Cranemec Group are now utilizing the latest wire rope NDT inspection technology during the cranes annual load test and thorough examination namely magnetic rope testing (MRT), this allows Cranemec to comply with ISO, BS/EN standard 4309 during the crane’s inspection
Magnetic Rope Testing (MRT) is a method of checking for defects and deterioration in steel wire ropes. MRT works by fully magnetizing a section of rope that passes through the sensor thereby detecting and measuring changes to the magnetic field caused by broken wires, corrosion, wear or mechanical damage.
Appraising the condition of a wire rope with internal breaks is therefore left to the inspector. But without the correct equipment this an impossible task, as the inspector only visually sees roughly 20% of the ropes metallic cross-sectional area leaving 80% to hoping you have not missed anything. By using the MRT method the inspector can comfortably inspect 99% of the ropes condition.
MRT equipment is lightweight and portable and can be attached to the rope whilst still in service. The rope is run through the magnetic head and the inbuilt sensors provide information relating to the current condition of the rope. Loss in Metallic Area (LMA) can be measured and Localized Faults (LF) can be detected including their location along the entire length of the rope.
So what is 4309, ISO 4309. 2017 states that MRT should be used where defects could exist which might not be identified by visual inspection alone. It also states that MRT shall be used as part of ongoing periodic inspections of the wire ropes fitted to cranes, winches and hoists. It all so states that new ropes should be subjected to an initial MRT examination (base trace) prior to it going into service, or as early as possible in its lifetime, this is to serve as a reference point for future comparison.