Movable bridge in the context of "Aerobridge"

A bridge is a structure that crosses an obstacle such as a river, lake, railroad, road, or ravine. Its primary function is to transport vehicles, trains, and pedestrians, but bridges may also accommodate pipelines, buildings, wildlife, and canals. Basic structures used in bridge design include arches, trusses, beams, cantilevers, suspension cables, and cable-stays. Bridges are configured in a variety of forms, such as viaducts, aqueducts, trestles, movable bridges, double-deckers, pontoons, and portable military bridges. They may also be categorized by their materials, which include wood, brick, stone, iron, steel, and concrete.

The history of bridges reflects the evolution of humankind's engineering technologies. The Romans and ancient Chinese built major bridges of stone and timber. During the Renaissance, advances in science and engineering led to wider bridge spans and more elegant designs. Concrete was perfected in the early 1800s, and proved to be superior to stone in many regards. With the Industrial Revolution came mass-produced steel, which enabled the creation of suspension and cable-stayed bridges that could span wide obstacles.

A submersible bridge is a type of movable bridge that lowers the bridge deck below the water level to permit waterborne traffic to use the waterway. This differs from a lift bridge or table bridge, which operate by raising the roadway. Two submersible bridges exist across the Corinth Canal in Greece, one at each end, in Isthmia and Corinth. They lower the centre span to 8 metres below water level when they give way to vessels crossing the channel.

The submersible bridge's primary advantage over the similar lift bridge is that there is no structure above the shipping channel and thus no height limitation on ship traffic. This is particularly important for sailing vessels. Additionally, the lack of an above-deck structure is considered aesthetically pleasing, a similarity shared with the Chicago-style bascule bridge and the table bridge. However, the presence of the submerged bridge structure limits the draft of vessels in the waterway.

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.

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 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 the deck remaining suspended above the passageway.

A jet bridge is an enclosed connector which most commonly extends from an airport terminal gate to an airplane, and in some instances from a port to a boat or ship, allowing passengers to board and disembark without heading outside and being exposed to harsh weather. Depending on building design, sill heights, fueling positions, and operational requirements, a jet bridge may be fixed or movable, swinging radially, or extending in length. The jetway was invented by Frank Der Yuen.

Similar devices are used for astronauts to enter spacecraft, which are installed at the appropriate height of the launch tower.