Wheel Safety Guide: Wheel Loss Analysis
Wheel detachment has consistently ranked as one of the major concerns of the transportation industry when it comes to vehicle safety. The risks associated with detachment of wheels from a vehicle justify to quite an extent, the concerns that have been raised over wheel security and the need to come up with effective measures to tackle this age-old problem.
Over the years, manufacturing of automobile equipment has taken several leaps in terms of design and durability of material, each increasing the safety and overall reliability of vehicles. However, despite these advances and the efforts taken to spread awareness regarding the importance of vehicle maintenance, wheel detachment from heavy commercial vehicles remains to be a cause of concern for operators.
Wheel detachment is mostly attributed to problems that develop in the design of equipment due to the extreme wear and tear that they are subjected to during the movement of vehicles. However, proper maintenance can play a significant role in controlling the conditions that can lead to wheel loss.
Although the annual frequency of accidents caused due to wheel loss is comparatively lower to the number of accidents caused due to other reasons, it is an issue that must be addressed to further increase vehicle safety in the UK.
Consequences of Wheel Loss
In most cases, a detached wheel comes to rest without causing damage or harm to the vehicles around. At high speeds however, wheel detachment can cause fatalities. A wheel which has come loose can accelerate to speeds as high as 95 mph and can rise up to heights of 50 metres above the ground. If it collides with a vehicle on its way at those speeds and height, it can exert a force that is equal to 10 tonnes on the colliding surface.
Research was conducted by the Transport Research Laboratory (TRL) that was commissioned by the Department for Transport. Its findings were as follows:
Wheel fixing defects account for nearly 7,500 to 11,000 problems related to wheel fixing
Other problems and their typical annual frequency have been stated below:
Wheel detachments – Between 150 and 400
Damage only Accidents – Between 50 and 134
Injury Accidents – Between 10 and 27
Fatal Accidents – Between 3 and 7
If wheel loss due to faults in equipment is considered, following is the share of each type of equipment failure:
The report also suggested that when components are properly tightened and in good condition, the current designs of wheel fixings are able to provide the required clamp load. The fastening of the wheel components is also caused due to joint relaxation and variations in torque to clamp ratio and component temperature.
The underlying problem is that the design of these components is not yet of the required resistance to put up with the massive amounts of friction that these components undergo. As a result, the components face severe degradation owing to the lack of a maintenance free design. It thereby necessitates careful handling of components.
Reasons for Loosening of Wheel Fixings
The vehicle itself contributes the most to the degradation of wheel fixings by exerting a variety of forces on them. These forces include heat effects, vibration, cornering forces and braking and acceleration.
Even the loosening of one wheel nut can cause the remaining nuts to come loose. With the loosening of several wheel nuts, the overall clamping force decreases. This reduction in clamping force affects the arrangement of wheel, drum and hub, causing them to become detached from each other as clamping force further decreases.
The wheel begins to move with respect to the hub, when the clamping force becomes lesser than the forces on the wheel. This movement causes remaining nuts to come loose and it also results in side loading.
If these problems are not identified in time, they can gradually progress to cause bigger issues such as fretting fatigue cracks, fatigue failure of studs, elongated stud holes and wheel separation.
According to the laboratory test programmes, following is the sequence of events that ultimately lead to wheel loss:
Settlement or deposition within the fixing causes constant friction leading to a reduction in clamping force.
As wear and tear increases, clamping force further reduces.
Some nuts may become ineffective in providing any clamping force whatsoever after they become loose beyond a certain extent.
If the studs lose their hold over the wheel, they might get thrown off it with tremendous velocity. Even if they do not leave the wheel right away, they could remain loose in their place resulting in elongation of stud holes. It is these factors that ultimately lead to the detachment of wheels from the vehicle.
Thus, wheel loss is majorly attributed to insufficient clamping force, which is possible due to the presence of dirt or damage between mating surfaces, low initial tightening torque and over-tightening. Reduced clamping force causes movement at the interface of wheel and hub and this can lead to loss of tension around the studs and bolts.
Following is a comprehensive list of reasons why wheel fixings can loosen:
Insufficient tightening of wheel fixing, leading to fret and wear of wheel.
