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Assessing locomotive compatibility on an SJ Rc6 electric locomotive in Sweden, showing roof-mounted pantographs and high-voltage equipment at a station platform.

Assessing locomotive compatibility under increased overhead line voltage

Customer: SJ AB, Sweden
End customer: Trafikverket, Sweden

Project tasks

  • Technical investigation
  • Documentation research
  • Identification of possible changes in locomotive high-voltage circuits
  • Cost estimation of the changes
  • Integration of the changes in the actual system

Our approach

PROSE began with a structured review of the Rc6 high-voltage system, analysing design documentation, component specifications, and historical modification records to establish the vehicle’s current technical baseline. Based on this analysis, we evaluated the impact of the increased maximum voltage on insulation coordination, component voltage margins, and protection systems. Where necessary, we developed alternative technical solutions to ensure compliance with the new operating conditions. Each option was assessed from both a technical and economic perspective, including feasibility, implementation effort, operational implications, and associated risks. The work was carried out in close dialogue with SJ as operator and Trafikverket as infrastructure owner to ensure transparency and alignment throughout the project.

Customer benefit

The customer gained a transparent and technically sound decision basis for operating the Rc6 fleet under increased overhead line voltage. Our independent assessment clarified voltage margins, component limitations, and protection requirements, creating full visibility of technical risks and modification needs.
By systematically comparing refurbishment scenarios, including cost and implementation implications, we enabled SJ and Trafikverket to prioritise measures based on safety, operational reliability, and long-term investment protection. With PROSE’s in-depth knowledge of Swedish rolling stock and infrastructure interfaces, the operators secured a technically robust and future-proof solution aligned with updated network standards.

 

Open door of a C20 metro driver cab in Sweden, illustrating onboard modifications and the need for verified electrical documentation.

Documenting a reconstructed electrical design for a metro driver cab air conditioning system

Customer: MTR Tech AB, Sweden

Project tasks

  • Collection of as-built electrical information from customer
  • Technical review and consolidation of handwritten updates
  • Reconstruction of electrical schematics
  • Verification of correctness and consistency
  • Formal release of approved drawings

Our approach

The project addressed the absence of controlled and verified electrical documentation following the installation of a new air-conditioning unit in the driver cab of a C20 metro vehicle operating in Sweden. The modification had been implemented by the customer, with electrical schematics updated manually, resulting in missing traceability, inconsistent information, and non-compliance with railway documentation standards. The objective was to reconstruct the as-built installation, verify the electrical design, and formally document and release correct, complete and compliant electrical drawings.

PROSE collected and reviewed all available technical input from the customer, including as-built installation details and handwritten updates to existing schematics. Based on this information, we analysed, consolidated, and reconstructed the electrical design and documented it into formal electrical schematics in accordance with applicable railway documentation standards. The resulting drawings were verified and issued under PROSE authorship, in close coordination with the customer’s engineers, ensuring accuracy, traceability, and controlled release. PROSE’s independence and deep understanding of railway electrical systems enabled efficient reconstruction even with incomplete and informal source material.

Customer benefit

By selecting PROSE, the customer obtained verified and formally released electrical documentation that accurately reflects the as-built installation. This restored full traceability, ensured compliance with railway documentation standards, and created a reliable basis for safe operation, maintenance, and future modifications. PROSE’s independent engineering approach and experience in reconstructing and validating modified or legacy designs reduced project risk and relieved pressure on the customer’s internal engineering resources.

 

   

Preparing and migrating technical documentation into the PRO(doc) documentation system

Customer: Transdev, Germany

Project tasks

  • Project management
  • Software management
  • Structure of the document management system
  • Uploading documentation to PRO(doc)
  • Training

Our approach

Transdev Hannover GmbH took over 13 Bombardier ET425.5 electric multiple units that were in service on the Hanover S-Bahn between 2008 and 2022. With the fleet takeover, the operator received the complete manufacturer documentation, including operating manuals, maintenance manuals and maintenance instructions.

PROSE was commissioned to adapt and consolidate the existing documentation and to merge manuals, instructions and guidelines into a unified documentation basis. An important part of the project was to prepare the documentation for integration into the XML-based PRO(doc) system to ensure structured data,
standardised content and controlled version management.

The work also included training Transdev employees in uploading, editing and maintaining documentation in PRO(doc). The project was based on close collaboration between PROSE Sweden and PROSE Germany in order to combine expertise in documentation management with operational vehicle knowledge.

