Rail to a new airport?

[nerd]

I make the total passenger numbers for the airports to something like ~130m/yr.
Assuming passenger numbers counts a round trip twice (I can't get any information on that topic?) that is 65m passengers per year in each direction.

If the airport is open to 360 days a year that is roughly 180,500 passengers per day or ~9000 passengers per hour.
If we assume a 50% capacity factor but with only 50% of passengers coming out of central london that leaves us at 9000 seats per hour.

400m double deck trainsets could easily get ~1500 seats with such short journeys as the ones we are proposing, which means 6 trains per hour or something.

So something like 3 platforms with rapid turnarounds?

A better idea might be an attempt to work out how many people use the rail services to the existing airports, and then assume that the remaining passengers either use the parks and rides or drive all the way to the airport.

EDIT:

Gatwick Airport station has 13 million passengers per year
Stansted Airport station is 3.8 million passengers per year
Luton Airport station is 2.4 million passengers per year
I have no information that is reliable for Heathrow station.

So that is 19.2 million passengers plus however many for Heathrow.

I will just fudge Heathrow by adjusting the 68 million passengers to about 44 million (to account for the transfer passengers), then set the number of passengers using rail to about 40%, taking us to 17.6 million passengers for Heathrow.

Giving us 36.8 million passengers for rail services out of the centre of the city. (Ofcourse some Gatwick passengers would be coming from the south).

That takes us about a 100,000 passengers per day, or roughly 50,000 passengers each way, or roughly 40 full trainloads a day, or perhaps 4 per hour.

EDIT #2:

I say we could set:

6tph Central London
6tph Gatwick
6tph Heathrow
6tph Luton/Stansted (stopping twice)

Which leaves plenty of room on the loop for other high speed services and international runs. As the lines out of the airport have 36tph potential capacity and majority of the loops would be loaded at far lower than the 24tph that suggests on the face of it.

You are out by a factor of two on most of those numbere HSTEd.

A 'London Hub' airport would need to handle at least 150m passengers per year, projected to more the 200m by 2050.

The Foster aiport proposal for the Isle of Grain - which would have involved transfer of all the scheduled business from Heathrow and Gatwick- incoroporated a HSR station to handle 300,000 passenger movements per day, plus a Crossrail link (onto the South East arm) to handle 150,000 passengers per day. Foster proposed 12 HSR platforms (on two levels) and two Crossrail platforms. It would be the largest mainlline station in the UK by passenger volume; slightly larger than Waterloo.

Granted that the Foster HSR line would also have served his orbital freight line; his passenger volumes are about right for a single London Hub located to the east of the city. He was assuming that a bit less than half of the passengers using the station would take an HSR link into central London (quite where was not clear, but probaly St Pancras); and the rest would arive on a semi-orbital HSR line alongside the northern half of M25 as far as Heathrow. Passengers from outer London, and the rest of the UK, would take the M25 to one of a series of entry stations along the HSR line (where all the long-stay parking and car hire would be located), and would then take a train into the hub airport.

The point is that, if the airport is on a island or on reclaimed estuary land, there can be no parking on site. The nearest parking would probably be across the Thames at Tilbury. Everyone (400,000 to 500,000 passengers pe day, plus 100,000 employess) would need to take public transport or a taxi to get onto the the airport site itself.

Numbers would be considerabley more manageable, if Stansted were to be chosen as a hub airport site; on the assumption that this would be a 'second' hub with Heathrow remaining open (as at Tokyo Narita). Heathrow has the capacity to handle over 80m passengers per year (the current impression of its being full is an artefact of the airlines deliberately using smaller than optimal aircraft, in order to fill their slots). Hence a Stansted hub would need to be able to accommodate 70m-100m passengers per year at most. Moreover, it is likely that a higher proportion would be able to drive and park near the airport; and (being on the north side of the city) a proprotion of trains could run through to Cambridge, Peterbough and the ECML.

A Gatwick hub would be a bit more problematic; mainly because there is propably not enough space to expand the airport site itself to full 'hub' status. But it could certainly handle 50m passengers per year with an extra runway - which might be just about enough. The problem for Gatwick is that it sits across the Brighton line, which is chock full as it is; and fitting a second HSR line into the City from Gatwick would be much more expensive than constructing one in from Stansted.

 

[JamesRowden]

A Gatwick hub would be a bit more problematic; mainly because there is propably not enough space to expand the airport site itself to full 'hub' status. But it could certainly handle 50m passengers per year with an extra runway - which might be just about enough. The problem for Gatwick is that it sits across the Brighton line, which is chock full as it is; and fitting a second HSR line into the City from Gatwick would be much more expensive than constructing one in from Stansted.

Plenty of space could be made to the North West of Gatwick if it is worth knocking down some villages and a few commercial buildings (an Airport metro service between the terminals and station could be built).

