Project Update – Flight of success
Most airports in the world by default have parallel runways. Interestingly, the runway system at the Chhatrapati Shivaji International Airport (CSIA) in Mumbai is equipped with a Cross Runway system. The system was created this way taking into consideration the wind direction at the location. Designated as 09/27 (Primary Runway) and 14/32 (Secondary Runway), these two runways at CSIA intersect each other at a common point making it relatively more difficult to operate, maintain, repair or reconstruct.
While overall Brownfield expansion of any airport itself has its unique challenges, overhauling the runway system is the most difficult part of this expansion. However, regardless of the difficulties, the airside operations team at the Mumbai International Airport Pvt Ltd (MIAL) decided to undertake reconstruction of the secondary runway (14/32) as part of the overall modernisation process of CSIA. The decision was based on the findings of numerous surveys and inspections undertaken with a view of strict compliance with the highest international safety standards. The team realised that it was critical to upgrade the runway system and create an efficient airside infrastructure by addressing all existing non-compliance issues.
Of course, a reconstruction project of this nature and scale cannot be done in isolation as it involves several stakeholders. In fact, even the smallest of activity undertaken at the airside requires comprehensive coordination as well as authorisation. Moreover, the actual implementation itself demands pinpoint precision. The base work for the project started in April 2009 with a series of meetings involving various agencies. All stakeholders were explained why it was necessary to undertake the reconstruction and what would be the long-term benefits of this project for CSIA.
Approvals had to be taken from all concerned authorities including the Directorate General Civil Aviation (DGCA), which is the decisive authority with regards to all development works undertaken at any airport in the country. MIAL conducted strict safety assessments and ensured that all apprehensions are addressed. A practical solution had to be devised for all possible concern areas that were identified in advance. A test run was conducted to check the compliance and feasibility of each solution.
Arriving at a time-frame
It was critical to involve the actual users of the runways – the airlines – in the planning process and coordinate with them during the reconstruction. It was a Herculean task considering the fact that 52 airlines (including domestic and international) collectively operate 4671 flights every week from CSIA. Air traffic over the last season’s schedule for each day and each hour was mapped. Finally, the closure time-frame was determined after taking into consideration the collective recommendations received from these airlines based on their respective schedules.
Thus, it was decided that Runway 14/32 (RWY 14/32) would be closed for aircraft movements from October 1, 2009 till April 8, 2010. The intersection between the two runways too would remain closed for reconstruction every Tuesday for six hours from 1200-1800 hrs, spanning a period of 22 weeks, starting October 27, 2009 to March 25, 2010.
When the intersection remains closed, aircraft movement is facilitated on a shortened runway from 1300-1700 hours on Tuesdays. The impact of these changes in operational parameters was already factored in the airline schedules. However on rest of the days, the runway operations function as usual.
The work required
Based on the findings of a detailed survey of the runway pavement, the work is carried out in three key areas. The first involves the RWY 14 Loop where three taxiways are being constructed along with a portion of parallel taxiway. RWY 14 end shall be raised and the turn pad (area specified for an aircraft to make a 180 degree turn before take-off) will be taken-off. The second area involves the centre loop where the slope correction and reconstruction of the runway intersection is undertaken. Currently, the taxiway’s N-N1 junction and W4-P junction are also being reconstructed. The third area is the RWY 32 loop where two taxiways are being constructed with one each on east and west. Maximum reconstruction is required in this area as the surface has deteriorated considerably.
The entire project is being implemented with a long-term perspective. This involves streamlining all maintenance issues so that long closures in the future can be avoided. MIAL is also working towards setting up a duct plan to help locate cables. This will facilitate the detection of taxiway or circuit lights requiring maintenance. This will be possible once cable mapping is undertaken throughout.
The main contractor for this project is civil engineering giant Larsen & Toubro (L&T). L&T has strategically planned the work schedule with aim of bringing out the maximum output in the stipulated six hours without compromising either quality or safety. In terms of resource requirements, about 22,000 metric tonnes of bitumen will be required during the 22 week schedule with nearly 1000 workers reporting at site every Tuesday. Considering the huge material requirement, MIAL has set up a hot mix plant next to the ATC tower. The plant has a capacity of producing 200 tonnes of asphalt mix per hour. A wide range of advanced equipment and machines are employed at the site to ensure complete compliance with speed, quality and safety requirements. These include four asphalt milling machines / cold planners, four asphalt pavers, three pneumatic tyre rollers and one trenching machine.