FACED with the need to turn out up to eight vehicles a week for Virgin’s West Coast Pendolino fleet, Alstom Transport has remodelled its assembly lines at Washwood Heath. At peak production, Pendolino cars will be moving down four parallel lines, and Alstom was keen to minimise intermediate handling.

The car bodyshells need to be supported at different heights at each work station, which is normally achieved by craning them between fixed stands each time the line moves forward. However, craning can cause delay and damage pre-painted bodies, so Alstom commissioned Somers Railway Engineering to develop an alternative solution.

Somers has supplied 36 gantries, which are used in pairs to support 18 vehicles throughout the assembly. Each gantry runs on the existing standard-gauge track, and can carry up to 20 tonnes. Screw jacks with telescopic support arms are adjusted to hold the vehicle in the required position at each stage. A bodyshell is mounted on a pair of gantries when it is delivered, and is rolled from one workstation to the next until it is lowered onto its own bogies.

The gantries are plugged into a local power supply, and have their own controls, which can operate several units in multiple if required. They have integral sockets so that unloaded units can be moved around the plant by a fork-lift truck. Vertical positioning is variable up to 1790mm above rail.

Combining the telescopic anvils with the scope for moving the stands, a wide range of vehicle widths can be accommodated, with provision for inboard or outboard jacking points. The width ranges from 1860 mm to a maximum of 3320mm, matching the Arlanda Express EMUs - the widest cars yet assembled at Washwood Heath. This high degree of flexibility means that the gantries will be able to support other vehicle designs once the Pendolino contract has been completed.

Somers Railway Engineering

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