Predicting the weather, when and how roads are salted/how the salt works, monitoring weather conditions, improvements to winter services and minimising the costs.
Between October and April a weather forecasting service is provided by the council’s contracted weather forecast supplier. This is an internet-based service available 24 hours a day, seven days a week.
A duty officer will assess the main forecast, which is made around mid-day and any other relevant data in order to decide what actions are to be taken over the coming 24 hour period. An instruction will be issued via e-mail to the relevant officers and external bodies, detailing the actions proposed. If the forecast weather is likely to change then the decision may be delayed until further updates are received.
The prevailing weather conditions are monitored by the forecast provider on a 24 hour basis. Should these vary significantly from the forecast data contact is made advising of the changes and, when appropriate, they issue an updated forecast. Ice detection stations are installed across the authority at 9 locations giving real time data. Additionally the authority has access to information from other stations in adjacent authorities.
The 'defined network' will normally be treated outside of normal working hours if it is forecast that ice or snow is likely to be present on road surfaces. The 'defined network' is made up of 17 separate routes across the East Riding, operating from four depots covering a total of 1,254 kilometres of roads. During periods when severe adverse weather is predicted, that is when the forecast indicates that ice or snow will remain beyond noon, the defined secondary network will be treated subject to the availability of resources. This is made up of 11 separate routes covering a total of 480 kilometres of roads.
Brine is used, which is a solution of water and salt and has a lower freezing point than pure water, putting salt on ice causes it to melt. Another effect of applying rock salt to an icy surface covered with water is that it disrupts the interface in which water molecules are constantly replacing each other from liquid to solid. When salt (or other impurities) form a solution with water part of the interface is blocked and the crystalline structure of ice emits more water molecules than the liquid water is able to replace. Therefore, the presence of rock salt in solution with water itself melts ice.
Due to the severe weather over recent years we have built two new salt barns, one located at Beverley and one at Carnaby (near Bridlington) these are used as strategic reserves in case of shortage. Most of our vehicles are now fitted with auto salting systems which direct the driver to where they need to go and adjust the salt spreading automatically. This year four new gritters have been purchased to replace some that were coming to the end of their useful life.
We use ‘pre-wetting’ technology on all of its vehicles. The 'pre-wetting' salting technique gives improved performance, with a reduction in salt usage. Pre-wetted salt adheres more readily to the road surface and is pre-activated by the brine allowing it to go into solution and work much quicker than conventionally spread salt. Spreading is more controlled resulting in more accurate distribution.