An expensive expansion of the capacity on the Brighton Mainline will be required even if Gatwick is not expanded. Extend HS2 to Brighton with a stop at Gatwick and the airport is accesible by High Speed rail to a large proportion of the country without increasing journey times between London and the North as the OPs suggestion would. Also Gatwick's already got a very good selection of rail lines with some that are presently underused (2tph Redhill-Reading [3 car], 1tph Redhill-Tonbridge [4 car]).

Another place that might well make sense for the Hub airport would be Ashford (Kent). Another place with a great variety of rail lines and it already has a High Speed line (which is apparently underused) to London and Eurostar services (since it is supposed to be a European Hub, direct high speed rail services to France and Belgium should be quite useful).

Some people in this thread have been suggesting closing all of London's airports as a result of opening a hub. The usefulness of a Hub is that it can have a good service to locations that would not be commercially viable at other airports (e.g. a city in the far east that presently does not have any services to Europe). Therefore, if it is already commercially viable to run frequent services to all major European destinations from Londons biggest airports at the momment, adding a hub on the other side of London of an existing airport should not effect the attraction for the customers on the same side of the capital (in London and out of London) as the existing Airport to such services.

 

[HSTEd]

You are out by a factor of two on most of those numbere HSTEd.

A 'London Hub' airport would need to handle at least 150m passengers per year, projected to more the 200m by 2050.

I have been struggling for good data on the subject, so I will use that estimate in my future calculations.

The Foster airport proposal for the Isle of Grain - which would have involved transfer of all the scheduled business from Heathrow and Gatwick- incoroporated a HSR station to handle 300,000 passenger movements per day, plus a Crossrail link (onto the South East arm) to handle 150,000 passengers per day. Foster proposed 12 HSR platforms (on two levels) and two Crossrail platforms. It would be the largest mainlline station in the UK by passenger volume; slightly larger than Waterloo.

My numbers were not attempted to identify the passenger numbers for the airport's station, I was proposing to primarily identify the number of passengers for the London end of the link, since that is the expensive part. (Adding additional platforms in central london is far more expensive and time consuming than adding them in the middle of nowhere where the crown estate is the only person you have to deal with).
Luckily Stansted and Luton are only 15% the size of Gatwick and Heathrow together so these numbers should still be reasonably valid as a first order estimate, I will adjust them up by 20% to make sure.

Granted that the Foster HSR line would also have served his orbital freight line; his passenger volumes are about right for a single London Hub located to the east of the city. He was assuming that a bit less than half of the passengers using the station would take an HSR link into central London (quite where was not clear, but probaly St Pancras); and the rest would arive on a semi-orbital HSR line alongside the northern half of M25 as far as Heathrow. Passengers from outer London, and the rest of the UK, would take the M25 to one of a series of entry stations along the HSR line (where all the long-stay parking and car hire would be located), and would then take a train into the hub airport.

I think St Pancras would struggle to cope without any domestic 400m paltforms.
Hence my suggestion of permanently rerouting C2C into Liverpool Street after Crossrail and completely reconstructing Fenchurch Street into the "Airport Terminus".

The idea of building a semi or fully orbital HSR line with lots of park and rides on it is something I support, it certainly avoids an insanely expensive construction of a motorway parallel to the M25, which is what would be required otherwise.

The point is that, if the airport is on a island or on reclaimed estuary land, there can be no parking on site. The nearest parking would probably be across the Thames at Tilbury. Everyone (400,000 to 500,000 passengers pe day, plus 100,000 employess) would need to take public transport or a taxi to get onto the the airport site itself.

Why? Parking really doesn't take up that much room, especially once you get parking structures like the 13 story monsters they have at Dallas/Fort Worth Airport.
Remember thanks to runway spacing issues (~1000m even with LAAS apparently) there will be large spaces between the parallel runways that are not being used for anything.
These spaces could be left open to the sea but this would be a waste of money since the cost of artificial islands is quite strongly dependant on the length of the "wall" that has to be built up before the interior space can be filled in.
Closing off both ends of these spaces and draining them would probably be cheaper (or atleast negligibly more expensive) than having six runway shaped islands with causeways between them, it also reduces the consequences if a plane wanders off the taxiway due to pilot error or winds or whatnot.
If you are worried about wind vortices or similar the infrastructure could be kept reasonably "short" above ground since the parking structure could easily start at the level of the estuary's seabed.

You can see this even in single runway offshore airports that have significant space spare on the "islands" which on the face of it would have been purchased at absurd expense.

Numbers would be considerabley more manageable, if Stansted were to be chosen as a hub airport site; on the assumption that this would be a 'second' hub with Heathrow remaining open (as at Tokyo Narita)

The thing about Tokyo is that until very recently Haneda airport was almost entirely domestic flights while Narita was the majority of the International flights, this meant that there was not enormous amounts of demand for transit between the two hubs.

In the London Scenario there is no enormous domestic air market and there likely never will be with the development of HS2 et al.
This means you are talking about having two international hubs which has obvious problems.

