Report - - Fleet Storm Relief Sewer - London - 2014/2015 | UK Draining Forum | 28DaysLater.co.uk

Report - Fleet Storm Relief Sewer - London - 2014/2015


Loyal to the Drain
Regular User

Visited with Ojay and Adders (two trips combined for one report)

I'd seen barely more than two or three photos of the Fleet Storm Relief Sewer over the years and was puzzled yet intrigued as to why this was.
I first set foot in the Fleet only last year and whilst it was fascinating and beautiful, a quick peek into its Relief tunnel provoked further interest.

The Fleet Storm Relief Sewer was built in the 1870s by the Metropolitan Board of Works to provide extra capacity for the Fleet main line sewer.
The Storm Relief roughly follows the course of the Fleet Sewer but is considerably deeper below ground than the Fleet. It is only by the Thames below Blackfriars Bridge that they are on the same level.
On a few occasions during its course, the Fleet Sewer above can overflow via drop shafts into the Relief.

(First Trip - Myself/Ojay/Adders)
We entered the Relief to the north west of St Pancras Railway Station and began the decent of the spiral stone staircase until we reached the 8ft tunnel. North of this entry point the tunnel soon shrinks and is a pain to walk in so we ventured south for some distance until we reached this nice junction deep below Grays Inn Road. (Pic #4)





At this point I became slightly apprehensive as I recalled accounts from more than one source that drainers exploring the Fleet Main Line above had heard the booming sound of water and witnessed the previously dry relief sewer below suddenly carrying rushing water.
Whilst Ojay and I took few shots of this junction, Adders scurried up the 6ft tunnel to have a bit of a butchers. A few minutes later the sudden sound of thundering water came from the tunnel that Adders had disappeared up. We were preparing ourselves to grab Adders from the oncoming tsunami but nothing happened. We waited and waited some more before a little trickle of water emerged from the tunnel which increased to a gentle flow only 5-6 inches high. Before long Adders joined us completely unscathed. We returned to where we entered and left the drain at around 1.30am to be greeted with the warm July night still simmering away at 26 degrees C.


(Second Trip - Myself and Ojay)

Entering the system again at the same point we made our way to the junction. Curious to find out what this thundering release of water involved we made out way up the smaller 6ft tunnel. Close to where we thought this intermittent discharge erupted was a staircase that we waited by until the thundering began. From here we would be safe if a torrent came towards us. It soon became clear that this thundering flow of water was nothing more than a modest flow emerging from a 300mm side pipe a little further upstream. It was all bark with very little bite!
On inspection of said pipe, the reason for such a noise was that the water is released high up from somewhere above parallel to this branch of the Storm Relief and falls into a plunge pit to dissipate the energy of the falling water before entering the relief. Mystery Solved - sort of anyway!

We then made our way from here all the way down to the end of the Storm Relief beneath Blackfriars Bridge.
The tunnel doesn't have that many features along its significant length to photograph but made for a pleasant stroll due to its sizeable 8ft diameter and pristine yellow and blue brick construction.




Here the flow is intercepted by the Low Level #2 sewer.
Beyond these oak damboards is the final and tidal section of the tunnel.




Finally a shot of the famous Fleet outfall chamber where the relief makes its appearance on the left hand side.


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Staff member
Very nice, some interesting moments down here, covered in fresh when I slipped in at the split in the mainline that night and had to walk across London smelling rather fragrant at silly O'clock, at least my tripod was available to help out on the last outing, best not forget the plate again :p


too old to be reckless
28DL Full Member
Excellent set of pics. Makes it all look freshly constructed (except for the remnants on the walls of course). Is the last pic almost next to the Thames ?


28DL Member
28DL Member
Great pictures, I was always curious about whatever was at the bottom of those CSO drop shafts in Ojay's and reports on the River Fleet. Now I got to see it with some great quality shots from both of you.


Loyal to the Drain
Regular User
Thanks for the comments.
This really was a very clean, pleasant explore and one which I had been looking forward to doing for quite some time!

@pauln: Yes the last photo is about 20m from a final set of flaps before meeting the Thames beneath Blackfriars Bridge.


28DL Full Member
28DL Full Member
Nice, your photos are amazing!

I love reading the stories you mentioned about previous trips. Always makes for a good read. Still not sure you'd ever get me down a sewer though haha.

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