LU - Why Victoria Line was built in deep tube size though it was a new project during WWII

[hkstudent]

When looking at the development of underground networks across the world, most countries stopped building sub-standard size underground since WWI.

However, this leads to my query that, why Victoria Line was built in deep tube size despite there's warning about the capacity issue since day 1 and the whole infrastructure was new instead of reusing any old tube tunnels.

Does anyone have any thoughts on that?

(lucky that Crossrail II which was planned as a tube line was rededicated as a mainline service, which the size of the train will definitely not be in deep tube size)

 

[DelW]

I don't know whether it affected the decision, but the Victoria Line did re-use the ex Northern Line City Branch tunnels at Finsbury Park.

(Edit) actually, I think it reused one Northern Line and one Piccadilly Line tunnel, as the layout was reconfigured to allow easier interchange between the two lines.

 

[Ken H]

The cost of tunnelling increases with diameter.
There were problems getting through congested underground areas with the larger tunnels. Especially if they wanted to stay in the grey clay band. - Kings Cross was especially difficult.
A larger diameter would have made some of the same level interchanges difficult.
LT had a policy of sending all Underground trains to Acton works for overhauls. The Victoria lines has a link to the Piccadilly Line to allow such moves. If the trains were larger, they would not fit through the Piccadilly line tunnels and expensive overhaul facilities would have to be provided at the Northumberland park Depot.

These I have remembered from the LT book 'The Story of the Victoria line I have somewhere. it was published around 1970. Sorry if I have misremembered.

 

[gordonthemoron]

Crossrail was always intended to be suitable for mainline trains as far as I remember

 

[JonathanH]

However, this leads to my query that, why Victoria Line was built in deep tube size despite there's warning about the capacity issue since day 1 and the whole infrastructure was new instead of reusing any old tube tunnels.

Did the technology of the time and budget allow construction of a mainline sized tunnel? The money available prevented it going as far as perhaps initially intended.

The approach to building the Victoria line still seems to have been quite rudimentary compared to modern standards.

https://www.bbc.co.uk/programmes/p00sc29t

First transmitted in 1969, this is the story of the construction of the world’s most advanced underground system where automated trains are driven along hand-finished tunnels.

 

[swt_passenger]

Crossrail was always intended to be suitable for mainline trains as far as I remember

However, I think there were serious suggestions to build Crossrail 2 as a traditional ‘tube’ line in its Chelsea-Hackney version…

 

[Ashley Hill]

Another film here. It doesn’t answer the question of why it was built that size though

 

[Dstock7080]

The needs to return the rolling Stock used for major repair and overhaul at Acton?

 

[91103eastcoast]

I seem to remember that there was an idea of saving costs by not giving the Victoria line it’s own depot and the trains being maintained at Cockfosters Piccadilly line depot, which would require trains to be deep tube sized.

 

[swt_passenger]

I don't know whether it affected the decision, but the Victoria Line did re-use the ex Northern Line City Branch tunnels at Finsbury Park.

(Edit) actually, I think it reused one Northern Line and one Piccadilly Line tunnel, as the layout was reconfigured to allow easier interchange between the two lines.

Yes that’s right, to give cross platform interchange in the same direction. Also existing station platforms and tunnels were included at Highbury, Oxford Circus and Euston.

 

[Gloster]

A pure suggestion. Could it have been that, because the line was a latecomer, it was going to have to go relatively deep, but the state of tunnelling technology at the time meant that this would have been astronomically (if one can use such a word of a tunnel) expensive and effectively unaffordable?

 

[Cricketer8for9]

But it’s not that deep, certainly less deep than the Piccadilly line at King’s Cross and Green Park.

 

[Snow1964]

I don't know whether it affected the decision, but the Victoria Line did re-use the ex Northern Line City Branch tunnels at Finsbury Park.

(Edit) actually, I think it reused one Northern Line and one Piccadilly Line tunnel, as the layout was reconfigured to allow easier interchange between the two lines.

There was also the twin 1 mile experimental tunnels bored in 1961 from Finsbury Park to Netherton Road Tottenham. One was bored with a drum digger as 14 feet and unbolted concrete segment linings of various thicknesses tried (eventually settled on 6 inch). The inside of the tunnels was minimum 12’6” but some parts with the thinner lining are over 13 feet diameter. The other was bored at 13’1” and used unbolted cast iron segments with a wedge section. The tunnels were appraising recent tunnelling techniques that hadn’t previously been used on the underground

I think Netherton Road shaft later became emergency stairs.

