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Park Street Bridge
Miller-Sweeny Bridge
Fruitvale Ave Bridge

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Bay Farm Island Bridge
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Location:
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.

See Location Map Page

Built:
The Fruitvale Avenue Railroad Bridge was built in 1951 by the United States Army Corp of Engineers.

Owner:
United States Army Corp of Engineers. The bridge is maintained and operated by the Alameda County Department of Public Works. The bridge is regulated by the United States Coast Guard.

Type:
The Fruitvale Avenue Railroad Bridge is a vertical lift draw bridge.

Operation:
The Fruitvale Avenue Railroad Bridge is operational year around 7 days a week, 24 hours a day. The bridges is maintained at a height of 65 feet above the water.  If a vessel needs more clearance a request must be made to the Bridge Tender on duty.

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.

Vessel Traffic:
The Bridge is maintained at a height of 65 Feet above the water and is considered passable by most vessel traffic. The bridge can be raised to a height of 135 feet to accommodate larger vessels.  There are hand full of openings a year where the bridge is raised to it full height.

Vehicle Traffic
The bridge receives approximately 60 train crossing per month.  No vehicles or pedestrian's are allowed on the bridge.

Maintenance:

The Alameda County Department of Public Works provides preventive maintenance to the bridge.

Facts:

  • Vertical Clearance Down Position MHHW (High Tide) 13 Feet
  • Vertical Clearance Up Position MHHW (High Tide) 135 Feet
  • Tower Height 185 Feet
  • Clearance Between Fenders 200 Feet
  • Maximum Load Limit N/A
  • Bridge Width 25 Feet 6 inches
  • Span Length 200 Feet

Information:
The Fruitvale Ave Railroad Bridge opened for service in June 1951.  The Bridge cost $946,757.00 to build.  The prime contractors were Ben C. Gerwick, Southern Pacific, Judson-Pacific, Murphy Construction, and Independent Construction Company.  The bridge is a vertical lift design so it has two support towers for the counterweights, machinery rooms, and span.  The towers are 185 Feet tall with the machinery rooms at the top.

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.

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