AREMA 136RE is one of the most widely specified heavy rail sections in North America. The designation 136RE means that the rail weighs 136 lb/yd, approximately 67.5 kg/m, and its profile is defined in Chapter 4 of the AREMA Manual for Railway Engineering. On international projects the same section is frequently sold as TR68.
What Is AREMA 136RE Rail?
AREMA 136RE is a flat-bottom tee-section rail with a head width of 74.61 mm, a base width of 152.4 mm and a total height of 171.45 mm. The heavy web and full rail head give the section high bending stiffness and good resistance to head wear, shelling and fatigue, which is why it is the standard choice for mainline freight, heavy-haul corridors and high-density commuter lines.
Standard Lengths of 136RE Rail
39 ft or 11.89 m is the traditional standard length. It was chosen because a 39 ft rail fitted inside a standard 40 ft gondola car with enough room for protective end packing. Today 39 ft sections remain common for turnouts, switch points, plug rails and emergency repair work.
80 ft or 24.38 m is the preferred length for new track construction. Longer sections reduce the total number of mechanical joints, which lowers long-term maintenance costs and improves ride quality and track geometry retention.
Custom lengths are available for bridge decks, special crossings and tight-radius curves. For mainline projects, 136RE sections are frequently flash-butt welded into continuous welded rail strings that can exceed 1,600 ft, eliminating joints almost completely.
136RE Rail Dimensional Specifications
| Parameter | Value |
|---|---|
| Section designation | 136RE (TR68) |
| Governing standard | AREMA Manual for Railway Engineering, Chapter 4 |
| Nominal weight | 136 lb/yd, approx. 67.5 kg/m |
| Total height | 171.45 mm |
| Base width | 152.4 mm |
| Head width | 74.61 mm |
| Web thickness | 17.46 mm |
| Standard lengths | 39 ft, 80 ft, or metric 12 m and 25 m on request |
All dimensions follow AREMA Chapter 4 and are verified after rolling by full-length ultrasonic inspection, straightening and end squaring so that each section is ready for welding or jointing.
Why Length Affects Track Performance
Every mechanical joint is a soft spot in the track. As wheels cross a joint gap, impact loads accelerate wear on the rail ends, sleepers and ballast. Longer rail sections therefore give three measurable benefits: fewer joints, lower dynamic impact and reduced maintenance. In continuous welded rail, the rail is restrained so that internal thermal stress is managed instead of being released through joint gaps, which is why CWR track requires high-quality ballast and elastic fastening systems capable of holding the rail in place in both summer heat and winter cold.
Ordering and Quality Verification
For projects outside North America, 136RE rail can be produced in metric lengths of 12 m or 25 m while keeping the AREMA profile unchanged. Each order should be supplied with a Mill Test Certificate listing heat number, chemical composition and mechanical test results, and sections should be inspected for straightness, surface defects and end condition before shipment so that field welding or jointing proceeds without rework.
FAQ
Q: Can 136RE rail be ordered in metric lengths? A: Yes. AREMA 136RE is frequently produced in 12 m or 25 m metric lengths for international projects, where it is usually called TR68. The profile dimensions remain identical.
Q: What is the maximum length available? A: Standard production lengths are 39 ft and 80 ft. Longer continuous strings can be supplied by flash-butt welding the sections for continuous welded rail projects.
Q: Why is 39 ft the traditional length for 136 lb rail? A: Historically, 39 ft was the longest rail that could fit inside a standard 40 ft freight car with room for protective packaging and end clearance.
Q: Does using longer rails improve track stability? A: Yes. Longer rails reduce the number of joints, which are the main sources of track geometry deterioration, so the track stays in alignment longer and the rail profile is protected from localized impact damage.
Q: What are short rails? A: Shorts are sections slightly shorter than the nominal length, usually resulting from end cropping during manufacture. They are often used in yards, sidings and repair areas where the full standard length is not required.