 

[Ashley Hill]

There was also the twin 1 mile experimental tunnels bored in 1961 from Finsbury Park to Netherton Road Tottenham. One was bored with a drum digger as 14 feet and unbolted concrete segment linings of various thicknesses tried (eventually settled on 6 inch). The inside of the tunnels was minimum 12’6” but some parts with the thinner lining are over 13 feet diameter. The other was bored at 13’1” and used unbolted cast iron segments with a wedge section. The tunnels were appraising recent tunnelling techniques that hadn’t previously been used on the underground

I think Netherton Road shaft later became emergency stairs.

Something for Tim Dunn to explore.

 

[Ken H]

Something for Tim Dunn to explore.

They were incorporated into the victoria line.

 

[Ken H]

A pure suggestion. Could it have been that, because the line was a latecomer, it was going to have to go relatively deep, but the state of tunnelling technology at the time meant that this would have been astronomically (if one can use such a word of a tunnel) expensive and effectively unaffordable?

Great northern and city was built to main line size. Opened 1904. Its still in use. As the Finsbury Pk - Moorgate line still in use today.

 

[stuu]

Did the technology of the time and budget allow construction of a mainline sized tunnel? The money available prevented it going as far as perhaps initially intended.

The GN&C was built 110 years ago for full size trains. Budget and geography, especially budget, were the constraints

 

[mmh]

A similar question is why was the Heathrow extension small bore? In hindsight perhaps it should have been full size and an extension of the District line rather than Piccadilly. Probably a hard question to answer at the time, and perhaps impossible now. Times change.

 

[Taunton]

Maybe it was just that it suited the traffic projections of the time (late 1940s/50s), and there wasn't value in going for something larger. The design followed shortly after the substantial expansion of tube lines well out over onetime main line tracks.

The bizarre one is the Finchley Road to Baker Street section, tagged on the end of a full size route (there were initially Metropolitan trains to Stanmore), but built tube size because it was to fit onto the Bakerloo. Then it got extended as the Jubilee to Charing Cross, but was stuck with that tube size section north of Baker Street. Then it was extended again as the JLE, which on traffic projections really needed full size trains, but for the third time was constrained by what had gone before.

I think Heathrow was made Piccadilly Line because apart from already being the line to Hounslow it served more of the points across Central London air travellers wanted to go to than the District, which in any event was already full on the south side of the Circle. Sending the Piccadilly to Richmond and Ealing instead would have needed a great rip-up of all the various flying junctions and platforms along the way.

 

[Dr Hoo]

However, this leads to my query that, why Victoria Line was built in deep tube size despite there's warning about the capacity issue since day 1 and the whole infrastructure was new instead of reusing any old tube tunnels.

Could you provide details of these "warnings"? The line was planned in far quieter times, with lower London population and steady government encouragement on both people and employment to move out to 'new towns' such as Stevenage, Crawley, Bracknell, Hemel Hempstead, Harlow and so forth.

I remember it opening, with some short-haul shuttles just between King's Cross and Victoria in the early years. Many trains didn't run beyond Seven Sisters or (once the second phase to Brixton opened) Victoria. Commuting on it daily in the mid 1970s I don't recall any real capacity issues beyond obvious spikes for football at Arsenal and Tottenham Hotspur.

 

[Snow1964]

Could you provide details of these "warnings"? The line was planned in far quieter times, with lower London population and steady government encouragement on both people and employment to move out to 'new towns' such as Stevenage, Crawley, Bracknell, Hemel Hempstead, Harlow and so forth.

I remember it opening, with some short-haul shuttles just between King's Cross and Victoria in the early years. Many trains didn't run beyond Seven Sisters or (once the second phase to Brixton opened) Victoria. Commuting on it daily in the mid 1970s I don't recall any real capacity issues beyond obvious spikes for football at Arsenal and Tottenham Hotspur.

As originally planned it was route C, one of a number of routes proposed for after World War 2 by a development committee created in 1943 or 1944. The more catchy Victoria line name only came about in mid 1950s.

Until about 1951 the northern end would have been north of Northumberland Park in Lea Valley, it was then switched to Walthamstow. The plan was to take over the existing platforms at Wood Street and convert them into islands with Chingford trains using new outer sides, but British Railways didn’t want disruption to its newly electric services, and didn’t want to lose any goods yard. It was cut back to platforms below Hoe Street (and also saved one train).

Highbury was added for city connections, and value of cross platform interchange meant some diversions of other lines. Warren Street was served as it was seen as a development area in early 1960s. For a while there was a plan to build section south of Green Park as line D (a route along King’s Road to Fulham), but was built to Victoria instead with option of further extension southwards.

Yes it opened in phases, about 3 months apart, initially Walthamstow- Highbury, then to Warren Street, then to Victoria. In 1971 the Brixton extension was added (but Pimlico wasn’t ready so opened in 1972). The scissors crossovers at these early reversal locations were subsequently replaced by trailing crossovers for unplanned reversals.