PRO(doc) was used as the technical documentation environment, specifically tailored to train maintenance. We combined expertise from PROSE Sweden and PROSE Germany, covering project management, MadCap Flare, document management, stylesheets, rules, XML structuring, and problem solving.

All available material was imported into the editing environment. PDF documents were converted to Word and harmonised in terms of styles, metadata, and layout. The document structure and design were developed in MadCap Flare, where the content was organised into a consistent product-based hierarchy and a maintainable table of contents.

Azure DevOps was used solely for source code management and version control to enable parallel work. A document list, created and maintained in Excel in line with the standard’s product-based structure, served as a working document and checklist throughout the project. Continuous technical support and transparent communication ensured efficient collaboration and traceability of decisions.

Customer benefit

Transdev now works with a standardised and well-structured documentation set that supports efficient maintenance and daily operations. The PRO(doc) documentation system, developed by PROSE, provides a searchable database with controlled version management, ensuring reliable access to approved content and updates.

The consolidated and migrated documents are published in a unified structure that simplifies future revisions. PRO(doc)’s responsive design enables use on any device, while document creation and updates are managed in MadCap Flare and exported to PRO(doc). With the training provided, Transdev can manage its documentation independently, supported by PROSE’s independent and specialised expertise when required.

 

         

Visualisation of SBB’s future long-track maintenance hall in Ticino, Switzerland, showing both a realistic rendering of the exterior with mountainous background and a technical 3D layout of the facility design.

Production concept and plant layout for a new maintenance workshop

Customer: SBB, Switzerland

Project tasks

  • Project management
  • Requirements analysis
  • Concept development
  • Client support

Our approach

SBB plans to build a state-of-the-art maintenance workshop for its vehicle fleets at the new NSIF industrial plant in the canton of Ticino. The long-track hall plays a central role: it is primarily intended for operational maintenance and the commissioning of vehicles after overhauls. The hall will be specially designed to meet the requirements of the latest SBB fleets and must therefore meet the highest standards of flexibility, efficiency and technical equipment. In addition to the infrastructure, the planning also includes operating resources, processes and interfaces to logistics and component reconditioning.

PROSE supported SBB with an experienced team of specialists in the design and planning of the long-track hall. The project approach was based on a thorough analysis of the vehicle fleets to be maintained and the existing operating processes. From this, we developed a production concept that combines proven methods with innovative technologies. The focus was on optimising processes, designing the plant layout, selecting suitable tools, media connections and operating resources, and integrating an automated logistics concept into production. In addition, safety standards and possible automation solutions were also examined. To support the client, PROSE also assisted SBB with the verification of plant plans, the development of internal decision-making bases, and workshops on plant layout with internal and external partners.

Customer benefit

SBB benefits from a robust, future-proof production concept tailored to the specific requirements of the long-track hall and takes production interests into account. Media connections, tools, and operating resources are defined with clarity and precision, enabling direct implementation during construction The optimised infrastructure enables efficient and safe maintenance of modern vehicle fleets.

By combining technical, operational, and workshop-level expertise, we ensured high acceptance among stakeholders and delivered a highly practical concept. As an independent engineering partner, PROSE provides objective guidance and a comprehensive view across processes, interfaces, and operational requirements.

 

 

Blue and white Västtrafik tram on route 3 to Kålltorp travelling through a historic city street in Gothenburg, Sweden.

Reverse engineering of new gears and housing for trams

Customer: Västtrafik AB, Sweden

Project tasks

  • Measuring of the gearbox housing
  • 3D modelling and technical drawings
  • Material definition
  • Definition of applicable standards
  • Risk assessment
  • Criteria for quality control

Our approach

PROSE applied a hybrid reverse-engineering method that combined mobile 3D scanning, mesh processing, and feature-based CAD modelling to reconstruct the gear housing. In parallel, we coordinated with the third-party supplier Zoerkler to perform precision gear measurement, material analysis, and hardness verification.
All interfaces, tolerances, and functional surfaces were systematically cross-checked against the physical components and validated through a structured CSM-RA risk assessment.
Based on these inputs, PROSE established updated 3D/2D documentation and a technical specification defining material, heat treatment, tolerances and surface-finish requirements in accordance with railway safety and documentation standards.

