Saft - Nickel-Cadmium Batteries for Mass Transit Applications

With more than 75 years' experience in the sphere of industrial nickel-cadmium batteries, Saft has been selected by rail and mass transit operators and major rolling stock manufacturers to equip more than 150 rail and mass transit networks in the world.

Saft offers dedicated products for diesel starting, emergency back-up power and standby power. These have a very high degree of reliability and trouble-free operation, while also reducing globally the total life cycling cost of the batteries.

NI-CD batteries for starting or emergency back-up

There are two major rail battery markets - railways and mass transit - which can be segmented in three major application fields:

Starting - battery power to start diesel engines on locomotives and diesel multiple units (DMUs)
Passenger coaches - emergency backup power for coaches, requiring usually backup times of three to five hours
Electric traction - emergency backup power for mass transit and electric locomotives (EMUs), covering metro systems (underground, elevated and ground level), rapid suburban rail networks, tramways, automatic shuttles and buses; backup times are between 20min and 90min, and often include buffer power for various on-board systems, such as door opening or braking

Sinter / PBE technology batteries

Saft produces three ranges of sintered / PBE batteries offering different performance characteristics.

Mass transit and rail integrated compact system (MATRICS): the MRX battery system has been purpose-designed to provide the perfect high-performance on-board battery solution for LRV, metro, EMU, locomotive and high-speed rail systems. Ithas been developed in response to customers seeking even smaller, lighter battery packages optimised for maximum performance, reduced maintenance and low life cycle costs. Capacities are from 70Ah to 260Ah.

SRX batteries are designed to answer the specific needs of rail transport in terms of power. They provide a very high level of performance, in particular for starting diesel locomotives and for emergency braking of metros and high-speed trains. SRX batteries are used where high current discharges are required. Capacities are from 22Ah to 375Ah.

SRM batteries are suitable for numerous rail applications. They are used for type M discharges (see IEC 60623), i.e. they provide optimally power for at least one hour. Capacities are from 25Ah to 440Ah.

Battery systems

Saft supplies a complete battery assembly and has developed a total service concept that ranges from initial research and development to system upgrades and replacement. Our design teams have worked with railway industry leaders to produce customised batteries that meet the most precise specifications. Saft nickel-cadmium batteries are available in various containers and crates in response to different needs:

In stainless-steel cell containers assembled into plywood crates
In plastic cell containers (standard or flame retardant) assembled into stainless-steel crates

Saft can now offer self-contained 24V to 110V battery units, including cell assembly into stainless-steel trays, having control and safety devices with simple interfaces. This allows reducing significantly the lifecycle cost. Accessories such as centralized water-filling systems are also an option.

Batteries intended for emergency power supply, in particular for lighting passenger coaches on inter-city trains, should have these characteristics:

Provision of autonomous power for three hours or more and, consequently a large capacity of 250Ah-450Ah
Be able to tolerate deep cycling often uncontrolled (overnight discharges)
Resistance to very harsh operating conditions (very high or very low temperatures over long periods, dust, humidity, and vibration)

References

Locomotives - EWS diesel locomotives in the UK, SNTF in Tunisia, locomotives in Italy, Netherlands and Taiwan
Passenger coaches - Belgium, Tunisia, Algeria and Pakistan
High speed trains – le Shuttle and Eurostar TGVs, France's TGV, Italy's Pendolino, the AVE in Spain, Sweden's tilting trains, Japan's mini-Shinkansen, Amtrak trains in the US, Korean TGV KTX
Metro (EMU/DMU) – Saft's SRX and SRM batteries equip different generations of rolling stock in Hong Kong, operating lines of the MTR Corporation, New Airport Express, Tung Chung Line, EMUs of KCRC and metros in Munich and Lisbon)
Urban transport/airport shuttle operators worldwide: Tokyo, Singapore, Paris, London, Stockholm, Milan, Caracas, Santiago, Chicago
LRVs and tramways including Hong Kong, Sheffield, Oslo, Paris, Grenoble, Montpellier, Dresden, Valencia, Dublin, Nantes and Sydney

Contact Details

Saft
12 rue Sadi Carnot
93170 Bagnolet
France
Tel: +33 1 49 93 19 18
Fax: +33 1 49 93 19 64
Email: IBG.info@saftbatteries.com
URL: www.saftbatteries.com

Saft is the world’s leading supplier in the Nickel-Cadmium segment, with major footholds in all segments, providing batteries to more than 150 railway networks and mass transit systems throughout the world.

Batteries play a key role in all contemporary rail and mass transit systems, whether these are diesel, electric or hybrid, intercity or urban, conventional or high speed. They are required to perform a number of functions, of which the most important are engine starting and the provision of emergency power.

In tunnels, fire and smoke are especially hazardous, and stringent precautions are taken to ensure that batteries do not propagate fire or emit smoke or toxic fumes. Total reliability of the back-up of the low voltage is crucial for all mass transit systems.

Batteries are installed on conventional train passenger coaches to provide a reliable in the case of the main power supply failure. They may come into operation not only for emergency purposes, but also whenever the train is at a standstill while the engine is still running.