The Importance of Proof Testing

In any manufacturing setting it is vital that a company designs and manufactures their products to safely, effectively, and efficiently meet the challenging applications of their customers. Complying with these requirements can be a daunting task for manufacturers who produce lifting equipment because of the demanding service environments in which their products operate. Including individual proof testing in the manufacturing process does not replace adherence to proper engineering design, effective manufacturing processes, or a capable quality program; it does, however, add one additional level of certainty for the customer who may be lifting tens or hundreds of thousands of pounds and exposing their personnel to serious risk.

Some manufacturers of lifting equipment have decided to use a “design validation testing (DVT)” model in lieu of individual proof testing. DVT is when a manufacturer proof load tests prototypes of spreader beams, lifting beams, or other lifting apparatus, but chooses not to include individual proof testing for subsequent production models.

Proponents of DVT argue that weld inspections, manufacturing processes, and quality assurance protocols, coupled with engineering calculations and analyses, negate the need for proof testing every piece of lifting equipment that a company manufactures. While these safeguards are useful tools for ensuring a lean and effective manufacturing process, no better safeguard exists to uncover the smallest point of failure that might originate in a vendor supplied item or in the manufacture of the actual product. The practice of proof testing all manufactured lifting products could ultimately prevent a lost load or injury to those nearby the lift. The nominal cost of adding proof testing to the manufacturing process can assure that no unforeseen issues have evaded the quality inspections performed throughout the manufacturing process.

The recently released International Organization for Standardization (ISO) 17096 addresses the issue of proof testing, but authorizes the use of calculations and analyses in lieu of carrying out physical validation tests. While it is accurate to state that performing proof testing for devices designed for extremely heavy applications is difficult and expensive, the vast majority of lifting devices offered in the global marketplace do not fall into this category. This fact repudiates any notion that proof testing would be impractical in normal manufacturing processes for regular duty capacity lifting devices. In cases involving very heavy applications it is the responsibility of the manufacturer and customer to account for the value of human capital placed at risk in such operations, which is worth far more than the added cost or inconvenience of proof testing the lifting device before use.

Responsible engineering procedures guide all manufacturers to physically test a lifter during its development, leading one to believe that such manufacturers possess the capability to perform proof tests for its lifting products.  If this is the case, then not performing proof testing as part of normal production operations could be considered a failure of an unspoken fiduciary responsibility of the manufacturer to its customers. There are manufacturers who strongly believe in this responsibility and assert that proof testing all products results in safer operations for their customers. These manufacturers will continue to go beyond the requirements of the current standards by proof testing all of their lifting products to ensure that their devices continue to meet the operational needs of their customers safely, effectively, and efficiently.   


Heavy Lift & Project Forwarding International released an article in their March/April 2016 issue pertaining the new ISO 17096 standard for proof testing.  Tandemloc offered the above response article.  The article was written by Dan Pratt, M.A., M.B.A., Project Manager for Tandemloc, Inc. 

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