Wednesday, January 13, 2010

Gritting Cambridgeshire

I've just been chatting to County Cllr John Reynolds on the phone, who as a former portfolio holder for transport was recounting detailed facts and figures about the gritting process. This is John's recent message to his constituents on the subject:
I want to update you on both the Cambridgeshire and national gritting situation and as I write this report (January 12th) the snow in our area is at last melting away but many other parts of the country are still gripped in deep snow and ice.

Cambridgeshire started the gritting season with all our four salt barns full with a total of some 12,000 tonnes, enough to do at least 60 full gritting runs which is the average number over each of the winter periods in the past 15 years. We have over the past ten years invested in 35 gritting lorries designed to the latest standards each of which can spread up to 5 tons of salt.

Salt works by turning the ice or snow surrounding each salt granule into a saline solution which has a lower freezing point than water. The action of traffic is essential for salt to be effective - moving the salt granules around and eventually meting the ice and snow.

Since 16th December we have carried out well over 40 runs, including on Christmas Day, plus undertaking a couple of secondary runs and numerous bits of spot salting on footways and cycleways. Each full gritting run uses over 200 tons of salt and covers about 42% of all county roads, the Highways Agency are responsible for the national road network.

We do have some material that is not suitable for the gritters which we are using in a targeted way to fill grit bins and to treat some of the busier footways. During this extremely cold spell we have worked with city, district and parish councils to treat as much as we can. Our teams have been working very hard, around the clock in very challenging conditions.

Nationally many areas have been harder hit than us, for example in the north and Scotland, this has meant that deliveries of replacement stocks normally destined for us have had to be redirected to those most in need. This happened last year and is a partnership between the Department for Transport, Local Government Association and salt suppliers to prioritise which authorities receive deliveries and when. Each council provides regular information on their salt stocks to help decision making.

As you know, like last year, we are seeing many potholes with many more likely to form in these extremely cold conditions. We are asking people to let us know of any problems in their area - they can notify us via our website or via the contact centre on 0345 045 5212 (contact centre is open 8.00 am-8.00 pm, Monday to Saturday). We will repair them as soon as resources and weather conditions allow.

Apparently there are a number of measurement stations across the county and information from them is combined with hourly predictions from the meteorological office to produce charts from which the decision to grit is made. The threshold for gritting is a predicted 2°C.

There is an arrangement with the city council for the city to have a daily supply of salt, which they can and do take to distribute to city centre footways as they see appropriate.

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