In October, the last eight of 20 new gates at Dallas Love Field (DAL) opened for business. To service the new gates, the Dallas Department of Aviation and Southwest Airlines partnered to install an $11.6 million fuel hydrant system. Both projects were carefully timed to coincide with the much-anticipated expiration of the Wright Amendment.
Project: Fuel Transmission & Hydrant System
Location: Dallas Love Field
Cost: $11.6 million
Funding: Southwest Airlines Bonds; Dallas Dept. of Aviation; FAA; various federal grants
Design: April 2009 - Jan. 2011
Construction: Jan. 2010 - Jan. 2015
Apron Design & Utilities: Huitt-Zollars
Terminal Architecture: Corgan and Assoc.
Apron Paving & Utilities Contractor: Munilla Construction Management
Hydrant Fuel System Design: Argus Consulting
Hydrant Fuel System Installation: Meccon Industries
Program Manager: William Manning
Electrical: EAS Contracting
Excavation & Pipe Removal: Unified Services of Texas
Horizontal Drilling: TCH Directional Drilling
Leak Detection Equipment: Hansa Consult of North America
Cathodic Protection: Corrpro
Epoxy Piping: Consolidated Pipe
Controls Systems: Custom Controls
Fuel Control Valves: AFTEC
Of Note: Airport & Southwest Airlines partner to prepare for increases in air traffic expected after expiration of service restrictions in mid-Oct.
Passed by Congress in 1979, the Wright Amendment protected then-new Dallas/Fort Worth International Airport by restricting DAL from offering non-stop service to states not adjacent to Texas. In 2006, a compromise was reached that allowed DAL to offer non-stop service throughout the United States beginning Oct. 13, 2014; but it is still limited to 20 gates and cannot offer international service.
Anticipating the recent expiration of key Wright Amendment restrictions, DAL went to work on its facilities. Joining in a public/private venture, Southwest Airlines and the city of Dallas launched the Love Field Modernization Program in 2006 - the biggest construction project at DAL since the 1950s. The complex $519 million program included terminal demolition and renovation; demolition of taxiways, taxi lanes and apron pavements to prepare for new pavement; improvements to utilities and drainage; and construction of a new hydrant fuel system.
With some of the airport's long-time service restrictions lifted, officials expect passenger traffic to increase from 8 million to 12 million per year. Naturally, all those extra flights will require fuel.
Mark Duebner, director of aviation for the city of Dallas, describes the new hydrant fueling system as state-of-the-art. "Two new 10-inch transmission lines have replaced the aging transmission system, which has been decommissioned and removed. The new system serves each gate with an in-ground hydrant pit and includes cathodic protection, high and low point pits and readily accessible valve vaults for ease of maintenance," details Deubner. "The system also incorporates a leak detection system and an emergency fuel shut-off system, which isolates five-gate segments of the fueling system while the remaining 15 hydrant pits can continue to operate."
Huitt-Zollars designed the airside civil improvements, including demolition and reconstruction of the apron and subsequent hydrant system work. The company's vice president, Gerald Prusik, PE, notes that the complex project included reconfiguring the sanitary sewer and an abundance of underground utilities and stormwater work in addition to the fuel system component.
As such, security fencing for aircraft operations areas was crucial. "We created our own sandbox, if you will, by fencing off an area, doing the work, then moving on to set up fencing in a new area," Prusik explains. "For the most part, however, workers were able to access the fenced-off work areas directly from non-secure landside areas without having to go through badge check procedures."
Huitt-Zollars contracted Argus to design the new hydrant fuel system. Project design began in April 2009, and construction took off in February 2011. The multi-phase project included the removal or safe abandonment of 13.5 miles of existing fuel line. Crews also installed 5,100 feet of two 10-inch fuel transmission lines from the fuel farm to the manifold and laid a 4,900-foot 10-inch hydrant loop to serve concourse gates.
Under the previous system, eight transmission lines from the fuel farm joined together at a manifold to feed the concourses; and six of those lines had been taken out of service. The two remaining lines served the old West Concourse, which remained in service throughout portions of the terminal renovation and construction of the new concourse. Old fuel lines were removed as construction proceeded, and lines running beneath the runways were drained and grouted with concrete.
