All about automatic snow chains

Your knowledge source for automatic snow chains traction aid

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What are automatic snow chains?

For the uninitiated, it may sound strange that something like snow chains can be automatic at all. To understand the concept, it’s fundamental to know that it is only in the tiny tyre footprint that chains – or any other traction aid – are effective. For traditional snow chains, the only way to get chain into the footprint of a rotating wheel is to dress the entire wheel with a net of chains, a work that could be risky, tiresome, and dirty. So, how do automatic snow chains work? Automatic snow chains use a faster, safer, and more convenient method: Just by pressing a button, a chain wheel starts rotating and continuously throws short chain-strands into the footprint.

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Why should I have automatic snow chains?

Chains are the most effective traction aid. They are durable and withstand heavy wear. However, mounting chains at a roadside could be risky. The passing traffic – often at reduced visibility – is a potential danger. Also, the work is tiresome as chains are heavy, the tyres are dirty, and the weather is often very cold at times when chains are needed. And, it takes time to mount! Mounting time varies according to circumstances, but typically it’s half an hour’s work – and the corresponding delay.

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With automatic snow chains, just by pressing a button, you get instant traction and just drive on. You don’t even have to leave the warm cab. Automatic snow chains are the unparalleled way to gain traction as:

  • The system is instantly effective – by pressing a button
  • No manual and tiresome mounting
  • Safety is optimal as the driver stays in the cab
  • No time delay caused by mounting / demounting

Simply, automatic snow chains are the safest and most convenient method to avoid delays caused by slippery road conditions. In this way, they can be regarded as a kind of insurance against various consequences of slippery road conditions. 

Vehicles suitable for automatic snow chains

Not all vehicles could be equipped with automatic snow chains. As a certain ground clearance is required to operate the chain wheel swing arms, there simply isn’t room enough for the system in a private car. Instead, it’s ideal for trucks, bigger vans, and buses.

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Commercial transport trucks
Mostly, productivity and profitability in the transportation business are dependent on timely delivery. Irrespective of the cause, delays may have severe consequences on business operations. Also, drivers’ convenience and well-being help to keep up productivity. Automatic snow chains for trucks are a tool for keeping the truck fleet rolling without delays caused by slippery road conditions.

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Buses
Whether coaches, school buses, or city transportation buses, passenger safety is imperative. Automatic snow chains improve both road and passenger safety by providing traction in icy road conditions, keeping the bus safely on the road.

For school buses and route buses, timely arrival in stops and destinations are vital. Automatic snow chains for buses are a tool for keeping up with the schedule and arrive on time.

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Rescue vehicles
For fire trucks, ambulances, and other vehicles used for rescue operations, arriving in time could be a matter of life or death. In emergencies where literally every minute counts, unnecessary delays could prove fatal.

Automatic snow chains for fire trucks and ambulances not only prevent rescue operation delays caused by icy roads. Instead, they are an all-year-around traction aid when rescue vehicles need to make their way in muddy parks, over wet lawns or other surfaces where the vehicle tyres don’t get sufficient grip.

Automatic snow chains problems

Despite the many benefits of automatic snow chains there are limitations and downsides.

  • They are not effective in deep snow. At a snow depth of approx. 6” or more, chains will not improve traction which makes automatic snow chains unsuitable for winter off-road terrain driving. In such driving conditions alternative traction aids may be a better choice.
  • Automatic snow chains are a pneumatic mechanical system permanently attached under the vehicle. As such it is exposed to harsh conditions like water, gravel, road salt and the likes. Accordingly, the system requires some maintenance. Typically, the system should be engaged at least once monthly – even in summer – to keep bearings evenly lubricated and moving parts in good working condition. To save weight and hassle, some owners demount the system during non-winter seasons. This will add to product life time.
  • Even if the system as such is sturdy and very reliable, the positioning of the chain wheel is vital for effectiveness. For optimal operation, the system must be tailored to the specific vehicle model, and accordingly, model specific mounting brackets are required.
  • Chains may break. Either as a result of excessive wear or due to damage. In such case a broken chain must be replaced for the system to be effective.

Automatic snow chains cost – expensive or cheap?

The cost for installing automatic snow chains is a drawback to some. At the cost of approx. €2,000 per drive axle (for vehicles with air brakes) plus installation cost, it can be considered as an investment in road safety, driver’s safety and well-being, and prevention of costly delays.

