Boris Airport is a good idea

20 November 2011
Even before the cabinet warmed to the idea, I though Boris Johnson's support for an airport in the Thames Estuary was the best solution to the problem of capacity at Heathrow. The problem is that any Heathrow expansion that made allowances for future growth would simply be too much for what is already an overdeveloped area, and freeing up capacity at Heathrow by moving capacity to other London airports has gone as far as it can realistically be pushed. This means any major increase in capacity has to be serviced by an all-new airport which also has plenty of space for further expansion. If you accept that capacity growth has to occur anywhere other than Heathrow, and that such a place has to make allowance for the possibility of replacing Heathrow, then a new eastern airport in the Estuary very quickly looks like the only viable option.

Spreading capacity

One of the problems are a large airport like Heathrow is that a lot of its flights are connecting flights, so the idea of offloading short-haul flights to other London airports such as Luton and Gatwick has already gone as far as it can go. In fact even these airports now have limited spare capacity, and their own incumbents (often in competition with Heathrow and its users) do not exactly welcome the link-ups. All this does is add extra logistical issues without solving the underlying capacity issues.

Heathrow expansion

Although billed as a third runway, it is pretty clear that the plans are really a third runway and a new terminal to go with it. The problem is that Heathrow is already surrounded by a lot of built-up areas, and if the competition arguments used by BAA is to be believed, then Heathrow is going to need a fourth runway before long. A third runway would mean Sipson disappearing, and a fourth would take out much of remaining Harmondsworth and Harlington as well. On top of this the Heathrow area is already an area of overloaded transport infrastructure. Of course on top of this you have political issues, many of them related to aircraft noise. Heathrow is unusual in being west of London (airports tend to be located north or south of cities), so the flight path goes over London itself. And of course you have the green lobby who think airports are inherently evil. Even if the politics are overcome, major logistical issues remain.


Heathwick is a proposed high-speed link between Heathrow and Gatwick, which I suspect only ever got on the radar because its route alongside the M25 would have made planning permission easier, it would have been relatively quick to build, and above all its £5bn cost is relatively cheap. However although BAA cited various reasons why the plan was a non-starter, I suspect that they are against it because Gatwick is owned by a rival. Nevertheless two main issues were still unaddressed:
One touted benefit of the link-up is that people would not need to check-in a second time, in much the same way as connecting flights do not need visa checks at hub airports. However this means maintaining airport security along the entire 35-mile stretch of track, which would necessitate the trains would basically being prison carriages. The most obvious reason for this, at least for red-top readers, is the need to prevent the rail link becoming a jump-point for illegal immigrants. The other problem is stopping people (and other things such as weapons) getting on, as otherwise the 15-minute alleged transfer time will be on top of the time it takes to re-screen all baggage.
Gatwick itself is already running at 80% capacity, and the viability of the plan is predicated on low-cost airlines vacating it in favour of Luton and Stanstead. This is a big assumption, so in practice Gatwick would have to be expanded. This is a hard sell for financing considering Gatwick's current users do not like the idea of the place being an outpost for Heathrow.

Gatwick expansion

Although good for competition, I have doubts about the politics and logistics of turning Gatwick into a Heathrow-sized airport. Fitting in a second north-western runway without obliterating either Charlwood or Hookwood would be tricky at best, and I think a new southern runway may be too close to the existing run-way (I am not sure of exact CAA requirements). In any case if an airport the size of Gatwick was to become Heathrow-sized, it would be such a big expansion that one may as well build a new airport.

What a Heathrow replacement needs

Realistically an all-new airport intended to take over from Heathrow would require at least three terminals (departures, arrivals, and transfers), and a minimum of four runways (two runways is insufficient, and an even number is needed as using one runway for both arrivals and departures is a bottleneck). A Heathrow replacement would also need high-capacity transport links to London, and unlike the north-western to south-western borders, and eastern side is not already heavily developed. It also provides much needed work for people from east London, who before long will be realising the actual legacy of the Olympics.