TrackJet Cost and Performance
17 March 2005
TrackJet has now been in use at BAA Gatwick for 3yrs, operating a twice yearly cleaning programme to remove rubber deposits from the Touch Down Zones on the main runway.
The twice yearly use of the process has resulted in a sustained cleaning performance and a 99% rubber-free surface availability post cleaning.
Cost efficiency has been enhanced by regular use. Initial cleaning outputs on contaminated surfaces were in the order of 550m²/h. This has now risen to 750m²/h to 800m²/h due to the depth of “deep clean” achieved by repeated use.
We are now able to undertake de-rubbering over a far greater area within the allotted work windows available to the maintenance engineering function. Target areas now include the most frequently used Rapid Exit Taxiways [RETs] and a central section of runway that is in use regardless of landing direction on our single runway. These areas suffer from high rubber contamination as a result of use by up to 800 aircraft movements per day at peak times.
Typically, a total area approaching 20.000m² can now be treated within a 25h work window. Due to the TrackJet’s less aggressive method of removal, we have found that the degree of “collateral damage” to the surface is much less than previously experienced.
The grooved asphalt surface has virtually zero erosion around the groove arrises and minimal matrix losses between the grooves. In essence this suggests that the surface (currently approaching its 5th year) has deteriorated far less than previous overlays which were cleaned using more traditional 600bar water pressure equipment.
Gatwick’s runway/landing zone surface has previously been replaced in 1988/96 and 2000; complete resurfacing took place in 1988 and 2000, and TDZ surfacing only in 1996 - repeat frequencies being due to a high degree of damage to the grooving by a variety of cleaning techniques.
Given the current much improved status of degradation it is estimated that the current surface's life span should far exceed that experienced previously. We used to expect to resurface TDZ areas at 8yr intervals followed by complete resurfacing at year 12.
Due to the much reduced degradation associated with TrackJet use, the overall life of the surface is now expected to be extended considerably. The current level of deterioration would indicate that TDZ areas should achieve 12yrs and possibly longer. The remaining surface may well far exceed this.
The financial benefits of extending life span by 50% are self-evident. The 2000 resurfacing exercise cost in the order of £17.5m.
