Report - Holloway Storm Relief, High Level SR & High Level and Ratcliff SR – London –Sep/Oct 2018

[TheVicar]

Explored with Tallginge.

I first started researching the High Level & Ratcliff Storm Relief about five years ago. I got so far and then something else distracted me and I forgot all about it until this August when Tallginge explored the end of the Holloway Storm Relief which continues on to the Ratcliff in Hackney.

Originally I had planned for this report to just be of the High Level & Ratcliff Storm Relief, but having ended up exploring the Holloway Storm Relief and the northern section of the High Level Storm Relief, it seemed best to present the lot in one report for ease of the reader’s understanding.
This I hope has been aided by the use of a map with the appropriate areas illustrated.

All photos were taken in Sep/Oct 2018 with the exception of #3 and #4 which were taken back in 2011 and #5 which was taken in 2015 and formed part of my report of the North Eastern Storm Relief: https://www.28dayslater.co.uk/threa...ief-sewer-deep-ochre-london-2011-2018.112726/

The Holloway Storm Relief (HSR) runs from Holloway to Hackney. It is 7ft in diameter and constructed from yellow brick for the upper two thirds and blue engineering brick for the bottom third.

Ojay’s report on the HSR provides some nice history of this drain so I won’t repeat it again here.

For a storm relief it is a pretty disgusting drain that really would benefit from a good clearing out. Much of the section between Holloway and Highbury is filled with gravel, stones and silt varying between six inches to well over a foot deep. In addition to this, sewage is almost permanently overflowing from the High Level Sewer (HLS) in Holloway, even when it has not rained in weeks.
There is very little to see in this section and combined with it being so nasty, I couldn’t be bothered to get the tripod out so just took a couple of quick flash photos (first 2) in a modern concrete chamber that joined the original tunnel. This is point A on the map.

In Highbury the HSR is intercepted by the North Eastern Storm Relief (NESR) at what is often referred to as the Orly junction and what a magnificent piece of civil engineering it is! This is point B on the map.
You will notice the very old wooden flap blocking the lower half of the tunnel heading east from this junction. Curiously, this was hinged to open and permit flows from east to west rather than the other way round which was the original purpose of this Storm Relief constructed by the Metropolitan Board of Works. I can only assume that this flap was installed when this junction chamber was constructed to divert all but the heaviest flows down the newly built North Eastern Storm Relief.
By 2013 the old wooden flap had been ripped from its rusty hinges and lodged in the stepped part of the junction chamber following what mush have been a severe cloudburst. It has only been prevented from being carried further by the chain attached to it as you can see in pic #5.

For years I had wondered what lay to the east of this junction along the HSR, and finally got to find out. After a relatively short distance, the tunnel splits into a pair of 4ft parallel tunnels for a distance of about 300 metres before resuming the single 7ft shape again. (Point C on the map).
We are not sure why this split was built, and the only thing I have been able to find is that the ‘New River’, which has since mainly been filled in used to run down the now grassy median of Petherton Road under which the HSR split section runs. This doesn’t however explain why the split section is so long.

Continuing east the going is slow and unpleasant as the water level is about 80cm deep, half of which is a varying mixture of thick silt, sand and gravel in varying proportions each step of the way for a few hundred metres.
Things began to improve when we got to the next features: a connection to the London Bridge Sewer to the south and a 3ft red brick Storm Relief leading up North to Stoke Newington. (Point D on the map)

Not long beyond this, there was another connection to the London Bridge Sewer. This is point E.

A good walk on and were had reached point F on the map in Hackney where the tunnel is intersected by a chamber that was added in the 1920s to divert the HSR just before its junction with the HLS. The two no longer meet as can be seen with the flow now spilling down three steps into the chamber and running off to a smaller 6ft tunnel on the right which is now marks the beginning of what is known as the Holloway Storm Relief Extension (HSRE).
The tunnel to the left is the last few feet of HSR which is blocked off by oak dam boards denying access to the HLS, however, a small hole in one of the boards affords a sneak peek at the turdy torrent flowing behind.

