During the harsh winter of 2009/2010, a certain salt supplier received a call from prime minister Gordon Brown imploring it to increase production.
A call from the PM is something most highways departments do not have to worry about. However, living next to Heathrow means it isn’t out of the question for Hounslow on an annual basis.
Hounslow Highways is the £800m 25-year PFI partnership between the council, VINCI Concessions and Ringway, which covers a fence-to fence solution for all assets as well as winter service.
Network manager and principal designer Satbir Gill (pictured inset) tells Highways: ‘Our main challenge in winter service is our proximity to Heathrow.
'We have to keep the network running all the time because if we don’t grit our network and it comes to a deadlock it will be very difficult to explain the situation. Dealing with those situations is very important to us and every time we have risen to the challenge and delivered.’
There are several key elements to Hounslow’s success. Firstly it maintains extensive and exclusive knowledge of its 132km winter gritting network.
‘We are very closely aware of our network; where the shaded areas are, where it is going to freeze,’ Mr Gill says, adding that this knowledge enables the authority to react immediately and efficiently with six gritters, across its six routes.
Past president of the Local Government Technical Advisers Group and current chairman of its London group, LoTAG, Mr Gill adds: ‘We closely monitor the network all the time during the severe weather situations by carrying out visual inspections along the routes.
In winter service you have to take instant action, before the snow falls. When the snow is falling you have to grit it at the appropriate time before there is accumulation.’
Hounslow Highways is supported in this process with several forecasts a day from the MET Office.
‘We do the pre-gritting and after that when the snow is falling we drive down the network to make sure no accumulation is taking place and we see how much residual salt is on the network by judging how much the snow and ice is melting and then we go for another run. That is how we programme our runs. It takes two hours for a gritter to complete a run. We take decisions in advance to avoid accumulation.’
Squatting like a small aircraft hangar in Hounslow Highways’ depot (directly under Heathrow’s flight path) the borough also boasts its own salt barn capable of storing 2,500 metric tonnes. The salt itself is monitored with the same eye for detail.
Mr Gill says: ‘We test the salt for the optimum moisture content as that gives you maximum value. The allowable moisture content is 0-4%. That is very important.’
In terms of keeping the network clear, the authority also manually controls works traffic lights along gritting runs to prevent the traffic building up on gritting routes. Another top tip from Mr Gill is the use of permits for roadworks on bus routes.
‘When we issue permits for roadworks we only allow one work at a time on a bus route. We have done a lot of work on our network and haven’t received any complaints about congestion. That is one major reason why. We keep this control over our works and the utilities, because there needs to be parity between the two.’
These all seem like practical, common sense ideas. Yet Mr Gill is not shy about promoting innovation and pushing boundaries and a recent pet project could see him have an impact on national attitudes. Mr Gill is calling for a sector-wide approach to investigatory levels for storm water.
‘There are no nationally agreed investigatory levels for storm water. So what we have done in Hounslow is agreed an investigatory level. On a high-level link road if there is an average of 15mm of water per square metre we have to make sure we rectify that. For residential roads the average is 20mm. At those levels we have to do some mitigation, such as putting a gulley or relaying the channel to allow the water flow.
‘Every council should be aware of national agreed investigatory levels because someone might say this puddle of 40mm is not dangerous. I would say 15mm is dangerous. It’s not good for the integrity of the road and it is dangerous for drivers and pedestrians.
‘So we have included this in part of our strategy. We are a pathfinder PFI in Hounslow and intend to share our views with Atkins and the Department for Transport to hopefully agree a nationally accepted investigatory level for standing water. I am taking this to LoTAG as well.’
Cold Comfort 2017, the 26th Annual Winter Maintenance Conference and Exhibition, takes place at the Ricoh Arena, Coventry on 17 and 18 May. For more details and to register, click here.