Customer benefit

The long-term availability of spare parts is ensured through updated and complete technical documentation that enables reliable future manufacturing of spare parts. This significantly reduces the risk of obsolescence for the parts involved.
Thanks to PROSE’s hybrid reverse-engineering approach, combining mobile 3D scanning, mesh processing, and feature-based Computer-Aided Design (CAD) modelling, the technical documentation was delivered in a time-efficient manner. At the same time, we ensured an uncompromised level of safety and quality compared with the current gearbox parts.
Throughout the project, PROSE maintained continuous dialogue with all involved actors to achieve solutions that meet the customer’s needs, supported by our independent position and broad engineering expertise.

 

Bid management for regional train maintenance contracts

Customer: EuroMaint Sweden

Project tasks

  • Bid coordination
  • Development of maintenance strategy
  • Depot and resource planning
  • Technical documentation
  • Obsolescence and component lifecycle analysis
  • Cross-functional team leadership

Our approach

PROSE acted as Bid Leader, and coordinated a cross-functional team consisting of engineering, procurement, and production experts. The team jointly developed technical and operational documentation, including maintenance plans, depot strategies, and component handling procedures. The work was carried out in close collaboration with stakeholders to ensure alignment with operational needs and regulatory requirements. The documentation was structured to support both strategic decision-making and practical implementation within the bid.

Customer benefit

By selecting PROSE as a partner, the customer gained access to structured and well-documented maintenance solutions tailored to the specific fleet and operational context. The collaborative approach ensured that procurement and production perspectives were integrated early in the process, reducing risk and improving feasibility. The final documentation supported the customer’s ability to submit competitive and technically sound bids, with clear strategies for lifecycle cost control and fleet availability.
The customer also benefited from PROSE’s independent expertise, broad rolling stock knowledge, and ability to deliver practical and implementation-ready material.

 

Blue and red trains at a snowy outdoor station platform at night, illustrating rail coupler upgrade and electrical interface integration for snowblower wagon type B257

Coupler upgrade and electrical interface integration

Customer: MTR Tech AB, Sweden

Project tasks

  • Requirements capture and definition of electrical interface
  • Design review
  • Update of technical documentation
  • Verification of electrical connections and signal integrity
  • Official drawing release and configuration control
  • Coordination with MTR during implementation and validation

Our approach

PROSE contributed to the design definition of the new electrical interface and collaborated closely with MTR engineers during system implementation of the upgraded coupling system be-tween the Snowblower Wagon Type B257 and the C20 train.
While MTR carried out on-site installation and testing, we re-viewed, clarified, and consolidated the draft electrical updates and ensured that all connections and signal interfaces complied with safety and operational requirements.
The verified and approved information was issued as official electrical drawings, released under PROSE authorship and re-viewed by MTR engineers.
This cooperative approach ensured full traceability, correctness, and compliance with railway documentation standards.

Customer benefit

​The customer gained a reliable and standardised coupling solution that reduced manual work in demanding winter conditions. The upgraded interface improved operational efficiency by ensuring full mechanical and electrical com-patibility between the snowblower wagon and the C20 fleet. Independent engineering review by PROSE ensured high quality and compliant documentation, providing confi-dence in the safety and integrity of the system. The result is a future-ready solution that supports safe, efficient, and well-documented winter operations.

 

 

Virtual representation of a train maintenance hall with roof structure, trains on parallel tracks and a yellow crane arm positioned above the vehicle for maintenance work.

Concept development for maintaining a new fleet in a historic depot

Customer: SBB, Switzerland

Project tasks

  • Project management
  • Requirements analysis
  • VR simulation & validation
  • Concept development

Our approach

New vehicle fleets are to be introduced at the service facility in Lucerne, which will require additional roof access, in particular through the use of a crane. At the same time, there is a need for extensive renovation and replacement measures within the depot and its surroundings. Planning these structural modifications is challenging due to monument protection, limited space and ongoing operations.

PROSE analysed the maintenance requirements of the new vehicle fleets in a structured process and developed several infrastructure options. Each variant was systematically developed, evaluated and documented to support transparent decision-making. Acting as interim project manager, PROSE coordinated specialist planners and internal experts and carried out the detailed elaboration of the variants to ensure consistent progress across all areas. We also supported coordination with monument protection authorities and used virtual reality (VR) technology to simulate, test and validate the proposed solutions under realistic conditions.

