energia: Rapid transit

Evidence: 100 • authority: 72

Rapid transit, mass rapid transit (MRT) or rail rapid transit (RRT) and commonly referred to as metro, is a type of high-capacity public transport that is generally built in urban areas. A grade separated rapid transit line below ground surface through a tunnel can be regionally called a subway, tube, metro or underground. They are sometimes grade-separated on elevated railways, in which case some are referred to as elevated, el or L trains – short for "elevated" – or skytrains. A common alternative term for rapid transit in North America is heavy rail. Rapid transit systems are usually electric railways that, unlike buses or trams, operate on an exclusive right-of-way, which cannot be acce…

Evidence: 49 • authority: 80

Research of a Problem of Terrorist Attacks in the Metro (Subway, U-Bahn, Underground, MRT, Rapid Transit, Metrorail)

Evidence: 49 • authority: 72

An underground city is a series of linked subterranean spaces that may provide a defensive refuge; a place for living, working or shopping; a transit system; mausolea; wine or storage cellars; cisterns or drainage channels; or several of these. Underground cities may be currently active modern creations or they may be historic including ancient sites, some of which may be entirely or partially open to the public. The term may also refer to a network of tunnels that connects buildings beneath street level that may house office blocks, shopping centres, metro stations, theatres, and other attractions. These passages can usually be accessed through the public space of any of the buildings conn…

Evidence: 49 • authority: 72

This list of metro systems includes electrified rapid transit train systems worldwide. In some parts of the world, metro systems are referred to as subways, undergrounds, tubes, mass rapid transit (MRT), métro or U-Bahn. As of 16 May 2026, 214 cities in 63 countries operate 965 metro lines. The London Underground first opened as an underground railway in 1863 and its first electrified underground line, the City and South London Railway, opened in 1890, making it the world's oldest metro system. As of 2024, the country with the most metro systems is China, with 54 in operation, including 11 of the 12 longest networks in the world and the 4 systems with the highest annual ridership numbers.

Evidence: 43 • authority: 80

A communication system custom designed for the Montreal metro rapid transit subway

Evidence: 43 • authority: 80

The Rapid Transit Subway Tunnel under the Harlem River

Evidence: 43 • authority: 80

Harlem River Tunnel of the Rapid Transit Subway

Evidence: 43 • authority: 92

Theoretical, Numerical, and Experimental Study on the Identification of Subway Tunnel Structural Damage Based on the Moving Train Dynamic Response.. As an important part of urban rail transit, subway tunnels play an important role in alleviating traffic pressure in mega-cities. Identifying and locating damage to the tunnel structure as early as possible has important practical significance for maintaining the long-term safe operation of subway tunnels. Summarizing the current status and shortcomings of the structural health monitoring of subway tunnels, a very economical and effective monitoring program is proposed, which is to use the train vibration response to identify and locate the dam…

Evidence: 43 • authority: 92

Rapid mobile inspection equipment for metro tunnels based on multi-sensor integration.. The acquisition of tunnel inspection data is fundamental to tunnel operation and maintenance. Existing inspection equipment is either based on laser scanning or CCD cameras. Laser scanning-based devices often struggle to detect cracks, while equipment based on CCD cameras is unable to acquire point cloud to assess tunnel deformations. In order to obtain high-quality, comprehensive data, this paper develops a mobile three-dimensional inspection device CKY-200, integrated with multiple sensors. The CKY-200 addresses the temporal and spatial synchronization issues of CCD cameras and laser scanners. Consider…

Evidence: 37 • authority: 92

Risk assessment of existing buildings in tunnel construction based on an improved cumulative prospect theory method.. As urbanization in China continues to rise, an increasing number of cities are constructing subway tunnels. However, due to the complexity and ambiguity of subway tunnel construction, there is a lack of precise methods to assess the impact of these constructions on surrounding buildings. Consequently, this study analyzes and summarizes past experiences and proposes the IVTSFS-CPT-EDAS model based on the CPT-EDAS evaluation method. This model establishes a risk assessment approach specifically for the impact of subway tunnel construction on existing buildings. The model's pro…

Evidence: 37 • authority: 72

Light rail (or light rail transit, abbreviated to LRT) is a form of passenger urban rail transit that uses rolling stock derived from tram technology, while having the capability to operate rolling stock on exclusive right of ways, on grade-separated section as well as in mixed traffic conditions. This capability gives LRT a greater flexibility than other transit modes. "Light" refers to the lighter passengers capacity of a line compared to rapid transit. The term was coined in 1972 in the United States as an English equivalent for the German word Stadtbahn, meaning "city railroad". Different definitions exist in some countries, but in the United States, light rail operates primarily along…

Evidence: — • authority: 92

Reconstruction-Driven Induction Thermography for AI-Assisted Surface Defect Detection in Welded Structures.. Welding is widely used to join steel components in energy storage systems, wind power generation systems, and transportation infrastructure. During service, surface defects in steel welds can promote rapid crack propagation and sudden fracture. To address this issue, this study presents an induction thermography framework for post-weld quality inspection of surface-breaking defects in welded steel structures. First, a yoke excitation structure was optimized and evaluated through numerical simulation and experimental validation, and its performance was compared with those of a straigh…