ON MAY 5 Bombardier Transportation unveiled a car body assembly technique which uses thinner and smoother vehicle sidewalls to increase passenger capacity by up to 10%, reports Geoff Hadwick.

Speaking at the UITP World Congress in Madrid, Bombardier Transportation President & Chief Operating Officer Pierre Lortie announced that a three-car trainset built using the Fully Integrated Carbody Assembly System (Ficas) developed at Kalmar will start trial running in Stockholm on June 30 under an agreement with AB Storstockholms Lokaltrafik.

A Ficas sidewall is formed of two smooth steel outer panels bonded to a rigid foam core. Unlike traditional car bodies which use a steel shell supported by steel cross-members, or welded aluminium extrusions, this approach is more akin to the lightweight monocoque bodies of modern aircraft and sports cars. A typical Ficas sidewall is up to 120mm thinner than a traditional bodyshell.

Use of Ficas on the modified Stockholm C20 trainset has resulted in a 210mm increase in interior width, allowing a wider gangway whilst retaining an identical seating arrangement. The 33% increase in aisle width translates into 10% more floor area for standing passengers throughout the 46·5m long three-section articulated unit, without any change in the external dimensions. SL hopes to carry an extra 35 passengers per unit, or 105 in a nine-car train - a 6·5% increase in capacity. The tare weight of the three-car set has also been reduced by 2·6 tonnes, improving energy consumption.

Noting that Ficas uses bonding and mechanical fastening as opposed to conventional welding, Bombardier emphasised that 'minimal investment in new production facilities is required.' This would also encourage more local assembly. Bomabrdier's Vice-President, Sales, for metro cars Rauno Boga said he was keen to see Ficas technology applied to the Movia modular product platform currently being used to build new cars for Guangzhou and Bucuresti.