Contaminants such as rust/scale, dirt or paint on the mating surfaces. This problem can be countered by regular cleaning and maintenance of contact surfaces.
Many drivers and technicians believe that applying extra pressure will prevent wheel nuts from coming loose. Over-tightening of wheel fixing leads to broken or stretched studs and causes them to be pulled through the hub. Irrespective of whether more or less torque is applied, when the material’s elastic material is exceeded it will result in stud failure
The torque wrench has been inaccurately calibrated or the calibration date has expired
Wheel fasteners have been used but their tightness hasn’t been maintained
Incompatible wheels have been fitted together
Unserviceable components and wheels have been fitted together
Interfaces and threads have not been lubricated adequately. If the initial clamping proves to be inadequate, it is mostly due to high friction loss and this problem can be solved by using the appropriate quantity of lubrication.
If lubrication is either applied incorrectly or excessively, it can lead to rapid deterioration of the mating surfaces of wheels.
Corroded wheel studs.
If studs have not been pressed completely into the hub or nuts are loose.
The assembled components are not in their right place.
The assembly of components is inappropriate relating to the torque and procedure applied.
Worn Wheel Spigots.
Seized or fractured wheel nuts washers.
Air impact tools when used incorrectly can cause issues, such as cracked nuts and washers and cross-threading. This is one of the many factors that torque depends on. Whether the torque applied is less or more depends on many variables and the contribution of each cannot be measured exactly.
A wrong sequence of tightening has been employed.
Variations in temperature can alter the surfaces which are in maximum contact with each other. If the surfaces melt, it can result in components getting misaligned thereby reducing the effective clamping load exerted on the wheel
While it is difficult to completely prevent the above problems from developing, it is however possible to detect them in time and prevent them from becoming bigger issues. With proper maintenance, the issue of wheel loss can be tackled effectively.
At Parma Group, we have a wide range of products that have been used extensively to increase the safety of vehicles on the road. Our products are of the required quality and standard to ensure that wheels are secured correctly.
Contact us today to know more about our products.
Wheel Safety Guide: Preventing Wheel Loss
In an earlier blog post, we laid out the reasons that can potentially lead to wheel loss. Understanding the reasons for wheel loss is essential, especially for businesses that heavily rely on a fleet of vehicles to go about their day to day functioning.
However, wheel loss is not just about ensuring businesses can continue to operate effectively. The issue of wheel detachment is also a lot more serious, as events like this can put another’s life at stake on the road.
Responsibilities towards Wheel Security
It is the legal responsibility of the driver of a commercial vehicle to ensure that it is free from any visible defects when it is about to be driven on the road. Any defects that are identified should be duly reported in writing.
This requires the drivers of the vehicle to carry out a careful visual inspection of the wheels and to rectify any possible defect that can cause a hindrance to the movement of wheels.
Drivers and Vehicle Standards Agency (DVSA) and Police officers have been vested with the authority to issue fixed penalty notices if these responsibilities are not adhered to.
Defective wheels and fixings attract a fixed penalty notice for a construction and use offence. Upon being served with such a notice by the examiner, the vehicle can be prohibited from being driven on the road.
From the nature of vehicle defects, the culpability of the driver will be determined and this remains to be the primary consideration when a fixed penalty notice is being served for a construction and use offence.
Operators are required to comply with this essential requirement of operator licensing, which is to maintain their vehicles in a roadworthy and safe condition. The DVSA and Traffic commissioners take strict action against those operators who follow a poor maintenance regime for their vehicles.
It is expected of the operators to make sure that all maintenance policies are being implemented, so as to prevent wheel defects from occurring. It is also recommended that all staff are properly trained in procedures concerning maintenance.
Third Party Contractors
It is common for operators to outsource the responsibility of vehicle maintenance to third party contractors. In these cases, the operators need to ensure that the necessary maintenance tasks are being carried out.
Operators are advised to request written copies of fitment policies and wheel inspection from third-party contractors. Operators may need to attach these copies in the contractual agreements that are signed between the two parties.
Operators should also perform spot checks to make sure that the contractors are adhering to the maintenance policies that have been framed.
