Field Study of Gatwick Airport on TrackJet Use
03 December 2004
Dieter Pade
Re: Trackjet
25 Nov 04
Dieter,
Further to recent activities on the runway at Gatwick I confirm that we have had another successful cleaning exercise. Our 5h x 5h access periods were fully productive with a total of 17.380m² of Touch Down Zone returned to 100% clean status.
Surface Damage / Cleaning Results
I believe that we are now beginning to see the full benefit of regular use of the TrackJet System as the cleaned surface doesn’t even show minor traces of retained rubber after the machine has operated.
By comparison with our previous best option for rubber removal, we are now achieving a far superior end product that is proving to be quicker / cheaper / more thorough.
Our previous preferred system - high-pressure water rotor blasting - used to produce an improved friction reading reaching 5.5 or thereabouts, but this was barely above the desired minimum to maintain our certification requirements.
Costs
The cleaning process with the previous system was also required at every opportunity [five cleans per year]. In order that we maintained this minimum friction level, outputs for total area treated on each occasion were rarely much more than about 8,000m² during a standard access window of 25hs - with TrackJet, we have reduced cleaning exercises to two per year.
Previously, costs were relative to plant / labour charges for the week with no firm reference to performance of the equipment, hence if the rubber build-up was high, a resultant slowing of output would generate a significant increase in the unit cost/m² of the task. At times this could result in m² charges approaching €3/m².
Benefits
The move to TrackJet has brought us a number of benefits:
- We can now confidently predict our financial liability for the work period
- We have much improved confidence in output levels, never less than 600m²/h and with regular use this is stretching beyond the 700m²/h mark
- A system that delivers a far greater level of plant reliability [no losses due to down time] whilst providing a more thorough “deep clean” to our landing surface. Grip tester readings of +7 and a significant reduction in our exposure to collateral issues around the cleaning process
- We no longer face the prospect of vast water consumption to achieve our desired aim, neither do we have concerns that having used perhaps 75,000l to 100,000l of water in a 5h period we may create an icing problem on our surface during winter months
- The highly efficient VACUFLEX unit removes all residual products leaving a virtually dry surface behind the machine
Finally, there is the question of damage to the runway surface itself. Our experience with rotor blasting systems suggests that we shorten the working life of the pavement by +50% due to damage to the matrix elements of the asphalt material.
TrackJet, by comparison, displays very little erosion on completed surfaces. After two to three years regular use, the groove arises in the surface at Gatwick Airport are still well defined and there is minimal bitumen / stone loss on the surface generally.
I commend the TrackJet system, it is undoubtedly the way forward for Gatwick Airport to maintain its landing surface in the future.
Ian Coates
Airfield Civil Maintenance Team Manager Gatwick Airport Ltd.
