BNSF North SIG Intermodal Improvement Project Seattle, Washington By Charles E. Burnham, P.E. David Evans and Associates, Inc. Trans-Pacific Trade Center Building 3700 Pacific Highway East, Suite 311 Tacoma, WA 98424 Phone: (253) 922-9780 E-mail: ceb@deainc.com Danniel J. MacDonald, P.E. BNSF Railway Company 1313 West 11 th Street Vancouver, WA 98660 Phone: (360) 418-6415 E-mail: danniel.macdonald@bnsf.com
ABSTRACT BNSF Railway Company (BNSF) wanted to increase capacity and efficiency at its Seattle International Gateway intermodal (SIG) facility by installing four wide-span, electric, railmounted gantry cranes. The project required complete redevelopment of an existing 13-acre site known as North SIG. Major project challenges included relocation/undergrounding of a City of Seattle electrical transmission line, soft soils, the addition of two power substations to serve the site lighting and gantry cranes, high groundwater, and on-site stormwater treatment. The new facility accommodates four wide-span, electric, rail-mounted gantry cranes and six rail spurs that can store a complete unit train, which increases capacity at the SIG facility by almost 50 percent. The new cranes are capable of stacking containers as well as loading and unloading trucks and railcars. The cranes have improved throughput at the facility by approximately 30 percent, supporting the growth of international commerce at the Port of Seattle. The zero-emissions cranes are significantly wider than traditional cranes, spanning three tracks and associated container stacking and truck transfer areas. They reduce the need for diesel trucks to move containers within the facility and decrease the facility's impact on the environment. Additionally, the new cranes regenerate power each time they lower a load and are quieter than traditional cranes. BNSF is the first railroad in North America to install these cranes. PROJECT GOALS BNSF wanted to enhance the facility performance at the SIG intermodal facility. The North SIG site was under-utilized and inefficient. The major goals of the project were to improve site efficiency and throughput capacity; lower operating costs per unit handled, and meet budgeted capital and life-cycle costs. In order to meet the goals, the site required complete redevelopment into a modern state-of-the-art facility capable of handling complete container trains at one time.
In addition to increasing track and container storage capacities, BNSF wanted to improve the operating performance of the facility and decrease the time required to turn container trains around. Both site improvements and new equipment contributed to meeting the goals. SITE HISTORY The project site has been in railroad use for nearly 100 years. The Milwaukee Road used the site for freight handling, as a Trailer on Flat Car (TOFC) facility, and equipment maintenance yard from 1916 until 1980. The Burlington Northern Railroad and successor BNSF used the facility for TOFC and container loading, and for equipment storage and repair in support of their Seattle International Gateway (SIG) intermodal facility until the construction of this project. An aerial view of the site prior to construction is shown in Figure 1 and ground perspectives in Figures 2 and 3. Figure 1 The facility was modified several times during its history, which presented a number of challenges to redevelopment. Figure 2 The site had substantial undocumented buried building foundations left in the ground during previous modifications. There were a number of active and inactive utilities including water and sewer, a large sewer force main along the entire westerly side of the site, and overhead power distribution and high mast transmission lines. The Seattle City Light power Figure 3
lines presented two of the largest challenges for the project. The transmission line limited the construction of improvements within its minimum clearance zone. The distribution line crossed the middle of the proposed facility and needed to be placed underground or completely rerouted around the site. The transmission line is shown in Figure 4. Figure 4 Existing storm drainage on the site consisted of various catch basins connected to the City of Seattle storm drain system. There were no stormwater treatment facilities due to the age of the facility. Much of the stormwater that fell on the site simply infiltrated into the gravel surface or evaporated. The existing system was largely abandoned and replaced as part of the redevelopment. PROJECT ELEMENTS A number of project elements were addressed to successfully bring the project on-line. Site redevelopment included complete demolition of the existing facility; relocation and protection of major utilities; construction of track, pavement, storm drainage, crane rails, power and Figure 5 communication duct banks, site lighting; and finally, erection of the gantry cranes. The new facility is approximately 1,900 feet long and 300 feet wide. See Figure 5. Track: Six new intermodal tracks were constructed with a total capacity of 7,800 feet to handle a complete container train within the intermodal yard operating area. The tracks were constructed with concrete ties and 141-pound welded rail. In addition to the intermodal tracks, an
approximately 2,300-foot-long car maintenance track was completely rebuilt along the length of the facility on the westerly side. Pavement: The initial design criteria for the pavement specified asphalt concrete with a 20-year, 100,000-cycle service life capable of supporting 262,250-pound axle loads generated by rubbertired top-pick container handling equipment. Due to the poor soils underlying the site and the extreme heavy design loads, the recommended pavement design was 12 inches of structural base, 6 inches of crushed surfacing material, and 21.5 inches of asphalt concrete pavement. By reducing the number of anticipated top-pick equipment cycles to less than 1,000 cycles and the service life to ten years, the recommended pavement structure was reduced to 7 inches of asphalt concrete, 6 inches of crushed surfacing, and 12 inches of structural base material. The reduction in service life under top-pick equipment loads was supported because during design, the proposed operation of the facility was modified to use large gantry cranes for most container handling operations. This meant that there would be only occasional use by top-pick equipment during the life of the facility. Nearly all of the equipment loads on the pavement will be generated by trucks hauling containers. Therefore, actual service life of the pavement is expected to be substantially more than ten years. Grading and Storm Drainage: The site is located in an area of high groundwater due to its low elevation and proximity to Elliott Bay. The site and the surrounding area sit on hydraulic fill placed in the early part of the 20th century. The soils are fairly weak and poorly drained. In order to provide adequate support for pavement, intermodal tracks and crane rail grade beams, site grades were raised 2 to 2.5 feet above existing ground. Raising the site also provided improved storm drainage.
