Has a South Coast high speed line ever been seriously considered?

[PTR 444]

Over the years, there’s been some suggestions on these forums for a high speed line linking London with Brighton and/or Southampton. I’ve never envisaged such a route as an obvious candidate for high speed because the cities they serve are relatively close to the capital while the area is dominated by commuter rather than intercity trains. Despite this, the population density is rather high in the area which would probably justify a case for a new line for capacity rather than speed reasons.


For this reason, I am wondering if a serious proposal or feasibility study has ever been considered or done for a London to south coast high speed line, either to Brighton and then along the coast to Southampton, or direct to Southampton via the M3 corridor. I know BML2 has been proposed but I’m discounting this on the grounds that it reuses existing tracks rather than build new ones from scratch. Basically I’m looking for any proposals for new build London - South Coast high speed lines with a minimum operating speed of 125mph (although the faster the better!)

 

[swt_passenger]

No, never. Pure forum fantasy. Why would London to Southampton via Brighton at 125 mph even be considered, when the extra distance is going to mean the journey will take longer anyway...

 

[Aictos]

Over the years, there’s been some suggestions on these forums for a high speed line linking London with Brighton and/or Southampton. I’ve never envisaged such a route as an obvious candidate for high speed because the cities they serve are relatively close to the capital while the area is dominated by commuter rather than intercity trains. Despite this, the population density is rather high in the area which would probably justify a case for a new line for capacity rather than speed reasons.


For this reason, I am wondering if a serious proposal or feasibility study has ever been considered or done for a London to south coast high speed line, either to Brighton and then along the coast to Southampton, or direct to Southampton via the M3 corridor. I know BML2 has been proposed but I’m discounting this on the grounds that it reuses existing tracks rather than build new ones from scratch. Basically I’m looking for any proposals for new build London - South Coast high speed lines with a minimum operating speed of 125mph (although the faster the better!)

I’m having trouble trying to understand any business case for this to go ahead.

Surely there are other ways for improvements to be done that actually have a decent business case?

 

[gg1]

The populations of the major South Coast towns and cities are far too low to justify the cost. Brighton, Southampton and Portsmouth are all smaller than both Coventry and Stoke, 2 cities which will be bypassed by, rather than served by HS2.

 

[swt_passenger]

Also, the Waterloo to Southampton direct route already follows the M3 corridor to all intents and purposes, so the question really becomes whether it is worth upgrading the line so that the fast pair could run at 125 mph?

I suspect the alignment would mostly allow that with the necessary power supply, ie AC OHLE, and signalling changes, the question is whether the slight capacity reduction due to longer braking distances would be acceptable. Oh, and you’d need to get all the Basingstoke to Southampton 75 mph freight out of the way...

 

[HSTEd]

No, never. Pure forum fantasy. Why would London to Southampton via Brighton at 125 mph even be considered, when the extra distance is going to mean the journey will take longer anyway...

You need to go much faster than 125mph but you could beat the journey time.

Even with stops at 30km intervals average speeds well over 100mph are definitely achievable, including all allowances for timetabling and such.

Southampton via Brighton with multiple intermediate stops is achievable in under an hour.

 

[Meerkat]

The populations of the major South Coast towns and cities are far too low to justify the cost. Brighton, Southampton and Portsmouth are all smaller than both Coventry and Stoke, 2 cities which will be bypassed by, rather than served by HS2.

Brighton is bigger than Stoke, Portsmouth and Southampton are near enough to Stoke’s population that one is bickering about how you count.

All three coast cities are in the awkward bracket of not being big enough for brand new HS lines but really deserving better than they get, particularly due to capacity issues at the London end - Portsmouth in particularly has a pretty slow service to London.

Longer term Southampton could do with more quadrupling to Basingstoke and 25KV to (probably) Woking to allow faster services.
Portsmouth needs better power supplies to Guildford and maybe there are some ways to straighten out some bends without unduly upsetting the South Downs NP? But how do you make capacity for the extra passengers....
Brighton needs serious junction improvements and more quadrupling at the Brighton end, and also might be a contender for 25kv outward from Brighton (lots of dual voltage stock already....)

 

[HSTEd]

The populations of the major South Coast towns and cities are far too low to justify the cost. Brighton, Southampton and Portsmouth are all smaller than both Coventry and Stoke, 2 cities which will be bypassed by, rather than served by HS2.

HS2's conception is something like 500 route kilometres. Possibly slightly more.
Even going all the way west to Weymouth would result in only about 240 route-km.

