railway turnout frog

Railway turnout helps a train to move from one track line to another pre-determined line, which happens usually at the station or a large number of marshalling stations are laid. After the turnout’s invented and laid, even if railway is a single line, two trains could run from opposite directions through construction of an out-section line which is longer than train, railway line can fully function to its limitation. As turnout features to complicated structure for design, great quantities and short life for use, low safety for train passing and maintenance for high frequency, it has been the respectively weaker and more important part in entire train track line since train track is used.

Classification of  Railway Turnout

Railway Turnout's Structure

A single turnout usually consists of a frog, a switch, two switch points, two guard rails, straight and curved closure rails, stock rails and switch stand. In addition, relative rail accessories include switch rods, combination slide plates, braces, tie plate, block and the others which may be varied to meet specific track requirements also play the important roles.

According to function and usage, turnout is generally categoried into simple  turnout, equilateral turnout, three-way turnout, double crossover and double slip switches. Of them the most common turnout is simple turnout.

According to different weights of steel rails, turnouts may be divided into different types. In China there are various types of steel rail, which includes 43kg/m, 50 kg/m, 60 kg/m, 75 kg/m and etc. Meanwhile, correspondent turnouts are designated to meet these tracks. In North America, types of steel rail are 12AS, 20AS, 25AS, 30AS, 40AS, 60AS, 80AS, 85AS, 90RA, 100RA, 100RE, 115RE, 119RE, 132RE, 133RE, 136RE, 141RE and etc. So correspondent turnouts are needed to design and produce out for them.

According to Number, all the turnouts are numbered to stand for different usages. Big Number usually represents high speed track for passengers or heavy-duty track. Small Number usually represents special track of industrial and mining enterprises or freight stations. In China turnouts touch on No.6，No 7，No 8，No 9，No 12，No 18，No 30，No 38 and No 42. In North America, all the frogs of turnouts are numbered to stand for different usages. They include Frog No. 4, Frog No.5, Frog No.6, Frog No.7, Frog No.8, Frog No.9, Frog No.10, Frog No.11, Frog No.12 and etc.

According to different types of rail sleepers, turnouts may be divided into different types. They include wooden sleeper turnout, concrete sleeper turnout and monolithic concrete bed turnout.

Railway Turnout Frog

Railway turnout frog is an important key component and necessary to lay focus on explanation. Frog consists of two point rails, two wing rails, two guard rail (also named check rail), tie plate, blocks, other accessories and etc. According to different production technologies, Frog may be classified into different types. They may be rail bound welded frog (RBW), welded boltless manganese frog (WBM), welded spring manganese frog (WSM), rigid bolted frog, rail bound manganese steel frog (RBM), solid manganese flat top steel frog, solid self guarded manganese steel frog (SSGM), (partial) flange bearing frog, jump frog, moveable point frog (MPF).

During use of frog, many problems are gradually emerged, for example, rail abrasion, rail cracks. In order to solve them and lengthen life of frog, manganese steel is popularly used to be as raw materials for frog production with adopting advanced technology of explosive depth hardened manganese steel (EDH).