ACE renewed the electrical control and the motor-gearbox combinations of a transfer loader in the NMBS traction workshop in Antwerp. The retrofit combines regenerative drive technology, precise automation and execution within just seven working days of downtime.
The transfer loader, built in 1992, was technically obsolete and the available electrical documentation no longer matched the actual installation. ACE delivered a future-proof retrofit with four overhauled motor-gearbox combinations, a new electrical control system, up-to-date EPLAN documentation and PLC software with master-slave control and load balancing. Braking energy is now fed back into the electricity grid.
Project details
Client
NMBS
Location
NMBS traction workshop, Antwerp, Belgium
Market segment
Automotive & Mobility
Sub-segment
Future Mobility & Infrastructure
Engagement model
Project engineering and delivery
Services
Machine building, integration, prototyping and panel building
Expertise
Industrial automation, electrical engineering, PLC software, drive technology, validation and testing
Technology and tools
Siemens SINAMICS regenerative drive technology, Siemens TIA Portal, EPLAN and PLC control
7
working days
Complete conversion within the available downtime
4
motors
Overhauled and synchronously controlled
±100 t
locomotive weight
Moved in a controlled manner
2,350 Nm
output torque
Per motor
The challenge
The NMBS traction workshop in Antwerp operated a transfer loader from 1992 with an obsolete Siemens S5 control system. Earlier modifications had not been consistently recorded in the schematics, so it was not fully clear how the installation had actually been built.
The first step was therefore to establish which connections, protective devices and components could be retained and which had to be replaced. The electrical engineering challenge was to translate this fragmented starting point into a complete, consistent and buildable EPLAN design that fitted a very short conversion window.
Key requirements
- Renew the complete electrical control system.
- Overhaul and modernise four existing motor-gearbox combinations.
- Control four motors synchronously and precisely.
- Move locomotives of up to approx. 100 tonnes in a controlled manner.
- Complete the conversion within seven working days of downtime.
- Test and commission the installation and train the operators.
The technical solution
ACE carried out a retrofit of the motor-gearbox combinations and the complete automation of the transfer loader. The existing mechanical structure was retained, while the motor-gearbox combinations were overhauled and the electrical control, cabling and control cabinet were fully replaced. This gave NMBS a reliable, energy-efficient and future-proof installation without the need for a complete new build.
Synchronised four-motor drive
Four synchronously controlled motors each deliver an output torque of 2,350 Nm and move locomotives of up to approx. 100 tonnes in a controlled manner. A master-slave architecture with load balancing in the PLC software distributes the load and keeps every movement precise.
Regenerative braking
Siemens SINAMICS regenerative drives feed braking energy back into the electricity grid instead of dissipating it via braking resistors.
EPLAN as the single reference
The EPLAN schematics form the unambiguous technical basis for panel building, cabling, testing and fault analysis. Clear component coding, connection data and terminal structures reduced the risk of errors during the conversion and make future changes and maintenance easier to manage.
From EPLAN design to built control cabinet
The new control cabinet was first designed in EPLAN. The EPLAN layout and schematics then formed the basis for panel building, cabling and commissioning.
Before and after
Motor-gearbox combinations
All four motor-gearbox combinations were overhauled and modernised, then reconnected with structured, labelled cabling.
Control system
The Siemens SIMATIC S5 control was replaced by a SIMATIC S7-1200 platform programmed in TIA Portal. Every component carries the designation used in the EPLAN schematics.
Cabling and braking energy
With regenerative drives, the braking resistors were no longer needed. The loose cabling was replaced by new cables, bundled and routed on cable ladders to the new control cabinet.
Our approach
Hardware, software and on-site execution were demonstrably aligned with one another, so that the available downtime could be used to the full.
Site survey and verification
A technical inventory of the existing installation, with the available schematics checked against the situation in the field.
Electrical design in EPLAN
Circuits, components, terminals, cabling and connections restructured and documented in EPLAN.
Design review for buildability
Design choices checked in advance for buildability, assembly and commissioning, resulting in a reliable engineering package for the new control cabinet and the on-site conversion.
PLC engineering in TIA Portal
PLC engineering developed in parallel in Siemens TIA Portal.
Conversion, commissioning and training
Overhaul, replacement, cabling, testing, commissioning and operator training completed on site within seven working days.
Scope of work
- Inventory and verification of the existing electrical installation.
- Up-to-date electrical schematics and connection documentation in EPLAN.
- Overhaul of four motor-gearbox combinations.
- Replacement of the complete electrical control system.
- Engineering and build of a new control cabinet.
- Installation of new cabling.
- PLC software development with master-slave control and load balancing.
- Validation, testing, commissioning and operator training.
The result
- Complete conversion within seven working days of downtime.
- Four overhauled and modernised motor-gearbox combinations.
- Precise, reliable control of locomotives of up to approx. 100 tonnes.
- Braking energy fed back into the electricity grid.
- Current, consistent EPLAN documentation for operation and maintenance.
- Delivered on schedule, despite an unexpected gearbox defect.
- Trained operators and a successfully commissioned installation.
Impact
The retrofit extends the service life of the transfer loader and improves its operational reliability and maintainability. Regenerative drive technology reduces energy losses during braking, while the up-to-date EPLAN documentation supports future fault analysis, maintenance and modifications.
Thanks to the combination of a renewed control system, precise automation and minimal downtime, NMBS has a sustainable installation that is ready for future use.
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Frequently asked questions
Why was the NMBS transfer loader in Antwerp modernised?
The installation dated from 1992 and ran on an obsolete Siemens S5 control system. Because earlier modifications had not been consistently recorded in the electrical schematics, an on-site inventory was needed first. The retrofit brought both the installation and the EPLAN documentation back to a current, maintainable standard.
How does the new drive technology make the transfer loader more energy-efficient?
The Siemens SINAMICS drives are regenerative. During braking, energy is no longer dissipated as heat via braking resistors but fed back into the electricity grid, so less energy is lost.
How did ACE keep downtime to a minimum during the retrofit?
ACE prepared the engineering, panel building, software and execution carefully in advance. As a result, the overhaul, replacement, cabling, testing, commissioning and training were completed within seven working days, even after a defective gearbox was unexpectedly discovered.