When the hatch covers, seals and coamings are not take care or serviced regularly, it will result in water entering the ship. Hence, testing the hatch cover on the regular basis is essential to prevent the damages to ship and assure the safety of the crews and other travelling in it. Listed are some of the water-tightness testing method of hatches:
The light testing method is done by the surveyor by battening down the hatches completely and then viewing the underside of the covers. It helps to check for any daylight or torchlight is shining through the gaps. This is the easiest and simplest technique to identify the defects at the right location. The disadvantage is that light testing is that it is not useful to identify the smaller gaps in the hatch covers.
Chalk testing is the traditional method is the process of applying chalk powder on the coaming compression bars and panel cross seams. The hatches are then closed and re-opened. The rubber joints are examined carefully to check the irregularities in the chalk markings. If it shows any irregularities, it is assumed that these areas are weather tight.
It is water leaking check method a constant jet of pressurised water is directed at the hatch cover seams and joints and surveyed to inside for leaks. The disadvantage of this method is that hold must be empty for the surveyors is stand, and cannot be performed in the sub-zero temperatures. It is a time-consuming process, and any variance in water pressure or distance of the jet leads to an incorrect result. Some port authorities do not allow this method as the run-off from the deck may lead to pollution.
Ultrasonic testing is the best, accurate and convenient method of testing the hatch-covers, doors, access hatches and ventilators for water tightness. The transmitter that emits the ultrasound is placed on the hold, and the hatches are closed completely for the surveyor to check the ultrasound leakage using the hand-held receiver or detector. Any defective seams or joints will leak the ultrasound even through the smallest opening, and it can be detected by the surveyor who walks around the periphery of the covers.
The benefit of the ultrasonic method is that the compression level of any seal can be detected and monitored, where the higher percentage of the seal would indicate the lower level of compression.
ABS Type Approved Portascanner WATERTIGHT, the Coltraco Product – is an ultrasonic watertight integrity tester. It can be used to identify leaks in a wide variety of watertight, airtight or weather-tight seals such as hatch covers, doors and multiple cable transits, with decibel readouts. The Portascanner WATERTIGHT has used on board bulk carriers for inspecting the Watertight or Watertight hatch cover for leak sites. The magnetic generator can be positioned inside the hold, on the hatch coaming. The crews of the ship can use it for regular maintenance and reduce the risk of cargo damage from water ingress, and by Marine surveyors for carrying out P&I, Classification Society or Insurance surveys. Contact us to know more about the product specifications.