Readers’ letters: Write to us and win… It’s a new year – come on, give it a go.

I am a 72-year-old retired millwright and am writing in to comment on the article about elevators that ran in the November 2019 issue. I was employed during the ’70s as a senior trade-test officer at the then Central Organisation for Trade Testing, and one of the trades we tested was that of a lift mechanic. In those days, computers and even PLCs (programmable logic controllers) were still a pie in the sky and everything was done manually with relays and timers. You can imagine what chaos it was to figure out when what relay must activate, and for how long. We had the opportunity to take a ride on top of the high-speed elevators in the Carlton Centre in Joburg, and I can assure you it is quite a scary experience. With the development of modern control systems the operation of elevators these days is much less complicated because a program takes charge instead of a physical and complex compilation of relays.

(PS. I’ve been enjoying PM for more than six decades.) ANDRE KRUGER

I can only imagine how tricky and intricate an important job like yours was, Andre, before complex computer systems and algorithms took over the tasks. Lifts still aren’t my favourite things and I’ll often choose the stairs if I can. Just recently, while in Los Angeles, I rode a very interesting lift arrangement in our hotel (the lobby was on the 70th floor!). Approaching the lifts, guests needed to key in their floor number and then the screen would tell you which of the six lifts to use. Once inside, there were no buttons for the floors

– it took quite some getting used to. – Mark, Editor