Collaboration & Quality Control Yield Lasting Runway Markings at Ocala Int'l

In early 2009, Runway 18-36 at Ocala International Airport in Florida was a patchwork of different pavements, and it had been nearly 20 years since its last rehabilitation or significant maintenance.

The runway's markings were also peeling and lifting in an

factsfigures Project: Runway Repaving & Markings Location: Ocala (FL) Int'l Airport Cost: $3.68 million Funding: 95% FAA, 2.5% state, 2.5% city Consulting Engineer: Reynolds, Smith & Hill Prime Contractor: Steven Counts, Inc. Airfield Markings Specialist: Sightline, LC Painting Contractor: Fausnight Stripe & Line Benefits: Markings are expected to last 4-5 years.

unusual way: The asphalt was cracking under and adjacent to the paint. "It was almost as if the paint was applied with a roller, (and) the cracks followed the roller lines," describes airport director Matthew Grow. "One wouldn't expect to see that on a runway."

A $3.68 million overlay and markings project, however, left the 7,457-foot runway with a dramatically different bird's-eye appearance by October 2009. Well aware that updates were needed, airport officials had petitioned the FAA for funds and, in turn, received an AIP grant that covered 95% ot the project. During the construction phase, crews worked for 76 days, with the runway out of service only one week for final paving.

Collaboration

Consulting engineer Reynolds, Smith and Hill (RS&H) enlisted Sightline, LC, to help with the markings aspect of the project. Sightline acted as a subject matter expert: helping the painter calibrate its equipment, making sure the sprayers worked properly and verifying paint and bead application rates, explains Bob Overby, PE, LEED AP, senior aviation engineer at RS&H. "They brought general best practices gained through their years," Overby relates.

Donna Speidel, president of Sightline, credits RS&H for recognizing the value of having an airfield markings consultant on the jobsite. "Having us involved in the striping provides a good end product that benefits the airport," she remarks. "When the markings are applied well, an airport like Ocala does not need to spend the money for maintenance for several years."

According to Speidel, RS&H's willingness to enlist a markings specialist sets it apart from other consulting engineers. The airport, in turn, appreciated the way the painting contractor collaborated with Sightline. "It's always great when you have a contractor that's willing to work with an engineer on a final project," says Grow, noting that some can be "cantankerous" about such arrangements. "When everybody has their eye on the prize, it definitely helps things out."

When the engineer, contractors and subcontractors work together to provide a high-quality product, the airport benefits the most, but everyone wins, adds Speidel.

Quality Control

Uniform application of paint and beads creates a stable coating that bonds well to the pavement, relates Speidel. Because the painting contractor used a road striping truck, which is not uncommon on runway striping projects, adjustments needed to be made.

"A lot of the markings out on the airfield are three feet wide and wider, so it's optimum to paint three feet wide in a single pass," she explains. "A road truck often has a two-gun setup; so in order to improve production, the applicator will position the guns up so they can get a 19-inch pass. That's not a problem as long as that 19-inch pass is good and uniform."

Working together, Sightline and the painting contractor adjusted tip sizes and calibrated the glass bead guns to synchronize with the speed of the truck relative to the width of the line being applied. Only with all the factors working in concert, were crews able to achieve the uniform markings the airport needed.

Florida's trademark humidity suspended painting just one evening. "High humidity is not a friend to airport marking application because it slows or stops the drying and curing of the paint film," explains Speidel. "In the early hours of the morning, when the mist starts to roll in, painting operations have to stop. It's one of the things that we monitor."

FAA specifications require surface temperature to be five degrees higher than the dew point during application.

Sightline also assisted RS&H during the inspection phase of the project. "It was very beneficial to have them give us their expertise on what to look for," recalls Overby. "They (provided) a value-added service that we hadn't considered before. There is definitely a benefit to having someone like them on-site to do what they did with the painting contractor."

No Time Like the Present

In the two years since Runway 18-36 was completed, no maintenance has been needed. And the pavement markings still look new, reports Overby.

"On a runway like Ocala, the markings should probably last at least four years, maybe five," Speidel says. The new two- to three-inch overlay, adds Overby, should last 20 years.

Although Grow agrees that the airport could go several more years before reworking the runway markings, the availability of state grants inspired him to schedule some touch-up work early next year. The centerline and select high-wear areas may also be repainted at the same time.