Cygnus DIVE used on HMS/M A7 Submarine
The submarine A7 is designated as a Controlled Site under the Protection of Military Remains Act 1986, this prohibits all diving operations without licence from the U.K. Ministry Of Defence. The A7 project team are the first to be granted a license.
As part of their study, the team of divers used the Cygnus DIVE underwater thickness gauge to measure the metal thickness of HMS/M A7. This helped to establish not only its current condition but over time can be used to monitor the rate of corrosion. Due to the pitting of the steel, the team used the gauge in single echo mode with a twin crystal probe. As the gauge has data logging capability, readings were logged to be analysed later at the surface.
Peter Holt, SHIPS Project manager and director, 3H Consulting Ltd., said “We used the 5MHz dual crystal as it gave the best results on the pitted steel we found on the many corroded ships hulls where we tried the UT gauge. The DIVE was reliable, very easy to use, has simple menu system and displays. The logging function was essential as we only had 13 minutes on the wreck each day; I could make lots of measurements and figure out the answer back home in post processing, we also didn’t have to write anything down or think too much as thinking isn’t so easy in 40m water with the effects of narcosis!”
There are many other supporters of the A7 Project, including the Universities of Birmingham and Plymouth, 3H Consulting and the Nautical Archaeology Society and we are very pleased that a Cygnus gauge can play a small part in what is a very worthwhile project.
There is lots more information to be found about The SHIPS Project and the A7 Project on the website www.promare.co.uk/ships/ and by following them on Facebook “The Ships Project”