‘tonne-km’ means the unit of measure of goods transport which represents the transport of one tonne (1000 kilograms) of goods by rail over a distance of one kilometre.
ciallaíonn “tona-km” an t-aonad tomhais d'iompar earraí a sheasann d'iompar aon tona (1000 cileagram) amháin d'earraí d'iarnród feadh aon chiliméadair.