What Is OTM Material? Other Track Material Explained

OTM material stands for Other Track Material: the essential railway components used to fasten, support and maintain the rails, excluding the rail itself and the sleepers. Typical examples are tie plates, rail anchors, track spikes, bolts, washers, rail clips and rail joints. OTM is what converts two loose steel rails and a row of sleepers into a safe, stable track.

Main OTM Categories and Their Functions

Component	Description and Purpose
Rail clips	Flexible elastic fasteners that press the rail foot onto the pad and sleeper, providing clamping force, gauge retention and vibration damping
Rail anchors	Applied to the base of the rail to prevent longitudinal movement (creep) caused by traction and braking
Rail spikes	Fasteners for securing rails, particularly on wooden sleepers; dog spikes and screw spikes are the two main families
Tie plates / baseplates	Plates between the rail and the sleeper that distribute the load and provide a stable seating surface
Rail insulators / pads	Isolate the rail electrically for signaling and reduce vibration; used mainly with concrete sleepers
Gauge rods	Maintain the distance between rails against spreading forces in curves and under heavy traffic
Joint bars and bolts	Connect rail ends mechanically with fish plates, fish bolts, nuts and spring washers
Insulated joints	Separate track sections electrically for track circuits while maintaining physical continuity

The Role of OTM in Track Structure

Secure Fastening

Track spikes, bolts and elastic clips fix the rails onto sleepers or baseplates so that the rail cannot lift, shift laterally or overturn under traffic. The fastening must hold the rail down while still allowing controlled longitudinal movement for thermal expansion.

Structural Stability

OTM components provide consistent support against the vertical, horizontal and longitudinal forces exerted by trains. Tie plates spread the wheel load over the sleeper bearing area, protecting timber from crushing and concrete from cracking; gauge rods resist track spreading in curves.

Movement Prevention

Rail anchors grip the rail base and bear against the sleeper to stop creep - the gradual longitudinal migration of the rail caused by traction, braking and temperature. Without anchors, rail movement can close up joints or drag the sleepers out of position.

Electrical Insulation

Specialized OTM such as insulated joints and rail pads provides electrical separation, which is vital for track circuits and for preventing stray-current corrosion in electrified lines.

Maintenance and Longevity

By distributing loads and preventing creep, OTM extends the service life of both rails and sleepers and reduces the frequency of geometry correction.

Typical Elastic Rail Clip Data

Elastic rail clips are the heart of modern fastening systems. They are forged from spring steel, heat treated, and hold the rail with a defined toe load. Representative models:

Model	Bar Diameter	Weight	Material
Type III	18mm	0.80 kg/pc	60Si2MnA
E1609	16mm	0.43 kg/pc	60Si2MnA
E1809	20mm	0.61 kg/pc	60Si2MnA
E1813	18mm	0.62 kg/pc	60Si2MnA
E2001	20mm	0.80 kg/pc	60Si2MnA
E2007	20mm	0.80 kg/pc	60Si2MnA
E2009	20mm	0.80 kg/pc	60Si2MnA
E2039	20mm	0.80 kg/pc	60Si2MnA
E2055	20mm	0.80 kg/pc	60Si2MnA
E2056	20mm	0.80 kg/pc	60Si2MnA
E2063	20mm	0.80 kg/pc	60Si2MnA
Heavy-section clip (85 series)	13mm	0.25 kg/pc	60Si2MnA
Heavy-section clip (309 series)	19mm	0.85 kg/pc	60Si2MnA
Heavy-section clip (401 series)	20mm	0.97 kg/pc	60Si2MnA
Heavy-section clip (415 series)	20mm	0.95 kg/pc	60Si2MnA
Heavy-section clip (601 series)	20mm	1.03 kg/pc	38Si7
Type 1 clip	13mm	0.48 kg/pc	60Si2CrA
Type 3 clip	13mm	0.48 kg/pc	60Si2CrA
Type 12 clip	13mm	0.53 kg/pc	38Si7
Type 14 clip	13mm	0.53 kg/pc	60Si2MnA
Special rail clip	13mm	0.48 kg/pc	60Si2MnA
Regional clip (Chile standard)	18mm	0.58 kg/pc	60Si2MnA
Drive-on spring anchor	25mm	0.49-0.68 kg/pc	60Si2MnA
Single anti-theft clip	20mm	0.25 kg/pc	60Si2MnA

Frequently Asked Questions

1. Is OTM the same as rail fasteners?

Not exactly. OTM (Other Track Material) is the wider category that includes rail fasteners plus all the other small track components: clips, spikes, bolts, washers, tie plates, rail anchors, gauge rods, pads and joints. Rail fasteners are the subset of OTM that performs the actual clamping of the rail to the sleeper.

2. Why are rail pads considered OTM?

Rail pads sit between the rail foot and the sleeper or baseplate to distribute load, damp vibration and provide electrical insulation. They are part of the fastening assembly and therefore part of OTM, even though they are not fasteners in the clamping sense.

3. What OTM components are needed for concrete sleeper track?

Concrete sleeper track typically uses elastic clips (E-type or tension clamp), cast-in or bolted shoulders, rail pads, insulators and gauge blocks. The exact package depends on the fastening system standard and the rail profile.

4. Can OTM components be purchased separately?

Yes. Components such as clips, pads, spikes and washers can be ordered individually for maintenance. For new installations, a matched set from one fastening system is recommended so that all parts work together and the toe load and insulation requirements are met.

5. How does OTM extend track life?

OTM distributes wheel loads over a wider area, prevents rail creep, damps vibration and keeps the rail electrically isolated. These effects reduce rail and sleeper fatigue, slow geometry deterioration and cut the maintenance effort needed to keep the track within limits.

6. What standards govern OTM supply?

OTM components are supplied to UIC, AREMA, BS, DIN, JIS, GB and AS standards depending on the rail system, or manufactured to customer drawings and samples. The standard fixes dimensions, material grades, hardness, clamping force and inspection methods.