TT Talk - Container building – caveat emptor* (part 1)
When building containers, the buyer is fundamentally seeking conformance to a series of requirements, although the focus may be on the detail of the product to be built, rather than defining the measure of quality. According to some experts, quality is a state of mind, which involves preventing errors from entering the manufacturing process, improving them as required and getting it right first time. In the container industry, can we see these basic requirements?
Quality management strategies can be described in a variety of ways and mean different things to different people. In essence, the aim is to achieve a systematic way of ensuring that organised activities happen as planned. This is, of course, quite different from a common perception of ‘quality’ as goodness, luxury or value.
What is quality?
One articulation of quality, delivered by businessman Phil Crosby 35 years ago, was the principle of ‘doing it right first time’ which included four major principles:
• The definition of quality is conformance to requirements
• The system of quality is prevention (ie. eliminating errors before they occur)
• The performance standard is zero defects (relative to requirements)
• The measurement of quality is the price of non-conformance.
Crosby’s assertion was that ‘quality is free’, meaning that the savings delivered by reason of a quality programme more than matched the cost. A key justification of this can be found in the fourth principle – non-conformance represents the uncertainty or risk that a product does not perform or last as long as expected. Thus, the price of non-conformity often relates to a failure – a failure of a component or surface treatment – which may lead to increased downtime, reduced life expectancy, injury or loss of cargo. This risk is mitigated when the buyer specifies the product and fully defines expectations, such as the materials to be used and the means by which the quality can be measured.
“Non-conformance represents the risk that a product does not perform or last as long as expected”
Some manufacturers may develop feedback loops to ensure that quality is built into their culture and manufacturing process, identifying waste and inaccuracies, defining a procedure for their elimination, implementing the changes and then checking that the product has improved. Other manufacturers may take a more relaxed approach, using quality control methods which require a systematic inspection regime to confirm that parts are as designed and scrapping those that are not.
Manufacturers may suggest that conformance to requirements is satisfied if a number of physical tests listed in the specification are undertaken. These tests are required to satisfy the requirement of the International Convention for Safe Containers (CSC), which is but one of the buyer’s requirements. The buyer also requires that the container is built using the correct materials and techniques, and the finished product has an appropriate life expectancy. The following case study highlights a safety issue
General cargo containers are fitted with a pair of swinging doors at the rear end through which the cargo passes when being packed or unpacked. They are designed to be secured shut with two locking devices on each door and swing approximately 270° to be tied back against the side of the container.
In this case, the specification for the doors included a material specification for the hinge pins, a grade of readily available and suitable stainless steel. After a short period the user of the containers complained that there had been a serious accident involving at least one door from a series of containers. On investigation it was found that all four of the hinge pins had sheered and when opening the door it fell, injuring the operator. It transpired that over time the doors had been getting harder and harder to open and close and even involved the use of fork trucks to pull them open and force them shut. Metallurgic analysis of the material used for the hinge pins found that the material was not a stainless steel and consequently corroded to such a state that they seized in the hinge blade.
Unfortunately the hinge pins are difficult to see after they have been welded into the j-bar on the container end frame therefore post assembly inspection is almost impossible. At the time of acceptance, and before the pins started to corrode, the doors would have operated satisfactorily thus hiding the non-compliance. The price was an injured worker and a large remedial bill.
A container buyer will equally be interested in paint coatings, both to maintain suitable brand image and protect against corrosion. Many containers are typically finished with a two or three coat system, the base level coating being specified as a zinc rich paint, with sufficient zinc solid to allow continuous conductivity across the entire structure, thus preventing corrosion. A non-conformance (ie. lower zinc content) would result in faster corrosion, shorter life span and a poor owner image.
The price of non-conformance may be measured in a number of ways, but the reduction of that price is the elimination or reduction of uncertainty. This requires knowing that there is strict adherence to the requirements set by the buyer, including the materials used. This leads to the inspection regimes
We gratefully acknowledge the assistance in the preparation of this article of Bill Brassington of ETS Consulting.
We hope that you have found the above interesting. If you would like further information, or have any comments, please email us, or take this opportunity to forward to any colleagues who you may feel would be interested.
We look forward to hearing from you.
Risk Management Director, TT Club
* Caveat Emptor
[Latin, Let the buyer beware.] A warning that notifies a buyer that the goods he or she is buying are "as is," or subject to all defects.