Winter on the roads

Two highways gritters parked with salt store shed behind

It’s REALLY busy for team Lincs Gritters

It’s cold outside - and that means it’s time for the Lincolnshire County Council gritter team to plunge into the freezing depths of the county, head out on our massive Lincolnshire road network and make things a lot safer for all of us.

It’s a job so huge that it’s difficult to understand.

To treat the majority of our 5,500 miles of county roads, nearly 30,000 tonnes of salt is stored across eight depots in our county. And any, or all, of our 47 gritters will be heading out multiple times a day when needed to spread the specially-treated salt on the routes we all use.

Darrell Redford is Lincolnshire County Council’s Network Resilience Manager and it’s his job to look after the gritter fleet. He’s the expert on all things gritty over the winter. He said:

“We’re ready to get out whenever the temperature drops and the roads need the layers of salt to increase grip levels. Our team is out in all hours to make the roads safer during the cold months ahead.

"Our drivers are very talented at what they do and we use a lot of science to work out when and where to spread the right amount of salt – the men and women of the gritting team plus that vital information is a combination that’s effective and efficient in keeping roads open in the worst conditions. "It’s very clear that what we do with our gritting programme is important for road users, but a large part of road safety also relies on everyone on the roads to drive accordingly, be safe and show appreciation to other road users.”

Science is the key to getting it right

Darrell says that it’s not just a case of taking a best guess at where the salt is going to be needed on the ground when temperatures plummet. There’s a lot more science constantly going on to make sure that resources are used to their fullest.

“We have 12 weather stations in Lincolnshire, and access to another eight outside of the county that aren’t ours, but we share them with other areas to help us predict what weather fronts are moving across the area.

“There are two stations in each domain, which are: the Wolds, the Coast, Grantham and Grantham Ridge, Lincoln Ridge and the Fens.”

Whilst some might think that Lincolnshire is fairly flat and consistent in temperature across the county, the reality is that values at ground level can vary wildly. The undulating landscape causes a wide range of temperature values to deal with.

“We see temperatures in the Wolds drop dramatically. They can go down a lot,” adds Redford: “And across the fens it tends to remain quite high.”

This exact level of critical live information means that the gritting team can be equally as exact about when, and where, they put the salt down. The lower the temperature, the more salt is needed for a specific spreading area.

He continues: “We have something called route-based forecasting where each route has its own forecast, based on the specific domains. This means that we can send out the appropriate gritters for the appropriate areas as needed. That alone save us a lot of money and resource.

“It’s very important that we know what areas are at what temperatures too. When the road temperature is down to -2 we spread 7g of salt per square metre, between -2 and -5 we salt at 12g, at -5 to -10 that figure goes up to 17g of spread and when snow is on the road, or the temperature is lower than -10 then we go to the maximum 20g per square metre. Knowing exactly where, when and how much salt to spread anywhere in the county is an exact science and it saves us a lot of cash.”

You want salt with that?

If you want to make a road more grippy, there are two types of salt you can use.

The first is white in colour (it looks like the salt you use when tucking into your dinner) and needs to be treated with a brine wash as it gets spread.

“Any salt that you use has to be treated so that it’s more sticky,” Darrell says: “One of the biggest problems that we face is loss of salt once it’s been spread. Things like wind, rain, traffic and a host of other factors can all have a big effect on how much salt stays in contact with the road surface.

“To mitigate for this, the salt is treated. Previously this would be done by mixing brine from the onboard tanks with the salt as it was spread. This added to the cost and wasn’t the most reliable of systems because if there was a blockage, or some other issue with the brine tank, then the solution couldn’t be used.

“So we, like around 40% of the country now, switched to a more reddish salt that is treated with molasses. The molasses comes to us as a by-product from sugar beet production and gets directly applied to the salt so there’s no need for brine or a brine-delivery system. The lorries can carry more, it’s cheaper all round and the molasses-treated salt sticks to the road very well.”

The patterns of highs and lows

Twenty-three years of working with the gritters in Lincolnshire means that Darrell and the team really understand weather patterns throughout the county’s winter. But seldom are two winters the same, as he explains: “Since I started with the gritting team in 2000 there has been a lot of variances in temperatures.

“The worst I’ve ever experienced in Lincolnshire was -22.5 which we saw at Newton on Trent during the 2010/11 ‘Beast from the East’ event. The county froze solid. I’ve never seen it as bad as that was in all the years I’ve been doing this job.

“On the other end of the scale, last year was the mildest start to a winter we’d seen – until this year when things have started to get cold even later.

“In 2021 we first spread on November 16. Last year was later than that and this year we’ve already been out a couple of times, but the first really cold period is about to hit us and we’re almost in December.

“Last year it was a combination of feast and famine. It was either very mild or really cold with not much between the two. There were some big jumps between temperatures. On a Friday in mid-December we were out in –5 degrees and by the following Monday it was back up to 14 degrees in the same location. That felt quite odd.

“In 2022 we went out salting on Christmas Eve but then we didn’t need to go out again until January 13. That was a long time to not have to grit in a winter.

“In fact, last year we were out for 43 days in total which isn’t a huge amount, but when we went out it was very cold indeed which makes everything that bit more tricky.

“But once the lower temperatures hit us in last January it did come back with a vengeance and affected us quite hard, we were then going out regularly until late February. It’s a long winter and when it hits out area it hits hard, so we make sure we’re ready and get out to keep roads open and people safe.”

Lincolnshire’s Gritter Crew – the stats

  • The county has a budget of £1.2m a year for salt. Last year the council spent £1,000,000 on the grippy stuff. The molasses-treated salt that is bought in will last for five years – this lifespan had never been tested though as the salt stored is always used well before the five years is up
  • There are 47 Gritters that serve the county – these range from mainly 26-tonne gritters with 10-tonne hoppers,18-tonne lorries with 6-tonne hoppers on the back and smaller 10-tonne versions with a 3-tonne hopper on the back
  • LCC holds 29,200 tonnes of salt in the county’s depots
  • On average, LCC uses 20,000 tonnes of salt a year
  • The most salt ever used in one winter was across the 2010/11 ‘Beast from the East’ brutally cold season. That year a massive 38,000 tonnes of salt was put down on the roads
  • There are 12 weather stations around the county feeding data back about the weather and road temperatures. LCC has access to eight others sited with other counties which help to more accurately predict weather systems as they come across the country

Are you winter ready?

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Published: 28th November 2023