"It was a challenging project," reflects Argus Vice President Chris Straub. "Phasing the project construction over four and a half years to make sure the airlines had a continuous supply of fuel throughout demolition and construction was a significant challenge."
Phase 1 included construction of a new general use building and removing or abandoning existing decommissioned fuel lines in the area. During Phase 2, crews demolished the North Concourse and removed or abandoned decommissioned fuel lines within the footprint of the construction area.
Phase 3 included construction of the eastern half of the new concourse, demolition and replacement of the adjacent airfield pavement, utility and stormwater facility upgrades, and installation of the eastern half of the hydrant loop, with a new transmission line from the existing West Concourse manifold to the new hydrant loop.
Phases 4 and 5 included construction of the western half of the new concourse, including removal and replacement of additional airfield pavement as well as utility and stormwater upgrades. In addition, the hydrant fuel system installed during Phase 3 was extended to encompass the western half of the new concourse. A portion of an existing 14-inch transmission line was temporarily used so the eight transmission lines running through the West Concourse tunnel could be removed.
The final portions of the West Concourse were demolished during Phase 4. Installation of two 10-inch transmission lines required directional drilling from near the tank farm to within the limits of Phase 4 construction. This was followed by installation of the lines to a new isolation valve vault that feeds the new terminal.
As program manager and Southwest consultant for DAL's $519 million modernization initiative, William Manning, PE, JD, knew to expect the unexpected during the hydrant fuel project. But it was still a surprise when crews discovered aviation fuel in a portion of the existing fuel system slated for drainage and grouting. "It was a tremendous exercise getting the old fuel out," recalls Manning.
Where fuel lines crossed a runway, horizontal drilling techniques were used to bore beneath the runway. Personnel from Meccon Industries, the company contracted for the fuel system project, characterize the work as very unique.
"Originally, the project called for 42-inch casing to hold two fuel lines inside and four 4-inch conduits above the fuel lines," explains Greg Curran, Meccon's project manager. "Instead, we were able to use horizontal drilling technology and drill three separate 1,000-foot bores beneath the runway. Two bores were used to install two 10-inch fuel lines and the third bore for communications conduits."
Prefabricated piping was installed in 300-foot lengths. At their deepest points, bores were 20 feet below ground surface.
"We had a lot of issues to deal with to control the slope of the pipe and ensure we didn't have high points that would trap air in the pipe," Manning adds.
The new system's looped piping is designed to maximize system flow rates and mitigate surge pressures. Isolation vaults are strategically placed to facilitate a zoned emergency fuel shut-off system, leak-detection monitoring and maintenance, while limiting the number of gates taken out of service. A new distribution header was installed at the fuel storage facility.
The new emergency shut-off system features push-button stations at each gate that will shut down appropriate motor-operated valves on the ramp to isolate the section of piping of concern and stop the flow of fuel. The system also sends an alarm to the tank farm to inform operators about the specific gate where the emergency has occurred. The emergency shut-off signals are processed by a programmable logic controller in the concourse, which in turn communicates with the tank farm via a newly installed fiber optic network.
Prepared for the Future
The new hydrant fuel system works in conjunction with the fuel farm Southwest built in 2006, complete with three 10,000-barrel aboveground tanks, pump pads and upgraded filtration and recirculation capabilities. The airline owns both assets.
Jim Stevenson, the airline's category manager of fuel supply chain management, is pleased with the new operations. "Putting a variable frequency drive (VFD) system in at the tank farm back in 2006 helps a great deal. Pump use is optimized via computer technology. With the VFD system, when multiple fueling activities occur and pressure drops, the system automatically brings another pump online. It's a great cost savings, because pumps do not just shut down and fire back up again, which creates a tremendous electrical power draw. The VFD system senses a drop in pressure and pulls another pump online slowly, thus using less current. When the system is not being used it goes into a bypass mode and eventually shuts down."
Praise for the coordinated relationship between Southwest Airlines and Dallas' Department of Aviation is pervasive. "They went into the program as partners, with a we're-going-to-make-this-thing-work attitude," Straub reflects. "That attitude trickled down to the design firms and contractors - everyone who worked on this project."
"We're excited," Stevenson adds. "With the fuel farm and hydrant system fully operational, passenger traffic in the first month after the expiration of the Wright Amendment was up 37%."