The Bay Farm Island Bicycle Bridge is the only drawbridge exclusively for bicycles and pedestrians in the United States. It is a single leaf bascule draw bridge which is located in the City of Alameda. It spans the inlet to the San Leandro Bay from the San Francisco Bay. A bascule bridge is a draw bridge that is counter-weighted so that it may be raised or lowered easily.
No powered vehicles are allowed on the Bicycle Bridge except powered wheelchairs. The speed limit for bicycles is 20 mph.
Construction on the Bay Farm Island Bicycle Bridge began in 1993 and was completed in 1995. It cost about 3.5 million dollars. It was built in coordination with the City of Alameda, State of California and the Federal Government. The Federal Government provided much of the funding but was not directly involved in the construction. The California Department of Transportation and the City of Alameda are currently responsible for maintenance of the bridge.
The Bicycle Bridge operates on the same schedule as the Bay Farm Island Bridge. The bridge shall open on signal; except that, from 5 a.m. to 8 a.m. and 5 p.m. to 9 p.m., the draw shall open on signal if at least 12 hours notice is given. Notice shall be given to the bridge-tender of the Bay Farm Island Bridge from 8 a.m. to 5 p.m. and to the bridge-tender of the Park Street Bridge at Alameda at all other times. The draw need not be opened for the passage of vessels from 9 p.m. to 5 a.m.
There are approximately 360 draw openings per year. Although draw bridges are required to open for vessel traffic even if that means that vehicular traffic must wait, there are some exceptions to this rule.
WORKINGS OF THE BRIDGE
The Bay Farm Island Bicycle Bridge was designed to operate in conjunction with the Highway Bridge, so whenever the Highway Bridge is operated the Bike Bridge also responds. While it's linked to the Highway Bridge, the Bicycle Bridge is a completely separate structure that can also be operated in manual mode allowing the Bridge to operate independently from the Highway Bridge. This mode is used mainly for testing and repair work.
The Bike Bridge differs from the other drawbridges in how it works. The other bridges use gearboxes and gears to operate. The Bike Bridge uses a electrical hydraulic system to move the span. Two huge side by side hydraulic pistons raise and lower the bridge. The hydraulic system is powered by two 50 hp motors. A 150 gallon tank and supplies the hydraulic oil used in the bridge operation.
The hydraulic system is controlled by a sophisticated electrical system of limit, pressure, and flow switches. There are no brakes on the Bike Bridge. The switches control the flow of oil and pressure which then control the speed of the bridge span. As a result, the Bike Bridge is smooth and quiet while operating.
A small walkway links Bay Farm Island's Bicycle and Highway bridges together. This gives the operators and maintenance crews access to the Bike Bridge machinery. The Highway Bridge contains the operating console for the Bike Bridge so the operator must run two bridges for each vessel opening.
- Vertical Clearance MLLW (Low Tide) 26'
- Vertical Clearance MHHW (High Tide) 20'
- Clearance Between Fenders Approximately 130 Feet
- Bridge Width 14 feet
- Bridge Length Approximately 750 feet
- Roadway Curb to Curb 11 feet
Note: All Vessels should use the Highway Bridge for clearance purposes. Even though your vessel may pass through the Bike Bridge it may not clear the Highway bridge