It is worth remembering that irrespective of whether a vehicle’s maintenance has been outsourced to a third party or not, it is the operator’s responsibility to make sure that the vehicle is being maintained in the right condition.
The drivers need to perform several checks before they can drive the vehicle on the road and they are also required to report any visible defects in writing. Following are some of the checks that should be performed related to wheels:
Visible damage to studs, nuts and other components
Cracked washers, nuts, wheels etc
Elongated stud holes
Signs of wheels becoming loose
Presence of bright metal in the area of washer and nut seating
Visible rust in the washer and nut area
Relative shift in position of wheel nut indicators, if any
Blocked ventilation holes
If the driver detects any loosening of wheels, they should check them physically. A calibrated torque wrench should be used by an individual who is adequately trained to perform this task.
If wheel security has to be checked when the vehicle is away from the vehicle depot, the driver should make use of a socket and bar, preferably the one supplied by the manufacturer. They should make use of a bar that doesn’t exceed the length of 500mm.
In addition to the above checks, a driver should also be trained to conduct the following responsibilities:
Setting a torque wrench correctly
Being aware of the manufacturers recommendations regarding the correct torque setting for the specific vehicle and model
To learn the appropriate method of using a torque wrench
To know when to stop applying pressure once the necessary amount has been applied, according to the setting on the torque wrench
Looking for signs of loose wheel nuts
Once the wheel nuts have been adequately tightened, the torque wrench has to be reset to zero
If any defect is spotted, it should be investigated and rectified before the vehicle is driven
If wheel nuts are found to be loose, the wheels should be removed and a competent person should examine the removed components to determine the reason behind the loosening of the wheel nuts.
Wheel Tightening Procedure
Wheels need to be fitted in a way that leaves scope for any expansion or contraction of metal due to the heat that the arrangement is subjected to. If any component has been removed and refitted, care should be taken to ensure that they have been correctly installed before the wheel is fitted again.
Light Engine oil should be used to lubricate the threads of the wheel studs. A drop of oil should be placed between the nut and captive washer.
Wheels should never be painted before mounting them onto the assembly.
Only tools that are specifically meant for cleaning should be used. The contact of sharp objects such as nail gun, with the threads or mating surfaces should be avoided.
The wheels should be carefully and squarely fitted over the studs so as to avoid damage to its threads.
Initially the wheel nuts should be fastened by hand.
Power tools should only be used during the initial phase of tightening. Further tightening should be provided with the help of a torque wrench. It must be properly calibrated and in good condition.
When using an air wrench to apply torque, airflow should be kept to a minimum setting. The nut should be run down to the wheel hub and precaution must be taken to ensure that it isn’t over-tightened.
The torque wrench should be set according to the instructions set by the manufacturer in the manual. The socket used should be of the correct size and depth.
The wheel should be lowered to the ground before the final tightening of wheel nuts is carried out to achieve the correct clamping force.
The wheel nuts should be tightened in the correct sequence as illustrated and should be set to the correct torque.
Over tightening of wheel nuts will be indicated by the fact that the nut doesn’t move during the procedure of applying torque.
Parma Group is dedicated to increasing vehicle safety on the road by providing vehicle accessories manufactured to match the required standards of quality and design.
Contact us today and make your vehicles more roadworthy.
Four Ways of Reducing the Rising Cost of Running a Fleet
After the Brexit vote, many UK SMEs have had to face rising costs, which has resulted in revenue dropping a considerable amount for numerous businesses.
These two economic factors have started to pile on the pressure for businesses that highly rely on a fleet of vehicles to carry out their fundamental operations.
The question that arises here is this: what can these SMEs do to reduce costs and protect themselves from the impending impact of Brexit, especially when it comes to their reliance on fleet vehicles?
Our team of experts at Parma Group have come up with four ways of reducing the rising cost of running a fleet:
1: Staying On Top Of Maintenance
The way your fleets are maintained has a huge impact on its fuel efficiency. Dirty engines tend to use more fuel, while wheels that are worn out, or those that do not have wheel nut safety installed can have a negative impact on your vehicles and eventually your business.
Additionally, poor understanding and application of maintenance techniques can also result in your business spending more money than needed. Hence, it is always advisable to keep on top your maintenance game, as prevention is always better than cure!
