Special Tunnel Works

[JR 15secs]

Can anyone help looking through some old traffic circulars 1950s there was mention of work associated with special tunnel works at locations on most lines. Whats it all about.

[abe]

In a word - floodgates. Eighteen were constructed in a ring around central London between 1953 and 1957. I believe that none are still operational. They were sited as follows:

Northern line

• North of Kennington (both branches)
  
• South of Tottenham Court Road
  
• North of Moorgate
  

Central line

• East of Tottenham Court Road
  
• East of Liverpool Street
  
• West of Bethnal Green (risk of flooding from the Lea Valley)
  

Piccadilly line

• East of Green Park
  
• South of Russell Square
  

The Victoria line was also constructed with a pair south of Green Park for the same reason. A single massive floodgate east of South Kensington (District/Circle) was also installed at (I think) the same time, this being the only one on a sub-surface line.

I hope that this helps!

[Deleted]

The Bakerloo Line gates might still work, and the Jubilee Line gates definitely work.

As for the rest... *shrug*

[Deleted]

abe said:

Central line

• East of Liverpool Street
  
• West of Bethnal Green (risk of flooding from the Lea Valley)
  

Isn't that essentially the same?

[abe]

There are two separate sets of gates between Liverpool Street and Bethnal Green. The gates closer to Liverpool Street are part of the ring around central London; those closer to Bethnal Green were installed to counter the risk of flooding from the east. The Lea Valley and Mile End area are very marshy ground. Why two sets were installed instead of one to serve both purposes I don't know...

One suggestion I have concerns the type of gate used. Unlike those installed in WWII (which slide horizontally across the tunnels) these gates descended vertically. It is not stated whether they slide or hinge down. If they are hinged then the direction of hinging will affect which side they are designed to take the pressure. Since the ring around central London was to prevent flooding outside this area in the event of bombing and a breach in the central zone the gates east of Liverpool Street would be designed to take pressure on the London side (west). The Bethnal Green gates would be fitted the other way to resist pressure from the east. This is just a hypothesis though...

And interestingly no gates were installed on the Bakerloo. Perhaps it was felt that the existing gates at Waterloo and Trafalgar Square were sufficient.

[Deleted]

That hinge direction theory sounds plausable. Thanks.

[Deleted]

embankment (district) has floodgates

[JR 15secs]

abe, thanks found a list on Clive's underground site although it says only 1 gate at Moorgate, on google search there is a thread that says special gates controlled from Bull & Bush and the WW2 gates from Leicester Square?

[abe]

I think that you're right about Moorgate. I believe that the gate is installed in a large tunnel (possibly adjacent to the crossover, although this is guesswork). The difficulty with the numbers is that some sources list sites, whilst others list gates. There also tends to be confusion between the WWII gates, which were indeed controlled from Leicester Square during the war, and the later gates.

The wartime gates were also controlled from Bull & Bush. The control panel from Leicester Square was moved there, probably in the early 1950s, and a new panel fitted next to it to control the new gates. It would appear that all had fallen into disuse (although were perhaps still operable) by the mid-1970s.

[Deleted]

Think i mentioned it elsewhere previously - but i've seen the Bakerloo floodgates at Embankment closed during the closure for Hungerford Bridge support re-boring circa 2000. A weird sight indeed! ;D