Prior Preparation

Tom Allett spoke to David Wilson, Gatwick’s Head of Airside Capital Projects, about the London airport’s winter preparations.

After experiencing a ‘once in a 25-year snow fall event’ in the winter of 2009/10 – and again less than a year later – Gatwick embarked on its largest ever snow clearing investment programme. (All images - GIP)

Several major European airports were badly disrupted by snowfalls last winter.  Some coped with the severe weather better than others.
Keeping paved areas clear of snow and ice to maintain flight operations is always a tough job, but if there is only one landing strip – and it happens to be the busiest single runway in the world – it is a far bigger challenge than a multi-runway facility.
Any take-offs and landings must stop while sweeping vehicles are on a single runway – there is simply nowhere to transfer aircraft movements.
Gatwick Airport suffered significant snowfalls in the winters of 2009/10 and 2010/11.  The weather, combined with the arrival of its new owners GIP, led to a major investment in snow clearing equipment.
David Wilson, Gatwick’s Head of Airside Capital Projects, has been directly involved in airport winter maintenance activities for nearly 20 years.  He told Airports International:
“After the winter of 2009/10, we sent representatives from our operations groups to Stockholm Arlanda, Helsinki and Oslo airports to learn from their snow teams’ procedures and processes.
“We had taken the [UK] Met Office’s advice that the snow received during the winter of 09/10 was a once in an every 20-year event, but the snowfalls we then had during November 30 – December 2, 2010 were even worse.  At that time, I was Head of Airside Operations and I decided there and then to look at the market and see what equipment was available.
Nine Overaasen RS400s and two Oshkosh snow cutters we among the largest of over 45 pieces of snow clearing equipment purchased by Gatwick.

“We spoke to colleagues in Zurich and, in the space of seven days, I was able to get six Schorling units inspected, shipped to Gatwick and operational in advance of the mid-December snow event.
“You may remember that in the first early December event Gatwick was quite severely affected while other airports in the south east of England didn’t have a flake of snow on them.  Then on December 17-18, we were all hit with a very similar volume of snow and we were able to use the equipment purchased from Zurich.
“Over that period we had about 12 inches (30cm) of snow and we were back open and operational, albeit with reduced flow rates, within about four and a half hours of the snow falling.
“After that December 2010 snowfall I went with Stewart Wingate to meet the Government’s Transport Select Committee (TSC) and we were questioned quite strongly about the steps we have taken to improve our snow preparations.
“However, even before that snow event a business case had been produced – and signed off by our CEO Stewart Wingate and the Executive Management Board – for £8.8 million (US$13.8m) to increase the volume of winter maintenance equipment we have available, particularly the heavy snow removal equipment.
“We bought nine Overaasen RS400 runway sweepers and a Mercedes-Benz tractor unit which gives us the ability to sweep the full [147ft] 45m width of the runway in one go.
“We have 9m ploughs on each vehicle but we also bought two Oshkosh snow cutter/blowers because, although we could move the snow to the shoulders of the runway, we also need to remove the snow banks that can form.
“Our equipment was fine for the previous ten to 15 years.  It had dealt with the volumes of snow it had faced, but the so-called once in 25-years event was too much and to get a repeat event just a year later was not acceptable to the Executive Management Board or to me.
“Having bought the equipment we can now clear the runway quicker than ever.  We calculate that with the nine Overaasen RS400s and the Oshkosh snow cutters we can clear the 8,415ft (2,565m) runway much, much quicker than in the past.
“All the heavy snow clearing equipment we purchased was new and after it arrived we changed things around and used our existing Schorling equipment, pulled by Unimog tractor units, to sweep the taxiways and apron areas.
“We also bought over 45 pieces of lighter equipment with smaller brushes on the front to clear the parking stands, the inter-stand clearways and the adjacent roads.  We have risen to TSC’s challenge and we will have to see how things go because all this new equipment and procedures still need to be tried out in a live environment.”
Years of experience in airside operations – Wilson was once Head of the department at Edinburgh – prompted him to chose this specific equipment.
“We just used our experience, looked at what was on the market and then got a couple of tractor vehicles in to trial so our guys on the ground could use them and give us their opinions about them.
“We didn’t trial the RS400s here at Gatwick, but we sent a number of members of the snow team out to Overaasen’s headquarters in Norway and used the equipment there.
“We looked at benchmarking against other airports in Scandinavia and northern Europe; seeing what type of equipment they used and took their feedback.  We talked to their transport teams about maintaining the equipment and, equally, found out how the guys doing the job at these other airports thought things could be done better.”
Wilson has personally performed hands-on snow clearing duties on many occasions during his career.  On equipment purchases he says: “As I now have an office-based leadership role and the responsibility for how we spent the £8.8 million, I could have just gone out and bought what I thought was best.  Having been involved in snow clearing activities in the past, I know you have to ask the ‘teams’ – the people who will actually do the job – what, in their opinion, is the best way to approach their task and which equipment will allow us to do it in the most efficient way.
“I think it is good leadership.  Stewart Wingate and I went down to the airfield ops team in January 2010 and said to the guys: ‘Tell us what you think is required’.  Not one single piece of equipment was bought without the formal approval of our airside ops team.”
All major airports have a snow plan that aims to provide the most efficient way of dealing with snowfalls.  The varied plans take into consideration such issues as wind direction and snowdrift.  Approximate clearance times depend on the depth of snow the airport teams face.  Wilson estimates it takes Gatwick’s team of eight snow-clearing vehicles an hour to sweep its runway and parallel arterial taxiways end-to-end.
To achieve this the vehicles move along the main runway in formation, driving with the wind behind so the drivers’ visibility is less impaired by driving snow.
When the group reaches the end of the runway it splits into two teams of four, each assisted by one of the Oshkosh snowblowers.
The snow team’s usual strategy is for a formation of eight vehicles to sweep the runway and arterial taxiways. When the group reaches the end of the runway, it splits into two teams of four, each assisted by one of the Oshkosh snow blowers.

