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Home » Refrigerated trucks: Not just a cooler box

Refrigerated trucks: Not just a cooler box

  • marimac 

By Benjamin Brits

Transport forms a major part of the cold chain and is also a critical element in the lifespan of various perishable goods.

The Rigid CryoFridge 450l tank. Image credit: Transfrig

The Rigid CryoFridge 450l tank. Image credit: Transfrig

The global pandemic of 2020 has forced many, if not all industries to rethink their strategies and their supply chains, and the cold chain has not been excluded. Some industry participants believe there will be a significant shift in future, driven primarily by the new habits of the consumer.

Economists in South Africa have also forecast that consumer behaviour will push these changes towards more varied delivery methods which would naturally require the adaptation of the cold chain and specifically refrigerated road transport. It may also lead to an effect of distribution centres being stocked with larger volumes, but less often.

However, changes in the cold chain are really governed by many parameters and cannot be determined by any single or particular element. In this feature we take a look at the overall view of refrigerated road transportation and further consider certain topical elements as well as possible future forms through our engagement with industry leaders.

Refrigerated trucks carry not only a valuable cargo but a significant investment for the owners. The correct components are required for the particular application as one would not want to have to incur a loss by products or produce not having been maintained under the correct temperature.

Trucks range from small 1-ton bakkies to large trailer trucks and can be configured with various systems including engine-drive systems, systems with a separate diesel engine and electric motor (diesel electric), eutectic systems, cryogenic systems and all-electric systems -creating a range to suit any application.

New technology in refrigerated trucks

New technology has lowered fuel consumption to 1.16l per hour. Image credit: Thermo King

New technology has lowered fuel consumption to 1.16l per hour. Image credit: Thermo King

One important aspect that must be brought forth from the start is that through development in the mechanics, electronics, insulation factors and various body work, technology has drastically improved over the years and newer vehicles are able to be fitted with many advanced options compared to what was available in the past.

Data and data management

Data logging and telematics is an advancing technology that most major manufacturers are already working with and have for some time. Data logging is considered an essential to provide information on various parameters, and telemetry is growing exponentially in the sector with its own advantages as better planning and operational efficiencies are sought out.

“For us as a local equipment supplier and servicer, data is extremely important and useful because we can monitor the operating parameters of the equipment and we can run various diagnostics. From a customer’s point of view for them to have their data logged in terms of temperature control is critical and forms part of their process management and planning,” says Peter Solomon, managing director of Transfrig.

Data logging and management further allows that at any time and any location where an issue arises, a technician can be dispatched to download the relevant data to investigate what the particular fault may be through diagnosis and then a corrective measure. For example, not reaching a target temperature may indicate an air pressure fault.

“Data also offers value to a business as a snapshot of what happens when, and this is also important in energy efficiency so running a system and storing energy can be planned to cater to peak demand times or trends,” adds Solomon.

Some of the various bodies produced by Icecold Bodies, a semi truck and ridgid truck. Image credit: Icecold Bodies

Some of the various bodies produced by Icecold Bodies, a semi truck and ridgid truck. Image credit: Icecold Bodies


Eutectics is another expansion in refrigerated transport that is being explored in many aspects as companies are looking to move to cleaner, more energy efficient types of systems.

In simple terms, Eutectic solutions are water-based with an additive used to decrease the freezing point. Different applications require different solution temperatures.

This type of refrigeration system is primarily used in ice-cream delivery trucks in South Africa and comprises a Kool-tube system. Instead of using a conventional evaporator, a series of beams are mounted in the body and the beams are filled with the eutectic solution. The beams are then frozen overnight and through natural convection the product is kept at temperature for the daily delivery cycle. No external power is required during the delivery cycle.

“We are developing a Eutectic system to be used over a broader temperature range. This includes multi-temperature solutions,” says Solomon.

 The Rigid CryoFridge 450 Slimline Evaporator. Image credit: Transfrig

The Rigid CryoFridge 450 Slimline Evaporator. Image credit: Transfrig

Liquid nitrogen and cryogenics

South Africa is said to be one of the forerunners in the world as far as cryogenics is concerned for transport refrigeration. The liquid is stored in a vessel beneath the load-box. Nitrogen is released from the tank and expands through pipes in the sidewalls into a heat exchanger. The Nitrogen is then released back into the atmosphere. Power for the evaporator fans and the controls for system are solar powered. The result is then zero on-road carbon emissions.