I'm afraid that things like Dallas Forth Worth or Hartsfield-Jackson Atlanta Airport show the direction of travel for major hubs, and that is towards biiiiiiig.
--- old post above --- --- new post below ---

Plenty of space could be made to the North West of Gatwick if it is worth knocking down some villages and a few commercial buildings (an Airport metro service between the terminals and station could be built).

This would be even more problematic than a Heathrow expansion if the current arguments over having a second runway at Gatwick are indicative.
A Thames estuary airport gets all this without knocking down thousands of houses, or at least without demolishing entire villages (which always plays badly in the press)

An expensive expansion of the capacity on the Brighton Mainline will be required even if Gatwick is not expanded. Extend HS2 to Brighton with a stop at Gatwick and the airport is accesible by High Speed rail to a large proportion of the country without increasing journey times between London and the North as the OPs suggestion would. Also Gatwick's already got a very good selection of rail lines with some that are presently underused (2tph Redhill-Reading [3 car], 1tph Redhill-Tonbridge [4 car]).

You want a large size north-south through station at Euston?
That is going to make the cost of my project look small.
The underground environment south of Euston road is overfilled as it is.

And the Brighton Main line's capacity cannot be feasibly improved without making the WCRM look like a triumph of frugality, a whole duplicate line will likely be required. (There is a reason I keep going on about a South Coast Shinkansen).

Another place that might well make sense for the Hub airport would be Ashford (Kent). Another place with a great variety of rail lines and it already has a High Speed line (which is apparently underused) to London and Eurostar services (since it is supposed to be a European Hub, direct high speed rail services to France and Belgium should be quite useful).

HS1 might be "underused" but I doubt it has the capacity necessary to handle the loads an airport the size of a major hub would require.
And then you have to somehow squeeze additional capacity into St Pancras to handle several full length trains an hour.

You an also obtain a high speed service from the continent into a East-of-London airport with a relatively shrot stretch of track through relatively open country.
The close-to-London parts of these things are always the expensive parts.

Some people in this thread have been suggesting closing all of London's airports as a result of opening a hub. The usefulness of a Hub is that it can have a good service to locations that would not be commercially viable at other airports (e.g. a city in the far east that presently does not have any services to Europe). Therefore, if it is already commercially viable to run frequent services to all major European destinations from Londons biggest airports at the momment, adding a hub on the other side of London of an existing airport should not effect the attraction for the customers on the same side of the capital (in London and out of London) as the existing Airport to such services.

That is a relatively simplistic view, there are other benefits, currently some European destinations recieve service from more than one London or South East Airport.
If South East airports are consolidated either large aircraft can be used that are more slot-efficient, or a greater frequency of service can be run to each destination.

The distances in the South East are sufficiently small that "moving around London" is not going to be a great time waster if the proper infrastructure is put in place.

EDIT:

At 90mph the Shivering Sand location is only 10-15 minutes further out than the Isle of Grain location.
So I dunno if its still viable or not... I will crunch the size of a London HSR terminus assuming no Crossrail extension.

EDIT #2:

And even if parking spaces are restricted on the island, having parking on the nearest available land would only require something like two platforms for a shuttle metro service along the bridges.

 

[JamesRowden]

You want a large size north-south through station at Euston?
That is going to make the cost of my project look small.
The underground environment south of Euston road is overfilled as it is.

Two underground through platforms at Euston would be enough with terminating services sent to the surface station. A similar setup could also be built under Victoria. In the Crossrail threads it has been stated that it is the underground stations that are the very expensive parts rather than the tunnels. Perhaps my idea could be joined with the present idea for Crossrail 2 (which has stations at Euston and Victoria).

And the Brighton Main line's capacity cannot be feasibly improved without making the WCRM look like a triumph of frugality, a whole duplicate line will likely be required. (There is a reason I keep going on about a South Coast Shinkansen).

I think that an extra pair of tracks into London from the Brighton Mainline is going to be required anyway. Network rail have looked at the possibility of 16-car trains and double decker trains and came to the conclusion that neither would be practical. I doubt that there is enough space on the surface through London and so I think that an Underground Express route (like HS1/2) that leaves the surface routes for semi-fast and stopping services would make a lot of sense. Also there is the advantage of redundancy (alternative route for passengers during disruption rather than having to travel on bus service, via Dorking or via Tonbridge).

You an also obtain a high speed service from the continent into a East-of-London airport with a relatively shrot stretch of track through relatively open country.
The close-to-London parts of these things are always the expensive parts.

But would it be worth running a frequent international service from the airport if the train did not also have non-airport travellers (e.g. Paris-London) as a Eurostar service that stops at Ashford would?

The distances in the South East are sufficiently small that "moving around London" is not going to be a great time waster if the proper infrastructure is put in place.

I was thinking about capacity problems rather than time (e.g. M25).

