whn - rivetted tank

Interesting water [feed ?] tank sitting in a field above the Wasdale Head Inn. Overall condition, well rusted !
Rivetted iron plate, with the top edge reinforced with a D-section strap. There are a couple of flanged outlet / inlet ports, without pipework, and some rust worm has made more holes.
It looks, to me, like a small mining tub that has been modified ...