What Are the Specifications of 115RE Rail and Tie Plates?

What Are the Specifications of 115RE Rail and Tie Plates?

Modern railway infrastructure relies on standardized components to ensure safe, stable, and predictable track performance under varied load conditions. Among these components, the 115RE rail and its corresponding tie plate represent widely adopted standards in North American freight and transit systems.

This article provides a technical overview of these components, their specifications per AREMA, and their roles in track integrity.

Technical Specifications of the 115RE Rail

The 115RE rail section is specified by AREMA. It is typically utilized in medium-to-heavy freight lines, regional railroads, and high-density passenger transit systems. The designation "115" refers to its nominal weight of 115 pounds per yard (approximately 56.9 kg/m).

The dimensional accuracy of the rail profile is critical to ensuring compatible fitment with wheel flanges and fastening systems. The key standard dimensions of the 115RE rail profile include:

The Role of the 115RE Rail Tie Plate

The 115RE rail tie plate (also known as a sole plate or base plate) is an essential interface between the rail base and the underlying tie (sleeper). Tie plates are primarily designed to perform the following structural functions:

• Load Distribution: They distribute the concentrated wheel loads from the rail foot over a larger surface area on the tie, reducing localized timber crushing or concrete degradation.

• Gauge Maintenance: By seating the rail within a defined recess (the rail seat), tie plates prevent lateral movement of the rail, maintaining a consistent track gauge.

• Rail Cant (Inclination): Most 115RE tie plates are manufactured with a built-in cant (typically 1:40), which tilts the rail slightly inward. This aligns the rail head profile with the coned tread of standard train wheels, reducing wear and improving steering.

Design and Punching Patterns of the 115RE Tie Plate

Because the base width of a 115RE rail is standardized at 5-1/2 inches, the tie plate must feature a matching rail seat width. These plates are typically manufactured from hot-rolled carbon steel in accordance with ASTM or AREMA specifications to provide sufficient tensile and yield strength.

Tie plates are punched with square or rectangular holes to accommodate spikes (cut spikes or screw spikes). The specific hole configuration depends on the track class, curvature, and expected axle loads:

• 4-Hole Punching: Common for straight tracks (tangent tracks) with lighter or moderate traffic densities.

• 6-Hole Punching: Frequently used on curved sections or higher-stress areas where additional anchoring is required to resist lateral forces.

• 8-Hole Punching: Typically reserved for heavy-haul lines, high-degree curves, or turnout transitions to maximize lateral stability and tie-bonding.

Installation and Compatibility Considerations

When selecting and installing 115RE rail tie plates, maintenance-of-way engineers consider several operational parameters:

• Fastener Selection: The choice between traditional cut spikes, spring clips (such as e-clips), or screw spikes depends on the tie material (wood, concrete, or composite) and the dynamic loads of the corridor.

• Tie Plate Length: Common lengths include 11-inch, 12-inch, and 14-inch designs. Longer plates distribute loads over a greater surface area, which is often preferable for soft timber ties or high-tonnage freight routes.

• Corrosion Mitigation: In coastal, industrial, or high-moisture environments, protective coatings or specific steel compositions may be utilized to extend the service life of both the plate and the underlying tie.

Frequently Asked Questions (FAQ)

• Can a 115RE tie plate be used with other rail sections?

The 115RE tie plate is specifically designed for rails with a 5-1/2 inch base width. Other rail sections sharing this exact base width, such as 119RE, may occasionally utilize similar plates, provided the rail seat depth, shoulder clearances, and overall load ratings align with engineering guidelines. It is generally not compatible with rails having wider or narrower bases, such as 136RE (6-inch base).

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  What material standards govern the production of 115RE tie plates?

These plates are commonly manufactured to meet AREMA Chapter 5 standards and ASTM A67 specifications for hot-rolled steel tie plates. These standards ensure appropriate chemical composition, mechanical properties, and dimensional tolerances.

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  Why is the 1:40 cant standard on most 115RE tie plates?

The 1:40 cant tilts the rail head slightly inward to match the conical shape of standard wheel treads. This profile match helps centralize the wheel contact patch, minimizes eccentric loading, and assists in the natural steering of wheelsets around curves.

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  How do worn tie plates affect track safety?

Excessive wear on the rail seat of a tie plate can lead to rail cant degradation, gauge widening, and uneven stress distribution on the ties. Routine inspections focus on identifying plate cutting (where the plate sinks unevenly into wooden ties) and cracks around the punched spike holes.