UNSEEN DANGERS
Tony Dale discusses the benefits of using infrared and ultrasound technology to reveal potential risks aboard
History tells us the seabed is littered with seafaring optimists, thankfully the invention and active use of thermal infrared cameras and ultrasonic emission detectors have since played a major part in helping superyachts and ships of all sizes to remain trouble free and seaworthy. SOLAS and numerous maintenance and Class advisory notifications certainly endorse them, with both methods improving our sensory abilities to see and hear beyond their natural capabilities.
Our vision and auditory systems have evolved to see and listen within a specific frequency and wavelength. Humans see within the range of 380-750 nanometers of the electromagnetic spectrum and listen in the audible sound range from 20 Hertz to 20kHz.
When employing the use of a hand held thermal infrared camera one can extend our visual acuity below the visual range to see lower energy states, into the thermal infrared region or thermographic range.
Observing into this lower energy realm enables the camera user typically the chief engineer or marine surveyor to distinguish equipment failure modes early. For instance, locating a loose high resistance electrical connection amongst many thousands located in a switchboard before item glows cherry red and an electrical fire hazard, or to monitor friction in shaft bearings to address lubrication needs against seizure, or to address degraded exhaust lagging to prevent an engine room fire if fuel comes into contact with its hot-surface. Other thermal camera uses include but are not limited to the identification of delamination, voids and cracks, even hidden repairs in hulls. Just as beneficial is the use of an acoustic ultrasonic listening device. The devices are designed to listen to frequencies above 20Htz and heterodyned down to our hearing range of 16,500Htz. This enables the surveyor to predict a harmful or unfavourable state from sound emissions alone.
Adopting ultrasound technology into the yacht’s PM regime enables low energy waveforms to be discerned, noises and waveform patterns characteristic of equipment failure modes, such as identifying defective bearings, electrical arcing, air leaks at door seals and in compressed airline joints, even when working in noisy environments such as an engine room.
Furthermore, when an ultrasound detector is combined with an ultrasonic emitter it becomes possible to saturate an area to reveal leaks at vital water and weather tight doors; what’s more this technique much like thermal imaging is soon grasped with continuous approved training and practice.
Geo Therm Ltd is an LR and ABS Registered Approved Service Provider for both Thermal Imaging services and Ultrasonic Leak Detection of Tightness-testing of closing appliances such as hatches and doors, etc., with ultrasonic equipment.
The qualified marine surveyor can hone into the direction of the loudest component (a technique called ‘Gross to Fine’) to pinpoint the enclosure leak, thereafter the chief engineer can execute a corrective action plan to prevent disruption to the yacht schedule, and hence maintain the seaworthiness of the yacht.
When the ultrasound detector is combined with a stand-alone ultrasonic emitter it becomes possible to saturate a closed room or passageway to reveal (from the other side of the enclosure) damage to seals at vital watertight doors, hatches, garage doors, windows, even air leaks at cable transits through bulkheads, to determine if the yacht is sealed and weathertight. This method is an approved Class and P&I service technique employed by cargo carrying vessels against water ingress to prevent water damage to cargo and vessel stability concerns.
Both thermal imaging and acoustic ultrasound detection techniques are non invasive, meaning there is no contact with energised equipment or rotating parts. Either survey type is clean, and performed in a timely manner to prevent schedule disruption.
Before your next voyage, the best preparation is doing your best today, so contact the services of a professional marine surveying company who can combine either technique so you do not become another historical statistic.
For more details Tel: +44 (0)1502 723241 or visit www.geothermltd.co.uk/marine
