Cargo access sealing system condition can be easily checked without interfering with other shipboard activities using MacGREGOR’s new type-approved Sherlog ultrasonic testing system. This testing system has now been certified as type approved by Lloyd’s Register. The equipment can be used to test the seals of hatch covers and RoRo equipment such as bow doors, stern doors, side doors, inner doors and ramps, and ramp covers. It can also be used to test bulkheads or any openings on board which need to be sealed, such as doors into refrigerated provisions stores and machinery spaces, and windows.
A unique feature of the Sherlog system is its integrated data-logger. Data can be downloaded to a PC, for subsequent use as a periodic survey information source for example, and can easily be forwarded by e-mail. Hatch cover leakage data, for example, can be downloaded for easy reporting and safe logging as required by IACS UR Z17 and classification societies.
The Sherlog system comprises two pieces of equipment: a portable ultrasonic multi-transmitter and a compact hand-held detector. When used to check hatch cover tightness, for example, the multi-transmitter is placed in the cargo hold in a central position, where it produces a uniformly distributed omni-directional sound field throughout the hold space. On deck, the hand-held detector is used to measure any sound energy leaking through the hatch cover seals, both around the hatch coaming and along panel joints. The transmitter sound is produced in a narrow frequency band and the detector is tuned to filter out just this band. So the inspector, wearing a headphone and reading a digital display, is not hampered by surrounding noise and can positively detect any leak greater than 0 dB. The detector logs the recorded dB values in its memory, which can then be downloaded.