CP Class 3500

CP Class 3500
Name	CP Class 3500
Powertype	Electric
Builder	Siemens, Alstom, Bombardier
Builddate	1990s–2000s
Totalproduction	25
Wheelarrangement	Co-Co
Length	20.5 m
Electricsystem	25 kV AC / 3 kV DC
Poweroutput	6,000 kW
Operator	Comboios de Portugal
Fleetnumbers	3501–3525

CP Class 3500 The CP Class 3500 is a class of mixed-traffic electric locomotives operated by Comboios de Portugal, introduced in the late 1990s for both passenger and freight services. Developed during a period of European liberalization and interoperability initiatives, the class reflects collaborations among major manufacturers and integration with Iberian and pan-European networks. Designed for dual-voltage operation and high tractive effort, the locomotives played a central role in modernizing Portuguese rail traction.

Overview

The design emerged from procurement influenced by the European Union, Direcção-Geral das Obras Públicas, REFER, Infraestruturas de Portugal, CP Carga, CP — Comboios de Portugal, and manufacturers including Siemens AG, Alstom, and Bombardier Transportation. Contracts were negotiated amid procurement decisions involving European Commission rules, World Bank consultancy, and national transport policies debated in the Assembleia da República. Testing programs involved collaborations with Instituto Superior Técnico, Universidade do Minho, and Instituto Politécnico de Viana do Castelo laboratories, and trials ran on lines connecting Lisbon Santa Apolónia railway station, Porto Campanhã station, and border crossings to Vilar Formoso railway station.

Design and Technical Specifications

The Class features a Co-Co wheel arrangement influenced by designs used by RENFE classes and SNCF prototypes, with traction systems supplied by Siemens Mobility and auxiliary systems from ABB Group. The electrical package supports 25 kV AC and 3 kV DC for cross-border operation with Redes Ferroviárias Nacionais signaling compatibility, and onboard safety integrates European Train Control System (ETCS) levels tested against ERTMS specifications under projects coordinated with Union Internationale des Chemins de fer. Bogie design benefited from research at Montréal's Bombardier labs and vibration damping studies in cooperation with Instituto de Soldadura e Qualidade.

Key components included silicon‑controlled rectifiers and later insulated-gate bipolar transistors supplied by Siemens AG, braking systems by Knorr-Bremse, and onboard climate control from Honeywell International. The traction motors are three-phase asynchronous units derived from concepts used by DB Fernverkehr and validated through simulations performed with software from ANSYS and MathWorks. The cab layout drew ergonomic input from Union Internationale des Chemins de fer guidelines and human factors teams from Instituto Superior Técnico.

Service History

After delivery, inaugural services were inaugurated by officials from the Ministry of Public Works, Transport and Communications and representatives of European Investment Bank, with ceremonial events held at Rossio Railway Station and Santa Apolónia. The fleet entered revenue service on intercity express duties linking Lisbon Oriente, Porto Campanhã, and international flows toward Vigo and Madrid Atocha. Over time, CP Class 3500 units featured in strategic deployments during infrastructure upgrades managed by Infraestruturas de Portugal and were subject to maintenance cycles at depots like Entroncamento depot and Guimarães depot supervised by engineers trained at Instituto Superior Técnico.

Operations and Routes

The locomotives operated on principal corridors such as the Linha do Norte, Linha do Algarve, and international sections across the Iberian Peninsula to junctions near Valença do Minho and Vilar Formoso. Timetables coordinated with operators like RENFE Operadora and freight partners including Cargonomia and Medway enabled combined passenger and freight diagrams. During special events like the Expo '98 legacy services, units ran on enhanced timetables connecting Lisbon Gare nodes and were rostered for charters serving Fátima pilgrimages and Porto São Bento excursions.

Livery and Numbering

Originally delivered in a livery reflecting corporate identity negotiated with CP executives and designers from Carris visual teams, the class wore color schemes incorporating elements seen on contemporaneous stock from RENFE and SNCF. Individual locomotives carried fleet numbers 3501–3525, with numbering conventions registered in national vehicle registers maintained by Infraestruturas de Portugal and conforming to UIC numbering guidelines. Special commemorative liveries were applied for anniversaries celebrated with partners like Fundação Oriente and cultural institutions such as the Museu Nacional Ferroviário.

Modifications and Upgrades

Throughout their service life the fleet received upgrades funded through programs involving the European Investment Bank, Banco Português de Fomento, and CP capital works. Upgrades included retrofits of ETCS equipment in collaboration with Thales Group, replacement of traction converters with IGBT modules from Alstom, and enhancements to passenger heating and HVAC units supplied by Johnson Controls. Mid-life overhauls were carried out at workshops run by Efacec and technical partnerships with Siemens Mobility to extend axle bearings, improve adhesion control, and install energy-regenerative braking tested with projects coordinated by Instituto de Engenharia Mecânica.

Preservation and Disposal

As newer rolling stock procured from Stadler Rail, Alstom, and Siemens entered service, several Class members were earmarked for storage, sale, or preservation. Disposals involved transactions with freight operators like Medway and leasing firms such as CFL Cargo affiliates, while preservation efforts engaged the Museu Nacional Ferroviário, heritage groups connected to Associação de Amigos dos Caminhos de Ferro, and private collectors who coordinated static displays at sites including Entroncamento Railway Museum and special events at Linha do Douro museums. Decommissioned units underwent recycling processes overseen by APEMETA standards and scrapping managed by industrial firms contracted through Infraestruturas de Portugal.

Category:Electric locomotives of Portugal