|Index & Notes|
Clustered in Space and Time -bare
Removing the visual distraction of the streets and houses, at left we have a single cluster that just kept getting worse - 64, 72, 77, 85, 88 - the breaks kept coming closer together. If this had been at one end of the main, we might have replaced just the cluster and cut-in a valve to separate that from the rest. But it was just in the middle of the valve-circuit, so we couldn't save much; we just replaced a whole block.
And that wasn't even a question, at right. Not so much multiple clusters as just everywhere. More breaks happened that we'd allow today as back then we were getting a thousand breaks a year (last year was 220) and we just couldn't get to it soon enough. I know it doesn't take a conference paper to tell you to replace this main, I'm just defining one end of the spectrum.
If I can draw your attention to the main at the bottom of this slide, the one with no main breaks at all since install in 1949, I can show you how it soon will become a single-cluster case - one we can save.
© Roy Brander, P.Eng 2016