Snow chain – Wikipedia

Snow chain mounted on a vehicle wheel

Channels on a snow-hunting truck

THE snow chains are a set of metal chain portions placed around tires intended to strengthen the adhesion of the vehicle already equipped or in the absence of winter tires on snowy surfaces. They are of different sizes adapted to the diversity of types of wheel sizes.

The snow chains were invented by the American Harry D. Weed living in Canastota. THE August 23, 1904 , a patent is issued to him ^{[ first ]} .

The July 16, 1935 , the Canadian Auguste Trudeau obtains an invention patent for his carrier and non -slip car chain ^{[ 2 ]} . The patent file contains the demand for invention, a description of the chain and the drawings of Auguste Trudeau authenticated by the prosecutor E.J. Fetherstonhaughu.

France [ modifier | Modifier and code ]

In France, their use is compulsory on at least two -wheel drive, indicated by the B26 panel and their end of prescription by panel B44 .

• The assembly operation must be anticipated.
• Make this one before arriving in a dangerous or narrow coast

Indeed the rise at altitude jointly increases many aggravating parameters.

• Wind: it increases the cold, wind cooling that increases with altitude (exposure);
• Cold: commonly, we admit a drop in first °C All 100 m ^{[ 3 ]} ;
• Quantity and density of snowfall, increasing with altitude but disappear as soon as one is above the clouds;
• racks, formed by the wind, possibly aggravated by special factors:
  • The intensity of the wind always increases a lot with altitude;
  • Complete them jointly: clearance and/or exhibition (no obstacles);
  • Complete it: the corridor wind effect (Venturi effect, which is also found on ridges) ;
  • Another aggravating mechanical element, with altitude, the flakes are more powdery (cold, small and dry), hence increase in reputation, saltation, and diffusion/suspension.
  • You have to be aware that the danger can appear in a few minutes in surprising thicknesses.
• Another condition can create a vicious circle: the strong wet snowfall, large sticky flakes:
  • drastically reducing external visibility, resulting in the impossibility of distinguishing obstacles.
  • internal visibility reduced by inner fog.
  • Loss of operation of the wipers (the sticky packets agglutinate and remove their flexibility, thus reducing their effectiveness).
• Incidence of the slope: it quickly becomes very delicate to make a sloping montage (example: poor handbrake efficiency).
• Isolation: distance from any possibility of receiving help.
• Transi and little, the driver may be unable to make this assembly.
• etc.

Despite all the preparations, in real conditions, the even experienced driver is surprised. The installation is too often done in dangerous conditions:

• Prepare the presiglizing triangle and the yellow vest (visibility),
• Ask passengers and passengers to get upstream (the most important!),
• possibly place an downstream passenger, to report the danger and encourage to slow down,
• Think that visibility can be very reduced (big snow time).
• Before tackling a pass, there are still specially fitted spaces.

• A maximum speed of general 30 To 50 km/h is recommended with the channels ^{[ 4 ]} .
• Dry road driving during an extended period uses channels faster but also tires.
• Some channels must be launched after traveling a short distance. An too large or not tense chain can degrade or even hang parts of the chassis or bodywork.

We now find on the automotive accessory market for so -called “universal” channels planned to adapt for all wheel sizes, anticipating a change of future vehicle and easy to climb. Some systems are no longer channels at all but studded bands fixed directly on the rim or special fabric envelopes coating the wheel, designated by the term “snow socks”. Some other systems combine chains and nails for snow and ice use.

Related articles [ modifier | Modifier and code ]

external links [ modifier | Modifier and code ]