Thanks to you for this, and to Beardy Rich for staying up late!
Sounds as if it was very messy, aggravating, time-consuming, labour intensive and certainly not cheap!
Cleaning the oil out must have been one heck of a task...
I have learned from a friend that QE2's double-bottom was found to be full of thick old oil in 1992.
It sounded as if this had been there for several years.
Purely out of interest, do you think there might have been any connection between the two events?
Later - 'PS' - How and where (on earth!) did you begin, in getting at the oil to get rid of it?
'Specially if the tanks and pipes were sealed?
Cleaning the oven/ drain pipe's bad enough,
Isn't it quite a toxic business?
(btw - there's no need to answer this question, specially if it's 'off limits',
it's just that curiosity is working over-time this evening!)