 

[HSTEd]

Two underground through platforms at Euston would be enough with terminating services sent to the surface station. A similar setup could also be built under Victoria. In the Crossrail threads it has been stated that it is the underground stations that are the very expensive parts rather than the tunnels. Perhaps my idea could be joined with the present idea for Crossrail 2 (which has stations at Euston and Victoria).

Two underground through platforms is unlikely to be sufficient if the incoming trains are using intercity layouts.
We are probably talking a significant portion of the entire High Speed traffic through Euston to generate sufficient connectivity.

I think that an extra pair of tracks into London from the Brighton Mainline is going to be required anyway. Network rail have looked at the possibility of 16-car trains and double decker trains and came to the conclusion that neither would be practical. I doubt that there is enough space on the surface through London and so I think that an Underground Express route (like HS1/2) that leaves the surface routes for semi-fast and stopping services would make a lot of sense. Also there is the advantage of redundancy (alternative route for passengers during disruption rather than having to travel on bus service, via Dorking or via Tonbridge).

Those two tracks will likely be required anyway as you say.
Which means that traffic capacity will probably not be available for an airport shuttle.

We are likely going to need to tracks out of London being largely dedicated to the airport shuttle (probably 6 or 10 full paths out of a possible 18 or something)

But would it be worth running a frequent international service from the airport if the train did not also have non-airport travellers (e.g. Paris-London) as a Eurostar service that stops at Ashford would?

The fact that it is an Airport means that it will have to have security anyway, indeed you could route passengers through an abbreviated security check thanks to them already having been partially cleared at wherever it is they came from. You could also allow international arrival passengers to pick up baggage airside and proceed directly to the Eurostar platforms with no further checks.

This means that the overheads for running extra destinations are far smaller than they appear.
If you only ran to destinations that have security detachments anyway, primarily Paris and Brussels and maybe CdeG then you have little additional cost.

Paths on HS1 are relatively cheap at the moment thanks to it being very lightly loaded east of Ashford.

I was thinking about capacity problems rather than time (e.g. M25).

Indeed, which is why both me and Norman Foster propose some sort of semi or fully orbital high speed railway with distributed "entry terminals".

 

[Bald Rick]

Indeed, which is why both me and Norman Foster propose some sort of semi or fully orbital high speed railway with distributed "entry terminals".

A fully orbital railway, which for the sake of argument follows the M25, but with bulges out to Gatwick, Luton and Stansted, plus a link into Central London, is going to be the thick end of 200 miles long in total. With some pretty spectacular civils to get to and from the airport and underneath the existing ones and in to London. Not unreasonable to assume £20bn+.

 

[HSTEd]

A fully orbital railway, which for the sake of argument follows the M25, but with bulges out to Gatwick, Luton and Stansted, plus a link into Central London, is going to be the thick end of 200 miles long in total. With some pretty spectacular civils to get to and from the airport and underneath the existing ones and in to London. Not unreasonable to assume £20bn+.

I make the orbital about 280km for a full loop and about 60km for a Northern City centre link connector that would approximately follow the route of the resurrected M12 motorway.

So about two hundred miles would be reasonable.

You can cut it down a little but that seems to be a reasonable estimate.

This is where large airports like this start to get very expensive, it is the connections rather than the airport itself.
But having an orbital high speed railway around London probably has various benefits that would present themselves.

I imagine the connections out to the airport island would be bridges shared with the roadways to keep the cost down, one connection being entirely "low level" and the other having a cable stay "high level" span in the middle to allow ships in and out of the estuary.

EDIT:

And Luton and Stansted Airports can have surface stations because the approaches are open.

 

[eps200]

The connections are what make coastal sites attractive not sure you can fit 6 runways on any of them though.

I've seen plans that have crossrail, DLR, HS1 and other run into it that would be one hell of a huge station.

 

[HSTEd]

The connections are what make coastal sites attractive not sure you can fit 6 runways on any of them though.

I've seen plans that have crossrail, DLR, HS1 and other run into it that would be one hell of a huge station.

I was referring to the Boris Island Proposal out by Shivering sand, ie in the middle of the Estuary.

Not the Isle of Grain proposal that requires the relocation of a huge LNG terminal.

 

[nerd]

I have been struggling for good data on the subject, so I will use that estimate in my future calculations.



My numbers were not attempted to identify the passenger numbers for the airport's station, I was proposing to primarily identify the number of passengers for the London end of the link, since that is the expensive part. (Adding additional platforms in central london is far more expensive and time consuming than adding them in the middle of nowhere where the crown estate is the only person you have to deal with).
Luckily Stansted and Luton are only 15% the size of Gatwick and Heathrow together so these numbers should still be reasonably valid as a first order estimate, I will adjust them up by 20% to make sure.



I think St Pancras would struggle to cope without any domestic 400m paltforms.
Hence my suggestion of permanently rerouting C2C into Liverpool Street after Crossrail and completely reconstructing Fenchurch Street into the "Airport Terminus".

The idea of building a semi or fully orbital HSR line with lots of park and rides on it is something I support, it certainly avoids an insanely expensive construction of a motorway parallel to the M25, which is what would be required otherwise.



