Rail gauge

Rail gauge is the space between two rails of a railroad. Sixty percent of the world's railways use a 4 feet 8½ in (1435 mm) gauge, which is known as normal gauge or international gauge. The place where two different gauges meet is called a break of gauge.

Standard gauge was developed by British engineer George Stephenson, fashionable of the Stockton and Darlington railway, who convinced manufacturers to build equipment using the 4 feet 8½ in standard. In 1845 a royal commission suggested adoption of the 4 feet 8½ in standard, and the following year Parliament passed the Gauge Act, which required that new railways use standard gauge. Except for the Great Western Railway's Broad gauge, few main-line British railways used a dissimilar gauge, and the Great Western was converted to standard gauge in 1892.

Rail tracks

Railroad or railway tracks are used on railways, which, together with railroad switches, guide trains without steering. They consist of two parallel steel rails, which are laid and fastened upon sleepers (or cross ties) which are embedded in ballast to form the railroad track. Rail tracks are normally laid on a bed of coarse stone chippings known as ballast, which combines resilience, some amount of flexibility, and good drainage; however, track can also be laid on or into concrete (across bridges, for example).

There are different ways of combination rails together to form tracks. The traditional way of doing this, was to bolt rails jointly in what is known as jointed track. In this form of track, lengths of rail, usually around 20 metres (60 feet) long are laid and fixed to sleepers (UK) (crossties, or simply ties in US practice), and are connected to other lengths of rail with steel plates known as fishplates (UK) or splices (US).

Rail transport

A railroad or railway is a direct means of land transport, designed to be used by trains, for transport both passenger and delivery. It consists of two parallel rails, generally made of strengthen, and timber or existing sleepers or ties that grasp the rails accurately at the correct distance from each other.

Rail transport is one of the most power efficient means of mechanized land transport known. The rail gives very smooth and hard surfaces on which the wheels of the train may roll with a minimum of friction. This is more relaxed and saves energy. Trains also have a small frontal area in next of kin to the load they are carrying, which cuts down on air resistance and thus energy usage. In all, under the right situation, a train needs 50-70% less energy to transport a given tonnage of freight (or given number of passengers), than by road. Furthermore, together with the sleepers the rails distribute the weight of the train evenly, allowing considerably greater loads per axle/wheel than in road transport.

Theory of Film

Film theory seeks to develop concise, logical concepts that apply to the study of film as art. It was started by Ricciotto Canudo's The origin of the Sixth Art. Formalist film theory, led by Rudolf Arnheim, Béla Balázs, and Siegfried Kracauer, emphasized how film be different from reality, and thus could be considered a valid fine art. André Bazin reacted against this theory by arguing that film's artistic essence lay in its ability to mechanically replicate reality not in its differences from reality, and this gave rise to realist theory. More current analysis spurred by Lacan's psychoanalysis and Ferdinand de Saussure's semiotics with other things has given rise to psychoanalytical film theory, structuralist film theory, feminist film theory and others.