Definition: The 30 kg/m Dividing Line
The Chinese classification, consistent with common international practice, separates rails by nominal weight per metre. Heavy rails exceed 30 kg/m and are defined by GB/T 2585, covering profiles such as 38, 43, 50, 60 and 75 kg/m. Light rails are 30 kg/m or less and are defined by GB/T 11264, covering 8, 12, 15, 22 and 30 kg/m profiles. The classification matters because it decides the steel grade, the rolling route, the fastening system and the foundation design.
Cross-Section Comparison
| Dimension | GB 60kg/m heavy rail | 30kg/m light rail |
|---|---|---|
| Nominal weight | 60.64 kg/m | 30 kg/m |
| Rail height | 176 mm | About 108 mm |
| Head width | About 73 mm | About 57 mm |
| Web thickness | 16.5 mm | About 12 mm |
| Governing standard | GB/T 2585 | GB/T 11264 |
The heavy rail section has a wider, thicker head and a thicker web because it must spread a 25 t or higher axle load over a long fatigue life. The light rail section is intentionally slim: it suits vehicles with axle loads around 6 to 10 t and lower operating speeds.
Performance Requirements
Heavy rails must provide high strength, toughness and wear resistance under repeated heavy loading, and they are specified with controlled sulphur and phosphorus, plus optional head hardening for heavy-haul and high-speed lines. Light rails need moderate strength and wear resistance, but they prioritise running smoothness and flexibility for frequent starting, stopping and sharp curves in urban operation. The steel grades therefore differ: heavy rails use pearlitic rail steels such as U71Mn and U75V, while light rails use lower-alloy grades permitted by GB/T 11264.
Manufacturing Route
Heavy rails are rolled from continuous-cast blooms in dedicated rail mills with in-line straightening, ultrasonic inspection of the full length, and optional heat treatment; internal soundness and surface precision are controlled to railway acceptance levels. Light rails are produced with a simpler rolling schedule and lower inspection depth, which keeps their cost down but limits their fatigue performance under mainline loads.
Laying Methods and Track Foundation
Heavy rail track requires a concrete sleeper bed or a thick, well-compacted ballast bed, laid with mechanised tracklayers and aligned by tamping machines. Light rails are laid on integral concrete slabs, elastic beds or even surface-embedded channels in urban roads, with simpler labour-based installation and less disturbance to surrounding traffic. The fastening system also differs: heavy rails use elastic fastenings with rail pads and clips, while light rails often use simple base plates, dog spikes or direct fastenings.
Applicable Vehicles and Buying Guidance
Heavy rail: mainline passenger and freight, high-speed trains, heavy-haul coal and ore lines, large factory and mine rail systems with high axle loads.
Light rail: trams, light metro vehicles, industrial sidings, warehouses, mining galleries and temporary construction tracks.
When specifying, define the maximum axle load, design speed and annual tonnage first, then select the profile. A 30kg/m rail on a line carrying 25 t axle loads fails by web buckling and head wear within months; a 60kg/m rail on a yard track wastes capital and complicates the turnouts. For export projects, also confirm whether the counterpart profile is governed by EN 13674-1 (for example 60E1) or AREMA (for example 115RE), because the section drawings differ from GB profiles even at similar weights.
FAQ
How is a rail classified as heavy or light?
By nominal weight per metre: over 30 kg/m is heavy rail (GB/T 2585), 30 kg/m and below is light rail (GB/T 11264).
Can light rails be used on a mainline branch with low traffic?
Only if the axle load and speed stay within the profile capacity. For mixed freight and passenger service, a heavy rail profile of 43 or 50 kg/m is the safer minimum.
What does the weight per metre mean for cost?
Rail cost scales with steel tonnage and section complexity. A 60kg/m line uses about twice the steel of a 30kg/m line per track-metre, plus heavier fastenings and foundations, which is why light-duty projects should not over-specify.
Are GB heavy rail and EN 60E1 (UIC60) the same section?
No. 60E1 is 60.34 kg/m with a 172 mm height and a different head and base geometry. They are not interchangeable; each profile must be matched to its own fastening and fishplate set.
What documents should accompany a rail purchase?
Mill test certificate with chemical composition and mechanical properties, dimensional inspection report, straightness and twist records, and for heavy rails the ultrasonic test report. The certificate must reference the governing standard, such as GB/T 2585.