What Are the Standard Lengths of AREMA 136RE Rail?
The standard lengths of AREMA 136RE rail are primarily 39 feet and 80 feet in the North American market. While 39 feet was historically the dominant standard due to the internal dimensions of traditional 40-foot gondola cars, modern Class I railroad projects now overwhelmingly utilize 80-foot sections to reduce the number of joints. For large-scale infrastructure, these sections are often flash-butt welded into Continuous Welded Rail (CWR) strings that can exceed 1,600 feet in length.
- 39-Foot Standard: This length is commonly used for specialized track work, including turnouts, switch points, and "plug" rails for emergency repairs where maneuverability is key.
- 80-Foot Standard: Currently the preferred length for new track construction, as it minimizes the total number of mechanical joints, thereby reducing the long-term maintenance costs associated with 136RE rail infrastructure.
- Custom Lengths: Depending on specific engineering requirements, 136RE heavy rail can be precision-cut to custom lengths to fit bridge decks, specialized crossings, or tight-radius curves.
GNEE RAIL produces 136 RE steel rail in a variety of lengths to meet diverse project specifications, ensuring each section adheres to the strict dimensional tolerances of AREMA 136RE. Production processes involve precise straightening and end-squaring to ensure that whether the length is 39 feet or 80 feet, the 136re rail profile remains perfectly aligned for welding or jointing.
What Are the Dimensional Specifications of 136RE Heavy Rail?
The 136RE (also known as TR68) is an AREMA-standard heavy-duty rail weighing approximately 67.41 kg/m (136 lb/yd). Key specifications include a height of 185.74 mm, base width of 152.4 mm, head width of 74.61 mm, and a web thickness of 17.46 mm. These rails are widely used for high-axle load, heavy-haul, and mainline freight applications.
Key 136RE Rail Dimensional Specifications:
- Height: 185.74 mm (approx. 7.31 inches)
- Base Width: 152.4 mm (6 inches)
- Head Width: 74.61 mm (2.937 inches)
- Web Thickness: 17.46 mm (0.687 inches)
- Weight: 67.41 kg/m (136 lbs/yd)
- Standard Lengths: 12m to 25m (customizable)
| Profile | Standard | Dimensions mm | Section S | Mass m | ||||
|---|---|---|---|---|---|---|---|---|
| H | B | C | D | E | cm² | kg/m | ||
| American standard | ||||||||
| 136RE (TR68) | AREMA | 185,70 | 152,40 | 74,60 | 49,20 | 17,50 | 85,90 | 67,50 |
What Impact Does Length Have on the Performance of Steel Rails?
The length of a steel rail is a critical engineering decision that dictates how a track handles heavy loads, extreme weather, and long-term maintenance costs. Here is how rail length impacts performance across four key areas:
1. Structural Integrity and Smoothness
The primary performance impact of length is the number of joints (the gaps between rail sections).
- Short Rails (33ft, 39ft, 80ft): These require more joint bars and bolts. Every joint is a "soft spot" in the track. As wheels pass over these gaps, they cause impact loads that accelerate wear on the rail ends, the ballast, and the sleepers.
- Long Rails (Continuous Welded Rail - CWR): By welding rails into strings that can be several miles long, the "clickety-clack" is eliminated. This creates a much smoother ride, reduces vibration-induced damage to rolling stock, and significantly increases the lifespan of the rail.
2. Thermal Expansion and "Track Buckling"
Steel is highly sensitive to temperature. It expands in the heat and contracts in the cold.
- In Short/Jointed Rails: The gaps between 39ft sections act as "breathing room." When the steel expands, it fills the gap. This makes expansion management simple but limits the speed and weight the track can handle.
- In Long/CWR Rails: Because there are no gaps, the rail cannot expand longitudinally. Instead, it builds up massive internal thermal stress.
- In Heat: This can lead to sun kinks (the track buckling outward).
- In Cold: This can lead to pull-aparts (the rail snapping under tension).
- Performance Impact: Long rails require heavy-duty fastening systems (like E-clips or SKL clips) and high-quality ballast to "pin" the rail in place and counteract these forces.
Frequently Asked Questions
- Can 136RE rail be ordered in metric lengths?
Yes, while AREMA 136RE is a North American standard, it is often produced in metric lengths (such as 12 meters or 25 meters) for international projects where it is referred to as TR68. The 136re rail dimensions remain the same.
- What is the maximum length of 136RE rail GNEE RAIL can provide?
Standard production lengths are 39ft and 80ft, but through welding processes, strings of 136RE heavy rail can be provided in much longer lengths for specialized CWR projects.
- Why is 39 feet the traditional standard for 136 lb rail?
Historically, 39 feet was chosen because it was the longest length that could fit inside a standard 40-foot freight car with enough room for protective packaging and end-clearance.
- Does longer rail length improve the 136re rail profile stability?
Longer lengths reduce the number of joints, which are the primary locations for track geometry issues. By using 80-foot 136 RE steel rail, the track stays in alignment longer, protecting the 136re rail section from localized impact damage.
- Is 136RE rail available in "shorts"?
In the industry, "shorts" refers to rails slightly shorter than the $39\text{ft}$ standard (often due to end-cropping during manufacture). These are sometimes used in yards or sidings where the 136RE heavy rail strength is needed but exact standard lengths are not required.
GNEE RAIL provides 136RE rail manufactured strictly to AREMA 2024 specifications, ensuring that all lengths meet the theoretical weight and physical dimensions required for heavy-haul infrastructure. Through the use of controlled rolling technology and full-length ultrasonic inspection, material consistency is guaranteed across every batch. Comprehensive logistics support and Mill Test Certificates (MTC) are provided to ensure that every 136 RE steel rail order is delivered with verified technical data for project compliance.
