What Are the Different Types of Rails in a Railway System?
Jan 15, 2026
A steel rail is a rolled steel profile installed in pairs to form the guiding and load-bearing surface for railway wheels. Its job is to guide the train wheels forward, withstand the enormous stress of a passing train, and transfer that load to the sleepers and track bed while providing a smooth, continuous rolling surface with the least possible resistance. Depending on axle load, speed, environment and application, rails are produced in different weights, cross-sections and steel grades under standards such as EN 13674-1, UIC 860, AREMA, JIS, DIN 536 and GB/T 2585.
Main Rail Classes by Weight and Application
| Rail type | Typical weight range | Main applications |
| Light rail | Up to about 30 kg/m | Tramways, mining tracks, industrial internal railways |
| Heavy rail | 38 to 75 kg/m | Mainline railways, metros, freight corridors |
| Crane rail | 40 to 120 kg/m (special profiles) | Port cranes, gantry cranes, steel mills |
Light rail focuses on flexibility and cost control, heavy rail prioritises fatigue resistance and high axle loads, and crane rails are designed for concentrated vertical and lateral wheel loads at low speed.
Light Rail: Standards and Typical Sizes
Light rails have smaller cross-sections and lower weight per metre, and are used in urban light rail transit, tram systems, mines, ports and factory logistics tracks.
| Standard | Rail size | Weight (kg/m) | Typical use |
| GB 11264 | 8, 12, 15, 18, 22, 24, 30 kg | 8 to 30 | Mining railways, factory tracks |
| JIS E 1103 | JIS 15, 22, 30 kg | 15 to 30 | Industrial and urban light rail |
| AREMA (ASCE) | ASCE60, ASCE75 | about 30 to 37 | Port and yard tracks |
| EN (grooved rail) | 59R1, 60R2 | about 59 to 60 | Embedded street tram systems |
Light rail steel grades are usually Q235B, 55Q or medium-carbon rail steel, balancing strength with easy cutting, drilling and bending. These rails are frequently supplied with drilled ends, curved bending and anti-corrosion treatment for overseas tram and mining projects.
Heavy Rail: Grades and Selection
Heavy rails are specified by standard, section and grade. Typical combinations include EN 13674-1 60E1 in R260 or R350HT, UIC 860 UIC54 or UIC60 in 900A, GB/T 2585 50 or 60 kg/m in U71Mn or U75V, TB/T 2344 premium grades such as U77MnCr and U78CrV, and AREMA 115RE or 136RE in SS, HH, LA or IH. The grade selection ladder is simple: standard grades for medium traffic, head-hardened or microalloyed grades for curves, heavy haul and high-speed lines. Selecting the wrong grade leads to rapid wear, head deformation or premature cracking.
Mechanical Properties of Common Light Rail Steels
For light rails, two steels dominate: Q235B and 55Q. Q235B per GB/T 700 has a minimum yield strength of 235 MPa, a tensile range of 370 to 500 MPa, elongation of at least 26 percent, and composition with carbon 0.12 to 0.20 percent, silicon up to 0.35 percent and manganese 0.30 to 0.70 percent, with sulfur and phosphorus capped at 0.045 percent. 55Q is a medium-carbon rail steel used for 15 kg/m and heavier light rails, with higher strength and hardness than Q235B to resist wear on busier industrial lines.
Frequently Asked Questions
Q: How are rails classified in a railway system?
By weight per metre and application: light rail up to about 30 kg/m, heavy rail from 38 kg/m upward, and crane rail as special heavy sections. Speed, axle load and traffic volume then decide the grade within the class.
Q: What is the difference between Q235B and 55Q rail steel?
Q235B is a low-carbon structural steel, easy to machine, with a yield strength of 235 MPa, used for the lightest rails. 55Q is a medium-carbon rail steel with higher strength and hardness, used for 15 to 30 kg/m rails on busier industrial and mining tracks.
Q: Which rail is used for high-speed railways?
High-speed lines use heavy rails, typically 60 kg/m class sections in premium grades such as U75V, U78CrV or R350HT, with very tight dimensional tolerances and full-length ultrasonic testing.
Q: Why are crane rails heavier than train rails?
Crane wheels run slowly but carry very concentrated loads with frequent starts and stops, plus lateral thrust. The heavy square section and thick web resist indentation and bending that a normal rail profile could not survive.
Q: Can light rail be used on a mainline?
No. Mainline axle loads and speeds produce stresses that a light section cannot carry, causing rapid wear, deformation and a safety risk. The section weight must match the traffic case.
Q: What does the weight in kg/m actually mean for a rail?
It is the nominal mass per metre of the rolled section, and it correlates with the section height, web thickness and foot width. Heavier sections have more bending stiffness and more steel available for wear, so they carry heavier traffic longer.
