Originally based in Millwall, London, Stone Manganese Marine moved to Birkenhead in 1942 after their original foundry was bombed nine times by the Luftwaffe.

In their huge foundry, ships propellors were cast and then finished to amazing tolerances before being fitted to boats or shipped away. The closure of the foundry was forced in 2002, and I first noticed the big buildings about a year ago when they were getting ripped down, seven days a week. I had no idea what went on there, assuming it was some old factory and never investigated closer.

Today all that remains is a 30 ton travelling crane and a selection of propellors owned by the MOD, which were produced as 'spares' for replica and restored vessels and will probably be moved or scrapped soon. We weren't there long before the astute security guard gave us our marching orders - a shame, it would have been nice to climb on the props and the crane.

All in all another sad end to an interesting piece of local industrial history. And no prizes for guessing where the propellors are now made...