Existing concrete and asphalt pavements were salvaged and crushed for reuse on the project as select fill. Reinforcing bar in the concrete pavement was salvaged and recycled. Figures 6 through 9 show pavement demolition, crushing and reuse on the project. To accommodate container storage, the maximum grade in container storage areas was limited to 0.5 percent. Track and crane rail grades were Figure 6 Figure 7 limited to 0.30 percent. This presented some challenges to storm drainage systems for the facility. Very tight controls on Figure 8 Figure 9 paving operations during construction were required in order to meet the grading tolerances. The north half of the site had an existing drainage system connected to an operating City of Seattle sanitary sewer line. The City required detention but no treatment for this portion of the site. Treatment was not required, since the water was sent to a city sewage treatment plant prior to discharge into Puget Sound. Detention was necessary to accommodate an undersized city sewer line. Detention storage volume was accomplished by using oversized drainage lines on the site in combination with a flow restrictor manhole immediately upstream of the connection to the city sewer system. The south half of the site required stormwater treatment, but no detention. Two alternatives for stormwater treatment were considered.
One option was a system of several large cast-in-place concrete wet vaults. Typical wet vault size needed to be approximately 110 ft. x 25 ft. x 10 ft. deep. The vaults need to be capable of supporting the 262,250-pound axle loads of the top-pick container handling equipment. Dewatering was required to construct these vaults. Due to the size, cost and constructability issues associated with the wet vaults, a second type of system was considered and ultimately used for the project. The stormwater treatment selected for the project was a two-stage storm filter system. The system included a vortex-style manhole to separate solids from the stormwater and a filter vault to collect other contaminants. The footprint of the total system was approximately 10 percent of the size of the wet vault systems and could be located outside of the area that would be used by the top-pick equipment. Including capital and maintenance costs for the first ten years of facility operations, the two-stage storm filter system is estimated to save nearly $1 million compared to the wet vault system. City Light Distribution Line Relocation: A major Seattle City Figure 10 Light distribution aerial line crossed the site at approximately the mid-point. This line was placed underground to eliminate the only overhead conflict on the site and allow the redevelopment as a craneserved intermodal facility. Approximately 330 feet of distribution line was placed underground in a concrete- encased duct bank Figure 11 constructed to meet City Light specifications. The work also included installation of several large laminated wooden power poles, large electrical vaults and demolition of the existing lines across the yard. Figures 10 and 11 show the underground duct bank and one of the vaults during
construction. Note the dewatering system that was required for nearly all of the underground work on the entire site. Crane Rails: Two pairs of 175-pound crane rails were constructed on 1,300-foot long grade beams. The crane rail gage is 123.5 feet. Figure 12 shows a typical cross section of the yard with cranes, intermodal tracks, truck lanes and container storage areas. As part of the crane rail Figure 12 construction, concrete encased electrical and communication duct banks were constructed along each of the outside crane rail grade beams. The duct banks carry power cables for the cranes, site lighting and communication cables, and fiber optics for site and crane communication, and operation controls. Site Lighting: High mast lighting was selected for the project to illuminate the yard and track areas. The lighting design utilized high-pressure sodium fixtures with hoods and lenses designed to limit light scatter to office, commercial and residential properties immediately adjacent to the easterly side of the facility.
Gantry Cranes: Four rail-mounted, wide-span, electric gantry cranes were purchased from Kone Cranes. BNSF was the first railroad in the United States to install these cranes. The wide span was selected in order to span over multiple tracks, truck lanes and, container storage areas. The cranes accommodate four high container stacking. Substations and Duct Banks: Two electrical substations were constructed for the project. One serves the site lighting and general power demands. The other serves the power needs of the four gantry cranes. The substations were constructed outside of the operating area of the terminal. All electrical and communication lines for the facility were placed underground to avoid conflicts with operations. SUSTAINABLE SOLUTIONS The North SIG Intermodal Improvement Project is an example of BNSF s continued dedication to sustainability in their operations and capital projects. The simple fact that the project redeveloped an existing BNSF facility from a low production operation into a very high production operation greatly reduced development impacts and a much improved carbon footprint. A number of the elements of the project contribute to a low impact sustainable solution to upgrading BNSF s North SIG Intermodal Yard. The most significant are: Gantry Cranes: The Kone style gantry cranes selected for the facility are zero emission cranes and are quiet. They provide more operational flexibility and efficiency to container handling by performing loading for both truck and rail cars. They are able to spot containers into storage anywhere on site up to four containers high. The need for diesel-powered trucks and container handling equipment to move containers within the facility is greatly reduced, thus reducing emissions. The cranes have nearly doubled the capacity of the SIG facility, while reducing
environmental impacts and supporting economic growth of international commerce at the Port of Seattle. In addition, the cranes and the new facility have increased facility throughput by nearly 30 percent. Finally, the cranes regenerate electricity into the grid every time they lower a load. Pavement Reuse: Reuse of the existing asphalt and concrete pavement on the site saved cost to the project and reduced the need to dispose of the material in a landfill. The project reduced the need to import select fill by recycling approximately 6,500 cubic yards of pavement. ACKNOWLEDGMENTS In addition to David Evans and Associates, Inc., the design team included BERGER/ABAM Engineers, Inc.; Northwest Utility Consultants, Elcon Associates, Inc.; and Landau Associates. BNSF engineering and intermodal staff who contributed to the success of the project included Danniel MacDonald, PE, Manager Engineering; Mike Powrie, PE, Project Engineer; and Sam Phanekham, Manager Facility Development. Thanks to all of them.