Having your fleets property managed and maintained will help you to ensure that they are running efficiently and most importantly, cost effectively.
2: Optimising through telematics
When you attach telematics, SMEs gain access to a rather huge, intricate set of fleet data. For example, people that are responsible for fleet management will have a better understanding of the routes being taken by their drivers, how efficient their driving is with respect to fuel consumption and how average speeds are impacting overall efficiency.
With this data, SMEs can improve their drivers’ overall performance. Alongside this, they can also monitor their drivers’ full journey details, which includes pence per mile calculations, without the need for receipts.
3: Use of Technology
Technology is a crucial part of most businesses today, and the use of it for the majority of sectors plays a vital role in making businesses efficient and reliable.
Similarly, we believe that technology can be very helpful for fleet managers to improve the productivity of their operations.
However, if fleet managers want to do this, they need to have complete access to comprehensive information (MI) protocols and processes, so that they can gather and analyse data effectively.
With an ability to analyse fleet data, SMEs can get back get in the driving seat and control cash management effectively. Access to fleet data will help businesses to work out which fleet is inefficient when it comes to fuel and maintenance, meaning they can make the necessary adjustments to improve.
4: Opting for a Fuel Card Solution
To save time and effort, your business should look into using a fuel card solution, if it isn't already. If you're not too sure what is involved, don't worry, as we will explain the basics below.
When a business works with a fuel card provider, they are given fuel cards which they issue to their employees. These fuel cards can be used in lieu of credit cards or cash at many petrol stations across the country.
A vast amount of petrol stations are involved with the fuel card scheme and locating refuelling points is super easy thanks to smartphone apps. But it's unlikely your employees will even need to use an app, as huge names such as Shell, Texaco, BP and Esso are a part of fuel card schemes.
Fuel cards are fantastic as they are a hassle-free payment solution, meaning companies don't need to deal with hundreds of invoices for fuel as they are billed directly.
Making your fleet operations efficient is not just about being cost effective and saving money either, as your business will also be saving precious time. And time is money, after all...
At Parma Group, we make sure that we are not only helping UK SMEs to save costs on their fleet operations, as there is far more at stake when it comes to logistics. Our aim is to make every road journey a better experience, and we play our part by providing wheel safety products to companies that are often behind the wheel
Minibus Safety what equipment do I need?
Remaining compliant and within the law is an important consideration for any minibus operator, we are often asked by companies what safety equipment do I need to be compliant, Whereas this list is not intended to be exhaustive it includes products that we are able to assist you with.
Schedule 7 of the Road Vehicles (Construction and Use) Regulations 1986 states that Minibuses must have a fire extinguisher that conforms to BS5423 (more recent legislation relating to fire extinguishers mean it must also conform to BS EN3 1996)
It is recommended that an extinguisher filled with Foam and must have a minimum test rating of 8A and 21B. Halon extinguishers are no longer legal in vehicles. A suitable one can be found here
If some passengers are using wheelchairs then two extinguishers should be carried aboard the vehicle one being in the passenger section of the vehicle.
Extinguishers should be tested normally once a year, some may have an expiry date and once this is reached they should be replaced.
It is advised that drivers are trained in the use of fire extinguishers and know where they are in the vehicle also the evacuation of the vehicle in the event of fire.
First Aid Kits
The same legislation also states that Minibuses must also carry a firs aid kit, there are several versions of PSV/PCV first aid kit available but they must include as a minimum the following items
10 x Antiseptic wipes (foil Backed)
1 x Conforming bandage (not less than 7.5cm wide
2 x Triangular bandages
3 x Large sterile unmediated ambulance dressing (not less than 15cm x 20cm)
2 x Sterile eye pads with attachments
12 x Assorted safety pins
1 x packet assorted adhesive dressings
1 x pair disposable gloves
1 x pair of rust free blunt-ended scissors
One of our most popular first aid kits which complies with this can be found here
All items in the first aid kit need to be kept in date if the date has passed they need to be replaced, if any items are used they also need to be replaced before the vehicle is used again.
