The Fruitvale Avenue Railroad Bridge is located on the Oakland Estuary (Oakland Tidal Canal), which is located in Alameda County, California. It spans the cities of Oakland and Alameda. The Oakland Estuary is a navigable water way with access to the San Francisco Bay and San Leandro Bays.
The bridge is manned by a alternating four person crew. The Bridge Tender on duty at Miller-Sweeny Bridge operates the Fruitvale Avenue Railroad Bridge. The Fruitvale Avenue Railroad Bridge is equipped with a Marine Radio, the working channel in the San Francisco Bay Area is Channel 9. Vessels can also gain a bridge opening by using a horn. The signal is a long blast followed by a short blast.
The Alameda County Department of Public Works provides preventive maintenance to the bridge.
The bridge is powered by four 19 hp motors. There are two motors in each tower one is the main operational motor the other is the backup motor, the motors run at 700 rpm. The bridge is stopped by 8 brakes. There are 4 motor brakes with 400 lb./ft torque. The motor brakes are the main stopping brakes when the bridge is being raised or lowered. The other 4 brakes are called the machinery brakes once the bridge is stopped these brakes are set manually by the bridge tender. The machinery brakes have a stopping force of 1200lb/ft torque. The machinery brakes can hold the bridge in place for long periods of time.
The Railroad Bridge is the only bridge in the County that uses a Direct Current (DC) motor control system. The other bridges are all Alternating Current (AC) designs. With the DC drive system, power to the bridge can be variably applied which gives the operator more control over the bridge. For example, on the High St. which is a AC design when you press the raise button it travels at one speed no variation. There are advantages to both types of drive systems. One of the drawbacks of the DC system at Fruitvale Avenue is its more complex at not as reliable as the other AC Designs.
Fruitvale Avenue has a unique power supply arrangement. Each tower of the bridge draws normal operating power from their side of the bridge. The North Tower draws power from the Bureau of Electricity (City of Alameda). The South Tower draws power from PG&E (Pacific Gas & Electric). Both power supplies have to be present in order for the bridge to operate under normal power. This requires a complex synchronization system in order to keep the bridge traveling properly. Without the synchronization the bridge will go out of alignment and possibly jam. The operator must carefully watch the gauges to ensure the bridge is moving correctly.
The power supply is interconnected so if one side loses power you can switch operating power from one side to the other. When using only one power supply the bridge runs on the emergency drive system under reduced speeds.
During the Loma Preita Earthquake in October 1989 the bridges main supporting bolts in the foundation were visibly stretched. Repairs to the mounting bolts were performed.