“A leading supermarket retailer in South Africa is running 300 liquid nitrogen trailer units throughout the country with this system. We are currently talking to one of the major air separation companies to try and develop this system to cater to a broader spectrum given its efficiency. The only downside to this technology in South Africa is that you need your own storage tanks. Hopefully in the not too distant future LIN fuel stations will be available,” adds Solomon.

Liquid nitrogen units have already been successfully introduced for use on electric trucks in Europe.

Anti-microbial protective coatings

Conventional cleaning and disinfection methods are not always effective or long lasting. From the time of initial disinfection, bacterial reproduction increases exponentially and has often reached a critical level before the next cleaning action. On contact with an anti-microbial surface, up to 80% of the pathogens will be killed within 15 minutes and over 99% in 2 hours. This means bacterial growth cannot occur, leaving your surfaces contamination-free for the useful life of the product.

“We are proud to announce that we can now offer an innovative surface coating with anti-microbial properties in our range of insulated and non-insulated bodies to assist in maintaining the highest standards in hygiene. Refrigerated transportation of pathogen susceptible food products such as meat, fish, poultry and dairy, necessitates the highest compliance in terms of hygiene standards. The transport of these food products is a particularly sensitive phase of the cold chain due to the constant loading and unloading involved and the subsequent contamination risk it poses,” says Burt Gildenhuys, managing director of Icecold Bodies.

The active ingredient works by disrupting the DNA of microbes, thereby stopping the bacteria from being able to replicate. The bacteria are then destroyed through damage to the proteins and cell membranes, causing catastrophic failure of the vital internal systems.

The Serco Frost liner trailer. Image credit: Serco

The Serco Frost liner trailer. Image credit: Serco

Solar energy

Solar technology has in part been implemented on certain systems but currently the technology is just not at the level to generate enough energy to power a refrigeration system for a typical standalone transport refrigeration system given the space you have available on a truck.

Solar is currently used for running fans and controls on the cryo-fridge system. It has also become popular to use solar for tail lifts. This has its own benefits as trucks are able to be switched off for example when using the tail lift that would otherwise require the engine to be idling – which uses diesel.

“We are close to completion with our battery-powered unit which will have an option of solar assistance. With the advancement of both solar and battery technology it may one day be feasible to have a standalone battery solar system on a truck,” says Solomon.

With solar energy, proportions are naturally relevant so solar could potentially be implemented today for smaller units. On the downside, in their current form, battery banks to store power are also heavy and reduce the vehicle’s payload, so the general view is that technology is just not ready, however in future the technology could be designed into the truck body or chassis in some way.

Hybrid technology

Recently Thermo King teamed up with Frigoblock, an expert in electric-powered solutions. The result was the industry’s first true hybrid trailer unit, offering all the benefits of both diesel and electric power.

“Diesel and electric power each have their own advantages. By combining them as a hybrid solution, we can ensure that a customer’s operation is fully adaptable to current and future environmental requirements,” says Thermo King.

The key challenges that face today’s refrigerated trailer fleet operators that led to this technology include:

Reducing their environmental footprint to comply with ever more stringent requirements from ordering parties.

Ensuring the distribution of fresh products in densely populated urban areas where access is limited to low-noise, low-emissions vehicles.

Retaining flexibility needed to operate either distribution or long haul as required.

“Further we have also recently launched a new unit that reduces fuel consumption down to 1.16ℓ per hour, and this unit is also axle-driven-alternator-ready for future developments,” says Thermo King further.

A thermally-efficient trailer supplied by Serco. Image credit: Serco

A thermally-efficient trailer supplied by Serco. Image credit: Serco

Adapting to market changes

Transportation, generally speaking, is something that is constantly being reviewed to find innovative ways to distribute goods at the most reasonable costs. From the perspective of the suppliers and manufacturers a lot of effort goes into designing products that give a low lifecycle cost, durability, easy repair and for the refrigeration trucks – quality thermal properties.

For all role players in the transportation sector, market changes determine a different delivery strategy and although, from the manufacturer and suppliers’ side, certain standards can be delivered, there are new factors and practices for deliveries that need to be considered with these market changes.