Coventry and SToke are only bypassed because the WCML will have masses of spare capacity once Birmingham/Manchester etc are dealt with.
There is nowhere beyond Southampton to serve really.

So I dont think the population is really the deal breaker.
Indeed classic compatibles running via Weymouth and Yeovil might even be competitive to the South West.
It is highly likely that even running via Southampton they would be competitive to Salisbury.

EDIT:

Using the Sanyo Shinkansen as an example, assuming ~60 second station stops, we can assume a 35.1km station spacing would achieve ten minute times, giving us an average speed of 210km/h.
That implies:

London-Gatwick Airport in 10-12 minutes
London-Brighton in about 20 minutes
London-Chichester in about 31-32 minutes.
London-Hilsea in about 40 minutes.
London-adj. Southampton Central in about 47 minutes
London-Bournemouth in about 60 minutes
London-Dorchester/Weymouth in about 71 minutes.

I imagine putting Brighton less than an hour from Weymouth would also do interesting things........

(EDIT #2, those journey times assume all trains stop all stations.
If we assume 10tph instead of 40 is sufficient, a fast service can reach Dorchester-Weymouth in 50 minutes non stop.
At which point Yeovil is only 1hr25 from London via that route, assuming electrification or a high speed classic compatible can be developed.

 

[Indigo Soup]

Also, the Waterloo to Southampton direct route already follows the M3 corridor to all intents and purposes, so the question really becomes whether it is worth upgrading the line so that the fast pair could run at 125 mph?

I think there's some attraction to the idea of a Waterloo-Southampton HSL, but not on the basis of speed.

Similar to the WCML southern section, the SWML approaches to London are full, hence proposals for a fifth track. Building 'HS3' instead as an offline bypass for fast trains makes a lot of sense to me at least. As well as making the journey from Southampton and Bournemouth to London quicker, I'd expect that you gain an appreciable number of paths for stopping services. Especially if you're able to run the Weymouth and Exeter services over it. Building for 140mph - which is after all the running speed of HS1 domestic services - and running AT300 bimodes would probably do the job quite nicely.

 

[gg1]

Brighton is bigger than Stoke, Portsmouth and Southampton are near enough to Stoke’s population that one is bickering about how you count.

True, the lesson for me there is don't believe the first google hit which I think must have exclude Hove from the Brighton populations. The general gist of my point remains, the major south coast cities are MUCH smaller than the destinations HS2 is primarily intended to serve, instead being broadly comparable to cities deemed to small to justify being served by HS2.

All three coast cities are in the awkward bracket of not being big enough for brand new HS lines but really deserving better than they get, particularly due to capacity issues at the London end - Portsmouth in particularly has a pretty slow service to London.

Longer term Southampton could do with more quadrupling to Basingstoke and 25KV to (probably) Woking to allow faster services.

Portsmouth needs better power supplies to Guildford and maybe there are some ways to straighten out some bends without unduly upsetting the South Downs NP? But how do you make capacity for the extra passengers....

Brighton needs serious junction improvements and more quadrupling at the Brighton end, and also might be a contender for 25kv outward from Brighton (lots of dual voltage stock already....)

On those points I agree.

HS2's conception is something like 500 route kilometres. Possibly slightly more.

Even going all the way west to Weymouth would result in only about 240 route-km.

Halving the distance wouldn't come close to halving the cost, the most expensive section of HS2 is the approaches to London, the same would apply here, and the land values of a possible South Coast route would be considerably higher than HS2.

Coventry and Stoke are only bypassed because the WCML will have masses of spare capacity once Birmingham/Manchester etc are dealt with.

They won't see much benefit from this extra capacity though, Coventry currently sees 3tph fast to London, Stoke has 2tph, even in the unlikely event they maintain this frequency, the services will almost certainly be slowed by additional intermediate stops. The best they can hope for is an extra stopper or two, whether this compensates for the loss of regular fast services to London is highly questionable.

The real off-route beneficiaries will be towns on the WCML south of Rugby along with the Trent Valley towns and destinations served by classic compatible services beyond Crewe. This is another area where HS2 wins over a south coast route, do any of the bypassed towns of the latter come anywhere close to the size of MK and Northampton for example?

I dont think the population is really the deal breaker.

I disagree, considering how controversial HS2 is on the basis of cost when it links the 6 largest conurbations in Britain, a route that costs more than half as much but benefits less than a quarter the population simply won't happen unless there is a huge change in public and media opinion to high speed rail. If in 20 years time HS2 proves to be a huge success and public opinion changes, it MAY become viable.

