An Investigation of Modern Physics by Brian Williams
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  • Prams – Design Gone Mad?

    Posted on May 6th, 2011 Brian No comments

    I was about 4 years old when I first learned to push a pram properly. I am not talking about a push-chair, those were easy to handle, even at 18 months old. I mean the old carriage built prams with the big wheels that normally ended up on trolleys and go-carts. After I had struggled for a few days I finally passed my test and my mother allowed me to transport my baby sister without having her guiding hand on the pram handle. After a week I could set the parking brake and just about put the hood up if it was raining. This was not easy because to me this pram was huge, I could only see my sister by standing on tip toe.

    69 years on I see adults struggling with pushchairs, (yes, pushchairs), that have been made using antiquated supermarket trolleys as the design standard. They are unwieldy, overweight and worse than supermarket trolleys for steering. They are frustrating to parents, take up too much space (at home and in the car), are overpriced and worst of all, are dangerous. Trapped fingers, broken nails, and like supermarket trolleys, are not interested in where you want to go.

    60 years ago push chairs went exactly where you wanted them to go, they were light, they were cheap, they folded up neatly and they were safe.


    Apart from the fact that that there is ‘Fashion’ to blame, the main problem is that nowadays knowledge and experience are ignored in favour of gimmicks. Every possible design of the pram was tried out in the 18th and 19th centuries. The carriage pram and the basic design of the push-chair were confirmed as the optimum for easy handling by young women (and 18 month olds).

    The most important basic design detail was that ‘no steering aids’ gave the best steering. Sounds silly but its true.

    Four fixed wheels gives a stable platform but also ensures that the pram travels in a straight line. Try pushing a modern push-chair in a straight line. As much energy is wasted in keeping to a straight line as is used in pushing the pram. (Just like the supermarket trolley)

    A slight pressure on the pram handle and the front wheels lift off the floor. The pram can now rotate freely on two wheels and will ‘turn on a sixpence’. If you push a pram with 4 fixed wheels along a 400 yard pavement you will probably have to make the occasional adjustment to it. Forgotten your purse? Slight pressure on the handle, swivel round, release pressure, and your on your way back.

    Four fixed wheels gives you total and easy control.

    I have little doubt that the modern push-chair was copied off the supermarket trolley. Unfortunately the supermarket trolley is designed to carry heavy loads and therefore cannot use four fixed wheels. Some Do-It-Yourself stores have adopted the principle of the original pram in having two main load bearing wheels to enable easy steering. Unfortunately, these are normally fitted with castor-wheels at both ends, so you are left with a trolley that is easy to turn but won’t travel in a straight line.

    Note that supermarket trolleys are based on factory trolleys and trucks which have to carry heavy loads. However, factory floors are normally flat and level. Although within the supermarket the floors are flat and level, the parking areas are not. In our local supermarket about 25% of the parking area is seriously sloped and sometimes it can take 4 or 5 attempts to get the trolley near to the car.

    Author; Brian Williams