In the cold chain, the major elements in getting goods from the producers to the distribution centres and from the distribution centres to the retail outlets is unlikely to change in the near future, however where changes will occur are from retailers to the consumers.

“Different trends have already started in South Africa so this will indicate in some instances smaller vehicles catering to an increased residential delivery and it will now become more important for the retailers to have access to multi-temperature vehicles because not all products can be kept at the same temperature,” says Solomon.

As with any new trends there is a teething phase and should you have made use of an online ordering system yourself, you may have seen for yourself the outcome where retailers have been caught on the back foot. Often communication with the client is an issue, and item picking is then incorrect, leading to a high error rate. Short stock items are just omitted creating a window for re-deliveries – which is naturally not as ideal as a delivery on the back of a motorbike with little or no temperature control. Even a small refrigerated truck delivering half-thawed frozen goods does not go down well with most recipients.

Gildenhuys also comments “E-commerce is definitely driving new shopping trends, but what is being done at the offload points and is the product still in a temp controlled state? Distributors need to be mindful that refrigerated bodies are not designed to bring products to temperature but to maintain temperature, so loading at the correct temperatures is critical as well as control of required temperatures during multiple offloads in a round trip. Reducing the opening and closing of doors and good practices need to be in place to minimise temperature gain that may affect the lifespan of perishable goods.”

“The pandemic has been the trigger to increase consumer ordering for home deliveries in South Africa. In Europe, this method has been extremely popular for about five years already – it’s convenient and saves people time. Until now, in South Africa, this hasn’t really taken off because consumers are just used to going to the shops. By forcing people to re-think how they order and receive goods, this is now where the purpose-built vehicles with multi temperature capabilities will come into play. So, if fresh produce retailers are serious about taking advantage of this trend and offering a quality delivery model, they need to gear up with the correct delivery setup to ensure maintained quality of the products,” says Clinton Holcroft, managing director of Serco.

Not just a ‘cooler box’

Refrigerated trucks, compared to what you would have seen 25 years ago, so much has changed. Supply of this equipment is one thing but how that equipment is looked after is another aspect. Suppliers and manufacturers have the technical skills and understanding but in some instances the customer base needs to be more aware of the technical and servicing requirements of the equipment they are using.

“Transport refrigeration units are seriously stressed pieces of equipment – if a truck does 10 000km a month, it could be said the fridge does 30 000km. Some fridges run up to 24 hours a day whereas the vehicles may only run for eight. The fridge as mechanical equipment takes a lot of strain which customers need to be aware of,” says Solomon.

The investment in a refrigerated vehicle is at least a five-year commitment, so customers are generally advised to think ahead. That being said, and although the supplier’s role is to ensure that the client gets the correct guidance, every client has a different strategy and there are other common business-wide challenges the transport industry sees as well.

The tough economy means that companies are more focused on keeping costs contained and one needs to separate the cheapest upfront cost vs the best lifecycle cost. It is a common trend that customers fall into the trap of just going for the cheapest truck and body, but the thermal performance, durability and fuel consumption is poor, and the vehicle ends up requiring continual maintenance. In these circumstances, customers should consider quality and durability that affords peace of mind.

The silent nitrogen unit on and electric truck in France. Image credit: Transfrig

The silent nitrogen unit on and electric truck in France. Image credit: Transfrig

“From a body-building perspective, in the past, one insulated body against another has been perceived as the same and hence it hasn’t been easy for customers to differentiate; and if they do go to the trouble of doing pull down tests, they find significant variances. We have done our own informal testing and have discovered up to 50% differences in the time it takes to get to temperature and then to maintain temperature, but this doesn’t always seem to be something that customers are taking into account when buying. This has a direct impact on your perishable goods, especially when you have multiple deliveries,” says Holcroft, adding “Which is why we have invested in a state-of-the-art PU foam injection process for manufacturing our insulated panels.”

Maintaining temperature is one of the biggest challenges for the industry so having a vehicle body that performs optimally definitely makes a significant difference. What has been seen in the industry is that some suppliers are using polystyrene on one end of the scale which obviously has a cost saving, but has a tendency to absorb water quite badly, so it’s not considered a good material.

Polyurethane (PU/PUR) foam is a far more acceptable insulation material for vehicle bodies, that comes in different densities and when injected under high pressure doesn’t absorb water easily. Thermal performance is also significantly better with this material.

