Record snowfall has covered the U.K., while cold temperatures are gripping Europe. Seoul and Beijing have seen their heaviest snowfalls in recent memory, and arctic temperatures have penetrated the U.S. far enough to threaten crops in Florida. For those who have to commute to work in such weather, this is a good time to appreciate the technology incorporated into winter service vehicles.
Sand- and salt trucks have evolved a long way from the era when two men with shovels used to stand on the back of a dump truck. Modern grit is a mixture of sand and rock salt, but the latter has deleterious effects not only on metal vehicle frames, but also on vegetation and freshwater lakes and streams. A variety of techniques have therefore been devised to keep roads on a "low-salt diet."
"Pre-wetting" the salt -- spraying it with brine as it's dropped -- helps it stick to the road better, meaning crews can cut back from 500 pounds per mile to 200...
Vehicle-mounted electronic thermometers let supervisors know how far above or below freezing the pavement is. Some truck cabs have up-to-the-minute weather radar so crews know how long it'll be before the freezing rain or snow hits...
To prevent the grit from being thrown off the road surface by vehicle tires, additional substances may be intermixed to increase adherence. The earliest additive was molasses, but it was difficult to use in cold weather and tended to attract cows and wildlife to the roads.
That means using brine, magnesium chloride and a sugar beet byproduct, which are mixed via a dozen yellow-handled valves marked with letters of the alphabet.
Fine-tuning the grit application to the weather conditions not only saves taxpayers money (one truckload of salt costs ~$800), but also reduces chloride levels in nearby lakes.
http://www.startribune.com/local/south/80513267.html. Photo credit Richard Tsong Taatarii, Star Tribune
One of my very first paid jobs was spending a long afternoon stenciling "DO NOT ENTER HOPPER WHILE AUGER IS IN MOTION" because someone had had their foot torn off after getting in to remove brick stuck in the screw. I guess they knew all about hoppers after that.
I will still use volcanic rock debris for our walkway, seeing as salt indeed has a detrimental effect on the environment (including our frant yard with its cranberries and ginko). But it's nice to see we have come a long way in the last couple of decades.
Keep on truckin'!
However the main reason is probably that central government is obsessed with cutting costs and told local authorities to budget for six days of snow and ice this winter. The justification? Global warming of course. So far it's been going on for over three weeks in places and the forecasters reckon there's another week to come.
You've just got to love central government that tries to blame other bodies for everything, but interferes with everything those bodies do. And when that meddling turns to shit? Blame the other bodies of course.
I have nothing constructive to contribute about salt trucks because I am completely unfamiliar with them.
I have to admit that I've NEVER even seen a salt truck in my entire life.
Your blaming Global Warming for the amount of snow in the UK?
So what do you call the amount of snow that hit us in the late 80's and 60's?
Also what about many many many years ago when there was a mile of ice over the UK?
Plowing is great and all; it must be cheaper and better for the environment. But it won't keep roads clear for long in a decent snowfall. I've never seen how pumice works, but it sounds like it could be a cheap alternative for places that have it in good supply.
None here in Brisbane.
:-)