Temperature-controlled road transport, and what it actually guarantees

A temperature-controlled trailer is an insulated box with a refrigeration unit sized to hold a set point against ambient conditions and the heat entering when doors open. It is not designed to bring a warm load down to temperature, and asking it to do so generally means the goods arrive out of specification while the equipment worked perfectly.

Goods must therefore be at temperature before loading. Where they are not, the problem is in the cold chain before the vehicle rather than on it, and that is where it has to be solved.

Different goods need different regimes: chilled produce, dairy, pharmaceuticals, frozen goods and goods that must simply not freeze all have different requirements, and some need a range rather than a number. Some need air circulation that a fully packed trailer will not permit.

The specification is the shipper's to give, because it comes from the product. A forwarder can arrange equipment that meets a stated requirement; it cannot determine what a particular product needs.

Doors open at a loading bay admit ambient air, and a trailer loaded in stages on a warm day can lose more temperature at the ramp than on the entire journey. A dock with a seal, a pre-cooled trailer and a quick load do more for a chilled consignment than a colder set point does.

Multi-drop deliveries compound this: every stop is another door opening, which is one reason a temperature-controlled part load behaves differently from an ambient one.

Temperature-controlled vehicles generally carry a recorder producing a trace for the journey, and a consignee with a quality regime will frequently ask for it before accepting the goods.

The trace records the air temperature in the trailer rather than the temperature of the product inside a pallet, which are related and not identical. Where product temperature is what matters, that is measured at the point of loading and of delivery rather than inferred from the trace.

LogisticID arranges European road freight. Temperature-controlled transport is being prepared as a service in its own right and is not arranged today, so this page explains how it works rather than offering it.

Where a requirement is temperature-controlled, saying so in an enquiry is still the right thing to do — it is the fact that decides whether a movement can be arranged at all, and it should not be discovered later.