From memory in 1970s alternate trains used to terminate at Victoria southbound or Seven sisters northbound (and at quieter times I think few terminated at Kings Cross). I lived in Walthamstow in late 1980s and even then on Sunday mornings service was only every 8-12 minutes, about third of the central service frequency. It was only after some 1972 stock was converted to run in middle of trains, thus displacing some ATO cabs to bookend extra trains, and increasing the fleet size was there more through trains to Walthamstow and Brixton.

 

[edwin_m]

Does having a full-size tunnel rather than a tube actually increase passenger capacity? The width of the trains is about the same and all technical equipment is below the floor or under the seats, so the floor area is similar for the same train length. There is less headroom, but that's mostly above the longitudinal seats, and in the aisles there's enough for everyone other than very tall people to stand (and being accessible to all groups wasn't a thing in the 60s, otherwise stations would have been built with lifts). On a main line train that space would have been used for luggage racks, but few people on the Tube have luggage (but it's an interesting point about why the Heathrow link was Piccadilly rather than District). So you basically lose a few square metres of standing space in each vestibule. To gain that back requires probably a doubling of the tunnel cross-section and therefore of many of the tunneling costs.

Additionally to that, someone has mentioned that parts of tunnels from other lines were re-used for the Victoria to provide cross-platform interchange, and re-building those stations would have been a lot more difficult if it had been necessary to enlarge them. I suspect the platform tunnels would have needed changing as well - they are bigger than main line running tunnels but I suspect the off-centre circular cross-section would still be foul.

 

[Magdalia]

The early 1960s plans for the Victoria line were on the assumption that the GN suburban network would be electrified before Victoria line construction was completed. At that time the technology for tunnel boring would have made standard loading gauge tunnelling prohibitively expensive in comparison to tube tunnels.

The opening of the Victoria line led to a big change in travel patterns from Walthamstow and a significant reduction in trains on the Chingford-Liverpool Street route. This allowed electrification of the Lea Valley line without need for any new rolling stock.

I worked in the Victoria/Westminster area for many years. I recall the 1980s off peak service being alternate Brixton/Seven Sisters and Victoria/Walthamstow. Terminating at Victoria always seemed of little value to me because emptying out the southbound trains took ages, almost enough time to get to Brixton. The Seven Sisters terminators went up to Northumberland Park to reverse and could be seen from passing trains on the Lea Valley line. I guess these were useful for crew changes.

It is difficult to pinpoint when the Victoria line became overcrowded, because the increase in use was gradual. This was partly a consequence of the increase in long distance commuting from north of the river. When I first started work most of my colleagues commuted into Victoria or Waterloo. But increased leisure use, especially West End shopping, was also significant.

By the millennium peak time travel on the Victoria line was getting very crowded. I can recall mornings where it took until the third train to be able to board at Kings Cross, and Victoria was frequently closed in the evening peak because of overcrowding. In the morning I switched to doing Thameslink to Blackfriars for the District line, and sometimes used this route in the evening too.

Travelling in overcrowded deep level tube trains is a very unpleasant experience where normal rules of social behaviour are suspended. I have not been in the Victoria line since I retired from work.

 

[edwin_m]

The early 1960s plans for the Victoria line were on the assumption that the GN suburban network would be electrified before Victoria line construction was completed. At that time the technology for tunnel boring would have made standard loading gauge tunnelling prohibitively expensive in comparison to tube tunnels.

The opening of the Victoria line led to a big change in travel patterns from Walthamstow and a significant reduction in trains on the Chingford-Liverpool Street route. This allowed electrification of the Lea Valley line without need for any new rolling stock.

I worked in the Victoria/Westminster area for many years. I recall the 1980s off peak service being alternate Brixton/Seven Sisters and Victoria/Walthamstow. Terminating at Victoria always seemed of little value to me because emptying out the southbound trains took ages, almost enough time to get to Brixton. The Seven Sisters terminators went up to Northumberland Park to reverse and could be seen from passing trains on the Lea Valley line. I guess these were useful for crew changes.

It is difficult to pinpoint when the Victoria line became overcrowded, because the increase in use was gradual. This was partly a consequence of the increase in long distance commuting from north of the river. When I first started work most of my colleagues commuted into Victoria or Waterloo. But increased leisure use, especially West End shopping, was also significant.

By the millennium peak time travel on the Victoria line was getting very crowded. I can recall mornings where it took until the third train to be able to board at Kings Cross, and Victoria was frequently closed in the evening peak because of overcrowding. In the morning I switched to doing Thameslink to Blackfriars for the District line, and sometimes used this route in the evening too.

