H&H provided consulting services to the Seattle Mariners for the inspection, rehabilitation, maintenance, and operation of their unique facilities. H&H performed a 100% hands-on condition inspection of the retractable, long-span steel trusses, comprehensively covering the structural, mechanical, and electrical systems. The truss spans over 450 feet and is over 200 feet from ground level. Non-tower structures (i.e., elements below the sill beam) were accessed by climbing the structure and utilizing available access ladders and walkways. The towers were accessed by climbing, rappelling lines, and harnesses. Records in the form of field notes and photographs were made, cataloging anomalies from ideal conditions. Inspection of the bogies entailed a visual survey of all weldments (with particular emphasis on welds), including primary, secondary, and tertiary equalizing beams and respective equalizing pin cap plates and bolts. Visual inspection of the towers encompassed structural members, bolted connections, welds and roof panel pin, and damper areas.

Access was accomplished through the use of the existing fixed access ladders and walkways and by free climbing of the structure. For higher areas, rappelling lines and harnesses were implemented to achieve a 100% hands-on inspection. The inspection was performed visually; the team was prepared with equipment to perform non-destructive testing as necessary. This equipment included a D-meter, die grinder, magnetic particle testing kit, dye penetrant weld testing kit, and wire brushes. Relevant plans and specially prepared field sketches were used for proper on-site cross-referencing and documentation, along with the appropriate field notebooks and digital cameras.

A team from H&H performed the annual inspection in accordance with the guidelines of the AASHTO Manual for Maintenance Inspection of Bridges, along with all of its supplemental documentation. H&H was also tasked with providing a detailed operations and maintenance program for the owner.