-steel piping. Many suppliers were backlogged and shipping delays added weeks to the timeline.
“ We struggled to source even basic CO₂-related components such as valves, fittings and pressure vessels. Everyone in Europe was building similar systems, so supply was tight,” recalls MacDonald. It was also at the commencement of CO₂ systems coming into favour in South Africa.
Compounding the issue, several major design changes were introduced mid-project. The facility’ s initial specification – with holding rooms at + 2 ° C and dispatch at + 4 ° C – was later revised to
colder operating ranges, including-1 ° C in certain areas. These adjustments required new defrost systems, additional evaporator banks and a complete re-engineering of the piping layout.
“ The temperature shift sounds minor, but it fundamentally changes the refrigeration design. We had to redesign defrost systems, revise load calculations and strengthen pipe supports – all while construction was in progress,” explains MacDonald.
ENGINEERING SOLUTIONS AND INNOVATION
The heart of the cold store is its CO₂based refrigeration system, chosen for its energy efficiency and environmental performance. The plant delivers 6.8 MW of cooling capacity, with advanced controls that allow subcritical operation during the cooler months- significantly improving performance and reducing energy use.“ Compared to traditional systems, this design cuts energy consumption by about 20 %. That’ s a big saving for a facility of this scale,” says MacDonald.
To manage the logistical complexity and tight timeframes, HC Engineering Solutions deployed multiple project teams and reinforced its on-site supervision. Senior management spent extended periods on the ground.
The Cape Town winter added its own obstacles. The rainy season began just as site work intensified, forcing teams to operate in muddy, waterlogged conditions. Meanwhile, the plant room was relocated from its original position to an external area, requiring additional re-routing of services and re-supporting of heavy pipework.
“ Some of the supporting steelwork had to be redesigned mid-installation. It was a moving target – but through collaboration and determination, we made it work,” says MacDonald.
Despite the setbacks, the project reached practical completion in April 2025, in time for the first fruit intake, with final TOC( Take- Over Certificate) handover in July.
PURPOSE AND FUNCTION OF THE STERI TUNNELS
One of the standout features of this facility are the steri tunnels. To quote MacDonald:“ Fruit comes in, is inspected, then immediately goes into forced cooling. In this facility we have four screening tunnels, each tucked into a large room with approximately 40 tunnels inside. That large-volume concept means that when the fruit arrives it doesn’ t disturb the room temperature too much, so efficiency is maintained.”
The steri tunnel concept is grounded in the export protocols for citrus from South Africa: for certain markets( such as the US, China and other parts of Asia) the fruit must undergo a cold-sterilisation treatment to eliminate pests such as the False Codling Moth( FCM).
During this treatment, the fruit’ s pulp temperature and ambient temperature must be held within narrow bounds( for example between-0.6 ° C and-1.2 ° C, as in this facility) for the full length of the protocol. MacDonald explains:“ The protocol – first forced cooling, then the last 24 hours a perfect log-lock at the target temp before sealing the container.”
From an engineering viewpoint, the design challenge is significant: the forced-air cooling tunnels must allow rapid removal of field heat, maintain a stable and uniform air / pulp temperature across pallets, ensure minimal thermal shock and interface seamlessly with racking, container loading logistics and downstream export scheduling.
The large-room / 40-tunnel design is advantageous because the large air volume acts as a thermal buffer when pallets are loaded or removed, reducing temperature spikes. The facility also needed staging rooms( holding rooms) and dispatch rooms built to export-standard design and certified by the appropriate authorities.
The steri tunnel therefore serves the dual function of ensuring export-market compliance( phytosanitary treatment) and maintaining fruit quality( by minimising temperature deviations, controlling humidity, preventing condensation and preserving shelf life).
“ The fruit comes in, gets the forced cooling down to between-0.6 and-1.2, the clock starts, and there’ s no mix with other fruit after that point.” This rigorous regime supports South Africa’ s citrus export competitiveness by meeting the strict requirements of destination markets.
LESSONS AND TAKEAWAYS
For HC Engineering Solutions, the project served as a demanding but rewarding experience:
• Late appointment pressure: joining midstream required flexibility and decisive leadership
Access to the cold room is via high-speed automatic vertical doors with protection bollards.
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COLD LINK AFRICA www. coldlinkafrica. co. za March / April 2026