Customer benefit

Through comprehensive support during the study phase and our expertise in maintenance planning, PROSE created a transparent and objective basis for all further decisions. The customer gained a clear overview of the planning status of all trades as well as coordinated cost and schedule plans. This enabled a smooth handover to the next project phase. The use of virtual reality (VR) technology supported the evaluation and optimisation of the infrastructure variants and helped to identify an optimal solution that met both operational and heritage conservation requirements.

 

   

Auxiliary bogie development for trams in workshop

Customer: Würzburger Straßenbahn GmbH, Germany

Project tasks

  • Auxiliary bogie development
  • 3D model (3D geometries for individual parts are part of the 3D model)
  • Combined welded assembly and machining drawings
  • Assembly drawing
  • Strength calculation results
  • Track guidance report

Our approach

PROSE has developed a workshop-compatible auxiliary bogie for temporarily relocating low-floor vehicles during maintenance work. The design is deliberately kept simple and allows the vehicles to be picked up without twisting. The aim was to create a solution that is functional, robust and at the same time designed in such a way that it can be manufactured and used independently by the operator. PROSE was responsible for the complete design – from the concept to the production-ready documents.

PROSE has a close relationship with Würzburger Straßenbahn GmbH (WSB), which has developed over the last few years through various successful co-operations. We were able to start designing the bogie quickly thanks to our familiarity with the technical requirements of the WSB fleet.

Our approach was to quickly determine the wheel diameter and by confirming the chosen parameters with the customer. This allowed us to move directly into engineering with a clear, shared understanding.

Throughout the 3.5-month design phase, we kept the process lean and efficient. Monthly status updates ensured the customer remained well-informed without requiring intensive involvement. Thanks to PROSE’s broad technical expertise, unnecessary iterations were avoided, contributing to a timely project delivery.

Customer benefit

Thanks to our close collaboration with the customer and our deep technical understanding, we were able to start development particularly quickly. The customer benefited from our in-depth expertise and understanding and was able to save a lot of time and effort. The solution was tailored precisely to the requirements of the workshop. The complete production-ready documentation, including 3D model, proof of strength and track guidance report, ensured rapid realisation. Thanks to our comprehensive and in-depth knowledge of industry standards, the conditions in the WSB workshop and close collaboration with the customer, we were able to anticipate challenges before they arose.

 

 

Operating load measurement and assessment of fracture mechanics

Customer: RAlpin AG, Switzerland

Project tasks

  • Operating load measurement
  • Wheelset shaft calculation
  • FE calculation
  • Fracture mechanics assessment

Our approach

The customer required two fracture mechanics analyses. On the one hand, the aim was to investigate what causes cracks to form on the back of the wheel flange and which factors contribute to crack growth. On the other hand, there was a need to provide a mathematical basis for the specified inspection interval for the wheelset shafts. Real operating load data should be used as the basis for the fracture mechanics investigations of PROSE.

PROSE carried out an unaccompanied measurement to record the operating loads on the routes travelled. For this purpose, a measuring system was installed directly on a bogie frame. This recorded the position of the vehicle combination over several days using an associated GPS antenna as well as the lateral and vertical acceleration and the rotational speed of the bogie using appropriate sensors. The measurement signals were continuously sent to a central storage unit via the mobile phone network. The real operating loads measured in this way formed the basis for the subsequent fracture mechanics tests.

The wheel disc cracks were investigated using two wheel types used by the customer. The load on these wheel types was simulated using MBS simulation based on the real load data.

To assess the fracture mechanics of the wheelset shafts, a wheelset shaft calculation according to EN13103-1 was carried out in a first step for orientation and to assess the general utilisation of the wheelset shaft. In a second step, cyclic crack propagation calculations were carried out at the critical shaft positions (positions with the highest bending stresses).

Customer benefit

Our fracture mechanics tests confirmed that the cracks in the wheel discs were not caused by braking behaviour or contact with the wheel control arm. Residual stresses were identified as a possible cause of the crack propagation. However, the fracture mechanics assessment of the wheelset shaft also confirmed that the existing test interval provides sufficient safety.

PROSE’s neutral and independent position and in-depth technical understanding gave the customer a solid starting point for further investigations. By utilising data from operational load measurements, the investigation could be tailored to real operating conditions, improving the quality of the results and increasing the client’s confidence in the findings. PROSE’s unique railway engineering expertise and extensive experience with rolling stock provides a bespoke, unbiased analysis that supports effective decision-making and long-term asset management.