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Types of snow chains for trucks

Traditional snow chains for trucks come in a vast variety of designs, sizes and chain dimensions. Depending on the vehicle’s operation and wheel dimension there are several factors indicating what type of snow chains would be the optimal choice. However, there is no such thing as one-chain-fits-all-purposes. As operation and driving conditions vary, so will the optimal snow chains vary.

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Automatic snow chains are a completely different story. Here, chains are slung under the tyre, and accordingly, they are independent of the vehicle’s wheel dimension. The chains are designed to provide best possible traction on icy roads, which makes them a very reliable traction aid in most slippery road conditions. However, deep snow (approx. 15cm or more) is a driving condition where automatic snow chains are ineffective, and traditional snow chains could be the better choice – provided they are designed specifically for deep snow driving.

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When to use snow chains?

The easy answer is: when winter conditions make the road icy and slippery and you need traction. But, there is more to it than this. National or regional regulations make snow chains either permissible or illegal to use. There are even areas where chains are required in some situations.

Why are snow chains illegal in some regions?

Snow chains cause heavy wear on dry road surface and tyres, and accordingly, they add cost for keeping roads in good shape. Also, the heavy mechanical impact on road surface will release particles that spread by air or by rain water. Obviously, snow chains also have an environmental impact.

However, in areas with typical winter road conditions, the pros of saving lives, reducing accidents and traffic jam in icy road conditions outweigh the cons of road wear.

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When to use automatic snow chains?

The easy answer is: any time you need more traction. As automatic snow chains are engaged just by pressing a button there is no need for considering whether the improved traction will be worth the mounting time and effort. Also, wear on dry road and tyres becomes a non-issue as you just disengage the system as soon as you reach dry road.

Even for interstate or international passage, the automatic snow chains are a non-issue. Driving in areas where chains are prohibited, you just don’t engage the system.

Automatic snow chains vs alternatives

All methods to increase tractions have their pros and cons. Considering different aspects like weight, ease of use, cost, serviceability, reliability, effectiveness etc., no method is the single best option. Rather, different aspects must be weighed together when comparing methods and decide which one best meets your demands.

No chains or other traction aid

Even if skipping traction aid is not really an option, there are trucks on the road without any traction aid whatsoever. In areas where icy road conditions are rare, many drivers rely on the heavy vehicle weight increasing static friction. Also, lifting an axle to increase weight on the drive axle is a method sometimes used, although this is illegal in many areas.
As opposed to this, traction aids do a most significant difference by safely increasing traction by introducing a higher coefficient of friction in the tyre footprint. Notably, chains are the most effective traction aid.

 

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Conventional snow chains

Snow chains come in a variety of designs, and there are chains for virtually any truck tyre dimension and intended use. Accordingly, they could be optimized for e.g., off-road terrain, different snow depths, road surfaces, or types of vehicles. Even if snow chains are quite expensive, they are wear-resistant and allow extensive use. The downside is the tedious mounting and demounting – a tiresome, time-consuming, and often risky work which sometimes makes drivers await too long for mounting / demounting. Also, regularly bringing out and then stowing away the chains is a dirty and heavy work.

In comparison, automatic snow chains provide equivalent traction on icy roads but, just by pressing a button, they are instantly engaged and disengaged with no waste of time or unnecessary wear on tyres and road as a result. When not in use, they are conveniently ‘stored’ under the vehicle chassis.

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Tyre cables

Tyre cables are similar to snow chains, but instead of chain links, cables are used to cover the tyre. Even though they possibly are not as effective as chains, they are lighter and are experienced as easier to mount and demount.

In comparison, automatic snow chains provide arguably better traction with no mounting / demounting work at all.

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Tyre socks

Textile socks provide good traction on snow – however, less good traction on black ice. They are lightweight and easy to stow away, as well as they are quick and easy to mount compared with conventional snow chains.
But, they are not wear-resistant and will quickly be worn out if used on dry roads. They are not suitable as the primary traction aid for the truck, but rather an emergency solution.

In comparison, automatic snow chains provide better traction and resist heavy wear. They don’t require mounting as they are engaged/disengaged from the cab – just press the button!

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Snow tyres / winter tyres

Winter tyres are designed for better road grip in snowy and icy conditions. As such they improve safety and maneuverability but, due to physics, rubber tyres simply cannot provide enough traction for all driving situations e.g., starting uphill on black ice. Also, winter tyres are a costly solution as a set of winter tyres for a heavy truck may cost thousands of Euros.

In comparison, automatic snow chains provide better traction and are effective when winter tyres as such are not – at the fraction of the cost for a full set of heavy truck winter tyres.

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