Tuesday, 08 December 2009 20:29 Written by Edward Jensz

Everybody knows what a tyre is, but not many know why tyres come in all different sizes. Explaining all of the variations makes the subject very technical and complicated. Here we endeavour to simplify some of the concepts and technical jargon.

Soon after man invented the wheel he realised that it wore out as he used it. A piece of material was then wrapped around the outside of the wheel either to rebuild it or prevent it from wearing out. This material wrapped around the outside of the wheel became known as a “tyre”.

In our modern world there are two types of tyres: solid and pneumatic:

• Solid tyres were the original type of tyre used. As the name suggests they are made up of some type of solid material that is wrapped around the wheel. There are many different types of solid tyres, which will be explained later.
• Pneumatic tyres have air pressure inside the tyre. The pneumatic tyre must be fitted to the outside of the wheel and inflated with air pressure. There are three types of pneumatic tyres: bias ply, bias belted and radial ply.

There is one simple difference between the solid tyre and the pneumatic tyre: A solid tyre pushes into the road surface and the pneumatic tyre sits on top of the road surface.

Say you are pushing a wheel barrow load of bricks over the lawn. If the wheel barrow had a solid wheel it would dig a rut into the lawn and get stuck, and it would be difficult to push. A wheelbarrow with a pneumatic tyre would roll over the lawn, leaving a small wheel mark, and it would be easy to push. In other words, the solid tyre digs into the soft lawn surface and the pneumatic tyre “floats” over the soft lawn surface.

What happens if you push the wheelbarrows over a hard concrete footpath? You would find that it is easier to push the wheelbarrow with the solid wheel than the one with the soft pneumatic tyre. This is because the solid wheel sits on top of the hard concrete surface and rolls easily, while the pneumatic tyre squashes out and deforms over the surface making it harder to push. The more air pressure you put into the pneumatic tyre the easier it is to push over the concrete foot-path.

The pneumatic tyre is very sensitive to the air pressure inside the tyre where the solid tyre is very sensitive to surface it is running on – this is the primary difference between solid and pneumatic tyres.

Different Types of Solid Tyres

The first difference in solid tyres is the type of material that the solid tyre is made from. The material could be steel, rubber, wood, leather or some type of man-made plastic material.

The second difference is the type of solid tyre - how it is made. Some are completely solid, others are hollow inside, some are filled with foam and some are pressurised inside. There are many other variations with springs and layered materials inside.

Different Types of Pneumatic Tyres

All pneumatic tyres are made of rubber reinforced with tyre cord. The three different types of pneumatic tyres - bias, bias-belted and radial - explain the different ways in which the tyre cord is place inside the tyre. Solid tyres do not have tyre cord inside to hold the air pressure.

In simple terms, a pneumatic tyre is made up of rubber just like a party balloon. The rubber party balloon is blown up with air pressure. The more air you put inside it the balloon gets bigger and bigger.

A rubber tyre is the same except tyre cord is put inside the rubber balloon to hold its shape against the increasing air pressure. The way in which this tyre cord is placed inside the tyre determines its type.

Solid tyres differ from pneumatic tyres as pneumatic tyres need air pressure inside them to work. The tyre cord inside them holds the tyre’s shape and determines what type of pneumatic tyre it is.

Friday, 30 October 2009 10:52 Written by Maxwell Shifman

Delta-V Experts, Dan Mawby and Racing Victoria have been chosen as the recipients of the 2009 WorkSafe Awards for Best Design for Workplace Safety. From the WorkSafe press release:

Running Rails Running rails have been a safety issue in the racing industry for many years, causing serious injuries to jockeys and horses involved in collisions. Track staff have also been hurt due to the manual handling required to set up and move rails. Designed and invented by Dan Mawby, tested by Delta-V Experts and used by Racing Victoria, this new lightweight durable UV-rated plastic running rail is a welcome replacement for the solid aluminium rails currently in use. The major improvement is that the horizontal rail doesn’t break from the impact of weight-bearing objects – instead, it elevates, springs and bends on impact. The design and flexibility of this rail system also has the ability to steer a horse back on track should light contact be made, therefore avoiding injury. The new Running Rail is in place at Flemington and Caulfield Racecourse and some training facilities. Contact: Racing Victoria – Bob Gilpin, 03 9258 4367 / Delta-V Experts – Dr Andrew Short, 0415984519 or 03 94812200

Maxwell Shifman and Dr Andrew Short pose with the 2009 WorkSafe Award

DVE was privileged to be a finalist in two separate categories at the awards, out of a total field of just 19 finalists (from 118 submissions), demonstrating our commitment to real-world improvements in workplace health and safety.

Thursday, 22 October 2009 11:32 Written by Maxwell Shifman

Michael Hammond and Kathryn Bion of Deacons Lawyers, Melbourne, have written an excellent article explaining the importance of legal professional privilege in OHS investigations:

Once the business has decided which incidents will be ‘critical incidents’, it should consider putting into place certain steps to assist in establishing privilege for any of its communications which are created for the dominant purpose of obtaining legal advice or in anticipation of litigation.  The key to establishing whether a communication (including an investigation report) was brought into existence for the dominant purpose of obtaining legal advice or in anticipation of litigation, is the intention of the person who created the document or commissioned its creation.

Therefore, careful consideration should be given to identifying the right person to commission or undertake the incident investigation.  Involving lawyers in the immediate aftermath of a critical incident will assist in establishing privilege for communications arising from the investigation.

Delta-V Experts always recommends that legal advice is sought prior to engagement to ensure that any potential claims to legal privilege are appropriately maintained.

Tuesday, 06 October 2009 13:42 Written by Maxwell Shifman

Delta-V Experts is proud to announce that it is a finalist in not one, but two categories in the 2009 WorkSafe Awards. The categories are:

• Best Design for Workplace Safety for Running Rails (in conjunction with Racing Victoria)
• Best Solution to a Health & Safety Risk for the Swan Rollover Protective Structure (already a winner of the SAE-E Bronze Award for Excellence)

Both of these innovations have resulted in significant improvements in mining safety and for horses and jockeys in the racing industry.

The Worksafe Awards dinner will be held on 29 October 2009 at the Crown Palladium, and will showcase the various safety innovations from all of the finalists.

Wednesday, 12 August 2009 13:12 Written by Maxwell Shifman

Delta-V Experts is pleased to welcome Shane Keegan to the team. Shane joins after 18 years in Victoria Police, where he gained experience  as a member of the Bicycle Patrol Group, Criminal Investigation Unit, Traffic Management Unit, Regional Traffic Task Unit and Road Safety Task Force Special Solo Unit. He also assisted the Major Collision Investigation Unit with motorcycle crash reconstruction.

Shane will provide motorcycle safety, bicycle safety and investigation services to DVE's clients.