Gritters?

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stevepuma
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Gritters?

Post by stevepuma »

Hi All, had a quick trawl and couldn't / didn't find this question anywhere else, so here goes...

If you're following a gritter on the motorways how long before it empties (assuming it's nearly full)?

This is because I caught up with a gritter coming over Shap on the M6 in my new (well it is to me!) car.
It was in lane two doing about 60, and I was faced with the usual dilema of do I wait and trundle along behind it forever, or do I thrash past in lane three, risking the paintwork on my (new to me) bonnet?

That prompted the thought process abave, so does anyone know the average distance a full load will cover on a motorway? Or even if there is an average distance?

Advice gratefully received!

Either way it didn't matter, 'cos I chickened out of both options and went for a brew at Tebay... :-D
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Re: Gritters?

Post by baroudeur »

stevepuma wrote: Sun Dec 20, 2020 14:22 Hi All, had a quick trawl and couldn't / didn't find this question anywhere else, so here goes...

If you're following a gritter on the motorways how long before it empties (assuming it's nearly full)?

This is because I caught up with a gritter coming over Shap on the M6 in my new (well it is to me!) car.
It was in lane two doing about 60, and I was faced with the usual dilema of do I wait and trundle along behind it forever, or do I thrash past in lane three, risking the paintwork on my (new to me) bonnet?

That prompted the thought process abave, so does anyone know the average distance a full load will cover on a motorway? Or even if there is an average distance?

Advice gratefully received!

Either way it didn't matter, 'cos I chickened out of both options and went for a brew at Tebay... :-D
It depends on the load weight, the spreading rate and the spread width which will vary according to conditions.

Gritters are limited legally to 56mph and will spread at a lower speed probably around 40/45 on a motorway.

Overtaking a motorway gritter could involve a lot more expensive bodywork repair than just a few chips to the paintwork!
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Re: Gritters?

Post by Glen »

A bit of rock salt spraying on you car isn't going to cause the bodywork to suddenly rust, in fact you'll get more salty spray on the vehicle once it has dissolved into a solution, some time after it has been spread.
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Re: Gritters?

Post by M19 »

Glen wrote: Sun Dec 20, 2020 15:49 A bit of rock salt spraying on you car isn't going to cause the bodywork to suddenly rust, in fact you'll get more salty spray on the vehicle once it has dissolved into a solution, some time after it has been spread.
No, the issue is the impact of fresh gravel sized rough lumps of salt with sharp edges onto the bodywork, chipping the paint.

Dissolved road salt sprayed on a vehicle from road traffic can be solved simply by washing it off.
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Re: Gritters?

Post by Glen »

Rock salt doesn't chip paint, it really doesn't.
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Re: Gritters?

Post by XC70 »

baroudeur wrote: Sun Dec 20, 2020 15:18
stevepuma wrote: Sun Dec 20, 2020 14:22 Hi All, had a quick trawl and couldn't / didn't find this question anywhere else, so here goes...

If you're following a gritter on the motorways how long before it empties (assuming it's nearly full)?

This is because I caught up with a gritter coming over Shap on the M6 in my new (well it is to me!) car.
It was in lane two doing about 60, and I was faced with the usual dilema of do I wait and trundle along behind it forever, or do I thrash past in lane three, risking the paintwork on my (new to me) bonnet?

That prompted the thought process abave, so does anyone know the average distance a full load will cover on a motorway? Or even if there is an average distance?

Advice gratefully received!

Either way it didn't matter, 'cos I chickened out of both options and went for a brew at Tebay... :-D
It depends on the load weight, the spreading rate and the spread width which will vary according to conditions.

Gritters are limited legally to 56mph and will spread at a lower speed probably around 40/45 on a motorway.

Overtaking a motorway gritter could involve a lot more expensive bodywork repair than just a few chips to the paintwork!
I have overtaken lots of motorway gritters and never suffered any bodywork damage.
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Re: Gritters?

Post by Truvelo »

Glen wrote: Sun Dec 20, 2020 17:42 Rock salt doesn't chip paint, it really doesn't.
It certainly sounds like it to me with the clattering and banging but my car is now 14 years old so I don't really care any more.

As for overtaking or staying behind I prefer to get past it as soon as possible although I time my manoeuvre to spend as little time alongside the gritter as possible. If there's a line of slow moving traffic in lane 3 I will hold back until it's cleared so I can get a clear run.
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Re: Gritters?

Post by coneman »

stevepuma wrote: Sun Dec 20, 2020 14:22 Hi All, had a quick trawl and couldn't / didn't find this question anywhere else, so here goes...

