What goes up…
… must come down. The pressures of meeting planning regulations called for an innovative solution when manufacturer and electrical contractor Christy Lighting was asked to install floodlighting at a new athletics track in Little Marlow.
By Andrew Brister
DONT GLARE AT ME
As well as the height of the Columns. Christy had to consider the potential for light to disturb residents. Sports lighting should adhere to BS EN 121932007. which covers.
• Optimising the perception of visual information used during sports events.
• Maintaining the level 01 v11.uaJ performance.
• Providing acceptable visual comfort.
• Reslrlctlng obtrusive light.
This standard breaks down lighting applications into four zones depending on location – from E1 (the most critical, which covers areas of outstanding natural beauty, such as Little Martow) through to E4 for inner city locations.
Manufacturers have developed ultra low-glare floodlighting to limit spill away from sports areas-beams are typically projected at angles of 65-70 degs to restrict light above playing surfaces.
Politicians, Olympic medal winners and parents are all in agreement – we need the best sporting facilities to inspire the champions of the future. But when it comes to athletics tracks and sports pitches, do we want floodlighting in our back yards? Such facilities are, by necessity, located in the heart of the communities they serve, and achieving planning permission for floodlighting to extend use into the evenings can be a fraught affair.
A project carried out by NICEIC Approved Contractor Christy Lighting offers a way forward for such schemes in sensitive areas, The lighting and electrical firm has developed a telescopic floodlighting column for an athletics track at Little Marlow In Buckinghamshire, as part of a major shake-up of sports facilities In the area by Wycombe District Council.
Wycombe Is undertaking a £30 million revamp of its centre at Handy Cross which, as well as new sports facilities, will see a food store, hotel, offices and park-and-ride facilities on the existing site. No space was left to relocate the current sports pitch and athletics track so a new artificial pitch has been built at nearby John Hampden Grammar School over the road and a home found for the athletics track at nearby Little Marlow.
Christy is carrying out the floodlighting and associated electrical Installation at both venues In a £220,000 contract for sports specialist Agripower, which in turn has a £2.7 million contract with Wycombe District Council.
While the Sports pitch at the school has conventional raise-and-lower floodlighting columns – also made by Christy – the fact that the athletics track at Little Marlow is in an area of outstanding natural beauty called For something different.
“This is. full-sile, eight-lane track. with a clubhouse, CCTV and parking – all in the green belt.” says Agrtpower’s project manager Mark Swatton. “The client wanted te1escopic columns and we turned to Christy – It’s the first time we’ve been called to do It and we’ve worked with Christy for more than 20 years.”
Breaking new ground
Indeed, Christy has more than 1.400 floodlighting schemes under its belt, but this is also a first for the company, which has developed a column that sits at a height of 4.5m when not being used end Is extended to 15m when events are being held. “There is guidance to deal with light levels, light spill and so on from floodlighting (see box), but that doesn’t deal with the daytime appearance; explains Christy’s managing director Greg Leslie. “Residents don’t want to sea a battery of 15m-high columns, so planning control dictated that the height should be no more than 5m when not in use,”
Christy has developed a column that can go up and down by an ingenious compressed air system, within finely manufactured aluminium tubes. Fully airtight seals perform a similar function to the piston rings In the construction of a motor car engine_ ‘We’ve tested the seals and had the columns fully extended for three days without any additional input of compressed air; says Leslie, The company will guarantee use for a minimum of six hours.
Residents don’t want to see 15m-highcolumns. so planning dictated the height should be no more than 5m when not in use’
While the telescopic columns themselves obviously add an additional cost, Leslie estimates that it is only a premium of around 10 per cent over the total project value – a small price to pay to get through planning, “if floodlighting is refused, then it’s difficult to make a track or sports pitch economically viable; points out Leslie.
“It gets dark after 4pm in winter, so you are dramatically increasing the availability of the facilities to the general public with floodlighting. Schools get to use the track and pitches in the day, but it’s in the evenings when adult sports clubs take over that you need floodlighting – It can give an extra 600 hours’ use per year:”
At Little Marlow, 10 columns are permanently mounted at a height of 4.5m. When the lights are switched on, the columns are energised and the air compressors extend them to their full 15m height In some three-and-a·half to four minutes, Similarly, they will retract when the lights are turned off; an automatic time clock ensures they cannot operate after a set curfew time or be inadvertently left on overnight. The compressors will evacuate air from the columns and they will be automatically lowered.
Tried and tested technology
The time taken for the columns to rise is exactly the same length of time it takes for the metal halide lamps to reach full brightness. Despite the increasing use of LEDs in all kinds of lighting applications, Leslie feels it is still some time before metal halide lamps can be bettered in sports floodlighting. “LEDs are not there yet.” he says.
“As you increase the power of LEDs you have problems with the heat produced and then the efficiency drops off, so metal halide is still the most efficient light source for this application.”
Neither does sports floodlighting have the run hours to justify the payback for LED, Whereas LED street lighting can easily run for 3,600 hours 8 year, typical sports floodlighting is only likely to notch up 600 hours. “We always install hours-run meters with our floodlighting and the average usage is around 500’600 hours a year, So you don’t have the usage to produce a viable payback, even if there was a saving in energy with the LED,” argues Leslie.
Christy has opted for 2kW Philips Optivlslon MHN-LA metal halide lamps to achieve 150 lux on the track. “I selected these long arc lamps for control of the beam to meet the environmental zone E1[see box), but more importantly because of the shape of the floodlight and the low windage area,” says Leslie.
“This offered the best aerodynamic shape and thus reduced the structural loadings, meaning that I didn’t have to design such a heavy structure to support them.”
Clearly, this was 8 happy contract. Leslie describes Agripower as “Incredibly supportive· and Swatton reciprocates the praise, “Christy will sort anything out. They are one of the best contractors we have working for us.” he says. Indeed, things are looking up for the firm Leslie founded with contracts director Terry Adams back in 1985. They see huge potential in a range of telescopic lighting systems, from tennis courts to full·size tracks like this one, The future is bright.