Bogies, wheels, and axles are the moving parts subject to the largest amount of stress in a train. Their safe operation directly depends on the condition of those critical components.

 

Careful inspection (visual, NDT, etc), adapted rectification (wheel lathe, surface planning or machining), and appropriate replacement of moving parts are therefore necessary for the safe performance of the rolling stock. Brakes (Discs and Tread) and suspensions (Primary, secondary, absorbers) are also a critical part of the DLD's maintenance activity.

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Having renovated several thousand bogies, the company offers both full service (from scheduled maintenance to complete strip-down) and spare parts delivery covering the following systems:

- Wheels, axles, tyres, axleboxes, and complete wheelsets (new and machining).

- Primary and secondary rubber/air suspension and shock absorbers.

- Brake discs, pads, tread soles, calipers, and control components.

- Bogie frames, transoms, structural pieces.

Diesel and Diesel-Electric traction remains a widespread mode of powering both passenger and freight trains in Europe. From engine components to auxiliary systems, Dobrich Locomotive Depot undertakes repair and maintenance, as well as spare parts delivery of most elements of the diesel traction chain. With a fully equipped engine overhaul workshop, we offer complete refurbishment services for the following systems:

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- Powerplant

- Fuel systems (Injection, control, pumps, tanks)

- Engine control

 

- Turbochargers

- Cooling groups, radiators, and blowers

- Gearboxes and drive shafts

- Alternators, generators & rectifiers

Electric traction covers both the full-electric trains and the electric systems of diesel-electric traction. 

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- Traction and auxiliary converters are tested and maintained. Design upgrades such as IGBT drives or galvanic insulation have been undertaken to increase performance and reliability.

- Traction motors are refurbished and tested: frame inspection, crack detection of rotary parts, re-winding and rotor balancing, brush and bearing replacement.

- Generators (Diesel-electric traction): Brushes, bearings, end bells, and fans.

 

- Balancing of all rotary parts.

- Converters, generators, and motors testing.

Electronics have become a crucial part of railway technology.

 

DLD splits its activities into:

Control electronics ERTMS/TCMS require careful maintenance and a high level of testing. With its specialized partners, DLD is capable enough not only offering maintenance, but also redesign services under the SIL1 to 4 certification level. Both hardware and software are covered by our activities:

- Electronic circuit reverse engineering & cloning

- Relay and FPGA circuit design for obsolete systems

- Gateways and TCN connection for (MVB, WTB, CAN) 

- Cockpit & control re-design (traction, brakes, door controllers, passenger information systems, etc)

- Software
Power Electronics

Mostly traction-related, covering static converters, battery chargers, and energy storage

- Fan and small AC or DC motors

- Electromagnetic components

- Integration of new equipment power supplies into existing trains

- Connectors

Wires and harness replacement & re-design

We maintain rolling stock bodies (corrosion, accident damage repair, painting) and are fully equipped to deliver complex liveries with our environment-friendly paint shop.​

- Complete bodywork restoration, accident & corrosion repair.
- Cleaning and surface maintenance services
- Surface treatment and painting

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For renovation of tramways and lighter rolling stock, our Depot offers bodywork re-design, and low-floor conversion: once a new bodywork has been designed to the operator's taste, we shall undertake the complete modification at our workshop, following a certified process: panelling, welding, structural modifications, glazing modifications, door changes, etc.

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We also offer interior renovation and maintenance, from cleaning to complete overhaul and modernization.