 

[HSTEd]

The real off-route beneficiaries will be towns on the WCML south of Rugby along with the Trent Valley towns and destinations served by classic compatible services beyond Crewe. This is another area where HS2 wins over a south coast route, do any of the bypassed towns of the latter come anywhere close to the size of MK and Northampton for example?

Hard to do an apple to apples comparison, given the fundamentally different population distribution on the south coast.

Between Bognor Regis and Brighton, some 35km away, there is only ~4km of sea front not developed.

The "towns" are smaller but they are almost continuous.
Northampton and MK are defined towns sitting, for the most part, in open fields.

I disagree, considering how controversial HS2 is on the basis of cost when it links the 6 largest conurbations in Britain, a route that costs more than half as much but benefits less than a quarter the population simply won't happen unless there is a huge change in public and media opinion to high speed rail. If in 20 years time HS2 proves to be a huge success and public opinion changes, it MAY become viable.

The Southern Region TOCs have capacity limitations that the northern half of the country could only dream of.
Such a railway, for a relatively short length, can revolutionise service across two of the largest TOCs (in number of trains operated)

 

[Indigo Soup]

Hard to do an apple to apples comparison, given the fundamentally different population distribution on the south coast.

I tend to use the ESPON Functional Urban Areas for these sorts of comparison because they take a more sensible view of what functions as a single 'city' rather than arbitrary historical boundaries. On that basis, the Portsmouth-Southampton metropolitan area alone is comparable to the East Midlands metropolitan area in size, and the Brighton-Worthing-Littlehampton metropolitan area is comparable to Edinburgh. The Bournemouth-Poole metropolitan area is also very large, though the New Forest helpfully splits it off from the region east of Southampton Water.

Because it's spread out into a large number of large towns in a band, rather than a handful of definable cities, the South Coast doesn't show up the same way in statistics - and nor does it lend itself to exactly the same solutions. Really, I think a 'South Coast Metro' would be more sensible than a Brighton-Southampton HSL.

 

[si404]

There's two main issues at play
1) London - South Coast capacity
2) along-coast speed and frequency - journeys are slow and infrequent given the size and proximity of the 2 main Functional Urban Areas (or, within them, the size and proximity of towns/cities)

A South Coast Metro would sort out the frequency, but not really the speed.

 

[HSTEd]

Really, I think a 'South Coast Metro' would be more sensible than a Brighton-Southampton HSL.

Well why not a South Coast High Speed metro.

35km stop spacings are close enough that local railways for the last leg will not drastically increase travel times.

 

[si404]

I'm guessing that 35km spacing has some leeway. Crow flies distances are:

Bournemouth - 38km - Soton - 25km - Pompey - 32km - Barnham* - 35km - Brighton - 30km - Eastbourne - 23km - Hastings - 38km - Ashford

That's rather a fast service along that corridor - Worthing and Fareham/Gosport would warrant stations due their size and distance from other stops, Bexhill probably as well with relative remoteless an additional factor.

*An interchange for western West Sussex rather than direct destination.

 

[PTR 444]

There's two main issues at play
1) London - South Coast capacity
2) along-coast speed and frequency - journeys are slow and infrequent given the size and proximity of the 2 main Functional Urban Areas (or, within them, the size and proximity of towns/cities)

A South Coast Metro would sort out the frequency, but not really the speed.

Perhaps the existing Coastway route could become a metro style service IF a South Coast High Speed Line gets built for express trains.

 

[30907]

The BML2 scheme is sometimes described (but not by themselves) as high-speed because it includes a new route from Croydon to Canary Wharf.
https://www.bml2.co.uk/
I vaguely recall that around 1900 someone proposed a high speed London-Brighton line to compete with the LBSC but I can't find anything online.

 

[PTR 444]

The BML2 scheme is sometimes described (but not by themselves) as high-speed because it includes a new route from Croydon to Canary Wharf.
https://www.bml2.co.uk/
I vaguely recall that around 1900 someone proposed a high speed London-Brighton line to compete with the LBSC but I can't find anything online.

I’ve never really envisaged this as a viable option. I mean why would people other than businessmen want to go to Canary Wharf over Central London?

I think the best alternative would be to have a 186mph high speed line starting from south of Mitcham Eastfields (services from Victoria would be diverted from the existing main line at the junction before Streatham Common), staying west of the BML for its entirety before rejoining it in the Preston Park area north of Brighton. It would involve a lot of tunnelling and demolition of houses in Wallington, but I think this would have less of an impact than any other potential route.