How Tall Is a 136 lb Rail? Height, Dimensions and Comparisons
Apr 09, 2026
How Tall Is a 136 lb Rail?
The standard height of a 136 lb rail (the 136RE profile) is 7 5/16 inches, which is approximately 185.74 mm. In the railway industry this height is measured from the very bottom of the base to the top of the rail head. Because the 136 lb rail is designed for heavy-duty freight and high-stress mainlines, it is significantly taller and more rigid than lighter rail sections.
Key Dimensions of the 136RE Rail
| Dimension | Imperial | Metric |
|---|---|---|
| Height | 7 5/16 in | 185.74 mm |
| Base width | 6 in | 152.40 mm |
| Head width | 2 15/16 in | 74.61 mm |
| Web thickness | 11/16 in | 17.46 mm |
| Section mass | 136 lb/yd | 67.5 kg/m |
| Reference standard | AREMA | |
Height Comparison Across AREMA Sections
Rail height is critical for the moment of inertia, which dictates how much the rail deflects under heavy axle loads. A taller section offers much higher longitudinal stiffness.
| Rail section | Height (inches) | Height (metric) |
|---|---|---|
| 115 RE | 6 5/8 | 168.28 mm |
| 132 RE | 7 1/8 | 180.98 mm |
| 136 RE | 7 5/16 | 185.74 mm |
| 141 RE | 7 7/16 | 188.91 mm |
For comparison, a UIC60 rail is about 172 mm tall, so the 136RE is visibly taller and provides higher structural strength under load.
Why Rail Height Matters
Rail height is not just a dimension; it directly affects performance and safety. The optimised 136RE height contributes to:
Improved bending resistance under heavy axle loads.
Better load distribution across sleepers and ballast.
Enhanced track stability in high-speed or heavy-haul systems.
Reduced risk of rail deformation over time.
FAQ
What is the exact height of a 136 lb rail?
The standard 136RE rail height is 185.7 mm (7 5/16 inches), defined by AREMA standards. It is a key part of the 136RE rail dimensions and affects track design and performance.
Does rail height affect load capacity?
Yes. A taller rail such as the 136 lb section provides better resistance to bending and deformation, which makes it suitable for heavy-haul and high-traffic railway systems.
Is the 136RE rail taller than the UIC60 rail?
Yes. The 136RE is about 185.7 mm tall, while the UIC60 rail is about 172 mm. The height difference gives the 136RE better structural strength.
Why is the 136RE profile designed with this height?
The profile is optimised to balance strength, stability and durability. The height improves bending resistance and load distribution, ensuring long-term performance under heavy loads.
How is rail height measured?
Height is measured vertically from the bottom of the base (the foot) to the highest point of the rail head, on a rail laid on a flat reference surface.
