A vertical-lift bridge or just lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck.
16-750: The Second Narrows Rail Bridge is a vertical-lift railway bridge that crosses the Burrard Inlet and connects Vancouver with the North Shore . The bridge's south end connects directly to the Thornton Tunnel , which connects it to the main Canadian rail network . As the name suggests, it is located at the second narrowing of the Burrard Inlet. During the Klondike Gold Rush , there were schemes to build
32-481: A bridge by either deflecting an aberrant ship from striking the piers of a bridge, or sustaining and absorbing the impact. Protecting bridges against ship collisions got attention of architects and regulators in the last third of the 20th century due to a marked increase in the frequency of collision accidents: worldwide, 30 major bridges collapsed in the 1960-1998 timeframe after being rammed by ships or barges, 321 persons were killed. The rate of smaller accidents
48-623: A "significant" share of overall construction costs. Therefore, alternatives are typically considered during the design phase: Highway designs in the US are subject to the AASHTO specifications, but the text does not contain specific procedures and recommendations. Railway bridges are built according to the "Manual for Railway Engineering" published by the American Railway Engineering and Maintenance-of-Way Association (AREMA). In Australia ,
64-401: A number of ships and being out of service for four years, the provincial government bought the bridge in 1933 and installed a lift section of the deck . In 1960, a new much larger and higher 6-lane Second Narrows Bridge with a 350-metre (1,150 ft) span was completed alongside the original bridge, and the original bridge was converted exclusively for rail use. In 1994, the new road bridge
80-567: A railway from Vancouver to the Dawson gold fields. The first stage in this would be to bridge Burrard Inlet and then build a railway north. John Hendry floated the Vancouver, Westminster, and Yukon Railway which built a line from Ladner to New Westminster and then to Vancouver via Burnaby Lake . This line was paired with the Great Northern Railway who also wanted trackage into Vancouver. In
96-579: A train across Burrard Inlet , the lift section is always in the up position to allow ships to go underneath. The current bridge has a vertical clearance of 46 metres (151 ft) at the main lift span fully raised (open position). The vertical lift section of the Second Narrows Railway Bridge provides 137 metres (449 ft) clear navigation width between rubbing fenders . However, the Ironworkers Second Narrows road bridge has
112-401: A vertical clearance of 44 metres (144 ft) and the shipping channel where the maximum horizontal clearance available is 110 metres (360 ft) wide. Vertical-lift bridge The vertical lift offers several benefits over other movable bridges such as the bascule and swing-span bridges . Generally speaking, they cost less to build for longer moveable spans. The counterweights in
128-454: A vertical lift are only required to be equal to the weight of the deck, whereas bascule bridge counterweights must weigh several times as much as 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. The biggest disadvantage to the vertical-lift bridge (in comparison with many other designs) is the height restriction for vessels passing under it, due to
144-677: Is much higher: there were 811 serious accidents that did not cause a collapse just in the United States between 1970 and 1974, with 14 persons killed. Minor collisions are routine: the US Coast Guard gets 35 reports per day. In the US, the turning point was the collapse of the Sunshine Skyway Bridge in 1980. Since then, There are several types of bridge protection systems used: Physical bridge protection systems designed to prevent catastrophic collisions are expensive and represent
160-528: The bankruptcy of all the interested railways. With it went dreams of the bridge and rails up Indian Arm, the Capilano valley, or via Howe Sound. However, the predecessor railways did sign contracts to build a bridge and a new Hotel Vancouver . Only after the war with huge increase in funding to improve harbours around the British Empire , partly due to problems associated with wartime shipping, did funds appear for
176-460: The completion of the 1925 bridge. And so the north shore port became an amalgam of operations with Canadian National , Pacific Great Eastern and Harbour and Wharves Commission all using the bridge when it was not out of service. North Vancouver ferries operated at this time as well. The essential wartime shipyards in North Vancouver underscored the need for reliable industrial access. Further,
SECTION 10
#1732837894017192-513: The deck remaining suspended above the passageway. Most vertical-lift bridges use towers, each equipped with counterweights. An example of this kind was built in Portland, Oregon, United States in 1912. Another design uses balance beams to lift the deck, with pivoting bascules located on the top of the lift towers. See List of vertical-lift bridges . Bridge protection systems Bridge protection systems prevent ship collision damage to
208-458: The expansion of Lynnterm, Wheat elevators, coal and the sulphur port in the 1960s indicated the growing use of the North Shore. Northern Construction Co & J.W. Stewart Ltd built the first bridge to connect Vancouver with the North Shore over the tidal bore of the narrows. The attached vehicle deck opened to road traffic in 1925 and the main structure to trains a year later. After being hit by
224-665: The process, various other railroads all became involved in the bridging scheme: the Canadian Northern Railway , Milwaukee Road , and the Pacific Great Eastern Railway . The bridge itself would be owned by the Federal Government as they had control of harbours and shipping, and would lease access to the railways as they did with the rail bridge in New Westminster. One of the main reasons was that there
240-555: Was renamed the Ironworkers Memorial Second Narrows Crossing in honour of the ironworkers who died in accidents while building it. However, the new bridge is still commonly referred to as the Second Narrows Bridge. In 1968, the original 1926 railbridge was replaced by CN Rail with a larger, higher lift bridge . A bridgetender activates cables and counterweights to raise the span. Unless moving
256-547: Was very little space on the south shore for wharves, thus railways wanted to develop the North Shore as the south side was occupied by another railway, the Canadian Pacific . A company was floated, the Burrard Inlet Bridge and Tunnel Company, and contracts were issued to span the tidal bore. At one point, a causeway was planned to dam the narrows and create bridges and wharves that way. World War I intervened, as did
#16983