Neoloy® Tough-Cells Stabilize Railway Track Improving Track Quality and Reducing Maintenance
PRS Neoloy 3D mechanical stabilization technology maintains track geometry and reduces maintenance by 6.7x.
The Railway Construction Challenge
Track maintenance, necessary for safe and efficient railway operations, is highly sensitive to substructure support, poor subgrade and/or ballast conditions. Track geometry degrades rapidly in these situations requiring frequent and expensive surfacing and ballast cleaning, as well as downtime. The cost of maintaining track infrastructure over time determines the economic worthiness of railway engineering solutions and not the initial construction or rehabilitation cost.
The Neoloy Tough-Cells Track Reinforcement Solution
The 3D Neoloy Tough-Cells cellular confinement system technology stabilizes the substructure and structural support in railroad track. Neoloy Tough-Cells usually placed at the ballast, subballast and/or subgrade interface area have shown to decrease the rate of track surface geometry degradation (both surface and cross-level) under a range of traffic loadings. The ability of Neoloy Tough-Cells to reduce the rate of degradation, particularly in these high degradation rate locations, is of great value for both in the construction of new lines and in the maintenance of existing lines (Zarembski, 2011).
Why Use Neoloy Tough-Cells to Reinforce Railway Track
Long-term track monitoring shows that Neoloy stabilization decreases the rate of track surface geometry degradation under a range of traffic loading by 7x, particularly in soft, saturated and expansive clay subgrades. Additional studies of rail embankment models show 40-72% less vertical deformation and 50-67% less lateral displacement under heavy cycling loading. This reduces surfacing, ballast cleaning, and related maintenance activities. The benefits include better track quality, higher train speeds and loads, less downtime and more profitable operations.
The NPA (Novel Polymeric Alloy) composition gives Neoloy Tough-Cells the engineering properties required by ISO and ASTM for rigid geocells:
- Elastic Stiffness (Dynamic Modulus) – maintain stiffness under dynamic loading > 500 MPa @ 60°C.
- Permanent Deformation (Creep) – less than 3% at the end of design life
- Cell Tensile Strength – maintain geocell geometry under load, >19 kN/m
The Neoloy Tough-Cells are proven effective soil stabilization solution for railways in expansive clay soils, peat and sand in projects worldwide. Compared to conventional ground stabilization methods, Neoloy Tough–Cells require less construction time, are more cost-effective, and have a significantly smaller carbon footprint.
- Trackbed stabilization – Neoloy alters physical and mechanical properties.
- Ballast life extended – by reduced lateral displacement, vertical settlement and aggregate attrition.
- Neoloy strength – high stiffness, dimensional stability and low creep under loading preserve track geometry.
- Reduce layer thickness – reduce sub-ballast layer and use locally available soils for sub-ballast.
- More effective than geogrids – does not require high grade aggregate and has 3D zone of influence.
- Easy and fast deployment – all-weather, easy and fast installation minimizes downtime.
- Improved performance – reduce vibrations, track deflection, and smooth transitions between areas of differing subgrades.
- Improved rolling stock performance – up to 40% heavier loads and 30% faster speeds over the same track.
- Operating expenses – stabilized rails reduce vibration and rolling stock wear & tear
- Sustainable – use of marginal infill preserves quarry resources, lowers hauling and pollution.
- Reduce maintenance – extend maintenance surfacing cycles.
- Cost effective installation – saves construction time, equipment and aggregate.
- Low total cost of ownership – durability extends track maintenance periods by >3x (perpetual superstructure).
How Does it Work
The Neoloy Tough-Cells confinement mechanism makes the Tough-Cell/ballast composite very stiff, strong and durable. Neoloy Tough-Cells confinement minimizes the relative movement of particles and prevents shearing of aggregate under loading. Ballast abrasion and attrition are reduced significantly, while ballast stiffness is increased. Neoloy also minimizes lateral and vertical deformation of the track substructure, which prevents differential settlement, and improves track stability.
Wide Range of Solutions for Railways
Neoloy Tough-Cells are cost-effective for new track construction and rehabilitation with low life-cycle costs, and are also suitable for:
- High-speed, heavy axle-load rail service
- Regions of poor subgrade, poor ballast
- Depots, turnouts, yards, stations, tunnels
- Earth stabilization for slope protection, bridge abutments
- Earth stabilized berms and noise barriers
Contact us to learn more about these solutions.