cantilever
横浜市は大型客船が横浜レインボーブリッジの下をくぐらないという難問に立ち向かっているようですが、NYCは同じ悩みをGoing up！で解決するようです。
Going Up! A Bridge Makes Way for Bigger Ships
When it opened in 1931, the Bayonne Bridge — with its parabolic arch connecting Staten Island and Bayonne, N.J. — was an engineering marvel, boasting the longest unsupported span of any steel arch bridge in the world. But the height of its roadway, at 151 feet above the Kill Van Kull waterway, is increasingly insufficient for the large container ships now calling at the container ports of Staten Island and New Jersey.
To ensure continued access for these ships, and for the even bigger ones likely to arrive after the opening of an expanded Panama Canal next year, the Port Authority of New York and New Jersey is undertaking a $1.3 billion project to raise the roadway of the bridge by 64 feet, to a height of 215 feet above the water. While the project itself is all but unprecedented in bridge engineering, the trickiest part lies in completing the construction while the bridge remains open to traffic.
How is it possible to increase the height of a bridge without closing it to cars and trucks? The answer lies in careful staging. First, the traffic will be shifted to the western side of the bridge’s roadway, with one lane going in each direction. The roadway and deck on the eastern side then can be removed, and the current concrete piers can be replaced with taller supports. A rolling gantry crane will lift and cantilever new segments of road into place to create a second and higher two-lane roadway.
With traffic diverted to this new roadway, by 2015, if things go according to plan, the old roadway and deck can be removed — allowing bigger ships to use the channel even before the new bridge is fully complete. Over the following two years, two additional 12-foot-wide lanes, as well as medians, shoulders and a shared-use path for pedestrians and cyclists, will be constructed.
cantilever 、この単語は知りませんでした。"to raise the roadway of the bridge by 64 feet"、 "careful staging"などと記事にあるようにこれは「片持ち梁(ばり)工法で持ち上げる」という意味ですが、横浜ではどうなのでしょうか。（UG）