Wilson explained that one group works along the northern runway, normally used only as a taxiway, while the other passes down the parallel taxiway, until they reach the other end of the airfield.  The eight vehicles then regroup to repeat the exercise for as long as required.
At the same time, members of the airport’s fire service and other staff from the airfield operations team drive the Schorling vehicles – formerly used on the main runway – along the taxiways as advised and required by Air Traffic Control (ATC).
“At the same time, around 120 of our office workers that may, for example, normally be administration, finance or property staff, are also helping out.
“Of course, we train them to work in an airside environment, with all the health and safety awareness required.  They then go out and drive small snow-clearing vehicles around our aircraft stands, adjacent roads and our baggage called forward points, where they can play a part in removing the snow.  That’s an asset that we’ve never had before.”  The staff also assist inside the terminal building, helping passengers with directions and other simple tasks.  Said Wilson: “It’s quite inspiring to be part of this and, should the snow come again, we are now better prepared than ever to get the airfield up and running efficiently again as quickly as humanly possible.
“When the airfield is declared open, it’s not just the runways and taxiways that we are talking about; it’s everything else we need from an operational point of view as well.
Snow-clearance work is carried out on demand and during significant snow falls there are inevitable delays and cancellations announced by airlines.  The Airfield duty manager decides achievable flow rates based on the number of stands available and ATC’s workload.
“It’s a very slick operation – it always has been – but when snow falls for 24 hours it is hard to beat,” said Wilson.  “The only circumstances though that stop us from sweeping are blizzard conditions – so bad that the drivers can’t see each other well enough to drive safely.
“The runways and taxiways are usually cleared pretty quickly, but the biggest challenge is to clear the stands that have aircraft parked on them, so we obviously work in close cooperation with the airlines and ground handling agents.
Wilson said he had been consistently involved in such preparations throughout 19 years in the aviation business – but never at the current pace – or above the single £8.8million invested.
Major international airports across Europe now recognise major snowfalls are becoming a more regular phenomenon although at unpredictable times.  After the considerable investment and training, does Wilson secretly hope his teams will face a weather challenge again this year?
“No! Absolutely not,” he replied emphatically.  He continued “If our new equipment doesn’t have to tackle any snow at all for the next 25 years I will be more than happy because the disruption caused to passengers during big snowfalls can be phenomenal; just too big.  Ware in the customer service business so we don’t want to see our passengers disrupted again.
“I’m sure that there are a few of our guys that would like to drive the big new trucks in anger, but no, the impact on our customers, staff and business [Gatwick lost tens of millions of pounds worth of business during previous heavy snowfalls] is just too great.
“Although we’ve spent a lot of money on new snow equipment it’s a sound investment because we could easily lose that kind of money in just a couple of days if we were caught unprepared for snow.
“A 24-hour closure could cost us millions in terms of income but there is also the cost and loss of income incurred by the airlines to consider as well.
Gatwick’s snow team vehicles are currently stored outside but the airport’s management team is looking at alternative options to best protect its investment.

Wilson said Gatwick now had every piece of equipment requested.  “But, if we were to have about 3ft (1m) of snow, then we wouldn’t have enough of the right equipment perhaps,” he said,  ‘However, based on the last two winters, we believe we have everything we need now.”
Six or 12 inches (15-30cm) of snow can present a major challenge, but a status system within the snow plan gives an indication of likely disruption if there is snow fall of up to two and half inches (6cm). The latter will cause some disruption, possible diversions, cancellations and even closure to clear the single runway.
“We’ve obviously discussed our snow plans with the Civil Aviation Authority, we’ve made the investment; taken the time to train our people and have prepared ourselves in a professional manner.  The airlines and handling agents are also ‘on board’ with what we are doing and so are the external elements like The Highways Agency and the railway operators,” said Wilson.
“Inevitably there will be disruption if heavy snow comes but we will be able to respond to it much quicker than we could do in the past.”
Gatwick’s airport ops team routinely spreads anti-icing material on its runway and taxiways and airlines anti-ice their aircraft when the forecasters predicts freezing conditions.  The airport’s first few anti-icing deployments of this winter season began in November when a hoar frost forecast also saw aircraft being anti-iced.  The airport used water-based potassium acetate substances supplied by specialist company Clearway in liquid and solid form.  For de-icing, Gatwick uses Glycol.  Wilson has recently finished a £250,000 (US$391,000) project to deliver area capacity for an extra 180,000 litres of storage of Glycol supplies.
The snow team’s vehicles need a large area of parking space and are currently stored outside, but Wilson says the airport’s management team is looking at alternative options to best protect its investment.  While the big snow clearing vehicles are effectively redundant during the summer months, a number of the snow team’s smaller pick-up type trucks are also employed to assist with airfield foreign object damage (FOD) patrol duties all year round.