1950s Floodgates

[Jack Barry]

Hoping someone can help, I know that these are not working or whatever you call it but my question is to do with the ones that could be remotely controlled. Now as I understand it was open, close and auto. Can anyone say what happened to the signals in the different postions.

 

[Dstock7080]

delete

 

[Jack Barry]

Signals on the approach would return to danger.
if in an automatic signalling area the signals would be plated as “X”.

Thanks but I think I worded my question a bit wrong. Looking at the photo of the controls it shows the key in the open position now if the key was moved would the signals go to back if moved from open to the auto position which is the next position or would a train have to go through first. The next position is close so I think we can assume that the signals would go back .

 

[John Webb]

There is a detailed description of the operation of these gates - the ones closing off lines under the Thames - in O S Nock's book "Britain's Railways at War" (Ian Allan, 1971, ISBN 01 7110 0239 8). The gates were closed by local operators on instructions from the traffic controllers' office; remote operation as such was not possible as inserts had to be placed in the track to seal the gaps next to the rails prior to the gates being closed. Operators had a diagram showing track occupation in their area, and interlocks with the signalling stopped them from shutting their gate until the line was clear of trains. The book does not say what happened to signals when the gates were shut, but I assume they were put to danger before the gates could be shut. Electric power closed the gates in a minute, hand operation took 4.5 minutes.

 

[Jack Barry]

There is a detailed description of the operation of these gates - the ones closing off lines under the Thames - in O S Nock's book "Britain's Railways at War" (Ian Allan, 1971, ISBN 01 7110 0239 8). The gates were closed by local operators on instructions from the traffic controllers' office; remote operation as such was not possible as inserts had to be placed in the track to seal the gaps next to the rails prior to the gates being closed. Operators had a diagram showing track occupation in their area, and interlocks with the signalling stopped them from shutting their gate until the line was clear of trains. The book does not say what happened to signals when the gates were shut, but I assume they were put to danger before the gates could be shut. Electric power closed the gates in a minute, hand operation took 4.5 minutes.

John,
The gates described in that book are WW2 ones it's the later 1950s that I asked about.

 

[John Webb]

John,
The gates described in that book are WW2 ones it's the later 1950s that I asked about.

I had assumed that the ones that existed in the 1950s were the same as those installed for WW2! If they were changed in the 1950s, I wasn't aware of it. From the signalling side I would expect that, as with the wartime gates, signals would be placed at danger prior to the operation of the gates, with appropriate interlocking to ensure trains were clear of the tunnels before they were closed off.

 

[Busaholic]

I had assumed that the ones that existed in the 1950s were the same as those installed for WW2! If they were changed in the 1950s, I wasn't aware of it. From the signalling side I would expect that, as with the wartime gates, signals would be placed at danger prior to the operation of the gates, with appropriate interlocking to ensure trains were clear of the tunnels before they were closed off.

I'd be very surprised if the gates had been changed in the interim period given the huge amount of infrastructure that was needing to be sorted post WW2.

 

[bionic]

I saw the gates at Embankment Bakerloo shut during engineeeing work on Hungerford Bridge circa 2000. Unless I'm very much mistaken the running rails had been sawn off at the point where the gates were. The line was suspended south of Piccadilly Circus.

 

[bramling]

I had assumed that the ones that existed in the 1950s were the same as those installed for WW2! If they were changed in the 1950s, I wasn't aware of it. From the signalling side I would expect that, as with the wartime gates, signals would be placed at danger prior to the operation of the gates, with appropriate interlocking to ensure trains were clear of the tunnels before they were closed off.

The 1950s gates were installed from scratch, and are very different to the WW2 gates. They’re not designed specifically to cover the Thames, but partition off a wider zone which basically amounts to the city of London. Unlike the WW2 gates which come across from the side, the 1950s gates come down from above. Of interest is that they’re only designed to serve one direction - hence being referred to as entry and exit gates. There’s a pair of gates immediately adjacent to each other east of Liverpool Street on the Central Line, one set for entry and one set for exit on each line, making four gates in total.

 

[John Webb]

The 1950s gates were installed from scratch, and are very different to the WW2 gates. They’re not designed specifically to cover the Thames, but partition off a wider zone which basically amounts to the city of London. Unlike the WW2 gates which come across from the side, the 1950s gates come down from above. Of interest is that they’re only designed to serve one direction - hence being referred to as entry and exit gates. There’s a pair of gates immediately adjacent to each other east of Liverpool Street on the Central Line, one set for entry and one set for exit on each line, making four gates in total.

Thanks for that - I assume that they thought it was worth having better gates - the WW2 ones were put in with some haste. The WW2 gates were not only put in to cover the river crossings, others went in near to other danger spots, such as the Fleet River/sewer in the vicinity of King's Cross. I wonder if the 1953 Surge Flood engendered their placement?

 

[bramling]

Thanks for that - I assume that they thought it was worth having better gates - the WW2 ones were put in with some haste. The WW2 gates were not only put in to cover the river crossings, others went in near to other danger spots, such as the Fleet River/sewer in the vicinity of King's Cross. I wonder if the 1953 Surge Flood engendered their placement?

I've always worked on the, perhaps conspiracy theory, basis that the 1950s gates were to provide a strategic ring round the city area, such that if this area was destroyed and flooded then there would still be an Underground system further out.

 

[Jack Barry]

I had assumed that the ones that existed in the 1950s were the same as those installed for WW2! If they were changed in the 1950s, I wasn't aware of it. From the signalling side I would expect that, as with the wartime gates, signals would be placed at danger prior to the operation of the gates, with appropriate interlocking to ensure trains were clear of the tunnels before they were closed off.

The WW2 ones were mechanical and the later ones were hydraulic as I understand.

 

[bramling]

The WW2 ones were mechanical and the later ones were hydraulic as I understand.

I think that’s right. Certainly the 1950s gates (generally referred to as the “Special Tunnel Works” gates) have rather large equipment rooms associated with them. In the case of Kennington there’s quite a complex system of tunnels giving access to the machine rooms - with rooms for both the floodgate equipment and the associated signalling equipment).

By contrast the WW2 rooms are rather smaller. As a spin off they also tend to be closer to platforms. Few of the 1950s gates are readily visible to the public eye as they tend to be a little way from platforms - from memory Tottenham Court Road on the Northern is the most visible - I’m not sure if this was a deliberate policy or just a by-product of the complexity of their construction.

 

[Jack Barry]

I think you are right as the 1950s gates cannot be seen as such unless you have a really good tourch but I don't think the drivers would be too happy though. There must have been a lot of construction involved with these gates.