Image by infomatique
The sleek silver Citadis trams, manufactured by Alstom, reach a top speed of 70 km/h on off-road sections, but travel at a slower speed where conflicts with other vehicles or pedestrians can occur. Red Line trams, at 30 m with a capacity of 235, are shorter than the 40 m Green Line trams, which have a capacity 358 including two wheelchairs.
In other aspects, the two lines are identical except that the clearance between the lines on the Green Line is slightly wider than on the Red Line. This will allow wider metro trains be run on the same tracks if a proposed upgrade to full metro service is implemented. This is possible because the route uses an old railway line and as such has few interactions with vehicular or pedestrian traffic. The Red Line was constructed largely on or beside public roads and is not suited to wider and faster metro trains.
The main engineering structures on the Green Line at present are Milltown Viaduct, also known as The Nine Arches, a large stone viaduct dating from 1854, and the William Dargan Bridge, a large new cable-stayed suspension bridge at Taney Cross, near Dundrum town centre.