Report - Holloway, Holloway Extension, High Level and Ratcliff Storm Reliefs (aka Heavy Mettle), London 2018

[tallginge]

Soz, was trying to keep it to two pages and this was one pic that was sacrificed! It's a weird way of preventing the thames from entering the storm relief while still allowing storm flows to get through. Not quite sure if they are duckbill valves. I've never seen one from inside before. They pulse when the tide moves them and we could hear it lapping against the other side. They're strange that's for sure. Don't know why they removed the old flaps as it's not getting connected to tideway. It's confusingly referred to as the holloway in this link as well - it's the ratcliff

https://anonw.com/2015/05/10/thames...ruction-site-at-bekesbourne-street-limehouse/

Work should have started here now. We might be able to find out at some point soon. Ojay put a cool 3d image of this end in his report.

 

[tarkovsky]

Soz, was trying to keep it to two pages and this was one pic that was sacrificed! It's a weird way of preventing the thames from entering the storm relief while still allowing storm flows to get through. Not quite sure if they are duckbill valves. I've never seen one from inside before. They pulse when the tide moves them and we could hear it lapping against the other side. They're strange that's for sure. Don't know why they removed the old flaps as it's not getting connected to tideway. It's confusingly referred to as the holloway in this link as well - it's the ratcliff

https://anonw.com/2015/05/10/thames...ruction-site-at-bekesbourne-street-limehouse/

Work should have started here now. We might be able to find out at some point soon.

That’s a great pic and makes a lot more sense now, thank you. I’m glad I asked!

 

[Killa]

Awesome report with cool pics to boot

 

[tallginge]

Found these at the archives as well Holloway SR gradient (or inclination) is 1 in 4000. No wonder its full of silt, jeez. Holloway Extension gradient 1 in 130 - that ought to keep it going.....Note the poo slide hasn't been built yet and the catch box beneath the ventilation grill. Again, if anyone wants the original photos just ask

 

[jezzyboo]

thats a brilliant report and pics simply stunning

 

[TheVicar]

Just read this report again from the comfort of my office chair with a nice cold beer and relived the fun of the trips we had to this drain.
It was a seriously long old trip from the twin tunnel section east of ORLY all the way down to the Thames at Limehouse via Hackney.
Here's a pic I found online of the outfall to the Thames at low tide.

 

[KCM]

Top class report, with great info and super pics. Just amazing what lies below our feet. Amazing world of drains. Thank you so much. Keep Safe..

 

[tallginge]

Yeah, was a particularly long trip this one and i thoroughly enjoyed its rankness! 5 miles underground that day including the pill. Feet were aching the following day that's for sure

 

[pastybarm]

Yes, looks like duckbill valves. Perhaps the wooden (?) flap that was there before needing replacing, and this was a more long term replacement. That shiny new metal thing must last a long time?

 

[synchronoscope]

Facinating as ever. Calcinated sections are stunning. Brilliant thank you.