Facts and Figures
Tigerbrain prepared an airfield master plan and 100 percent plans and specifications for the parallel taxiway, arm/de-arm pad, three connector taxiways, and an aircraft parking apron; a clear water rinse and wash rack; access to maintenance and fuel cell hangars; and a separate taxiway to a compass calibration pad. The taxiways are all hot mix asphalt using DoD airfield asphalt determined to be available in Saudi Arabia. The parking apron and arm/de-arm hardstands are concrete. The project encompasses an approximate total of 82,648 square meters of asphalt mainline pavement, 39,692 square meters of asphalt shoulders, and 43,918 square meters of concrete pavement.
The initial design phase was for twelve MH-60R rotary wing aircraft with the master plan showing an additional capacity of up to 60 aircraft, including future but unknown Army and Air Force missions on the airfield. The developed master plan accommodates all future rotary and large frame fixed wing missions for the Royal Saudi Navy. The parking apron is sized for the current mission of twelve aircraft and expanded to accommodate an additional 48. An apron is required to have two connector taxiways. Therefore, the size of the apron and the location of the taxiways were considered to accommodate future construction. The apron was designed slightly wider than required so that the construction barrier will not impede aircraft on either of the connector taxiways when the new apron addition is being built. The extra widening of the apron is currently declared as a shoulder, but built with full strength concrete pavement. This will prevent the future expansion of the apron from interfering with maneuvering of the aircraft.
The unique site consideration that was analyzed during design was stabilization of the existing poorly graded sands with high sulfate contents. The site required up to 3 meters of cut and fill of loose wind-blown sands. The runway ends were already built and contained drainage basins that were too shallow. These conditions required research of economically feasible methods to stabilize the existing soils to provide a working platform for construction. Tigerbrain developed grading and drainage designs to minimize the amount of earthwork required to meet grading criteria, as well as additional drainage basins with conveyance to drain the prior basins to an area away from the airfield.
Developing arming/de-arming berms to protect from misfires from hung munitions presented multiple challenges. The initial airfield requirements were for four rotary wing arm/de-arm positions. Due to siting requirements and aircraft maneuverability, barrier protection is necessary to protect both the occupied buildings down range and the nearby ready-munitions buildings. Several protection barriers were considered. Although the earth berm may appear to be a low-cost option, it poses long term maintenance concerns in this environment because the wind-blown sands will continually erode the earth berm and create a sand dune tendency on the airfield. Also, sheet metal requires less site area and impact on airspace than earth berms. As a result, the sand-filled sheet metal wall is preferred over an earth berm. The sheet metal berm will be 7 meters high and 130 meters long.
Another challenge included understanding the condition of the existing airfield lighting circuitry and adapting to the current standards. The existing runway and lighting system were designed to ICAO criteria for commercial air traffic. After the original construction, the airfield was declared to become a Naval Air Base. The airfield lighting was unique in that it was controlled in three vaults at the north, middle, and south ends of the airfield. Each vault controlled every third light on the airfield. This is different than a typical DoD airfield where a vault may control one quadrant of an airfield with its circuitry being interwoven to every other light. Accordingly, Tigerbrain investigated and traced existing circuits and tower control systems in order to adapt a commercial lighting system to Navy requirements.
The project required a magnetically neutral site for the compass calibration pad necessary to the MH-60R aircraft. The master plan needed to site future fixed wing and rotary wing aircraft needs, as well as future planned high massed lighting. This coupled with setbacks from airfield chain linked fences, underground circuits, and electrical vaults made siting the pad for convenient access challenging. Eventually a location at the far north end of the airfield that maintained magnetic neutrality without inhibiting aircraft maneuverability was identified. In addition, a portion of the taxiway was designed to accommodate heavier aircraft since it will eventually be included in a large aircraft transient apron. This will allow the future aircraft to continue to access the compass pad through the taxiway.
The current mission requires a clear water rinse as the airfield’s proximity to the Arabian Sea necessitates rinsing all salt deposits after every flight. The challenge was locating the facility between the parallel taxiway and the apron to minimize the amount of aircraft in cue that could block taxying traffic on the parallel taxiway.
Another challenge involved the airfield geometry as it was originally design for civilian commercial traffic. The radii and fillets were substantially larger than required for DoD. In addition, portions of the high speed exit taxiways were constructed. Tigerbrain determined a method to convert the high speed exits into typical DoD ladder connector taxiways.
This design-bid-build project is currently at the 100% stage of the design.
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