Links to other memoranda in this series:

1. ComparativeBenefits of Trams and Buses in Urban Public Transport
2. Dispelling the myth that trams need special seperate segregated path through traffic
3. “Glue-in-the-Road” TramTrack Systems versus Conventional Deep Excavation Methods
4. Why trams are essential to improve city productivity
5. Overhead wire-freeTechnologies for Tram Propulsion
6. Birmingham Tramworks Show Utilities Don’t Always Need to Be Moved: Minimal-Dig Track Methods in Action – A UK & International Perspective

Draft 5

Technical Memorandum 5 – Wire-Free Technologies for Tram Propulsion

Subject: Comparative Analysis: Wire-Free Costs
Date: June 2025
Prepared for: Bristol and Bath Tram Association / West of England Transport Association

Executive Summary

Overhead wire-free tram technologies—such as onboard batteries, ground-level power supply (GLPS), flywheel hybrids, and hydrogen/biogas systems—are gaining global traction due to their lower visual impact, reduced infrastructure cost, and rapid deployment potential. This memorandum examines key technologies in Europe, the Middle East, Australia, and the Americas.

Case studies from Florence, Birmingham, Barcelona, Coventry, Doha, and Los Angeles demonstrate that battery-electric and Very Light Rail (VLR) systems can reduce installation costs and nearly eliminate overhead lines in sensitive urban areas [1–5].

Innovations by TIG/m in Doha, Aruba, and LA, alongside Coventry’s VLR prototype, show that turnkey, overhead wire-free systems can be installed quickly, cost-effectively, and with minimal disruption—offering cities a sustainable yet visually integrated transport solution [5, 11–13].

As detailed in Technical Memorandum 4, tram systems have consistently supported city productivity by improving connectivity and reducing congestion. Modern overhead wire-free technologies and rapidly installable surface-level tracks enhance this proven effect by making tram deployment faster, less visually intrusive, and more feasible in historic or spatially constrained environments.

It should be noted that for many years overhead wires have been used throughout many historical cities with few complaints about the visual intrusion. Nevertheless, when new schemes are suggested this is one of main objectins – the visual, so wire free overcomes this issue. For example in Vienna the tram wires aare physically attched to the Grand Opera House

1.0 Wire-Free Propulsion Technologies

1.1 Onboard Battery Systems

• Florence Line 3 (Italy) employs Hitachi Rail’s OBESS (On-Board Energy Storage System) to operate fully overhead wire-free in its UNESCO-listed city centre—eliminating overhead catenary with a 5 km electric range [1, 2].
• Birmingham Westside Metro (UK) launched the UK’s first battery-operated tram segment in December 2019, retrofitting Midland Metro trams and achieving a £9.24 million infrastructure saving [3, 4].
• Msheireb Tram (Doha, Qatar) similarly operates without wires to preserve aesthetic integrity in its urban setting [5].

1.2 Ground-Level Power Supply (GLPS: Alstom APS)

• Bordeaux, France pioneered GLPS in city centres (2003) [6].
• Barcelona Waterfront Extension (2024) introduced 2 km of APS, serving ~24,000 extra passengers daily and removing ~2,000 cars per day [7, 8].

1.3 Biogas & Flywheel Hybrid Systems

• Parry People Mover (UK) trains (Class 139) have operated since 2009 on a Stourbridge branch line using flywheels and LPG/biogas engines—achieving high frequency with ultra-low emissions and no overhead wires [9, 10].
• Ultra  Light Partners are developing a biogas-fuelled light rail vehicle….https://www.bioenergy-news.com/news/biomethane-powered-railcars-could-be-introduced-in-the-uk/

1.4 Very Light Rail (VLR) & Other Wire-Free Systems

• Coventry Very Light Rail (UK) has developed a battery VLR prototype with shallow 300 mm embedded track, achieving early test runs in May 2025. Track costs are around £7–10 million/km—well below the £25–60 million/km norm for conventional trams [11–13].
• TIG/m Systems have implemented embedded track with battery/H2/hybrid trams, achieving rapid installation rates (300–400 m/week) in international pilots (Doha, Aruba, LA) [5].

2.0 Installation, Cost & Visual-Impact Benefits

2.1 Cost Advantages

• Battery segments eliminate catenary costs (typically saving £3–5 million/km) [4].
• VLR track systems can cost £7–10 million/km vs. £25–60 million/km for traditional tram tracks [11–13].

2.2 Visual Integration

• Florence, Bordeaux, Barcelona, and Doha avoid overhead clutter in heritage areas through overhead wire-free solutions [1, 6–8, 5].

2.3 Speed of Construction

• Coventry’s VLR was test-launched within weeks of laying embedded modular track [11, 13].
• TIG/m trams achieve installation speeds of 300–400 m/week [5].

As discussed in Technical Memoranda 2 and 3, effective deployment of overhead wire-free trams requires integration with coordinated traffic signal systems and appropriate track construction methods to ensure reliability, minimal disruption, and operational resilience.

3.0 Comparative Case Examples

4.0 Discussion

Overhead wire-free technologies align with urban ambitions to reduce costs, preserve aesthetics, limit disruption, and deliver cleaner transport. Battery and hybrid rail systems outperform conventional catenary systems in heritage zones and high-density centres.

Concerns remain around battery lifespan and charging. Yet, for short-distance or central-city lines, these systems are effective now.

VLR technologies—especially Coventry’s battery VLR—address cost and construction-time constraints, making tram systems economically viable for medium-sized cities. Meanwhile, GLPS and flywheel solutions offer low-profile alternatives fitting specific urban contexts.

While modern overhead wire-free systems improve deployment and integration, it is important to note that even older, more costly tram systems—using traditional catenary infrastructure—have historically delivered substantial economic and productivity gains. As outlined in Technical Memorandum 4, these benefits include expanded labour market access, urban densification, and commercial vitality. Overhead wire-free technology does not create these effects—it amplifies and extends them.

References

1. Hitachi Rail (2023). Battery-powered trams in Florence – case study.
2. Light Rail Transit Association (2017). Florence Tramway Battery Operations.
3. WMCA (2024). First Midland Metro battery conversion saves £9.24m.
4. CAF (2021). Battery Tram Technology for Birmingham.
5. Guardian News (2025). TIG/m case studies in Doha, Aruba, LA.
6. Alstom (2023). Bordeaux APS Overview.
7. Railway-Technology (2024). Barcelona APS deployment.
8. UITP (2023). GLPS for Urban Integration.
9. Parry People Movers Ltd. (2023). Technology Overview and Stourbridge Line.
10. WDB Group (2024). Stourbridge Light Rail.
11. Coventry City Council (2024). Coventry VLR Pilot.
12. The Guardian (2025). Coventry track installation and cost.
13. BBC West Midlands (2025). VLR Launch and Timeline.

Links to other memoranda in this series:

Links to 5 other memoranda at the foot of this page

1. ComparativeBenefits of Trams and Buses in Urban Public Transport
2. Dispelling the myth that trams need special seperate segregated path through traffic
3. “Glue-in-the-Road” TramTrack Systems versus Conventional Deep Excavation Methods
4. Why trams are essential to improve city productivity
5. Overhead wire-freeTechnologies for Tram Propulsion
6. Birmingham Tramworks Show Utilities Don’t Always Need to Be Moved: Minimal-Dig Track Methods in Action – A UK & International Perspective