West Seattle Swing Bridge

The West Seattle Swing Bridge carries the Spokane Street traffic across the Duwamish River. Its two 7500 ton concrete spans are the heaviest swing bridge spans in the world.  While at Hamilton Engineering, Gil Lund was Principal Engineer, responsible for the design of the unique hydraulic operating system for this bridge.

During the early bridge concept design phase it was discovered that using concrete instead of a conventional steel structure for the bridge spans could provide significant savings in the construction cost.  To accomplish this it was necessary to design a swing bearing that could handle the heavy loads of the concrete span without at the same time producing a large friction torque from the swing bearings.

Kingston Loading Ramp

The Kingston Ferry Terminal is located in the Puget Sound on the Washington State Ferry Systems Edmonds to Kingston run.  The passenger loading system is designed to allow pedestrian loading on the upper deck of the ferries at the same time as cars are loaded on the lower car deck.  While at Hamilton Engineering Gil Lund was Principal Engineer, responsible for the conception and design of the unique hydraulic operating system for the loading ramp.

The loading ramp must be able to elevate vertically to accommodate the high tides of the Puget Sound as well as adjust to the deck heights of the multitude of boats employed by the Ferry System.  The resulting total design elevation of this system is 23 ft.

1st Avenue Bridge

The First Avenue South Double Leaf Bascule Bridge carries the First Avenue traffic across the Duwamish River.  The original bridge spans carried four lanes of vehicular traffic across the river.  Because of the large increase in traffic load on this road it was decided to add another four-lane bridge adjacent to the old structure.  Although the old bridge used an electro-mechanical drive, it was decided to use a hydraulic drive system for the new bridge. While at Hamilton Engineering Gil Lund was Principal Engineer, responsible for the conceptual design of the hydraulic drive system for the new bridge.  Four hydraulic cylinders acting directly on the large trunion shaft of the bridge accomplish the bridge span lift.   These cylinders are located in opposing pairs on each side of the span.

Evergreeen Point Bridge

The Evergreen Point Floating Bridge carries State Route 520 across Lake Washington from Seattle to Bellevue. The bridge has a telescoping type draw span that opens at infrequent intervals to allow large ship traffic to the south end of the lake.  The draw span is also opened in heavy winds to reduce the load on the bridge anchoring.  The original bridge used a system of chains, pulleys and counterweights to lift the draw spans.  Due to severe maintenance problems, it was decided to replace the original draw span lift system with a set of direct acting hydraulic cylinders.  The motions of the cylinders are synchronized by a closed loop electro hydraulic position control system.  While at Hamilton Engineering Gil Lund was Principal Engineer, responsible for the conceptual design of the hydraulic span lift system for the bridge refit.

WWII Aircraft Recovery

While at Hamilton Engineering Gil Lund spent many years working on engineering concepts and field work related to the recovery of several WWII airplanes from the Greenland ice cap. The group of 6 P38 twin engine fighters and 2 B17 bombers made an emergency landing on the ice cap while on a ferry flight from the US to England in the summer of 1942. They were subsequently covered with 300 ft of snow and ice. In 1986 a group from Atlanta, Georgia hired Gil to help them locate the airplanes and excavate them from the ice. The project lasted for many years and eventually one B17 and one P38 was recovered. The P38 has currently been restored to flying condition.

1420 MAPLE AVE SW SUITE 101 - RENTON, WA 98057 - (206) 973-1025