RPS recently project managed the rehabilitation of runway 06-24 at Shannon Airport. In 2017, Shannon Airport carried out the resurfacing of 75 per cent of its main runway, within extremely tight night-time possession windows. The €14 million investment ensures the integrity of the runway for the next 20 years.
Image from the point cloud scan survey, which RPS carried out over five nights in early 2016.
Shannon Airport is located adjacent to the Shannon estuary. Its main runway known as – 06-24 – at 3,199m in length, is the longest runway in Ireland and is capable of handling all aircraft types. In 2017, the airport handled 1.74 million passengers. The airport is open 24 hours a day, seven days a week, with no curfews, slots or noise restrictions.
Commercially, Shannon airport is part of Shannon Group plc. It is operated by the Shannon Airport Authority (SAA). In 2012, SAA split from Dublin and Cork airports and operates as a stand-alone company. In order to finance the vital runway rehabilitation works, Shannon Airport arranged a loan facility from the Ireland Strategic Investment Fund (ISIF).
The first phase of the runway rehabilitation process was the completion of a pavement evaluation survey. This was carried out in 2015. The survey concluded that the runway was structurally acceptable, taking into account future design traffic.
RPS Group arranged for a surveyor to carry out a detailed topographical survey. The availability of access to the runway for a detailed survey was extremely limited. Given the tight window of availability, RPS chose to carry out a point cloud survey of the runway, over five nights, in early 2016.
The Porous Friction Course (PFC) and underlying asphalt material, which extend to approximately 75 per cent of the runway length, were in excess of 30 years old. Both these material layers had already exceeded their intended design life. The preferred technical paving solution was Grooved Marshall Asphalt (GMA).
The essential requirements for the project were to:
Produce a runway with adequate pavement bearing capacity for a lifespan of 20 years;
Create a runway surface with a uniform surface and good wet friction characteristics for landing aircraft;
Provide good crack resistance so as to minimise any future foreign object debris (FOD) risk, and;
Provide new energy-efficient LED aeronautical ground lighting (AGL) for the CAT I edge lighting and the CATII lighting.
Other key features of the design included laying new cabling and installing new lighting pots for the replacement LED AGL. The drainage channel and gullies along the edge of the runway had to be reformed and rebuilt.
Work on the runway commenced before the end of April 2017. The contractor had, on average, 90 workers and 70 vehicles at work every night. The available work window was between 11.30pm and 4.30am, five nights a week, from Tuesday to Saturday.
Work had to cease at 4.30am every morning so as to allow for a FOD safety sweep of the runway. It was inspected and then formally handed back to air traffic control prior to the landing of the first transatlantic flight from New York at 6am.
The pavement overlay was laid in three layers: base, binder and wearing course. The contractor laid only one type of course per night, so as to avoid any confusion with respect to material types.
The upgraded runway was completed by the end of September 2017, ahead of schedule and under budget.