It is also controversial whether the Romans maintained a military presence to protect the ford , nearby , across which the convoys of lead from Lutudarum Wirksworth joined Rykneld Street at Derventio ( now part of Derby ) , en route for the North Sea ports .
The Roman army might have been there to protect the ford nearby where people from Lutudarum Wirksworth passed before joining Rykneld Street at Derventio ( now part of Derby ) which was N-shaped route for the North Sea ports .