“As far as the insulation goes, there are two main criteria – maintaining temperature and energy efficiency. Energy efficiency is largely determined by the insulation medium used – and the technology within the insulation product used. PUR is the most effective insulation per thickness and insulation density is also key on the structural side. On the other hand, the logic that is often used and overlooked being “the product arriving at temperature” is very ambiguous as one never looks at the costs – for example, diesel usage used to maintain the temperatures during the delivery process,” says Gildenhuys.

For export products that carry quite a significant value, rejected goods receive a much lower local market price and this is particularly where clients will feel the impact of lower quality – ringing true that refrigerated trucks are not just a ‘cooler box’ and hence cannot be seen as such.

Local vs imported

South African companies and particularly local manufacturers who are exposed to international competition have moved their views more towards catering internationally. The advantage is not only being price-competitive, but also being able to offer quicker turnaround times, which in some instances can be a critical benefit.

“Local supply is as good as any imported products, so although imported goods do pose a threat, South Africa has come a long way and are world-class in many aspects,” says Solomon.

“In some respects, international competition is a threat as the South African industry hasn’t entirely moved with world trends and is still supplying according to old methodologies driven by the markets not supporting new trends. Everyone should be supporting local business, and retailers should be dictating on the standards needed that suppliers and manufacturers comply with. Imports are only an alternative because they offer different technology that provides new advantages for the sector that are not yet adopted locally such as GPR bodies, anti-bacterial materials and properties like vapour permeability,” says Gildenhuys.

Holcroft adds, “Having imported products in South Africa raises local standards by default. We are already competing against some of the best products available internationally and as local manufacturers we offer the advantage of improved prices and turnaround time, with similar features and performance. However, everyone knows that supporting local manufacturers is important to create growth in an economy – it’s essentially easy enough to let equipment be made overseas and then import them here, but as you see in other world-leading countries, they use local manufacturing to promote growth and also encourage global players to set up local manufacturing plants to support the local jobs.”

Industry standards and SABS’s test chamber

A light-weight 1-tonner vehicle. Image credit: Serco

A light-weight 1-tonner vehicle. Image credit: Serco

Collectively the role-players believe that industry needs to have a standard that is actually achievable and that is policed. Overall, the age-old mindset needs to change to understand that cheap isn’t necessarily the best solution. Generally speaking, the food producer or even a fleet operator has very little knowledge of the thermal cycle and required controls. Similarly, the foam supplier or truck body builders have no idea of food processing. All these elements need to be brought together to sing from the same hymn sheet.

“The biggest issue for the industry is that testing is voluntary. SABS testing is expensive and the fleet operators are not prepared to pay the extra fees and then rather make use of the ‘fly-by-nights’ to build a cheap body and in effect drive prices so low that the reputable companies don’t have sufficient resources to carry out their own R&D on improved technology. I also feel a SARDA type association needs to be reborn and get industry to work together from the supplier to the retailer or outlet,” says Gildenhuys.

“The concept of the SABS test chamber was good as it was intended to uplift standards. Many of the reputable industry stakeholders are committed to it but no one has followed through because it’s just too expensive and therefore it’s just not cost-effective for the body builders to make use of. It can work, it must work and we need to find a way to make it work for the industry – we believe all it requires is the correct management and perhaps this best sits with a private institution,” adds Solomon.

“Unfortunately for the sector there are no real regulations and the test chamber that SABS introduced was a way to provide a yard stick to ensure that an insulated body is in fact a proper insulated body. The market has been quite price-sensitive and the cost of the test is expensive even compared to international rates. The difference between South Africa and Europe is that in Europe it’s legislated that your vehicle to transport perishable goods must have a test certificate, but here there is no such requirement, so being a voluntary process is a hinderance. Because of the lack of standards and enforcement you create a market where one considers why a company would spend the money on environmentally-friendly products that are better for food, hygiene and the general cold chain management. The current ‘white elephant’ could easily be converted into a useful tool that the industry actually needs because the cold chain and food safety is a serious topic. Implementing formal certification for the transport of perishable goods could potentially raise local standards,” says Holcroft.

A changing factor would be the insurance industry participating in standard upliftment by requiring certain certification to be in place for transport, retailers and fleet managers. This would manage the complaints where the product arrives at 18 degrees when it is supposed to be 8 degrees.