Travelling in overcrowded deep level tube trains is a very unpleasant experience where normal rules of social behaviour are suspended. I have not been in the Victoria line since I retired from work.

I saw something on the Internet recently suggesting that there was going to be a separate branch from Seven Sisters, which may explain the third platform there and the rather lavish depot branch.

The line also suffers from several of the busiest stations having access right at the same end of the platform, so train loadings can be uneven. The rebuild of Kings Cross in around 2010 provided a second access towards the other end, but the sort of people who want to be at the end nearest the exit are often also the sort of people who would continue to use the old one because the new one is further to walk.

I agree deep tube lines can be highly unpleasant, and also prefer to use sub-surface when there's a choice. But I doubt that figured in whatever the 1960s equivalent of the spreadsheet was, when they decided what size to make the tunnels.

 

[Ken H]

I saw something on the Internet recently suggesting that there was going to be a separate branch from Seven Sisters, which may explain the third platform there and the rather lavish depot branch.

The line also suffers from several of the busiest stations having access right at the same end of the platform, so train loadings can be uneven. The rebuild of Kings Cross in around 2010 provided a second access towards the other end, but the sort of people who want to be at the end nearest the exit are often also the sort of people who would continue to use the old one because the new one is further to walk.

I agree deep tube lines can be highly unpleasant, and also prefer to use sub-surface when there's a choice. But I doubt that figured in whatever the 1960s equivalent of the spreadsheet was, when they decided what size to make the tunnels.

They did consider cut and cover to main line dimensions, but that was discarded as it would need to run under streets, and so would not be able to go on the best route. Also keeping to streets means it would have some sharp curves. Remember, some sharp curves on the tube where they tried to stay under streets are an operating problem even today.

 

[stuu]

Does having a full-size tunnel rather than a tube actually increase passenger capacity? The width of the trains is about the same and all technical equipment is below the floor or under the seats, so the floor area is similar for the same train length. There is less headroom, but that's mostly above the longitudinal seats, and in the aisles there's enough for everyone other than very tall people to stand (and being accessible to all groups wasn't a thing in the 60s, otherwise stations would have been built with lifts). On a main line train that space would have been used for luggage racks, but few people on the Tube have luggage (but it's an interesting point about why the Heathrow link was Piccadilly rather than District). So you basically lose a few square metres of standing space in each vestibule. To gain that back requires probably a doubling of the tunnel cross-section and therefore of many of the tunneling costs.

Additionally to that, someone has mentioned that parts of tunnels from other lines were re-used for the Victoria to provide cross-platform interchange, and re-building those stations would have been a lot more difficult if it had been necessary to enlarge them. I suspect the platform tunnels would have needed changing as well - they are bigger than main line running tunnels but I suspect the off-centre circular cross-section would still be foul.

The S-stock is about 30cm wider, which is about a whole row of people in crammed conditions. Bigger trains also mean people can get in and out easier, which must help dwell times and thus increase capacity

 

[Dr Hoo]

The S-stock is about 30cm wider, which is about a whole row of people in crammed conditions. Bigger trains also mean people can get in and out easier, which must help dwell times and thus increase capacity

Surely that depends primarily on the amount of door width available.

For any given door configuration, having more people in (or intending to join) the vehicle would tend to worsen dwell times.

 

[stuu]

Surely that depends primarily on the amount of door width available.

For any given door configuration, having more people in (or intending to join) the vehicle would tend to worsen dwell times.

Fair point, but the idea is for everyone to get on and off who wants to (I'm well aware this isn't always possible), so doing it quicker must be better. High capacity metros always have lots of doors for that reason

 

[RT4038]

However, this leads to my query that, why Victoria Line was built in deep tube size despite there's warning about the capacity issue since day 1 and the whole infrastructure was new instead of reusing any old tube tunnels.

On Day 1 the line opened between Walthamstow and Highbury, and there was definitely no capacity issue. Even after the line was open to Victoria there was no real capacity issue; south of Oxford Circus it was quite quiet until the Brixton extension opened. I should imagine overcrowding really started in the 1990s as the tube became busier.

The Victoria Line took a long time to get authorised, as the country was cash strapped in the 1950s when it was first proposed. Digging tube tunnels would have been cheaper than full size tunnels - if they had held out for that kind of money it would have just been seriously delayed (it was delayed enough as it was)

 

[BayPaul]

Surely that depends primarily on the amount of door width available.

For any given door configuration, having more people in (or intending to join) the vehicle would tend to worsen dwell times.

Go and stand on the platform at Hammersmith on a busy peak, and compare the District to the Picaddilly trains. The S stock just swallow people, compared to having to squeeze past each other to get on and off the Pic trains.