Vertical lift bridge
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| Vertical lift bridge | |
|---|---|
| Image:MovableBridge lift.gif | |
| Ancestor | Truss bridge, |
| Related | Bascule bridge, swing bridge, folding bridge, retractable bridge |
| Descendant | Submersible bridge, table bridge |
| Carries | Automobile, pedestrians, truck, light rail, heavy rail |
| Span range | Short |
| Material | Steel |
| Movable | Yes |
| Design effort | medium |
| Falsework required | Depends upon degree of prefabrication |
A vertical lift bridge or lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck.
The vertical lift offers several benefits over other movable bridges such as the bascule and swing span bridge. Generally speaking they cost less to build for longer moveable spans <ref>Troyano, Leonardo Fernandez: "Bridge Engineering: A Global Perspective", Thomas Telford Publishing, 2003, p. 731</ref>. The counterweights in a vertical lift are only required to be equal to the weight of the deck, whereas bascule bridge counterweights must weigh several times more than the span being lifted. As a result, heavier materials can be used in the deck and so this type of bridge is especially suited for heavy railroad use.
Although most vertical lift bridges use towers each with counterweights, some use hydraulic jacks located below the deck. An example is the 16m span bridge at St Paul avenue in Milwaukee <ref>op. cit., p. 729</ref> (see also table bridges). Another design used balance beams to lift the deck, with pivoting bascules located on the top of the lift towers <ref>op. cit., p. 732</ref>. An example of this kind was built at La Salle in Illinois, USA.
The biggest disadvantage to the vertical lift bridge is the height restriction that results from the deck being above the passageway.
A lift bridge over the Erie Canal at Lockport... |
...elevates at both ends... |
...and nears its upward position. Pedestrians may cross when it is up using stairways. |
Contents |
[edit] Examples
[edit] Canada
- Bridges 5 (Glendale Avenue Bridge), 11 (Allanburg Bridge) and 21 (Clarence Street Bridge) on the Welland Canal, all built during the late 1920s as part of the Fourth Canal expansion project (1913-1932). In addition, there are also Bridges 13 (Main Street Bridge), 17 (Dain City Railway Bridge) and 18 (Forks Road Bridge) on the Welland Recreational Waterway (a former channel of the Welland Canal). However, these bridges have not been operational since 1973. Bridges 13 and 18 have had their counterweights removed while the machinery for Bridge 17 has been dismantled. In addition, Bridge 18 no longer possesses its towers; they were removed for ease of maintenance.
- Pretoria Bridge over the Rideau Canal in Ottawa, Ontario
- Selkirk Lift Bridge over the Red River in Selkirk, Manitoba
[edit] United States
[[Image:Tower Bridge Sacramento edit.jpg|250px|thumb|right| Tower Bridge in Sacramento, California
- Aerial Lift Bridge - an automobile bridge in Duluth, Minnesota which began life as an aerial transfer or ferry bridge.
- Arthur Kill Vertical Lift Bridge - at 170m span, the largest in the world.
- ASB Bridge - A bridge that handled both trains and cars on two decks over the Missouri River in Kansas City, Missouri.
- Burlington-Bristol Bridge - A two-lane bridge over the Delaware River that joins Bristol, Pennsylvania with Burlington, New Jersey between Philadelphia and New York City.
- Chesapeake and Delaware Canal Lift Bridge - a single-track railroad bridge over the Cheapeake and Delaware Canal in Delaware that was built in 1966 for the Pennsylvania Railroad and replaced an earlier structure when the U.S. Army Corps of Engineers widened the canal in the mid-1960's. It is the only bridge of its type along the canal, with earlier highway lift or swing bridges being replaced by high-level crossings.
- Hastings Rail Bridge - A single track railroad bridge at Hastings, Minnesota over the Mississippi River
- Main Street Bridge - A four-lane bridge over the St. Johns River in downtown Jacksonville, Florida.
- Marine Parkway-Gil Hodges Memorial Bridge - designed in 1937 by David Steinman.
- Park Avenue Bridge - 160m span in New York City, replaced a swing bridge in 1960.
- Portage Lake Lift Bridge - A bridge which connects the Michigan cities of Hancock and Houghton
- Stillwater Bridge - A highway bridge that joins Stillwater, Minnesota with Houlton, Wisconsin over the St. Croix River.
- St. Paul Union Pacific Vertical-lift Rail Bridge - A single-track railroad bridge in downtown St. Paul, Minnesota over the Mississippi River.
- Tower Bridge - A four-lane bridge over the Sacramento River connecting Sacramento, California and West Sacramento, California.
- Sarah Mildred Long Bridge and Memorial Bridge - Two lift bridges (out of 3 bridges) over the Piscataqua River between Portsmouth, New Hampshire and Kittery, Maine.
[edit] France
- Pont de recouvrance - Over the Penfeld in Brest giving access to the military arsenal.
[edit] United Kingdom
- Kingsferry Bridge - built in Kent in 1960.
- Turnbridge Locomotive Lift Bridge - highly unusual bridge at Turnbridge in Huddersfield.
- Salford Quays lift bridge - carries pedestrians across the Manchester Ship Canal.
- Tees Newport Bridge - 82m span, first major lift bridge in the UK.
[edit] See also
- Movable bridge for a list of other movable bridge types
- Table bridge for a vertical lift bridge without visible lifting means
- Submersible bridge for a similar disappearing bridge
[edit] References
<references/>de:Hubbrücke fr:Pont levant lb:Hiefbréck nl:Hefbrug pl:Most podnoszony