If you're following a gritter on the motorways how long before it empties (assuming it's nearly full)?

This is because I caught up with a gritter coming over Shap on the M6 in my new (well it is to me!) car.
It was in lane two doing about 60, and I was faced with the usual dilema of do I wait and trundle along behind it forever, or do I thrash past in lane three, risking the paintwork on my (new to me) bonnet?

That prompted the thought process abave, so does anyone know the average distance a full load will cover on a motorway? Or even if there is an average distance?

Advice gratefully received!

Either way it didn't matter, 'cos I chickened out of both options and went for a brew at Tebay... :-D
In answer to your question " how long till it empties" and the "average distance travelled on a full load" there are many factors to consider such as width of road ie. S2/3, D2/3/4, etc , the rate of spread ie 10 /20 /30 /40grams per metre sq, density of the salt ie. has it been stored outside or kept dry in a barn, and the accuracy of the automatic spreading equipment ( I don't think there can be many "old skool" with levers and dials in the cab /manually set hopper doors left) , another factor which will increase the distance will be machines fitted with pre-wetting equipment which I believe reduces usage by approx 1/3 so giving further distance.

All the modern machines have road speed related equipment ie the faster you go the more it puts out, slow down and it puts out less - but still puts out the correct rate set.
So to give an example we'll look at the following, a 9 tonner (3 axles) fully loaded and spreading at the rate of 20g/m/sq on an S2 road with an average width of 7m will get approx 63 miles/100 km on a full load.
Like I say there are many factors that would affect the distance you would get on a full load but laying at 20g/m/sq, 1 tonne will get you 7km on an S2 or 2 lanes of a D3 if you are spreading in lane 1&2 and using the passing movement of traffic in lane 2 to throw salt into lane 3.

Of course as I said above you will get further if you are using salt/brine mix but as I had long retired by then its not something I'm too familiar with.
I know there's a depot at Skirsgill in Penrith so if you were travelling N/B you would have sat behind him to J40.
Hope this helps.
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Re: Gritters?

Post by baroudeur »

XC70 wrote: Sun Dec 20, 2020 18:57
baroudeur wrote: Sun Dec 20, 2020 15:18
It depends on the load weight, the spreading rate and the spread width which will vary according to conditions.

Gritters are limited legally to 56mph and will spread at a lower speed probably around 40/45 on a motorway.

Overtaking a motorway gritter could involve a lot more expensive bodywork repair than just a few chips to the paintwork!
I have overtaken lots of motorway gritters and never suffered any bodywork damage.
Perhaps "do not pass" should be introduced as in other countries?

My point was that when passing a gritter you will have no idea of the road conditions ahead. Hitting a pile of slush or standing water at 60+ could be a recipe for trouble. During 21 years in charge of gritting operations I saw a lot of foolhardy drivers who couldn't wait. :(
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Re: Gritters?

Post by XC70 »

baroudeur wrote: Mon Dec 21, 2020 16:33
XC70 wrote: Sun Dec 20, 2020 18:57
baroudeur wrote: Sun Dec 20, 2020 15:18
It depends on the load weight, the spreading rate and the spread width which will vary according to conditions.

Gritters are limited legally to 56mph and will spread at a lower speed probably around 40/45 on a motorway.

Overtaking a motorway gritter could involve a lot more expensive bodywork repair than just a few chips to the paintwork!
I have overtaken lots of motorway gritters and never suffered any bodywork damage.
Perhaps "do not pass" should be introduced as in other countries?

My point was that when passing a gritter you will have no idea of the road conditions ahead. Hitting a pile of slush or standing water at 60+ could be a recipe for trouble. During 21 years in charge of gritting operations I saw a lot of foolhardy drivers who couldn't wait. :(
It all depends on the conditions. Very often the gritters will be out of an afternoon or early evening getting ready for overnight freezing temps. When I am driving and catch up the gritter on the motorway it is usually a good few degrees above freezing, dry and clear. Rarely am I following one in snowy or slushy conditions.
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Re: Gritters?

Post by Big L »

baroudeur wrote: Mon Dec 21, 2020 16:33
XC70 wrote: Sun Dec 20, 2020 18:57
baroudeur wrote: Sun Dec 20, 2020 15:18
It depends on the load weight, the spreading rate and the spread width which will vary according to conditions.

Gritters are limited legally to 56mph and will spread at a lower speed probably around 40/45 on a motorway.

