Upper Claremont resident John Powell is blowing the whistle on crime, literally. In the three months since he first turned his attention to designing and manufacturing a whistle that is robust, small and very loud, the demand for this safety device has grown exponentially.To date, hundreds of units have been placed in the field in and around the Western Cape as well as in Nelspruit and Pretoria. But Powell says the popularity of the device caught him by surprise – he originally designed it as a safety precaution for his wife, Deidre, and his daughter, Clare Upton, who is an avid hiker.“No matter what your emergency is – be it being attacked or falling out of sight on Table Mountain – you need attention drawn immediately to maximise your chances of survival and the old whistle technology ticked all the boxes.”Powell says if you can be heard you can be saved.“Even quality electrical safety devices fail when you need them and I wanted something for my family that was durable and not reliant on signal or power from any source, especially and including when walking or cycling in our forests.”The manufacturing engineer took the old technology and redesigned it to fit his specific needs – a whistle that is small enough to fit on a key chain but that can be heard from at least 2km away. The average rock concert generates about 108 decibels in noise. Appropriately named WISL, this safety device clocks in at 110 to 120 decibels.Three hard blows are the internationally recognised signal for distress.“Most people have fallen into the habit of ignoring an alarm when they hear it go off but a whistle is different. There are numerous stories on the internet of how a whistle saved lives and prevented attacks on women and children, in particular.”Realising what benefits WISL could hold for community safety, Powell gave samples to members of the UCSA, a local security company, to gauge their reaction. Powell describes their feedback as enthusiastic, appreciative and thankful.It wasn’t long before family, friends, and neighbours began to ask for their very own whistles.“One lady wanted one for her elderly father who was living on his own in his flat. This way he could alert the neighbours if he fell. Another wanted one for her daughter who was being followed.”Things just naturally progressed from there and WISL is now being sold in a number of outlets at R60 each.However, to stay true to the product’s community project roots, Powell says that anyone with a 3D printer is welcome to contact him for the STL format files so they can print this product for their family and friends – on the condition it’s not done commercially.“I have used standard, freely available design principles and modified them to suit my requirements,” he saysAt present, Powell is using 3D printers, which he built, to manufacture the plastic whistles.Powell has been a tinkerer since the age of four when he first helped his Uncle Cliff to build radios and televisions. He has never stopped manufacturing since then and – 69 years later – his list of accomplishments and inventions is long indeed. Besides having been the project developer of various industrial and residential developments through the years, he has also founded several manufacturing businesses in plastics, machinery and 3D printing.Powell says 3D printing incorporates everything he has learned through the years. “It is going to change the world as we know it – digital inventory solutions from suppliers around the world will provide on-demand production. The digital files being downloaded and printed at the point of need (many even on your desktop) will largely replace expensive global shipping and warehousing of parts that are often never needed.”He says there are, of course, still many issues to be addressed but it’s all taking place and the technology is moving incredibly fast. “About five years ago, there were a lot of people who had never heard of it. Back then, printing body parts was something people had not imagined being possible and today they are doing it. “This printing is one of those technologies that we tend to overestimate in the short term and underestimate in the long term. We can’t even imagine what will be possible a few years from now.”V For more information on WISL, visit https://3dprinted.world/wisl.