A rather sad breakthrough

After weeks of struggling, the first two tank base plates have been removed, to make way for the lift shaft. Two more base plates - each 4 feet square and weighing almost half a ton each - have still to be removed, to accommodate the stairway which accompanies the lift shaft. Our original plans sought to avoid the removal of any base plates. The lift and stairs would have gone in a three storey annex, so preserving the tank intact and keeping open the possibility that it could one day hold water again. Access to the tank would have been over, or through one of the sides. This would have meant the removal and retention or re-use of just two side plates - a simple and far less destructive scheme. The Conservation Officer preferred the present approach which does at least retain the external look of the tank - but the penalty is the destruction of the tank's intended function.

Seeing daylight from within the tower, the hole in the tank base measures 8 feet x 4 feet.   The iron hard sealant surrounding each base plate had to be cut away then the plates were jacked up from below, using the wide lower flanges of the beams at the jacking locations - see below.

Here we get our first daylight close-up of one of the cast iron beams which support the tank. It is 18 inches deep. The top flange is narrow but the lower flange is wide enough for my hat to rest on. The hat gives a better idea of the size of these beams.   There are 14 of them.

From above, on a rainy day, we see one of the removed plates alongside the big hole in the tank base.   It would have been easy to simply smash the base plates but we have tried very hard to remove them complete, in the interests of conservation.   Not quite sure what to do with them though!

A discovery made during this operation was that the easiest way to drill a hole through 1 inch thick cast iron is to use an SDS drill fitted with a masonry bit, on hammer drill setting.   Whoosh - straight through.   Noisy though.