Why? Parking really doesn't take up that much room, especially once you get parking structures like the 13 story monsters they have at Dallas/Fort Worth Airport.
Remember thanks to runway spacing issues (~1000m even with LAAS apparently) there will be large spaces between the parallel runways that are not being used for anything.
These spaces could be left open to the sea but this would be a waste of money since the cost of artificial islands is quite strongly dependant on the length of the "wall" that has to be built up before the interior space can be filled in.
Closing off both ends of these spaces and draining them would probably be cheaper (or atleast negligibly more expensive) than having six runway shaped islands with causeways between them, it also reduces the consequences if a plane wanders off the taxiway due to pilot error or winds or whatnot.
If you are worried about wind vortices or similar the infrastructure could be kept reasonably "short" above ground since the parking structure could easily start at the level of the estuary's seabed.

You can see this even in single runway offshore airports that have significant space spare on the "islands" which on the face of it would have been purchased at absurd expense.



The thing about Tokyo is that until very recently Haneda airport was almost entirely domestic flights while Narita was the majority of the International flights, this meant that there was not enormous amounts of demand for transit between the two hubs.

In the London Scenario there is no enormous domestic air market and there likely never will be with the development of HS2 et al.
This means you are talking about having two international hubs which has obvious problems.

I'm afraid that things like Dallas Forth Worth or Hartsfield-Jackson Atlanta Airport show the direction of travel for major hubs, and that is towards biiiiiiig.
--- old post above --- --- new post below ---


This would be even more problematic than a Heathrow expansion if the current arguments over having a second runway at Gatwick are indicative.
A Thames estuary airport gets all this without knocking down thousands of houses, or at least without demolishing entire villages (which always plays badly in the press)



You want a large size north-south through station at Euston?
That is going to make the cost of my project look small.
The underground environment south of Euston road is overfilled as it is.

And the Brighton Main line's capacity cannot be feasibly improved without making the WCRM look like a triumph of frugality, a whole duplicate line will likely be required. (There is a reason I keep going on about a South Coast Shinkansen).



HS1 might be "underused" but I doubt it has the capacity necessary to handle the loads an airport the size of a major hub would require.
And then you have to somehow squeeze additional capacity into St Pancras to handle several full length trains an hour.

You an also obtain a high speed service from the continent into a East-of-London airport with a relatively shrot stretch of track through relatively open country.
The close-to-London parts of these things are always the expensive parts.



That is a relatively simplistic view, there are other benefits, currently some European destinations recieve service from more than one London or South East Airport.
If South East airports are consolidated either large aircraft can be used that are more slot-efficient, or a greater frequency of service can be run to each destination.

The distances in the South East are sufficiently small that "moving around London" is not going to be a great time waster if the proper infrastructure is put in place.

EDIT:

At 90mph the Shivering Sand location is only 10-15 minutes further out than the Isle of Grain location.
So I dunno if its still viable or not... I will crunch the size of a London HSR terminus assuming no Crossrail extension.

EDIT #2:

And even if parking spaces are restricted on the island, having parking on the nearest available land would only require something like two platforms for a shuttle metro service along the bridges.

Some good points there HSTEd; though I don't think that Dallas/Fort Worth is in an estuary.

The main 2011 forecasts of passenger traffic are here;

https://www.gov.uk/government/uploa...ment_data/file/4503/uk-aviation-forecasts.pdf

They project (page 157) 183m terminal passengers per year at London ariports in 2050. But this is constrained to current runway capacity; with big consequent expansion at Birmingham, Manchester and East Midlands. A London Hub would remove these constraints; and would be projected to carry all the scheduled business. Some 30-40m can be assumed to continue to use low-cost and charter services out of non-hub airports.

Whether it is realistic for a single hub to carry all the scheduled business is another matter; but it is key to the Hub proponents that this is the way forwards, and their business models don't work if it is not the case.

You may know better than me, but I am not aware of any airport that allows parked cars alongside the runways; and I suspect that there are safety reasons why this is the case.

All the Estuary island proposals that I have seen have assumed no private car access to the airport site (many have assumed that there would be no passenger terminals on site either - so that the Estuary itself is entirely 'airside'). It is partly about the economics of reclaiming land only to park cars on it. But much more about the horrendous cost otherwise of providing sufficent road capacity into the site. The usual assumption is that only buses and taxis get on site; parking, car-hire and passenger pick-up are all restricted to off-site locations with a shuttle lilnk.

 

[L&Y Robert]

If anyone wants to see a good case for shutting Heathrow then visit Kew Gardens on a summer's day when there is a westerly wind. Sitting and trying to enjoy the flowers and trees whilst a 747 or the like passes above you every minute or less should make the point.

