The Rosedale railway was there to transport the iron ore (partiallly extracted by the kilns at Rosedale) down to Battersby junction (and then on into M'boro). It had a big height difference which was "sorted" by the Ingleby Incline which was a 1:5 hill, where the weight of full trucks coming down hauled the empty trucks back up.
There were also Iron mines in Glaisdale dale. The old workings are full of water an provide spring water for the farms up there, The raw ore from there was transported down to the village where the furnaces were. There is an old railway line on the Glaisdale moor top. Whether this was used to transport ore down to the village (there is a big height differential between the moor and village), where the furnace were by the railway, via a similar "incline set up" I'm not sure. They may be the remains of Paddie Waddles railway which was a project to link the Glaisdale Mines to Lingdale / Moorsholm mines that had a lot of cuttings and bridges built but was never completed.