The HSRE runs parallel to the HLS for a distance of roughly 400 metres, but at just over 100 metres downstream the path to explorers is blocked by another set of dam boards (or should that be damn boards)!
A small gap at the bottom of the dam allows the minimal flow to continue on below.
To the right is a steep brick ramp of just over 6ft in height with an additional 2ft of wooden boards at the top.
When the sewer is in spate, this part of the HSRE acts as an inline detention tunnel until it reaches capacity at which point the water will overtop the boards at the top of the ramp.

The top of the ramp marks the beginning of the High Level Relief (HLR). This photo taken at the top of the ramp shows a wooden flap that leads from an overflow tunnel on the HLS which runs above the HSRE.
Turning around to face south with our backs to the wooden flap, the tunnel takes on a pill shaped construction and is about 7ft high.
Not long into the journey here, various little side pipes spew forth a filthy cocktail of PPP. (Piss, Poo & Paper, plus probably more if I’d studied the contents more carefully)
This is not something we were expecting to join a Storm Relief Sewer.
Along the way we ducked below a local sewer that passed above with a little over flow flap in the wall of the Storm Relief.
In this area lots of mineral deposits hung from the roof sporting an splendid array of wet wipes, fanny napkins, jimmy hats, plastic bags etc.

Continued.......

 

[TheVicar]

With the sound of running water becoming more of a roar, the familiar sight of a staircase guarded with a pair of heavily ‘decorated’ catch chains came into view. (Point G on the map)
This reminded me of the staircase in The North Western Storm Relief at Notting Hill only this had the luxury of a handrail and the steps were not quite as slippery.

While Tallginge climbed up a ladder to see what was above, I found myself humming ‘Handrails and Jamrags’ by Rod Stewart while negotiating the heavily laden catch chains!

Once we reached the bottom of the stairs the tunnel changed shape to a regular round brick pipe but only 6ft in height. We continued a little further, but due to time constraints we exited the drain as the Ratcliff was calling.

If you haven’t lost the will to live after reading this far, then before the photos of the High Level Relief you will recall that our path downstream in the Holloway Storm Relief Extension was blocked by the dam boards. Here it was necessary to return to street level and walk south before dropping back into the HSRE at what marks its end and the start of the High Level & Ratcliff Storm Relief (HLRSR). See point H on the map.
Here the HLS sewer passes above in an overflow chamber which leads down into the HLRSR.
In this photo, the end of the HSRE is to the right and the start of the HLRSR is to the left.

This picture was taken facing north showing the end of the red brick tunel HSRE.

We ventured up the final part of the HSRE until we reached the other side of the boards that blocked our path earlier on. The only option here was to turn around and head south beyond our entry point and begin the long journey (over 3 miles) all the way from Hackney, down though Stepney and Bethnal Green until we reached Limehouse where the drain terminates at the Thames.

The high-level and Ratcliff storm relief sewer was constructed between 1881 and 1884 which is pretty impressive considering the length it runs for.
For such a long drain, the features were few and far between, although a little way south of the previous photo the Wick Lane branch joins the main tunnel from the east by way of an iron flap. (Point J on the map)

Going downstream, an umbrella would have been a good idea for some sections, as there was a considerable amount of water raining down from the tunnel roof for much of the trip which got us quite wet. The constantly seeping water also caused plenty of mineral formations, some of which made a noticeable impact on the capacity of the tunnel in parts and provided plenty of stalactites for more litter and bathroom products to wrap themselves around and dangle in your face.

One rather nice but inconvenient feature was where the drain split into two smaller 5ft tunnels that then quickly flattened into 3ft horizontally oval cast iron tunnels which curved around a bend as the drain passed below the tube lines that run close to Mile End Road.
Getting through this part involved shuffling along on the knees which I have to admit wasn’t my favourite part of the trip. (Point K on the map)

The interesting thing here is that when we came out the other side of the tunnels and turned around, there was a third tunnel now which lead off west to join up with the NESR as shown
in this photo that Tallginge took when we visited it earlier on in the year. You can see the tunnel marked in green on the map running to the left of Point K.

