페이지 정보작성자 최고관리자 댓글 0건 조회 276회 작성일 20-05-14 18:02
Q Interview with Coltraco Ultrasonics: Why should I test seals using ultrasound?
A With navies such as the Indian Navy and Royal Navy successfully implementing ultrasonic testing of watertight seals as part of their onboard safety management, Coltraco Ultrasonics answer questions about the importance of ensuring watertight integrity to delivering the Safeship®: protecting crew, cargo and vessel.
Q Why is watertight integrity an issue?
A In 1989 IACS introduced its guidance to owners concerning the care and survey of hatchcovers as follows: “Loss of weather-tight integrity continues to be a constant factor leading to cargo damage which could result in a threat to the safety of the crew, the ship and its cargoes, despite advances in modern shipbuilding technology, construction, navigation and means of preventing ingress of water into hold spaces.”
The importance of watertight integrity to hatch-covers is equally applied to testing hatches, watertight and weathertight doors, and internal multiple cable transits as found onboard the wide range of maritime vessels and infrastructure (including naval, shipping, shipmanagers, marine surveyors, classification societies, offshore oil and gas, offshore renewable wind). Other regulations such as SOLAS Reg II-1/11.1–Initial Testing of Watertight Bulkheads etc requires “a thorough inspection of the watertight bulkheads shall be carried out” using ultrasonic leak test or hose test or equivalent test.
Little appears to have changed over the intervening years.
Q What risk does water ingress pose to the crew?
A Lives are at stake. This is unacceptable and must change.
As the main cause of vessel loss is sinking, the maintenance, testing and monitoring of watertight hatches, doors and multiple cable transits on vessels is essential. A watertight hatch cover is designed to prevent the passage of water in either direction under a head of water for which the surrounding structure is designed. Many mariners may think hatches are robust, monolithic structures, thereby failing to appreciate the small tolerances on panel alignment and gasket compression. It is both better and safer to think of hatches as complex, finely-made structures, to be handled with care.
CASE STUDY: 2015 El Faro incident
The case study of the 2015 El Faro disaster exemplifies the danger of water ingress. SS El Faro was a United States-flagged, combination roll-on/roll-off and lift-on/lift-off cargo ship crewed by U.S. merchant mariners. All 33 crew members tragically died in the sinking, when El Faro sailed from Jacksonville into Hurricane Joaquin, while heading to Puerto Rico. The wreckage was discovered more than 15,000 feet below the sea surface, Northeast of Acklins and Crooked Island, Bahamas. The NTSB have concluded that gaps in safety management contributed to the sinking of the El Faro. One of the significant issues was “poor watertight integrity which allowed seawater into the ship” stating that this accident may have been avoided if “crew had more information about the status of the hatches”. The tragedy of the El Faro has exemplified why it is crucial for the watertight integrity of vessels to be upheld.
Coltraco Ultrasonics strongly believe that tragic incidences such as these must become a thing of the past. Safety of life at sea is paramount when pushing forward with the implementation and development of regulations.
Q How are we failing to protect the crew by not maintaining seals?
A Wrongly applied and poorly maintained cargo hatch covers and sealing systems increase the risk of cargo and vessel becoming damaged by water. The most common wet cargo problems include leaking cross joints, and compression bars, rubber gaskets, hatch coamings, drain channels and cleats in poor condition.
The importance of continually maintaining seal integrity must take a more prominent position in ship maintenance scheduling as demanded by regulations:
SOLAS Reg II-1/11.1 states that hatches and watertight seals must be regularly tested: “Where a hose test is not practicable [sic] it may be replaced by [sic] an ultrasonic leak test or an equivalent test. In any case a thorough inspection of the watertight bulkheads shall be carried out.”
Q How is ultrasound used to ensure watertight integrity?
A The Swedish P & I club recommend using Ultrasound. As stated in their 2018 report “A much more effective method is to use an ultrasonic device, which is designed for this purpose and can pinpoint the area which is leaking, and if the compression of the gasket is sufficient. The advantages of using this type of equipment are evident, since ultrasonic tests can be carried out during any stage of the loading without risking cargo damage. The test can also be completed in sub-zero temperatures. The ultrasonic test should be carried out as per the class requirements.”
Ultrasonic testing is a dramatically more sensitive, accurate and reliable method for testing cargo hatch covers, bulkheads and doors for watertight integrity on all vessels. A multi-directional ultrasound emitter is placed in a hold. The opening being tested is then sealed and the receiver is switched on ready to receive any leakage of ultrasound via a set of headphones. An increased reading of ultrasound signal signifies an issue with the integrity of the door/hatch. Further, and closer inspection will allow identification of any specific leakage site along with it’s severity. This test will take approximately 10 minutes and requires only one operator.
Q Which is the best ultrasonic test kit for hatch cover testing?
A Owners, managers, marine surveyors, third party servicing companies and other mariners have pledged their support for the Portascanner® WATERTIGHT for years.
For 3 simple reasons: “it is faster, better, cheaper” than any competitor. But don’t just take Coltraco Ultrasonics’ word for it, here are 3 customer testimonials:
“We did some transit inspection work on one of our customers vessel using the Portascanner and we are very pleased with your instrument. We are looking forward extending our service offer using it.”–Techsol Marine, Canada
“The fleet was equipped with a unit per Bulk Carrier and the units are and working well, providing the confidence that there will be no problems with water damage claims.” Ship Management Company
“Our PORTASCANNER WATERTIGHT unit performed well during the entire period of use, proved rugged and we feel sure that if it had not required returning for mandatory calibration and certification, the unit would have performed well for many more years to come.” Captain J.F. Holmes, Botrans
Q Where can the Portascanner® WATERTIGHT be used?
A The Portascanner® WATERTIGHT is designed to identify leak sites in a wide variety of watertight, airtight or weathertight seals (such as hatch covers, watertight doors and multi cable transits), with decibel readouts to comply with classification society requirements.
The Portascanner® WATERTIGHT has been used globally to ensure safety, with ship owners, ship managers, oil & gas facilities and navies amongst others, committing their approval to the instrument. In 2018 the Indian Navy chose the Portascanner® WATERTIGHT to protect its fleet, with a similar service provided to other navies such as the Royal Navy, used onboard the HMS Prince of Wales. By using a Portascanner® WATERTIGHT, these navies are able to protect its sailors by ensuring the hatches, doors and cable transits are watertight.
The Portascanner® WATERTIGHT is:
Faster: designed for ease of use from poorly educated crew up to chief engineer–no need for extensive and expensive training courses, simply read the operating instructions in the kit and away you go
Better: most mathematically accurate to 0.06 (+/-0.02mm) to identify leak integrity quickly and easily allowing prompt maintenance if required
Cheaper: never beaten on price guarantee from Coltraco Ultrasonics who are used to serving the world’s leading fleets for 30 years
The Portascanner® generator is the most efficient of all on the market. Unlike the old “Hedgehog Generator”, the Portascanner® generator has excellent battery life, it is light and small, has magnetic mount, is highly sensitive and uses smart pinpoint technology to direct ultrasound to the seals during testing.
Coltraco Ultrasonics focus on benefitting the crew; designing innovative ultrasonic solutions which the crew will be happy to use by being easy to operate, quick, accurate and a better method to traditional techniques. These ultrasonic alternatives hereby increase the likelihood of tests being regularly conducted, in line with regulations and even going above and beyond for more frequent testing. By so doing, the crew will be creating a safer ship, and critically saving lives.