Approach paths and take-off paths, several of each, side by side like feather dusters on the ends of several parallel sticks, to say nothing of associated stacking areas, all these are part of the airport pattern, and hang out of the bit of coloured land for the airport itself. So it isn't just an area of land, and a handful of transport threads - there's all the air-side stuff as well, up there, overhead - quite close sometimes, noisy and - risky? Five mile square for the airport land, fifty mile square for all that. And the wider zone might (I don't know, but I've heard it said) overlap with similar air-space zones from other airports. Off-shore is the only answer, but I'm mindful of another set of experts who tell me sea level is going to rise, by how much? I don't know, but any off-shore airports will have to be sea-level-rise proof as well as everything else.
--- old post above --- --- new post below ---

Should rail decide the location of a NEW AIRPORT ?
So here is my big idea:

The U.K. needs a big new airport. The runways at Heathrow were laid out nearly 65 years ago and are too close together to safely allow simultaneous parallel approaches. The terminals and taxiways are jammed together on a very restricted site hemmed in on all sides by houses. This creates a great deal of inconvenience at the airport: congested taxiways, inefficient passenger handling, difficulties in transferring between flights and car parking etc etc.

This creates a very poor impression for visitors and potential customers for U.K. PLC. Overseas I see a growing number of smart new airports which have space to grow.

We need to start planning for an airport to take us toward the 2050’s and beyond!

But where to put it ?

I had a go at this last July, I think it was, following an article in the magazine of my profession. Thread title "Suitability of Heathrow as a location for an Airport". It's still available on the Forum.

 

[LE Greys]

If anyone wants to see a good case for shutting Heathrow then visit Kew Gardens on a summer's day when there is a westerly wind. Sitting and trying to enjoy the flowers and trees whilst a 747 or the like passes above you every minute or less should make the point.

Approach paths and take-off paths, several of each, side by side like feather dusters on the ends of several parallel sticks, to say nothing of associated stacking areas, all these are part of the airport pattern, and hang out of the bit of coloured land for the airport itself. So it isn't just an area of land, and a handful of transport threads - there's all the air-side stuff as well, up there, overhead - quite close sometimes, noisy and - risky? Five mile square for the airport land, fifty mile square for all that. And the wider zone might (I don't know, but I've heard it said) overlap with similar air-space zones from other airports. Off-shore is the only answer, but I'm mindful of another set of experts who tell me sea level is going to rise, by how much? I don't know, but any off-shore airports will have to be sea-level-rise proof as well as everything else.

There are various answers to that (almost as many as there are climate scientists). Taking a reasonable median case would be a seven metre sea level rise, so basically trace a line around the seven metre contour line and there is your new coastline. That means that Heathrow is suddenly coastal, because London has disappeared beneath the sea (along with quite a few other cities, most of the Netherlands, some of Freisland and the edge of Denmark http://flood.firetree.net/ ). Assuming that we save London somehow, although the Underground might become a bit impractical, then an airport to the east suddenly has to build walls at least 20ft higher than if planned today, and even those might give way to a particularly strong storm surge.

There's also the problem that takeoffs (noisier than landings) are aimed directly at the East End. Move your referance point to Windsor Castle, and you will see the effect of that. By pushing the airport farther out, you lose its effectiveness, but mitigate the noise problem. That's another reason why I'm so keen to use Stansted, it's to the north, so an east-west runway aims takeoffs at mostly open country (including my house, but they're generally past 7,000ft by then) rather than a city.

<EDIT> Looking closer at the map, 7m isn't quite as bad as I suggested, although it's still massively inconvenient for London, it wouldn't quite kill the city, just turn the low-lying areas into a new Venice, mostly south of the Thames.

 

[HSTEd]

Why would take offs be aimed at the east end?

Take off would be pointing out to sea just as landings.

You can do parallel opposite bearing approaches/take offs now. (Simple way to do this is to have three terminals, each assigned a pair of runways, one for taking off and one for landing and stick with this mode of operation as much as possible).


And with regard to the whole car park runway spacing thing, Heathrow has cars parked in the open within 150m of the runway edge (northern side of the northernmost runway).

EDIT:

And the simple answer to the 7m sea level rise thing is to build a 7m high wall across the Thames Estuary and deploy pumping stations to dump the Thames Estuary into the sea.

Such a wall is far shorter than coastal defences along both sides of the Estuary and doesn't ruin all those nice sea views over the Estuary which would be reduced to a brackish lake.
The airport would also either be behind this wall or incorporated into it.

 

[ian959]

I am not sure that I am following your thoughts but you do know that generally takeoffs are into the headwind and landings are with the tailwind so even in a six runway airport usually only two are in operation at any one time (assuming 3 paired runways on three different headings). Most airports with crossing runways tend to avoid using more than two runways even in still wind conditions to avoid potentially dangerous jet wash conditions.

No airport I know of would contemplate using all six runways at once so the concept of assigning a terminal to a specific runway would be completely impractical. It would also make approach air traffic control more complicated as all flights for a particular airline would have to be directed to one terminal. So for instance British Airways flights would all have to be directed to runway X in order to use terminal A which is not practical.

