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Raw magnetism

Offshore Marine Technology: 3rd Quarter 2020



McNetiq has launched a product line of ‘magnetic anchors’, designed to protect personnel from falls when working at height in port, inside a shipyard, aboard a vessel or on an offshore platform. The McNetiq Fall Restraint provides a magnetic connection between the worker and a steel surface – the latter typically on the wall, though possibly on the ground. Edwin van der Heide, who co-founded McNetiq in 2014, tells Offshore Marine Technology: “There are no limits for particular environments in which you can use the magnets, as long as there is steel to anchor onto.”


Naturally, this would apply to environments with steel decks and walls. However, if steel surfaces are absent from the worker’s surroundings – which may feature wooden or concrete surfaces instead – a steel plate can be mounted onto the surface to provide the anchor point for the solution.


The operative is connected to the anchor point via a working line and harness, which prevents him/her from moving too close to an unprotected or hazardous edge and falling. The anchor comprises a switchable permanent magnet, which can be turned on and off using a special key with a ratchet. The anchor is nickel-plated, weighs 19kg and measures 307mm x 120mm x 64mm. 


The anchor incorporates McNetiq’s patented Controlock technology, an electric-free solution; the permanent magnet constitutes a “literal inexhaustible source of energy”, the company says. This is intended to make operations less expensive (by eliminating the need to purchase and charge batteries) and safer; there are no electrical components that can be short-circuited, or cause an explosion, in the event of a fire.


The anchor’s force of magnetic attraction will depend on variables such as: the type of steel used; the thickness of the surface; and the air gap between the magnet and surface. These factors can affect the break-away force, which is the force required to detach the magnet from the surface. A similar consideration is the ambient temperature in the operational zone, as higher temperatures can cause the break-away force to decrease.


“Steel surfaces have different thicknesses and different layers of paint and, sometimes, rust," says van der Heide. "All the circumstances of the steel influence the force of the magnet.


"For instance, our scaffold anchor has a maximum capacity of 2,500kg but only in ‘ideal circumstances’ – 45mm of plain carbon steel without any air gaps in the form of paint or rust.” Should the operator require a greater break-away force than one magnet can provide, several magnets can be used in conjunction, van der Heide adds. A handheld reading unit is used to help determine the force prior to commencement of work.