AFTER commuters slammed council bosses over Christmas for failing to keep the roads clear of snow the local authority showed it was ready and waiting for the next downfall. Lancashire Evening Telegraph reporter Liam Murphy went out with the gritters to see what they do.

AS forecasters yesterday warned of more severe weather likely to hit East Lancashire a rarely recognised part of the emergency services was already taking action to protect the public.

Blackburn with Darwen has four teams of gritters ready and waiting 24 hours a day ready to grit tons of salt on 250 miles of the borough's main roads.

Peter Hunt, director of direct services which oversees the gritting, as well as repairs to the borough's roads and street cleaning, explained how the principal routes are first to be gritted. These are A roads and roads around Blackburn and Darwen.

He said: "We have worked out over the years the most economical routes to take, with the aim of making sure drivers only cover a route once on a journey and that when he is driving he is gritting.

"We try and get the major routes in to and out of the town covered first and then we look at the rat runs and the rest of the bus routes." Other roads through higher areas also receive special attention when bad weather is forecast.

The borough has eight gritters, four "frontline" four-wheel drive vehicles specially designed for the job which cost around £70,000 apiece and can also function as snowploughs, and a further four which can also be adapted when not needed for gritting. There is also a snowblower bought 18 years ago which is brought into action when the snow is particularly severe and too deep for the snowploughs to deal with. Peter Hunt said: "Since we have had that the winters seem to have improved, so it's a good investment! However it's worth its weight in gold when it is needed."

Each day around lunchtime the council's technical services department receives a specialist forecast from the Met Office which flags up potential bad weather and determines if the gritters will be out on the roads that evening.

Sensors buried in the roads at Belmont and Altham by Lancashire County Council also give the experts more details about road conditions and the need for gritting.

Ian Gildert from Blackburn who has worked for the council for 24 years and is one of the drivers and supervisors, said the call usually comes through just after lunch and the drivers, who all know their routes, begin gritting in early evening if frost is expected overnight. He said: "We sometimes get it wrong, now and again, and that is unfortunate, but we can only rely on the weather forecasters."

All the drivers have Large Vehicle Licences and are trained to drive the gritters, but have other "day jobs" with the council. Because they are classed as an emergency service there are no tachographs to check how long they continue driving, and if necessary are called out through the night.

The grit used is rock salt crushed to less around 6mm across from a quarry in Cheshire and when heavy snowfall is expected this is spread from the back of the truck at around 40 grammes per square metre. It's job is to mix with the snow and raise its temperature so it melts.

Each wagon holds around eight tons, and the borough has a store of 2,000 tons ready. Experts say the action of cars driving over the salt and mixing it with the snow is needed for the gritting to be effective. For "precautionary" gritting -- when frost is expected -- around 60 tons would be spread in a night, but when it snows heavily and the gritters are out all day several hundred tons are used. A computer system monitors how much salt remains and informs the borough's suppliers so regular tops ups can be made.

Controls in the truck allow the driver to control how fast it comes off the belt at the back of the truck and a revolving disc is used to spread it across the road -- sometimes to the annoyance of other drivers.

Ian Gildert said he had seen occasional road rage from other drivers when they are stuck behind the large yellow vehicles which trundle along little more than 25mph most the time. He said: "They get upset when they get too close to you and their cars get salted. And they pull up right behind you when you're stopped at traffic lights."

He said: "People don't realise when it's rush hour and cars are blocking the way I can't get through. It's not like the police who can switch on their blue lights."