This is the reason why some airports - Chicago O'Hare for instance - have shorter parallel runways for smaller aircraft to avoid crossing movements when conditions permit use of more than two runways. The only airports I know that actively use crossing runways are the likes of Perth International Airport where traffic is much less dense than London would be and suitable gaps can be inserted into the approach paths to accommodate dissipation of jet wash turbulence prior to the next cross runway activity.

 

[HSTEd]

I am not sure that I am following your thoughts but you do know that generally takeoffs are into the headwind and landings are with the tailwind so even in a six runway airport usually only two are in operation at any one time (assuming 3 paired runways on three different headings).

This indeed used to be the practice, but the increased runway lengths available now and the drastically improved engine performance of modern jets (to enable them to climb out more rapidly and thus reduce fuel consumption by reducing time at low altitude) has made this largely unnecessary, which is why airports tend towards having parallel runways now.

Most airports with crossing runways tend to avoid using more than two runways even in still wind conditions to avoid potentially dangerous jet wash conditions.

All six runways would be parallel, as the are at Heathrow and major hubs like the aforementioned Hartsfield-Jackson airport in Atlanta.

No airport I know of would contemplate using all six runways at once so the concept of assigning a terminal to a specific runway would be completely impractical.

LAAS and more advanced conventional ILS systems are now permitted to make wingtip-to-wingtip parallel take-off/landing moves with runway spacings of only 1050m.

Many major hubs now use all their runways at once during normal operations, indeed the monster airports in the US would be unable to support the moves they do using only two runways.

It would also make approach air traffic control more complicated as all flights for a particular airline would have to be directed to one terminal. So for instance British Airways flights would all have to be directed to runway X in order to use terminal A which is not practical.

Why not?
Most flights already know the runway they will be assigned before they even take off, and it is no more difficult than controlling the air traffic arrangements of three closely spaced airports separately.

You could arrange for end-around taxiways like they have at Atlanta to allow traffic to across the airport avoiding the runways but the use of those would be avoided wherever possible for the simple reason that it would delay the arrival of flights at the required terminal.

This is the reason why some airports - Chicago O'Hare for instance - have shorter parallel runways for smaller aircraft to avoid crossing movements when conditions permit use of more than two runways. The only airports I know that actively use crossing runways are the likes of Perth International Airport where traffic is much less dense than London would be and suitable gaps can be inserted into the approach paths to accommodate dissipation of jet wash turbulence prior to the next cross runway activity.

But the runways would not be crossing... all six would be parallel, probably designated Runways 9L, 9C, 9R, 10L, 10C and 10R (27R, 27C, 27L, 28R, 28C, 28L for landing aircraft), assuming you made all six runways double ended for resilience purposes.

EDIT:

It appears that are relatively few problems with parking relatively near the runway and that the "safety" margin is relatively short.
If we are looking for large amounts of long stay parking on the airport island then various Automated Parking Systems could be workable which can park lots and lots of cars into very small spaces.

More conventional multi storing parking could be provided adjacent to the terminal buildings themselves and could be made very tall, as we have access to the entire volume above the current bed of the estuary.
This could cope with the hopefully relatively small amount of short stay parking required.

And if the HS1 connector line for Eurostar is laid out correctly another lighter weight park and ride facility could be provided at Ashford International to allow traffic from that end of Kent to be pulled away from places like Southend Airport.

 

[starrymarkb]

You seriously want departures and arrivals to meet head on?

I can see the CAA and NATS having a fit!

Look at somewhere like EHAM where even when 4 runways are in use there are no crossing movements where possible.

Also aircraft will avoid landing or departing into a tail wind. Up to 5kts tail component is allowed, beyond that you have to land/depart into the wind. And before you say build perpendicular to the prevailing wind take into account Narita which was built that way and is notorious for rough approaches and go-arounds!

 

[HSTEd]

You seriously want departures and arrivals to meet head on?

Why not? Any sort of collision at a thousand knots impact speed is likely to have the same result as one at 100 knots.... two burning crashing debris piles with everyone dead.

And a collision would only be possible with an ILS failure.

Look at somewhere like EHAM where even when 4 runways are in use there are no crossing movements where possible.

Also aircraft will avoid landing or departing into a tail wind. Up to 5kts tail component is allowed, beyond that you have to land/depart into the wind.

Unfortunately I forgot about that, so I decided to calculate where a Shivering Sand Airport having takeoffs to the west would cause noise problems.
Using the heathrow departure maps it appears that noise is considered to be a serious issue for approximately 25km down-range from the end of the runway.

If you go 25km straight west from Shivering sand you end up somewhere between Canvey Island and Sheerness, essentially the "noise zone" is entirely over the estuary, you don't even noise pollute the LNG terminal at the Isle of Grain.

That is rather proof over any serious development in the Thames Estuary.

And before you say build perpendicular to the prevailing wind take into account Narita which was built that way and is notorious for rough approaches and go-arounds!

