Ultra-sonic tightness tests

Hatch covers are an important piece of equipment on board of general cargo ships and should be in proper weather tight condition in order to comply with the International Convention on Load Lines. Moreover, also hip operators, Cargo Interests and their Insurers have an interest to protect cargoes from (sea)water damage, as such contamination can significantly depreciate the value of the goods. Various types of inspections are available to evaluate the weather tightness of hatch covers, of which ultra-sonic tightness (UST) tests have become quite important in the last few decades.

At IMCS Spain, we always perform a complementary visual inspection. Our experience shows us daily that the ultra-sonic tightness alone is not enough to establish a well-informed assessment about the weather tight condition.

Not only our experience in this matter has led us to strongly profess that the UST test is best paired with a visual inspection. The International Association of Classification Societies (IACS) stipulates in its UR Z17 procedural requirements that the operators should have knowledge of different closing appliances including their design functioning and sealing features. The DNV tightness testing procedure states that in case measurements taken during an ultra-sonic tightness test are less than 10% of open hatch value (OHV), the hatch cover can be considered weather tight, subject to verifying the design and the condition of the hatch cover, the coaming and the drainage arrangements.

Good industry practice requires that the UST test operator is well familiar with and knowledgeable about hatch cover designs, hatch cover operation, maintenance, repairs, etc.  

It is a persisting misassumption that hatch covers can be considered weathertight if they successfully pass an ultra-sonic tightness only. At IMCS Spain we perform about 175 UST tests per year. All of them are accompanied by a complementary visual inspection, to ensure that our clients receive a full picture and can take well-informed decisions.

We work on behalf of P&I clubs, Shipowners, Charterers, Insurers and Shippers and all our surveyors are qualified and certified to work with the ultra-sonic tightness testing equipment of SDT International.

Full detailed test reports including results of the visual inspection and high quality photographs are submitted within 48 hours.