Schmidt jet sweepers have been put to use on runways and taxiways around the world and they have had to cope with the harshest of conditions. Dubai, for example, is hot and sandy, creating problems for GSE as well as all sorts of other equipment and aircraft
Dubai International Airport is the world’s busiest international airport. Last year, the number of passengers moving through its facilities increased by 10.9% compared to 2014. Measured in terms of total passenger traffic – both national and international passengers – the gateway ranks third globally, only surpassed by Hartsfield-Jackson Atlanta International and Beijing Capital International Airport (BCIA).More than 100 airlines offer over 240 destinations on six continents through Dubai International. With up to 1,100 aircraft movements a day at peak times having to be handled in a climate that sees very little rain indeed, the challenges regarding apron surface cleaning are tough. In addition, Dubai experiences extreme temperatures of up to 45°C in the shade, as well as the hot and dry Shamal winds that come in from the north in summer, blowing sand over the airport’s runways and other surfaces.
In such conditions, the airport has turned to the Schmidt ASC990 high-performance sweeper, chosen – the manufacturer notes – as the result of a strict selection process. The first few ASC990 truck-mounted sweepers have been in use at Dubai International since 2002; an additional six vehicles are to be put into use by 2017.
“The combination of high-performance sweeper and airport stand cleaning equipment was a key argument in our selection process,” says Johnny Saliba, head of Gargash Machinery GMGT, the dealer for Aebi Schmidt products in the region. “It permits maximum flexibility while keeping the use of resources to a minimum. The high reliability and the excellent sweeping results, even at high operating speeds of up to 40km/h, were additional convincing arguments.
The ASC990 is very sturdy; the hopper bottom, for example, is made of steel.
Moreover, the hydraulic tilting of the dirt hopper by 52° without having to start the auxiliary engine is a very convenient option, he adds.
The ASC990, a modification of the Schmidt AS990 (the additional C in the designation refers to the airport stand cleaning option of this unit) is easy to service and, vital in Dubai, easily handles fine desert sand. The interior of the two flow-optimised suction nozzles is hot-vulcanised as standard, resulting in low friction and thus less wear and tear, the ASC990’s manufacturer explains. In addition, it is approved for application at an external temperature of up to 54°C, even when employed at full performance.
The vehicle is not only designed to prevent potential damage to aircraft on runways caused by foreign object damage (FOD): it is also designed to mitigate the risks posed by leaked liquids, such as oils, by collecting them and cleaning the dirty apron through the application of a mixture of detergent and water in a single pass. For this, six water nozzles and six detergent nozzles are positioned in front of the unit’s two disc brushes. The water nozzles are supplied by a hydraulically operated water pump and the detergent nozzles by a separate pump. The disc brushes rub the cleaning emulsion of water and detergent into the surface. The loosened material is then collected in the hopper via the rear-mount suction-sweeping unit.
A suction fan ensures an airflow rate of approximately 32,000m3/h. The liquid suction unit can be mounted between the axles, on the rear or as a quick-change system on the rear of the ASC990. The quick-change system enables the transfer of the rear-mount suction unit for the liquid suction unit in just a few minutes.
The Swiss Aebi Group and the German Schmidt Group merged in 2007. Aebi Schmidt has factories in Switzerland, Germany, the Netherlands and Poland.
New designs
The ASC990 is by no means Schmidt’s only jet sweeper product offering. Schmidt took the decision just a couple of years ago to create a new generation of jet sweepers in the form of new variants of its CJS Compact Jet Sweeper and TJS Towed Jet Sweeper products.
The schedule for the new Schmidt CJS and TJS vehicles was a challenging one but, within just 18 months, the two new jet sweeper models were presented to customers and potential customers at Salzburg Airport on 13 April this year. The day’s highlights included demonstration of various Schmidt vehicles on the airport and the presentation of the two new systems.
Besides the new EuroMot 4 auxiliary engine, adaptation to new Euro 6 vehicles and technical changes, the focus was also placed on the design of the new CJS and TJS systems. Indeed: “The design agency had a clearly defined assignment,“ Theresia Winkler-Flügel, Schmidt’s product manager for airport devices and its manager of the technology project, recalls. “Firstly, the vehicle was to be redesigned to become fresher and more dynamic. With the design of the new CJS and TJS, we additionally wanted to initiate a component-sharing concept which can be transferred to other vehicles of the airport family at a later point.
“At the same time, however, certain variables, such as better access to the battery, hydraulic unit or other internal components, had to be taken into account in order to make maintenance easier for our customers. In addition, a new fan system now almost completely prevents fine snow particles from being drawn in. Last but not least, the question of the hood material had to be addressed.”
Clemens Schwörer has also been involved in the development project in a leading capacity from the very beginning. He works for Schmidt as a design engineer in the field of snow clearance. “In addition to the tight schedule, the greatest challenge in this project was the reconciliation of technical functionality and new design. The body had to be adapted to a new carrier vehicle, since the previous vehicle model, the Mercedes-Benz Actros Euro 5, was superseded by the new Mercedes-Benz Arocs Euro 6, with adaptation meaning in this case the total conversion of the carrier vehicles in terms of elevating the frame and the drive train to create space for the brush.
“We also had to turn a hand to the auxiliary engine to implement the currently valid EuroMot 4 emission standard. All in all, you could say that everything above the truck chassis has been redesigned and reconstructed,” Schwörer says. “Another important aspect during the development phase was the question of the optimum material for the hood, which had previously consisted of aluminium sections. The old design allowed relatively little flexibility, in addition to involving the risk of corrosion resulting from aluminium reacting with certain de-icing materials. For this reason, we decided to use a four-part plastic hood made of GFRP (glass fibre reinforced polymer). This also permits a high level of flexibility as regards the design.”
The first-ever Schmidt CJS was delivered to Frankfurt and Stuttgart Airport in the late 1980s, where they are still in service today. In addition, the towed version, the Schmidt TJS, was launched onto the market in 2004. Today, more than 500 Schmidt CJS vehicles are in use, among them 119 at German airports, more than 100 in Russia, more than 70 in China and 49 at civil airports in Great Britain.
