Hybrid Identity: UIC 597 and the Marking of Bimodal Semi-Trailers

UIC Leaflet 597, titled “Piggyback system – Semi-trailers on bogies – Characteristics,” is the technical standard governing bimodal transport systems (often known by trade names like RoadRailer or Kombirail). Unlike standard intermodal transport where a trailer sits on a wagon, in this system, the reinforced semi-trailer becomes the rail vehicle body by sitting directly on a dedicated rail bogie. Chapter 5 is crucial as it defines the Marking and Inscriptions required to identify these specialized units within the railway network.

The Role of Chapter 5: Distinguishing the Hybrid

A bimodal semi-trailer looks almost identical to a standard road trailer. However, structurally, it is a train. If a standard trailer were mistakenly coupled to a rail bogie, it would collapse under the tension forces of the train line. Chapter 5 prevents this catastrophe by mandating a strict visual identification system. It ensures that only certified, structurally reinforced trailers (capable of bearing up to 1500 kN or more in traction/compression) are accepted for bimodal train formation.

Key Marking Requirements

According to UIC 597, every bimodal semi-trailer must bear a specific coding plate (usually yellow with black text) that provides essential data to the railway operator:

• System Code: A letter identifying the specific bimodal technology (e.g., “R” for RoadRailer, “K” for Kombirail) to ensure compatibility with the adapter bogies.
• Rail Weight/Dimensions: The tare weight and braking weight relevant to rail operation (which differ from road values).
• Authorization Number: A unique approval number indicating the vehicle has passed the static and dynamic tests of UIC 597 (Chapter 3 and 4).

Comparison: Bimodal (UIC 597) vs. Standard Piggyback (UIC 596-5)

It is vital to distinguish between a “Grab Handling” trailer (pocket wagon traffic) and a “Bimodal” trailer. The table below highlights why the marking in UIC 597 is unique:

Operational Safety

The markings defined in Chapter 5 are the “passport” for the vehicle. During the train formation (marshalling), the ground staff checks these plates to verify that the semi-trailer is compatible with the specific bogies available at the terminal. Without a legible UIC 597 plate, the unit is rejected immediately, as using an incompatible or uncertified trailer could lead to a train separation or derailment.