Continuing on for 10 minutes or so we notice the water level beginning to rise.

Before long, there is a lovely junction chamber where a heavy cast iron flap is held open by some strong chains.
Beyond this flap is a short tunnel leading to a drop shaft into the Low Level Sewer. The regular flow which would have headed on down to the Thames was now being diverted down there instead by a 3ft dam board blocking the final stretch of tunnel behind the camera from where this photo was taken. This is point L on the map.

Climbing over the dam board and trudging through thick mud for a couple of hundred metres or so, we finally reached the end of the drain at point M on the map.
It was different to what we were expecting as a very recently installed temporary structure had been placed just beyond the iron work that would have supported four cast iron flaps.
The structure has been installed to allow work to begin on the much needed connection to the Thames Tideway tunnel which will considerably reduce pollution of the river, much of which are solids that do not break down naturally such as wet wipes and plastics.

The 4 black circles you can see in the structure are a type of valve that permits heavy overflow from the drain into the river but not vice versa. It was evident that the tide was well in at this point and at a higher level than we were as the 4 valves were moving slightly as the waves on the other side were lapping up against them. This was slightly unnerving so the photo was taken quickly before we returned upstream to a nearby exit point and finally some fresh air!

Thanks to Tallginge for the company and backlighting skills!

 

[Ojay]

Great report and pics, always good to see this stuff first hand as trying to fathom It all out from maps and previous accounts has always been hard work

The whole thing is a festering mess unlike other reliefs..

Yes as for the ‘new river’ I’m not convinced that’s the reason as the split ends where that is/was located.

I’d say it was probably pipe jacked there due to poor land conditions and/or to relieve the area and local basements from flooding similar to the counters and Kensington situation.

 

[TheVicar]

Great report and pics, always good to see this stuff first hand as trying to fathom It all out from maps and previous accounts has always been hard work

The whole thing is a festering mess unlike other reliefs..

Yes as for the ‘new river’ I’m not convinced that’s the reason as the split ends where that is/was located.

I’d say it was probably pipe jacked there due to poor land conditions and/or to relieve the area and local basements from flooding similar to the counters and Kensington situation.

Cheers Ojay!
It certainly is a filthy old bit of drain, the Holloway.

I'm not convinced the New River has anything to do with the split either as the Storm Relief runs too far underground for that to have been a problem and as you say the river ran towards the very end of the split and not right in the middle. It's just a shame there is so little history on these magnificent underground brick creations!

 

[tallginge]

Another thorough and detailed report, mate Was nice to see that staircase in the HL relief, that split in the holloway and the nice overflow chamber from the HL into what "used" to be the start of the HL and Ratcliff relief, I'd not seen them pics anywhere before. It's good to finally have an understanding of how that whole area now drains, especially as there's no detailed info available to better explain exactly why they added to certain sections, how they constructed them and when.

Regarding the split - it is below what used to be Aberdeen Park, an old private estate (1860's) with a church in the middle but the church isn't quite above the split and the New River, although culverted and nowhere near as deep, is only above the last 30m of the split from the eastern end, so why i'm no nearer to explaining its purpose or why it's much longer than any other i've come across

I’d say it was probably pipe jacked

I don't know a lot about the history of pipe jacking but wouldn't have thought the Victorians would do that with brick pipes. The split could well be something to do with bad ground conditions, though, with a larger tunnelled pipe either sinking under it's own weight or too much ground water entering the tunnel because it was so big! Two smaller tunnels would take longer and be more costly but that may have been the only practical way of building them. What I do know is the split was built at the same time as the rest of the Holloway and not added at a later date.

