A railbus is a lightweight rail vehicle that operates under its own engine power and is typically designed for low-capacity passenger transport. These vehicles, which have a body structure similar to a bus, operate on railway tracks and offer an economical solution especially in areas with low passenger density.

Definition and General Characteristics

Unlike conventional train sets, railbuses do not require a locomotive for traction. The engine and passenger compartment are located on the same body. They usually have a modular structure with 1 to 4 cars and are capable of bi-directional operation.

_{Two-Car Railbus (Generated with Artificial Intelligence)}

Operating Principle

Railbuses are typically equipped with diesel engines, which operate either through a hydraulic system that directly drives the wheels or via a diesel-electric system that powers electric motors through a generator. This setup allows for:

• Easy forward and reverse movement
• Reduced maintenance needs
• Energy efficiency suited to low-density routes

Areas of Use

• Commuter Transport: On small intercity or town routes
• Rural Line Applications: To reduce operating costs on lines with low passenger numbers
• Touristic Lines: For nostalgic or scenic transportation in picturesque areas

Use of Railbuses in Türkiye

In Türkiye, TCDD Taşımacılık used railbuses for many years on low-density lines. Especially during the 1980s and 1990s, Uerdingen and Fiat-type railbuses were widely used. Since the 2000s, these vehicles have gradually been replaced by more modern DMU (Diesel Multiple Unit) train sets. TCDD successfully used railbuses on rural lines particularly in regions like Afyon, Eskişehir, and Balıkesir, making a significant contribution to the revitalization of conventional lines.

Advantages

• Low Operating Cost: The locomotive-free design reduces fuel and maintenance expenses
• Bi-Directional Driving: Can operate without the need for turning maneuvers
• Low Noise and Vibration: Especially in new-generation models, passenger comfort is high
• Quick Deployment: Offers a flexible transport solution

Limitations

• Limited Passenger Capacity: Insufficient for high-density lines
• Performance Issues on Sloped Terrain: Not suitable for hauling heavy loads
• Only Suitable for Low-Speed Lines: Not compatible with high-speed rail infrastructure

Railbuses offer an economical, environmentally friendly, and practical transportation option, especially on low-density lines. As in the past, railbuses are expected to play an important role in developing regional transport in Türkiye in the future. With domestic production capabilities and new technologies, more modern versions of these vehicles may once again come to the fore for rural and semi-urban transportation.