This is a view across the width of the tank from the top of the access ladder showing the collapsed remains of a wooden walkway and handrails. A joist hanger on the far side is seen to the right of the transverse rail. The pipe flange to the left is the top of the water inlet pipe. Presumably it had further pipework - and possibly a float valve bolted to the flange.The floor of the tank is something of a wild flower meadow.
Structural engineer Andrew Wood is standing on one of the corner braces. He is a six footer and this gives an idea of scale. The tank sides are six feet tall (two 3 foot plates one atop the other).
In the corner is the overflow pipe.
Each base plate is 4 feet square, bolted to its neighbours at 6 inch intervals through vertical flanges 3 inches high. This means that the tank does not dry out, except in prolonged hot weather as rainwater puddles in each 4 foot square dish.
It can be seen that the vegetation has a high proportion of moss.
In the corner is the overflow pipe.
The bracings inside the tank are:
- cross braces to resist the outward pressure of water on the tank sides
- diagonal braces connecting the tank floor and sides
- less easily seen corner braces
- each cross brace has two vertical posts
The square holes along the top of the tank sides may have provided fixing points for railings or other equipment. The tank side plates all have flanges perforated by these holes at 6" centres. Some of the side plates are specials, where fixing lugs are cast in for the attachment of bracing rods.
The joints between plates are caulked by about 1/2" of whatever-it-is. I am told they used a mixture of putty, tar, iron filings and sulphuric acid, which produced a watertight seal as the mixure expanded. We need to verify this and shall almost certainly have to tackle this concoction when some base plates are removed for access, skylights etc.
- diagonal braces connecting the tank floor and sides
- less easily seen corner braces
- each cross brace has two vertical posts
The square holes along the top of the tank sides may have provided fixing points for railings or other equipment. The tank side plates all have flanges perforated by these holes at 6" centres. Some of the side plates are specials, where fixing lugs are cast in for the attachment of bracing rods.
The joints between plates are caulked by about 1/2" of whatever-it-is. I am told they used a mixture of putty, tar, iron filings and sulphuric acid, which produced a watertight seal as the mixure expanded. We need to verify this and shall almost certainly have to tackle this concoction when some base plates are removed for access, skylights etc.
One tank base plate was cleared of vegetation to expose the make up of the tank base.
Each base plate is 4 feet square, bolted to its neighbours at 6 inch intervals through vertical flanges 3 inches high. This means that the tank does not dry out, except in prolonged hot weather as rainwater puddles in each 4 foot square dish.
It can be seen that the vegetation has a high proportion of moss.
Fabulous project, we're considering buying a much smaller water tower in Berkshire, but it's brick and concrete. My experience of old Dutch Barge repairs suggests you consider spray foam on the underside of the tank floor to stop condensation, and poured bitumin (poured thick onto felt layers) into the tank sections to stop the rot. Good luck!
ReplyDeleteRichard and Annie
Thank you Richard and Annie for that encouragement and advice. I was thinking of bitumen for the base of the tank. There will be about a foot of insulation on top of the tank base so that may cure the condensation on the inside - we shall soon find out. Presently the condensation on the inside is like a shower of rain when the atmospheric temperature rises rapidly.
ReplyDeleteMark Rand