Read the text, try to guess the meaning of the words you do not know, and then analyze how many meanings you can guess correctly or nearly correctly.

Throughout the world, millions of people travel each day with perfect confidence in transport reliability. Bridges and tunnels play an important role within the transport infrastructure network. Risks have increased in recent years with the ageing of Railway and Motorway ES. Most bridges and tunnels do not meet traffic demands, which have significantly changed since their initial opening.

All serious bridge and tunnel accidents must be given a lot of attention. Professional engineers must provide evaluations of bridge management practices on numerous motor and railways and identify structures with extremely poor structural conditions or structural deficiencies. They must thoroughly review the train accident data and adopt stringent safety assurance protocols to prevent deterioration or degradation of railway bridge conditions in order to reduce the risk of structural failures and casualties. A review of motor and train accident/incident reports revealed that most of them were caused by the structural failure of motorway and railway bridges, and that several small railways have no bridge inspection at all.

The main reasons causing the failures and collapses of Railway and Motorway ES can be divided into three groups: natural disasters (earthquakes, hurricanes, floods and avalanches); the shortcomings in engineering and technical calculations of the structures; negligence, ignorance and violation of construction and maintenance recommendations.

Earthquakes cause a number of Railway and Motorway ES failures and collapses. More than 100, 000 quakes occur each year, and no place on the Earth is safe from tectonic pressure. Sudden, abrupt and violent shifts in the Earth’s crust result in vertical and horizontal displacements, which bring the piers into an inclined position or crush them and throw off the spans. But it is worth noting that during the most reported quakes the Railway and Motorway ES have not been damaged as much as other civil engineering structures. An earthquake crushed about 85% of dwellings in Tokyo on September 1, 1923 but only 337 out of 1028 bridges went out of service. Moreover, the Great Tashkent Earthquake in 1966 did not raze any Railway and Motorway Engineering Structures.

The impact of ice is also dangerous for bridgeworks. In 1938-ice accumulation on the Niagara River cut the arch span abutment. The 256 m span collapsed under the weight of ice build-up which accumulated during 36 hours and reached more than 27 m at a distance of 120 m., and nothing was done to blast it away. The bridge had been in service for forty years and the piles of ice twice reached the threatening danger point during that period. One more reason for bridge collapse is the scour of pier foundations. In 1881-the current speed in the Russian River Uvod increased due to channel constriction. It produced a 5 m hollow in the soft riverbed, the pier foundations lost stability, and the bridge collapsed. The next challenge for bridges is their construction and maintenance in harsh freezing conditions. The superficial knowledge of metal and its structural element behaviour resulted in a bridge collapse in Belgium in 1938. When the air temperature dropped abruptly to subzero some of the metal arch elements broke without any additional loads. The high carbon content of steel causes this metal condition, known as cold brittleness.

Each railway should maintain an accurate inventory of their bridges. Railways need to conduct detailed comprehensive bridge inspections at least once per year, and competent engineers must determine the capacity of each bridge. Bridge inspection information should be accurately recorded in detail, and describe potential problems.

Tunnels also play an important role within the transport infrastructure network. Safety Standards guarantee a high level of safety for the users of tunnels. Nevertheless, most long-distance rock tunnels have encountered problems with extremely large water inflow, which can cause tunnel collapse. Owing to the enclosed space of a tunnel, accidents, particularly those involving fires and collisions, can have dramatic consequences leading to the disruption of the transport system and severe disturbances in the economy, of a whole region. Fires can have the most serious consequences that involve injuries, fatalities or extensive material damage. The main dangers are highly toxic accumulations of gas and smoke.

The tunnel fire accidents with the highest number of fatalities all occurred in tunnels with narrow profiles and with a single-track bore on a single-track line. During the period from 1940 to 2001, 26 serious rail and metro accidents in different tunnels have been identified. Among those serious accidents, is the fire in the Baku metro in 1995. There is reason to believe that the narrow cross-sectional area of this tunnel (28m²) contributed significantly to the severity of the accident because most of the people who died did not manage to get out of the train, or got out too late. A larger cross-sectional area may have allowed more time for evacuation before the concentration of heat and smoke became unbearable.

Railway convention throughout the world has always been that a train on fire, in a tunnel, must first be driven out of it. Therefore, it is very important to ensure that the train can be evacuated at the first confirmation of a fire, or to allow the safe escape of passengers, and the installation of fire suppression stations in each running tunnel. In the Euro tunnel fire, the train stopped next to an emergency exit but the concentration of smoke and fire gases, following the train, made it difficult to use the exit, until a bubble of fresh air was injected into the tunnel through the emergency exit. The passengers escaped into the parallel tunnel.

Security is the new watchword, in the world, which makes the transport system authorities more vigilant because dramatic terrorist attacks have caused a large number of fatalities. An explosion in the Moscow Metro killed four passengers and injured twelve others in 1996, and in 2004, a suicide bomb attack destroyed a metro train, during the morning rush hour, resulting in 40 fatalities and about 140 casualties. Therefore, the transport system must increase its preparedness, detect potential threats and take the correct immediate action. Public transport staff must be well trained to prevent dangerous situations and handle incidents once they have happened. Video-surveillance systems, allowing recording, should be installed to observe tunnels, turnout tracks at the endings of the lines etc. Video images have to be constantly analysed to detect abnormal situations. The alert systems, based on the video recording, should also work automatically.

The designers of R& M ES must plan them with the aim of reducing the opportunity for crimes to be committed. The design features should include the absence of dark corners. Emergency intercoms, call buttons and alarms must be clearly marked. Closed-circuit television cameras (CCTV) should be situated at the end of each platform. Much has to be done now because the security of railway and motorway engineering structures is Job Number One every day.

Exercises:

Find the words or phrases that mean natural disasters, causalities, safety and security actions. Using dictionaries, find more words and terminology and word combinations with the same meaning. Exchange them with your partner.