Road Salt / Grit ........An alternative ??

[fly258]

Due to the shortage of road salt , would sea water sprayed onto snow / ice covered roads not melt the snow and stop it refreezing?
Seems a simple and cheap alternative but only if it would work, obviously.

[ChuckFickens]

seawater freezes at about -2C, we have seen temperatures far lower than that over the last couple of weeks so it would just freeze (nice for an ice rink, not so great for a road)

[DrFilth]

plus some people driving on it may get seasick

[fly258]

So how come the sea only freezes at very extreme temperatures?
And why don't road salted roads ice up at -2?

[DrFilth]

they use rock salt on the roads

[DrFilth]

http://en.wikipedia.org/wiki/Brine

[factor-fiction]

There is a calculator here, fly, if you want to investigate further.
http://www.csgnetwork.com/h2ofreezecalc.html
The freezing point varies depending on things such as the amount of salt and the pressure.
Hi chuck- I thought seawater freezes at close to 0 degrees F so that would be about -18 degrees C, but that's a distant memory from school days

[ChuckFickens]

knew that would be the next question :)

The density of sea water raises as it gets to it's freezing point, meaning as soon as the water at the surface of the sea is cooled enough for it to freeze it sinks and is replaced by slightly warmer water from below, this process will keep repeating until the entire depth of the water is at a low enough temperature to freeze, only then will ice start to form on the surface of the sea.

Road salt only works down to a certain temperature, then it will do nothing at all and what point it will work or stop working depends how much salt there is , seawater has a salt content of about 3.5% so doesn't freeze until -2C, a 10% solution of salt in water wouldn't freeze until about -6C an a 20% solution wouldn't freeze until about -16 (though in reality salt stops working on roads at about -10C)

[buildersmate]

In any event, the only hint of 'shortage' is linked to the limitation of the transport system. There's millions of tonnes of the stuff deep underground in Cheshire and yet more underground in N Ireland. There's hundreds of tonnes already on the surface in Cheshire - just waiting shipment.
In the age of 'just in time' processes, news-hounds simple can't get their simple heads around the concept, and they seem to translate the (valid) news that there's only x days supply in the local depot (where x is a small number) to mean that we are about to run out. Far from it - the only risk to supplies is in the event that the lorries can't get to Cheshire and back.
Smart that the question might appear on paper, where precisely would you propose to stockpile hundreds of tonnes of sea-water? It's exactly the same issue - so it doesn't actually solve anything.

[Teleph0ne]

The sea doesn't freeze because of the salt content and the fact that it is constantly moving. I have seen ice build up on the beech from the spray where it settles

[ChuckFickens]

"where precisely would you propose to stockpile hundreds of tonnes of sea-water?"

We have a handy storage depot located just off the coast.

[jackthehat]

It's snowy and frozen here in Blackpool.................

Can you see where I'm going with this ............? ;o)

[jno]

You'll soon be taking a stroll to Dublin, jack?

[buildersmate]

Yeah, but it's no good there. Mrs Angry from Tunbridge Wells wants to know that's no further than 5 miles from her (Kent) local council depot. That's what all the irrational fuss is about.

[jackthehat]

Me 'n' the huskies, jno. :o)

[jno]

remember to take a box of matches in case you have to eat the huskies in an emergency then

[heathfield]

Local councils took Met Office forecast advice on the temperatures and snowfall expected this winter, and laid in what they thought would be sufficient in the way of salt and grit. Look where it got them!

Regarding seawater, our council has gritter trucks that spray water on the salt and grit they're spreading. This creates a strong brine solution that acts more quickly on the snow and ice than would cold dry salt.