 

 

Innovative service and operating concept for S-Bahn transport

Customer: Forchbahn AG, Switzerland

Project tasks

  • Scenario and variant supply and operating concept 2035+
  • Concept for on-demand operation with ATO
  • TARGET system architecture and gap analysis to the ACTUAL system landscape
  • Determination of requirements for later migration of the new vehicle

Our approach

PROSE supported Forchbahn in the tendering process for a new vehicle fleet. This also raised questions about the future service and operating concept of the S18 Zurich Stadelhofen – Esslingen line. In order to utilise the opportunity of a new vehicle fleet, PROSE developed various scenarios regarding vehicle lengths and the change in the current service concept through the use of automatically operated vehicles in the direction of on-demand operation at off-peak times. The scenarios were developed for different service levels, depending on the time horizon.

Based on the existing old vehicles, the timetables, the planned timetable and the frequency surveys of current operations, we analysed possible vehicle concepts and the resulting number of new vehicles. We specifically analysed the possibilities with long and short trains as well as the operational and technical reserves. We also developed a 2035+ service and operating concept using fully automated multiple units on the Forchbahn’s infrastructure. In addition to the migration and service steps in the introductory phase, this also included the concept for the introduction of on-demand operation during off-peak times. The tender process defined a target system architecture and vehicle requirements for future migration.

Customer benefit

Based on the actual data, PROSE conceptualised the target state and derived opportunities and risks for the respective thrusts in the service and operation. These were reflected in workshops with those responsible at Forchbahn. The results were integrated directly into the tender documents. This ensures that the vehicles are suitable for operation in the long term and that nothing stands in the way of the subsequent implementation of ATO-on-demand operation. PROSE’s knowledge helped Forchbahn make well-informed decisions early in the process, reducing future risks and supporting long-term operational efficiency.

 

 

Assessment of Tram Vehicle’s Compatibility with Planned Track Layouts

Customers: Würzburger Straßenbahn GmbH (WSB), Germany; HAVAG Hallesche Verkehrs-AG, Germany; Basler Verkehrs-Betriebe (BVB), Switzerland

Project tasks

  • Ensuring Tram Compatibility: Confirmation that existing tram vehicles can operate on planned track layouts
  • Track Layout Optimisation: Proposal of alternative track layouts that can be passed safely and without causing damage or derailment to the trams

Our approach

The track layouts of tram systems often have very individual characteristics due to the topography or the historical development of city centers. The tram vehicles need to be compatible for these specific infrastructure conditions. As a result, there is limited standardisation or harmonisation between vehicles and tracks in tram systems. Modern tram vehicles are often multi-articulated vehicles. Their vehicle length can extend over several track elements such as changes in horizontal curvature and changes in vertical gradient. In general, all vehicle sections are connected to each other in an almost torsionally rigid manner – apart from a small amount of flexibility in a few roof joints. Long articulated vehicles are therefore often sensitive to torsional loads, such as those that arise when combining small curve radii and large changes in vertical slope.

When planning new tram tracks, the question therefore regularly arises whether the existing vehicles can negotiate the newly planned route. The safety objectives are especially the safety against derailment and the damage-free bearing of the loads that occur. Furthermore, sufficient gaps between vehicle parts or the ground clearance underneath the vehicle can also be objectives.

PROSE investigates trafficability while using multi-body system (MBS) simulations, as they are used internationally during the development of rail vehicles. The simulation model contains the specific properties of the vehicles under assessment. This includes the overall vehicle concept, the detailed mass distribution as well as the individual running gears with their suspension levels, etc. Furthermore, the simulation model includes the track, which is characterised by the track layout to be tested, local track gauges and groove widths as well as any flat grooves. In addition, elastic track bed properties or geometrical track irregularities can be considered.

In the computer simulation, the vehicle models are moved over the planned tracks. The relevant combinations of boundary conditions such as the load, winter stiffening of the rubber springs, the wheel/rail profiles, the running speed etc. are considered. The simulation results are evaluated against assessment criteria from standards (e.g. safety against derailment) or evidence documents of the vehicle (e.g. bearable loads). If trafficability is not yet ensured, PROSE varies the track layout in a stepwise approach. For this purpose, previously agreed premises are followed which parameters, such as the superelevation or vertical slope etc., should be changed as a priority or must remain unchanged e.g. for urban planning reasons.

Customer benefit

An immediate benefit is the planning reliability that results from the proven trafficability of the new track. At the same time, the risk of late effects such as cracks occurring in the vehicle structure after the construction work has been completed is minimised.

 

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