A business case for washing a container fleet usually adds up water, detergent and energy and concludes that washing is cheap. That is the visible part. The larger costs are the labour to move containers to and from the wash, the floor space the wet and drying containers occupy, and the service life the process consumes by handling. Where those are included, the economics of a washing programme often look quite different.
The direct costs
Water, detergent, energy to heat the water and to run the drying stage, and any effluent treatment. These are easy to measure and they are usually the smaller half. Where a wash runs at temperature every day, the energy line is the largest of them and it is also the one most sensitive to the temperature setting – a wash at sixty instead of eighty costs substantially less to heat.
Labour is usually the biggest line
Containers have to be collected, brought to the wash, loaded, unloaded, dried, stacked and returned. Those movements are manual in most operations and they happen twice per wash. Where a fleet is large, the labour of moving containers around a wash process exceeds the cost of running the process, and it is the line most often omitted from the estimate.
Floor space, wet and dry
A wash operation needs space for containers waiting to be washed and containers drying afterwards. The drying side is usually larger, because drying takes longer than washing. Where a facility is short of space, the drying area is the hidden cost of the programme, and it is worth calculating in square metres before committing rather than discovering it afterwards.
What the process costs in container life
Every wash is a handling cycle, and handling is what wears containers out. Thermal cycling embrittles them slowly, mechanical action abrades them, and the movement between wash and service is where most containers are dropped or knocked. A fleet washed every trip will need replacing sooner than the same fleet used on a closed loop, and that replacement cost belongs in the business case.
The cost of not washing
Set against that: a contaminated load, a customer rejection, a recall, or a failed audit. Those are rare and expensive, and their expected value is the probability times the cost. Where the probability is low and the cost is moderate, washing every trip is hard to justify. Where the application is food contact or medical, the probability is not the question – the requirement is.
Reducing the cost without reducing the standard
Wash at the lowest temperature that works, which is usually lower than the default. Recover heat from the effluent. Wash only the containers that need it, by lane rather than by fleet. And dry with air movement rather than heat where the duty allows. Four changes, and together they typically halve the running cost without changing the standard achieved.
Outsourcing, and when it wins
A contract wash costs per container and removes the capital, the space and the labour from the site. It adds transport and it takes longer. Where a site is short of space or the volume is irregular, outsourcing usually wins. Where the volume is high and steady and the space exists, in-house usually wins. The comparison is straightforward once all the internal costs are on the table.
What to measure before deciding
Containers washed per week, labour hours spent moving them, square metres occupied by wet and drying stock, and containers retired per year. Four numbers, and they turn an argument about whether washing is expensive into a calculation. The frequency question that drives all of it is covered in how often a container needs washing.