The Tower Bridge replaced the 1911 M Street Bridge in Sacramento, which was originally a swing through-truss railroad bridge.
Initially designed with a 52 ft (16 m) wide roadway with sidewalks, with single lanes for cars flanking a large 13-foot (4.0 m) center lane for trains.[4] The towers are 160 ft (49 m). From east to west, the bridge consists of a 30 ft (9.1 m) long girder span, a 167 ft (51 m) long eastern truss approach span, the 209 ft (64 m) long central lift span, a 193 ft (59 m) long western approach span and four 34 ft (10 m) long girder spans. With the draw up, there is 100 feet (30 m) of vertical clearance above high water with a 172-foot (52 m) wide navigation channel between the timber pier fenders. Although the lift span weighs 1,150 short tons (1,040 t), the use of an equal amount of counterweights (located in each tower) means the span is operated with two relatively small 100-horsepower (75 kW) electric motors.[4]
Comments