Founded in 1983, Cygnus Instruments Ltd is a UK manufacturer of high-quality ultrasonic testing equipment.
Cygnus prides itself on making high quality ultrasonic equipment that is rugged, simple to use and is always
focussed for the job in hand.
Hatch Cover Inspection
Poor maintenance of hatch covers, seals and coamings, resulting in water entering a ship’s hold can lead to highly expensive or even devastating consequences. Testing that hatch covers are weather-tight is a fundamental requirement for preventing damage to cargo and ensuring the safety of a vessel and its crew.
Ultrasonic testing is the most accurate, repeatable and convenient method of testing hatch covers, doors, ventilators and access hatches and is the preferred method of inspection by P&I Clubs.
Ultrasonic Hatch Cover Testing is an accurate, repeatable and convenient method of testing hatch covers, doors, ventilators, access hatches, etc.
A transmitter emitting ultrasound is placed in the hold and the hatches are then fully closed. On deck the surveyor wearing headphones will walk around the periphery of the covers using a hand-held receiver or detector and will be able to hear ultrasound leaking through any defective seams or joints - even through the smallest of openings.
A percentage scale is used with an open hatch emitting 100% of the ultrasound. DNV and ABS state that during an inspection any reading over 10% indicates an area of potential leakage.
When a vessel is at sea and is pitching and flexing, seals that were demonstrated to be tight when the ship was stationary might potentially leak. A benefit of the ultrasonic method is that the level of compression of a seal can also be detected and monitored through periodic maintenance checks. A higher percentage reading indicates
a lower level of compression and could indicate a seal which will leak when the ship is in rough conditions.
While ultrasonic hatch cover testing has been available since the 1980s, Cygnus Hatch Sure has advanced the current technology with fully automatic Open Hatch Calibration (OHC) to set the Open Hatch Value (OHV). This ensures consistent results from hold to hold with a lightweight and extremely powerful 19 x 40 KHz element transmitter. This is powerful enough to saturate the largest cargo hold with ultrasound. The variable output transmitter has six selectable power levels allowing the unit to also be used in confined spaces, such as for testing watertight doors.
The Cygnus Hatch Sure system is comprised of two main components: a powerful ultrasound transmitter with 19 x 40 KHz elements and a hand-held receiver. Designed for ease of use and powered by standard rechargeable batteries, the whole system is extremely light and aircraft friendly for passenger cabin transportation.
The Cygnus Hatch Sure leak detector is a purpose-designed, robust and very lightweight system; as such it has become the market leader for Ultrasonic Hatch Cover Inspections and is the preferred choice of multinational ship management companies across the globe who want to test hatch covers quickly, accurately and cost effectively.
Cygnus Hatch Sure is ABS Type Approved and accepted by all P&I Clubs. The Cygnus product training syllabus has been endorsed by the International Institute of Marine Surveyors (IIMS).
