Edgbaston Priory - A lightbulb moment!

David & John Lawrencein Tennis

Over the last decade, lighting rigs have become more and more commonplace in elite sports stadia around the world. From Wembley Stadium in London to the Bernabeu in Madrid, more and more images of sports surfaces adorned by artificial sunlight are coming to light (excuse the pun!). However, the idea of venues with more restrictive budgets being able to harness this growing technology has largely been a pipe dream.

In this article, the Edgbaston Priory Club Grounds Management duo of Dave Lawrence (Grounds Manager) and John Lawrence (Assistant Grounds Manager) explain how they hope their latest project might just start to make lighting rigs more accessible within the industry

Sunlight is vital to growing good grass and, to host events like the Aegon Classic Birmingham, we need good grass tennis courts. In a roundabout way, this explains why we have been so desperate for a lighting rig since the completion of our Ann Jones Centre Court in 2013. Anyone who has been to our site will be familiar with the construction, i.e. the sunken court. Basically, in order to get planning permission, the court had to be dug down, rather than built up. This means that the court playing surface is at the bottom of a 'massive hole' where air movement is limited and shadows are much longer.

The air movement is a relatively easy fix; we position fans around the court for nine months of the year and switch them on for a few days each week, creating our own artificial wind. These are the same fans we use with our inflatable rain covers in the summer, so it's really just a case of utilising something we already have on site in a different way. Creating sunlight, however, is a much more difficult hurdle to clear.

Whilst it looks very impressive, our centre court is a horrendous for growing grass, particularly at the south end. The court surface is already around fifteen feet below the surrounding ground level and, in addition to this, there are some rather significant trees at the south end of the court. The result of these obstacles is that, in the depths of winter, as much as half of the court does not get any natural sunlight.

Over the last few years, this has caused issues which we've had to work hard to overcome. Consistency across the surface is key to producing a good tennis court, but the south end has routinely come out of winter much weaker than the north end. This is largely down to the light, or shading, issues. Soil temperatures vary massively, which means that growth is varied, and we also see a fair amount of damping off and higher disease prevalence at the south end of the court.

Now, as has been evidenced in recent years, we've managed to pull off a major turnaround in the spring and balance things back out by the time the Aegon Classic Birmingham comes around. However, this certainly isn't ideal and definitely isn't easy to do; so, in an ideal world we came to the conclusion that we needed to get sunlight to the south end of the court during the winter, thereby reducing the variable conditions from the north to the south end. If we reduce the climatic variation, we should reduce the variation of condition of the playing surface and, therefore, improve the consistency of the court.

Of course, getting sunlight to the court is much easier said than done. The trees which contribute to the shading issues could be cut down, though this would not be popular for anyone with a love of conservation - ourselves included! And this would only alleviate the issue by a couple of feet - there would still be a huge area of the court not getting any sunlight due to the wall at the south end of the court.

On this basis, a lighting rig was the only solution. There isn't a way that we could get natural sunlight to the court, without cutting down a lot of trees and rebuilding the court, all of which adds up to a huge cost. However, whilst we aren't by any means a poor organisation, we simply don't have the budget to purchase bespoke lighting rigs. Some of the units seen on football pitches run in to the tens of thousands of pounds (we've even heard suggestions that a bespoke rig like the one we've managed to have built could have topped the £100k!). Therefore, we had to start to think outside the box.

Our first thought turned to how we could access lights at as low a cost as possible. This is when we decided to pinch an idea from Greg Smith, now Sports Grounds Maintenance Manager at the University of Nottingham. In his previous role as Grounds Manager at Notts County Football Club, we remembered a project he had developed where grow lights used in illegal cannabis farms, which had been confiscated by the police, were donated to the club and attached to their own 'homemade rig'. It would be entirely fair to say that the blueprint for our project was based around the work Greg did at Notts County. https://www.pitchcare.com/magazine/notts-county-fc-grow-grass-with-seized-cannabis-lamps.html

With our borrowed idea in place, we made enquiries with the local police force about what they do with such confiscated materials and, once we had explained that the type of grass we wanted help growing was entirely legal, we were pleased to discover that the force had already donated a significant quantity of similar equipment to Warwickshire County Cricket Club, where Gary Barwell (Head Groundsman) had carried out a similar project to build a rig for the outfield.

We were lucky enough to be invited to have a look around the West Midlands Police Cannabis Disposal (WMPCD) team's headquarters and were staggered by the amount of equipment (and drugs) they confiscate every week. As it turns out, they are more than happy to donate confiscated articles to good causes, whether it is lights to sportsgrounds or compost to community garden projects. Fortunately for us, this meant we were able to source all the lights for our rig completely free of charge.

