It could be part of a flu system, but I'm more inclined to think it's a form of Leat to direct water to wherever they needed it in the works shops. (There's no evidence of smoke or soot accumulation in the tunnels. Soot from lead smelting is thick nasty stuff), The water could have been used to power a waterwheel. Is there any evidence of a waterwheel on the property?
I did have second thoughts afterwards about my flue theory, for the reason you state; no soot on the walls of the tunnel. There is a rectangular kind of trough, running long the bottom left edge [14:35], which has water running through it. Whether it always did, I don't know. But I can't see the full tunnel being solely used for water. It seems too big. Where I look forward in the direction of the rear of the ruined buildings [12:21], it looks like the tunnel has been bricked up [presumably at a later date]. So it seems like it once opened directly into one of those buildings. Which is also puzzling, as it seems unlikely you would have a huge torrent of water running directly into such a relatively small building. As to waterwheels; none that I'm aware of. Mind you, for such a large and long-lived industrial complex, there's very little in the way of documentary evidence of what it looked like "back in the day". I've not been able to find any illustrations or old photos.
It could be part of a flu system, but I'm more inclined to think it's a form of Leat to direct water to wherever they needed it in the works shops. (There's no evidence of smoke or soot accumulation in the tunnels. Soot from lead smelting is thick nasty stuff), The water could have been used to power a waterwheel. Is there any evidence of a waterwheel on the property?
I did have second thoughts afterwards about my flue theory, for the reason you state; no soot on the walls of the tunnel.
There is a rectangular kind of trough, running long the bottom left edge [14:35], which has water running through it. Whether it always did, I don't know. But I can't see the full tunnel being solely used for water. It seems too big.
Where I look forward in the direction of the rear of the ruined buildings [12:21], it looks like the tunnel has been bricked up [presumably at a later date]. So it seems like it once opened directly into one of those buildings. Which is also puzzling, as it seems unlikely you would have a huge torrent of water running directly into such a relatively small building.
As to waterwheels; none that I'm aware of. Mind you, for such a large and long-lived industrial complex, there's very little in the way of documentary evidence of what it looked like "back in the day". I've not been able to find any illustrations or old photos.