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Rail profiles describe the unique cross-sectional shapes of railway tracks, with examples including Barlow, Bullhead, and Vignoles. Modern tracks are standard rolled steel with a basic I-shape, and weight is identified in pounds per yard or kilograms per meter. The evolution of tracks has led to stronger and more durable designs, including the flanged T-beam and LR55 types. The basic I rail profile is still in use today, while the LR55 system is used for tram tracks embedded in road surfaces.
Rail profile is a term that describes different types of railway tracks according to their unique cross-sectional shapes. This method of description has been used to identify railway track types for centuries with early examples including Barlow, Bullhead and Vignoles railway profiles. Modern conventional railway track sections are generally standard rolled steel members with a basic I-shape consisting of a head section and a band and foot section. Most rail profiles also have weight identifiers expressed as pounds per yard (lb/yd) or kilograms per meter (kg/m).
The humble section of railway track has followed a rather winding evolutionary path since the carriages of the first horse-drawn wagons crept leisurely along wooden rails. Power has since given way to steam power and today’s modern high-speed diesel and electric trains. Railroad track sections have grown in strength and durability from the early wood and cast iron rails to today’s flanged T-beam and LR55 types. Although the “fish belly” tracks of the early 1800s are a far cry from modern rails, the railroad profile identification system of that time is still in use today, albeit with fewer common profiles.
The profile of a track section is the shape of the rail when viewed in cross section. In the early days of rail transportation, a number of different track profiles were used as technology advanced and trains became heavier and faster. Common examples of the time included Rail Rail, Barlow Rail, Bullhead and Vignoles profiles. Each followed a basic I design pattern with the main differences being the size ratios between the three main parts of the track sections. These parts are the head, the cloth and the foot of the rail profile. The head is the widest upper part of the I on which the train wheels rest, the net is the thinnest vertical support and the foot is the wide lower part of the I that is attached to the braces or sleepers.
The basic I rail profile is still in use today and is commonly known as a flanged T profile. This rail shape features a foot that is considerably wider than the head, and a fairly high riser section. These track sections are also produced in different sizes grouped by weight by length. These are identified by kilograms per meter or pounds per yard with common examples being 30 kg/m (60.5lbs/yd) and 60 kg/m (121lbs/yd) for railway tracks and 5.95 kg/m (12lbs/yd) for crane rails
Another modern rail profile design is the LR55 system. This rail profile is used where tram tracks are embedded in road surfaces. The LR55 system consists of a V-shaped flanged track that sits on a cushion of polyurethane mastic in a concrete channel flush with the road. This allows for minimal noise transfer to the tram and prevents electrical leakage from motorized tracks.
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