The items should be kept in a suitable container which is clearly marked as a first aid kit and the driver should know where in the vehicles this is kept.
There are a number of safety signs that should displayed in the vehicle so that all passengers can clearly see, a No-Smoking sign has been a legal requirement for over a decade now. Also it is the responsibility of the operator to ensure all passengers wear seatbelts while travelling on the vehicle, this can be done by an announcement before the journey begins but an easier alternative is to place a seat belt sign/sticker within sight of each seat which has a seat belt fitted.
We supply various safety signs for vehicles and they can be viewed here
When carrying school children it is legal requirement to display a school bus sign both at the front and the rear of the vehicle.
These need to be reflective, the front should be a minimum of 25cm x 25cm and the rear a minimum of 45cm x 45cm.
When there are no children on the bus these should be removed, there are several different fixing methods available and these can be viewed here
Why do wheels come off HGV and PCV’s and does it matter?
Having been involved in the Heavy Goods Vehicle (HGV) and Passenger Carrying Vehicles (PCV) industry for over 20 years I have always been conscious that wheel loss has been a long standing industry problem however it hadn’t really affected me, that changed a few weeks ago.
Driving along a busy dual carriageway with my family I was suddenly aware of a wheel leave a coach in front of me cross both carriage ways and run up the embankment on the other side.
Does wheel loss matter? If I had been travelling a little faster that wheel would have hit my car and possible hurt my family or myself. It mattered to the people travelling on the coach as their excursion was interrupted and it mattered to the operator and driver who had to sort out the problem.
Still don’t think it is a problem watch this short clip I found on Youtube,
So why do wheels come off?
Having spoken to many operators some have never lost a wheel in forty years of business another I spoke to had lost a wheel which caused a fatality, there are several reasons why wheels become detached from HGV and PSV vehicles, some of which I list below:
Poor Maintenance – Possible the most obvious cause and the easiest to remedy, wheels and studs need to be checked for defect before fitment there should be no cracks in the wheel and stud holes should not be elongated. The wheel and hub need to be free of rust and any loose paint wire brushed off, any rust on the studs should also be removed and the studs should lightly oiled.
Stretched Studs – Wheels are held on by a finite clamping force. When fitting wheels the nuts should be wound onto the stud by hand and then tightened to the correct torque with a torque wrench this varies between 500Nm- 850Nm. If a power wrench is used to fit the wheel there is a danger of over torqueing and stretching the stud, this will cause the stud to lose its elasticity and could lose clamping force.
Change of Temperature – If a vehicle is driving in an inner city it will be doing a lot of braking this can cause the wheel and hubs to become hot, the same is if the vehicle is driving in very hilly or mountainous areas. If there is then a sudden storm with heavy rain causing puddles, floods etc. there is a possibility the wheels will come into sudden contact with cold water which will cause the steel to contract and wheel to lose torque.
There are other possible reasons why wheels become detached, there also tried and proven ways to prevent this happening. Apart from good maintenance there are several products on the market that can prevent operators becoming a victim of wheel loss.
What do I need to look for in a Safety Helmet?
A safety helmet is required where these is a risk of being injures by falling objects.
Shells are primarily made using UV stabilised high density polyethylene (HDPE) or Acrylonitrile Butadiene Styrene (ABS), harneses are made using low density polyethylene or Terylene webbing.
To comply with European standard EN397 2012 all helmets must be marked with;
Size or size range in CM on both shell and harness.
Informative label with specified working on shell material eg ABS, HDPE etc.
The year and quarter (or month) of manufacture.
It is not recommended that helmets should be used 5 year after the date of manufacture.
What ArmourAll wipe should I be using?
ArmorAll® Matt Finish Dashboard Wipes are a quick and easy way to clean dashboards and trims without adding shine. The extra-strength wipes are specially formulated to clean vinyl, rubber and plastic surfaces. They can also be used for many non-automotive applications. They are non-toxic and can be easily disposed of. Highly efficient, just one wipe can treat an entire dashboard.
All Round Wipes
As a result of the increasing consumer demand for convenience, ease of use and efficiency, wipes have become an extremely popular product form. ArmorAll® was the first to introduce ArmorAll® All Round Wipes to the automotive category.