Overtaking a motorway gritter could involve a lot more expensive bodywork repair than just a few chips to the paintwork!
I have overtaken lots of motorway gritters and never suffered any bodywork damage.
Perhaps "do not pass" should be introduced as in other countries?

My point was that when passing a gritter you will have no idea of the road conditions ahead. Hitting a pile of slush or standing water at 60+ could be a recipe for trouble. During 21 years in charge of gritting operations I saw a lot of foolhardy drivers who couldn't wait. :(
Once you are close enough to be considering overtaking a gritter the road conditions ahead of it are likely to be very similar to behind it. Salt doesn't clear ice/snow/slush instantaneously.
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Re: Gritters?

Post by stevepuma »

Thanks all for the responses, and a lovely detailed one from Coneman... I'm amazed how far they can go!
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Re: Gritters?

Post by crazyknightsfan »

Possibly a completely ignorant question here, but I am wondering what impact (if any) salting/gritting of roads has on your cars? Especially in the north and Scotland this would be a normal fact of life and I can't imagine completely washing/cleaning a vehicle after every commute to work.

Question arises because some gritting operations have just begun in New South Wales with a big cold snap passing through, causing many roads not normally subject to ice or snow to be subject to ice and snow.
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Re: Gritters?

Post by KeithW »

crazyknightsfan wrote: Fri Jun 11, 2021 02:38 Possibly a completely ignorant question here, but I am wondering what impact (if any) salting/gritting of roads has on your cars? Especially in the north and Scotland this would be a normal fact of life and I can't imagine completely washing/cleaning a vehicle after every commute to work.

Question arises because some gritting operations have just begun in New South Wales with a big cold snap passing through, causing many roads not normally subject to ice or snow to be subject to ice and snow.
In a word RUST, that said modern vehicles are much better protected than they were 30 years ago so its far less of a problem than once it was.

If you want the technical explanations it goes like this. Rust is due to the basic electrochemical reaction between iron and oxygen that forms iron oxide, which is accelerated by rainwater that contains traces of iron ions. Add sodium chloride (road salt) and it reacts with the snow to melt it by lowering its freezing temperature, the material releases ions that accelerates the reaction which in turn on unprotected steel results in fast-spreading rust. Add dissimilar metals such as chrome plating to the mix and it goes into overdrive.
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Re: Gritters?

Post by Chris5156 »

crazyknightsfan wrote: Fri Jun 11, 2021 02:38 Possibly a completely ignorant question here, but I am wondering what impact (if any) salting/gritting of roads has on your cars? Especially in the north and Scotland this would be a normal fact of life and I can't imagine completely washing/cleaning a vehicle after every commute to work.
Id be astonished if anyone ever did that. Generally speaking the winter is very wet and your car will get a good soaking on a regular basis with clean water from above that will sluice off a lot of it. Most people will also wash their car periodically. But it would be unusual to carry out any particular regular maintenance to protect from salt or grit beyond that.

I do wonder, though, whether vehicles sold in parts of the world that don’t have salted or gritted roads would react differently - would the body undergo different treatment or protective coatings, for example?
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Re: Gritters?

Post by 2 Sheds »

KeithW wrote: Fri Jun 11, 2021 06:36
crazyknightsfan wrote: Fri Jun 11, 2021 02:38 Possibly a completely ignorant question here, but I am wondering what impact (if any) salting/gritting of roads has on your cars? Especially in the north and Scotland this would be a normal fact of life and I can't imagine completely washing/cleaning a vehicle after every commute to work.

Question arises because some gritting operations have just begun in New South Wales with a big cold snap passing through, causing many roads not normally subject to ice or snow to be subject to ice and snow.


In a word RUST, that said modern vehicles are much better protected than they were 30 years ago so its far less of a problem than once it was.

If you want the technical explanations it goes like this. Rust is due to the basic electrochemical reaction between iron and oxygen that forms iron oxide, which is accelerated by rainwater that contains traces of iron ions. Add sodium chloride (road salt) and it reacts with the snow to melt it by lowering its freezing temperature, the material releases ions that accelerates the reaction which in turn on unprotected steel results in fast-spreading rust. Add dissimilar metals such as chrome plating to the mix and it goes into overdrive.
My first car was 6 years old in 1972. Within just a few months after getting it I had repair bills for new subframes which far exceeded the price of the car. All due to severe corrosion, hidden beneath, mainly because of road salt. In those days if you saw a car over 5 years old which didn’t have rust patches on the bodywork it was something to comment on. We used to buy tins of tar (under seal) to paint on the underside, then later on came Waxoyl, injected into hollow sections and sprayed on. I never understood why it took manufacturers so long to get to grips with corrosion. Intentional rapid built in obsolescence perhaps.
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Re: Gritters?