Good times down there, bud, plenty more to see

 

[Killa]

First class report, very well documented!
Awesome pics, well done
Ref. Pipe jacking, possibly tunnelled using cast iron segments, then lined in brick? Earliest reference I have on pipe jacking is 1970’s, usually with concrete pipes, but correct me if I’m wrong.....

 

[Killa]

On the last pic, showing the outfall, these must be “duck valves”, but they look undersized compared with the remains of the old flap valves, which resemble those of the outfall of Deep Ochre.

 

[TheVicar]

First class report, very well documented!
Awesome pics, well done
Ref. Pipe jacking, possibly tunnelled using cast iron segments, then lined in brick? Earliest reference I have on pipe jacking is 1970’s, usually with concrete pipes, but correct me if I’m wrong.....

On the last pic, showing the outfall, these must be “duck valves”, but they look undersized compared with the remains of the old flap valves, which resemble those of the outfall of Deep Ochre.

Thanks Killa!
You are correct about the duckbill valves, I'd never seen or heard of them before but they are a very ingenious invention.
As you say they are smaller than the old flaps that they replaced but assuming they are a temporary measure while the Tideway interceptor is being worked on combined with the flap to the Low Level sewer being kept open, they will hopefully do the trick.

 

[pastybarm]

@TheVicar : Your comments about agc ue over on uer.ca aside, to respond to the duck valves discussion, they have them at the manchester square pumping station outfall in Blackpool, there may be a pic still on this site, but not sure now. I do recall there being a report on said location on this site though. pb.

 

[Lord Oort]

Wow, that was a great report and fucking awesome photos mate!!

 

[siologen]

Such a grotty system lol.
This and Counters Creek... its like someone fucked up the gradient, n they just end up full of sitting water and piles of toilet.
I was down at the outfall, in 2009, the old iron flaps had fallen off n been replaced with an aluminium affair.
Until these reports, i dont think all of this sydtem has been explored.
The Upper Holloway, and mid section of the Ratcliff had, but id never seen pics of the H-J sections, nor that smaller link to the NE SR.
Hard Yards fellas!
That upper concrete section behind the square flap was boring AF when i did it.

 

[TheVicar]

Such a grotty system lol.
This and Counters Creek... its like someone fucked up the gradient, n they just end up full of sitting water and piles of toilet.
I was down at the outfall, in 2009, the old iron flaps had fallen off n been replaced with an aluminium affair.
Until these reports, i dont think all of this sydtem has been explored.
The Upper Holloway, and mid section of the Ratcliff had, but id never seen pics of the H-J sections, nor that smaller link to the NE SR.
Hard Yards fellas!
That upper concrete section behind the square flap was boring AF when i did it.

Hi Siologen,

The Holloway really is a grotty tunnel of filth but it was good to finally see what it had to offer. It always bugs me to see a bit of a drain and then keep on wondering what the rest must look like or lead to because I ran out of time to see it all.
I reckon you are right about the gradient, it appears to be practically level for most of the route west to east.
Yes hard yards but good fun

Do you know the name of the sewer behind the boring square flap? I'm sure I remember reading about it at one point but forgot the name.

 

[tallginge]

As a storm relief i doubt there's very much fall along its length at all. It just 'relieved' the high level when it was full and eventually used to flow back into it. Looking up that shaft, that we walked west of orly to, goes to show how much fall the high level has. That'll not silt up!

 

[Ojay]

Im fairly certain it’s not sewer behind the flap, it’s a piped dropshaft that deals with surface run off from the Emirates, I remember Winch has a pic of it around the time of construction or soon after, there wasn’t a flap there at that point unless that feature was further West as I turned back around the Emirates years ago as a.) appeared featureless and b.) was full of silted crud and was disgusting and that’s coming feom me!!

 

[siologen]

Do you know the name of the sewer behind the boring square flap? I'm sure I remember reading about it at one point but forgot the name.

I knew it as simply the North London SR. Its about a mile of dry featureless RCP, with a few drop shafts.