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Local cable security

The Reslock is a South African designed and patented electrical cable protection device, which can be installed on any cable that has or will be installed in an extruded plastic ducting system underground, to prevent the theft or forced removal of the cable.

The Reslock was designed by Glenn Kotze, an electrician by trade and was employed by the Durban Metro as a sub contractor for the past 15 years, where he was involved in replacing all the 'forcibly removed cable', which prompted the invention. He started with the design in 2004 and has taken six years to perfect what he explains as the ultimate in cable protection.

The Reslock device is installed in line, at intervals of six metres of cable duct. This then becomes an integral part of the completed ducting system, allowing the cable to be pulled through the duct without any complications. It consists of two matching plastic moulded sections, 390 mm long, manufactured from 30% glass filled nylon. The electrical cable is then secured on the internal surface of one of the sections, by means of a plastic clamp with a steel insert, which in turn is bolted through the plastic section with U bolts onto the steel backing plate with galvanised U bolts.

All the steel parts supplied are manufactured in either 3CR12, stainless steel or galvanised mild steel, depending on the customer’s requirements. The completed Reslock is held together and secured to the plastic ducted system, by means of four stainless steel bandit straps, thus creating the completed secured system.

Up to four cables of 25 mm diameter can be clamped in any one duct, as every second Reslock will then be the clamping unit. The Reslock is water resistant once strapped together. The trench is then backfilled and compacted to a recognised compacting specification.

In recent trials, 50 metres of 10 mm Airdac and 16 mm 4-core cable were laid in an 800 mm deep trench complete with cable ducting. The Reslocks were placed at six-metre intervals and three metres of cable was left out, for 'pulling' purposes. A 4 x 4 Land Cruiser in extra low drive was used to attempt to pull out the 10 mm Airdac, which eventually broke off where the chain was tied onto the cable. The testers then attempted to pull the 16 mm 4-core out with a TLB, which nearly tipped over and again the cable broke where the chain was tied. The first Reslock was exposed and there was no damage to the cable nor any signs that the cable had moved. The insulation layer of the cable was the only part of the exposed cable that was damaged.

This video can be seen on the website www.reslock.com

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