Post by Isleworth1961 »

Chris5156 wrote: Fri Jun 11, 2021 10:12
crazyknightsfan wrote: Fri Jun 11, 2021 02:38 Possibly a completely ignorant question here, but I am wondering what impact (if any) salting/gritting of roads has on your cars? Especially in the north and Scotland this would be a normal fact of life and I can't imagine completely washing/cleaning a vehicle after every commute to work.
Id be astonished if anyone ever did that. Generally speaking the winter is very wet and your car will get a good soaking on a regular basis with clean water from above that will sluice off a lot of it. Most people will also wash their car periodically. But it would be unusual to carry out any particular regular maintenance to protect from salt or grit beyond that.

I do wonder, though, whether vehicles sold in parts of the world that don’t have salted or gritted roads would react differently - would the body undergo different treatment or protective coatings, for example?
I understand it that many manufacturers building 'global' cars put on better anti-corrosion treatments on cars built and sold in countries where winter road salt was used.
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Re: Gritters?

Post by WHBM »

Chris5156 wrote: Fri Jun 11, 2021 10:12 I do wonder, though, whether vehicles sold in parts of the world that don’t have salted or gritted roads would react differently - would the body undergo different treatment or protective coatings, for example?
Very much so. Met someone from Minnesota USA (lots of winter salt) in Los Angeles (no salt). He said he was seeing cars on the road there in normal use which had long disappeared from Minneapolis. Apparently if you had the car well additionally undersealed at new (common there), had a full underneath water/steam wash in the Spring, etc, it would be about 6-7 years before you started to notice the rust. Most cars there eventually failed the annual test for underbody or side panel corrosion before major mechanical issues got them, which latter was the norm in Los Angeles after maybe 15 years.

The US manufacturers seem to make no difference in their treatments for different markets.

You get other corrosion issues in the USA from other causes. The most surprising is in Miami, which you would think was also free from this, but the opposite. The cars there corrode the opposite way, from the top down, you find corrosion of the main roof panel, and at the corners of the pillars, especially the A-pillar either side of the windscreen. It's due to the coral dust in the air, which is mildly acidic (notably, far more so than the "acid rain" complained of in Europe). The Miami Metro, mostly elevated on viaducts, had the trains specially manufactured of stainless steel.
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Re: Gritters?

Post by KeithW »

Chris5156 wrote: Fri Jun 11, 2021 10:12 Id be astonished if anyone ever did that. Generally speaking the winter is very wet and your car will get a good soaking on a regular basis with clean water from above that will sluice off a lot of it. Most people will also wash their car periodically. But it would be unusual to carry out any particular regular maintenance to protect from salt or grit beyond that.

I do wonder, though, whether vehicles sold in parts of the world that don’t have salted or gritted roads would react differently - would the body undergo different treatment or protective coatings, for example?
Probably not, I know that in Malta where there is no road salt used it was far from unusual to see lots of old British made cars that the rust bug had made an endangered species in the UK.


I know the same is true of some of the southern US states, a cooleague of mine in Columbus Ohio who was a classic car collector would make frequent trips to California and Arizona in search of classic cars and trucks.
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Re: Gritters?

Post by rhyds »

Historically there was a big difference in rust resistance between various manufacturers, whereas now pretty much everyone is about the same.

For many years Italian cars would suffer in the UK's harsh (compared to Italy) winter climate, with rust problems being well known on FIAT, Alfa and especially Lancia cars. However in the late 80s/early 1990s FIAT had consolidated the Italian manufacturers and had started using galvanised bodyshells which cured the rust issues almost overnight.

The other big rusters were Japanese cars, due to a combination of the mechanicals lasting longer than most European cars (so the bodywork was what eventually scrapped them) and because Japan has a safety/MOT-style test at around 10 years old for its domestic car market which is very, very strict and expensive to get a car through (e.g. the steering rack must be replaced due to age, which is easily £250+), which meant that Japanese cars weren't rustproofed to last 10-15 UK winters. And the rustproofing wasn't just Waxoyl/Ziebart style coatings either, simple measures like plastic wheelarch liners would make a massive difference.

However, with modern cars having a massively increased amount of non-ferrous panels (plastic bumpers/alloy bodywork etc) rust is much less likely to kill a car these days, even in the harsh UK winter climate
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