The lights donated by the WMPCD are 600 watt sodium bulbs, coupled with a metal hood reflector. The result being that we end up with light being thrown over an area of around eight metres (from a two metre height). Because of the environment the lights are generally used in, the bulbs are produced to give light off at the ideal spectrum for green plants to be able to absorb it. While LED technology may, in time, overtake sodium lights in terms of efficiency, the mere fact we were able to get any artificial lights for our rig, and at no cost, was a huge bonus for us. That said, the lights are proven to have a positive effect on plant growth - just ask the previous owners!

Having secured the light units for our project, the next step was to find a way of mounting them so that they could be utilised on the centre court. Mounting them threw up two major issues. Firstly, whatever we built needed to be able to house the lights in a dry environment; electricity and water don't mix well! Secondly, there could not be any centre supports on the rig. We needed to be able to span the full width of the court on one boom section; a full twenty-one metres. In order to do this, it would take some seriously strong materials, and some clever engineering.

This kind of building was certainly outside of our skillset, and so we began the task of contacting companies for their support. Initially, we looked at the possibility of purchasing a lighting gantry - a bit like those used in theatres for hanging lights from a ceiling - on the basis that, if the boom was strong enough, it could be mounted on a bespoke trolley at each side of the court. However, we struggled to make any progress with this option. It therefore became apparent that we would need to have something bespoke built.

Despite the concern that this would be the part of the project that made it financially impossible, we contacted several companies and eventually managed to get a response from DEM Sports Ltd. It turned out that they also built the original rig frame for Warwickshire County Cricket, so had a bit of experience and knowledge in this area. Granted, the scale and size of our rig was a big step up from anything they had built before, but it was a challenge they willingly took on.

A set of engineering drawings later suggested that DEM had a solution for us, and, with funding secured for a surprisingly low cost, production was given the go ahead. We took delivery of the rig in September, which consisted of the metalwork and a waterproof cover (it would then be up to us to fit the lights and electrics). By our own admission, we've had the rig 'over-engineered', although we don't see that as a bad thing. DEM have ensured that every possible bit of support on the overhead boom has been included to make sure that the rig will last, and importantly, not collapse!

Because of the access issues with our centre court (there is only a small tunnel in and out - just about wide enough for a tractor and a small trailer), the rig splits into four separate sections. Each section has its own removable support legs, so this means that, when putting the rig up, we push the four sections together, bolt the boom sections onto each other and then remove the supporting 'transport' frames, thus giving us one twenty-one metre lighting rig.

Once the unit was built, with cover on in position, we then set about fitting the lights and electrics. There are fifteen light units in total on the rig, or one every 1.4m. Originally, we'd considered putting on double that amount, but the lights appear to be so effective that we determined it would just be a waste of electricity! Once all the lights and cabling were in place, we got our in-house electrician to complete the final connections and sign off the unit as safe. We had our own lighting rig!

The benefits of a having a lighting rig are obvious; ultimately, it allows us another tool to 'play God' with our microclimate. Removing variables from managing sports turf should, in theory, make achieving better results more accessible. The barrier to these advances though is always money. It is, therefore, worth noting that we've managed to have our rig manufactured, delivered to site, built and wired up for less than £7.5k - less than some pedestrian cylinder mowers!

Now, we are not suggesting that every sports ground in the country has the money for one of these, or a need for one. However, where there may be a requirement, we'd like to think that this sort of cost is less eye watering than some of the bespoke systems available in the market place.

We should also point out that this shouldn't be seen as a knock at the high end products currently being brought to market. There are some fantastic innovations in this area and, if we had the money to spend, we are sure we'd be in the queue waiting for ours to be delivered. However, reality is that we don't have that sort of budget available, so we've had to think outside the box. What we'd really like to see, off the back of our development, is for more of these sorts of rigs to be produced at other venues around the country.

At twenty-one metres, our rig isn't too far short of being able to light up a whole cricket wicket. We have real sympathy for our colleagues in cricket trying to produce early season pitches in cold, wet weather. Maybe a rig like ours (albeit a couple of metres longer) may be of some use in cricket. Similarly, there are plenty of other stadium venues in tennis that will have some shading issues. A rig like ours might offer a solution for those venues too.

This type of rig doesn't have to be confined to tennis and cricket either. With the right tyres fitted, the rig could be used on any surface - for example there's no reason why it wouldn't work in a football stadium environment. In fact, if it was coupled with undersoil heating, the effect could be superb!

Our hope is that someone can take the progress we've managed to make, and take it a step further. Ultimately, our rig is just the evolution of something we saw done at Notts County by Greg Smith. It would be great to read an article in a couple of years' time to see someone explain how they have evolved our development and taken it to another level again. In an industry where being able to get the best result from the smallest budgets is a vital skill, we're sure there must be more ideas out there!

We're also pleased to say that we've already had interest in the project from a couple of different companies who fancy that they could build rigs too. That competition in the market place can only be beneficial for the end user. Hopefully, that competition will continue to drive prices down and make the technology more accessible to more grounds professionals, so that more surfaces can benefit and continue to improve the quality of the surfaces our industry is producing.
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