Parma Industries’ Phil Pittock looks at some of the best methods to prevent wheel loss

According to the 1891 census, my great, great grandfather, Jerimiah Pettit, was a bus driver, living in Acton, West London so he probably drove one of George Shilibeer’s omnibuses which ran from 1829 until 1911. Similar buses were introduced elsewhere in the UK, typically drawn by two or three horses and with emission problems of a different nature than today.

Nearly 70 years later, Michael Flanders and Donald Swann were singing to us about the Transport of Delight, ‘That big six-wheeler, scarlet-painted, London Transport, diesel engine, 97-horsepower omnibus’ – probably referring to an RT or a brand new Routemaster. Some youngsters back then used to roam the capital and surrounding country trying to spot all 8000 buses on the London Transport fleet. Happy days.

Now our streets and public are served by modern vehicles with ever-increasing technology, safety, power, efficiency, reliability and environmental sympathy. A quick glance at ADL’s spec-sheet for the Enviro400 for example shows a level of advancement that dear old Grandpa Jerimiah could never have dreamed of.

The more things change…

Some things have not changed, though. Passengers for one; maybe their attire and their means of amusement while travelling has evolved but they still expect to reach their destination safely and on time.

Wheels are another constant. From Shilibeer’s day, through the decades of history, the wheels on the bus have to go round and round – and they also have to stay on. Everyone understands the idiom ‘the wheels fell off the bus’ to describe something that ends in disaster but no one appreciates it when it happens.

And it does happen. Still. Wheel safety specialists, Parma Industries, report that they often have customers coming on and asking advice as to the best wheel safety options. The answers are there, the products are available, but it is shutting the stable door after the horse has bolted – now there is an expression old Jerimiah would have understood; it would have wrecked his day too.

So what should the wise operator do and what products are available?

Wheel loss

The wheel loss dilemma has spawned a whole range of security products in recent years and these can be broken down into different categories:

• Indicators

• Locking Nut Methods

• Wheel Nut Clamps for:

• Pairs of nuts

• Complete wheel nut set

• Electronic Sensors

Indicators are the most prolific and have been around for a long time with brand names including Checkpoint, Propoint, Dustite and Procap. These coloured devices are aimed at helping the driver on a daily check to identify if one or more nuts has become loose. Simple and effective but only if the driver or fitter actually performs the physical check. These items will not prevent wheel loss so it is a help but not a solution.

There are a few Locking Nut methods on the market such as Disc-Lock or Nord Lock, which replace or modify the OEM wheel nut/washer fitments with versions containing a cam-locking or wedge-effect design. In the event of a nut losing clamping force or torque, these introduce tension in the material faces to prevent the nut becoming loose and hence avoiding wheel detachment.

Wheel Nut Clamps come in various forms and the most common being those that secure two adjacent wheel nuts so that one of them becoming loose is held in position but the other which prevents complete detachment and wheel loss. A number of these are now available from the time-honoured Prolock along with the Ric Clip and Checklock which are made from metals through to Checklink, Prolink and the ultimate Zafety Luglock.

Other products are designed to secure all the wheels nuts together such as the Squirrel and Safewheel devices and more recently, the Wheel-Sentry.

In the last year, an innovative new-comer to the market has been Wheelysafe which complements a TPMS system with electronic sensors to provide in-cab warning of potential wheel nut detachment.

All of these offer an array of options to baffle the fleet engineer or compliance officer or whoever manages the safety of the fleet. Each product has its advantages and disadvantages. However, doing nothing is not a good option, especially when faced with a public enquiry following a wheel loss incident.

Decisions need to be made based on specific operations, overall cost and downtime considerations coupled with well managed maintenance procedures. Products with a long safety record and which are simple to fit and remove are likely to be favoured over against more complex and costly options. Specialist companies such as Parma Industries can help with the implementation of effective systems and devices to really make wheel loss a thing of the past.

For more information: 01728 745700,