Indeed, I was proposing an East-West runway.

 

[starrymarkb]

Why not? Any sort of collision at a thousand knots impact speed is likely to have the same result as one at 100 knots.... two burning crashing debris piles with everyone dead.

And a collision would only be possible with an ILS failure.

With the flow in the same direction you massively reduce the chances of a mid air collision, landing aircraft will be on the ground before departing aircraft leave it. In fact the only potential conflict is with go arounds. Also with aircraft departing away from arrivals then it is possible to turn aircraft fairy quickly (1 mile from the airport passing 500ft QFE) rather then having them fly parallel to the inbounds until passing about 7000ft

You do realise ILS is liable to interference from vehicles and aircraft on the ground. This isn't a problem during normal operations as the autopilot is disengaged well before touchdown (sit near the front of an A320 during approach and listen for "BLEEPBLEEPBLEEP...PIPPIPIP - that's the Master Warning sounding for Autopilot being disengaged, followed by a warning of reduced navigation precision - it is audible in the cabin) and the pilots will hand fly. In conditions that require Autolands then the ILS critical areas must be kept clear which is a pain! You really don't want that during normal operations!

Another issue would be with TCAS - if it gives an Resolution Advisory then the Pilots must comply with it regardless of ATC or procedures.

 

[HSTEd]

Well hopefully normal operations would be conducted with something like LAAS, with an ILS or MLS system only operating during times when GPS is not available for whatever reason.

But yeah, relying on instrumented approaches all the time is a can of worms all its own.

 

[LE Greys]

With the flow in the same direction you massively reduce the chances of a mid air collision, landing aircraft will be on the ground before departing aircraft leave it. In fact the only potential conflict is with go arounds. Also with aircraft departing away from arrivals then it is possible to turn aircraft fairy quickly (1 mile from the airport passing 500ft QFE) rather then having them fly parallel to the inbounds until passing about 7000ft

You do realise ILS is liable to interference from vehicles and aircraft on the ground. This isn't a problem during normal operations as the autopilot is disengaged well before touchdown (sit near the front of an A320 during approach and listen for "BLEEPBLEEPBLEEP...PIPPIPIP - that's the Master Warning sounding for Autopilot being disengaged, followed by a warning of reduced navigation precision - it is audible in the cabin) and the pilots will hand fly. In conditions that require Autolands then the ILS critical areas must be kept clear which is a pain! You really don't want that during normal operations!

Another issue would be with TCAS - if it gives an Resolution Advisory then the Pilots must comply with it regardless of ATC or procedures.

The trouble with doing a London version of the Concorde Turn is it would place you over either Southend (turning north) or the Medway Towns (turning south).

 

[eps200]

Isn't Heathrow not set up for steep paths? I assume any new airport will be?

Hoo peninsula seems like it would be massively less expensive to use beside noise what is the flaw with it? I suppose fitting 6 runways might be a problem but i always envisaged 4 max length and two shorter ones set aside for smaller planes segregating by plane size helps capacity anyway.

I assume a 6 runway layout would be laid out something like this terrible ms paint sketch.
Black lines are runways grey boxes are terminals
Yellow box works as a standard 6 runway hub close parallel pairs set up for jumbos.
Red box is operationally separate takes all the smaller planes no movement conflics
Blue box contains all the other bits an bobs you need control tower staff facilities rail hub, staff car park, wagon aces, taxi rank ect. The blue box can go anywhere really.

[/url][/IMG]

I suppose you could run with 6 full length not sure how terminal layout would work load balancing the middle pair.

 

[HSTEd]

Six full length runways is far more flexible than 4 full length and 2 short runways for obvious reasons.
With the general trend towards larger platforms, the shorter runways would have problems.

An island would tend towards to square for reasons of reducing the amount of outer "barrier rock" to be laid. So having multiple different runway lengths doesn't help really.

And the Hoo Penisular doesn't really solve anything compared to Heathrow, the resulting development will hem it in, and a takeoff to the west will simply put the Dockland under the "noise zone".
Shivering Sand puts the noise zone over open water, and can be expanded effectively without limits (it is probably unreasonable to assume that a 6 runway airport will be big enough in the long term).

Also you have to demolish several villages and a massive LNG Terminal.

Surely you could arrange the terminals between the runways, remember you need ~1000m plus between each runway unless you want to hamstring the airport, it will be expected to maintain normal operations during instrument landings so you have to watch your runway spacings.

 

[eps200]

I know if you take of one end and land the other you can have a400m spaced pair.

It just hit me that this is probably the way to do 6 with a huge station under it. running each set of 2 runways plus terminals as an operationally separate airports with one given over to freight and two for passengers.
[img=http://s23.postimg.org/iqfvghcd3/airport.jpg]

I was looking at the isle of grain where fosters plan is right off the end of said peninsula, shivering sands would require truly insane civil's and it makes rail connection's much harder place it right on the tip with a bunch of reclaimed land and you get 20km of river and fields to climb over.