On Thu, 10 Feb 2005 19:27:54 +0000, Tom Anderson
wrote:

and the inevitable eventual
conversion (in places, reversion!) to heavy rail is going to be
apocalyptic.

Why convert to heavy rail? You can build a light rail system for long
trains and high capacity - look at many of the German U-Bahnen
(specifically Hamburg, which is a superb system) for an example.

Neil

--
Neil Williams in Milton Keynes, UK
When replying please use neil at the above domain
'wensleydale' is a spam trap and is not read.

Best to look at the incomplete viaducts from the top of a 69 or 474 bus!

Tom Anderson wrote in
:


This is the thing that really gets my goat about the DLR - complete and
utter lack of any foresight. Yes, at the time it was built, the area
didn't have a lot of traffic, and a light railway with two-car trains
was quite adequate. However, it was obvious that this wasn't going to
be the case forever, or even for very long. ...

I agree, though the area has come along a very, very long way since the DLR
opened (remember Canary Wharf on day 1 - it had no buildings on it atall).

BUT building the DLR cheaply meant that it did get built and without the
DLR Docklands would have remained an isolated backwater.

Other transport proposals can learn from this.

David

Stephen worheedatworheeddotf9dotcodotuk wrote:

Whilst were on about the DLR, the public enquiry into 'Capacity
enhancement' (upgrading to 3 car trains) started this week.Â*Â*DLRÂ*sayÂ*most
of the objections have been withdrawn, so it looks likely to go ahead.

I'd have thought that it'd be more cost-effective and more satisfactory for
passengers to keep increasing the frequency of trains, instead of making
them bigger. What's the theoretical top limit for frequency of DLR trains?
--
Ian Tindale

Ian Tindale wrote:
Stephen worheedatworheeddotf9dotcodotuk wrote:


Whilst were on about the DLR, the public enquiry into 'Capacity
enhancement' (upgrading to 3 car trains) started this week. DLR say most
of the objections have been withdrawn, so it looks likely to go ahead.


I'd have thought that it'd be more cost-effective and more satisfactory for
passengers to keep increasing the frequency of trains, instead of making
them bigger. What's the theoretical top limit for frequency of DLR trains?

Whatever they can push through North Quay Junction, which is the
bottleneck for the entire network.

Frequency enhancement was considered through doubling of Bow Church to
Stratford and remodelling of North Quay and Royal Mint Street junctions
(to remove the conflict between northbound Stratfords and southbound
Canary Wharfs at the former, and between services to/from Tower Gateway
and eastbound Banks at the latter); however, the cost was similar to the
3-car plan, but for only a 25% capacity increase rather than 50%.

That implies that the network is already at the upper limits of
frequency in the peaks for any services passing through North Quay or
Royal Mint St. Curtailing some services has also been considered (i.e
having them terminate without passing through these junctions, e.g.
Poplar - Beckton) but was considered as highly inconvenient to passengers.

--
Dave Arquati
Imperial College, SW7
www.alwaystouchout.com - Transport projects in London

"Dave Arquati" a écrit dans le message de
...

big SNIP

Four-car trains were considered as part of the planning process but were
rejected at this stage as the infrastructure works would be
prohibitively disruptive. A light railway just isn't designed for the
sort of passenger numbers the DLR is now expected to deal with, and I
think these 3-car works are designed to plug the gap; the Woolwich
extension will make things worse, but hopefully the Jubilee signalling
upgrade and car addition will mitigate matters. Crossrail is needed.


Just why do you think "the Woolwich extension will make things worse"?
Surely, by providing another cross-river route further downstream, that
extension of the LCY branch will reduce the curent traffic demand on the
Lewisham extension, especially that coming from potential Crossrail
passengers. But, needless to say (?), all the station sites on the Woolwich
extension must be suitable for expansion to accommodate four-car trains,
even if fitted out for only two-car or three-car trains initially.

Regards,

- Alan (in Brussels)

Dave Arquati wrote:

Whatever they can push through North Quay Junction, which is the
bottleneck for the entire network.

Frequency enhancement was considered through doubling of Bow Church
to Stratford and remodelling of North Quay and Royal Mint Street
junctions (to remove the conflict between northbound Stratfords
and southbound Canary Wharfs at the former, and between services
to/from Tower Gateway and eastbound Banks at the latter); however,
the cost was similar to the 3-car plan, but for only a 25% capacity
increase rather than 50%.

That implies that the network is already at the upper limits of
frequency in the peaks for any services passing through North Quay
or Royal Mint St. Curtailing some services has also been considered
(i.e having them terminate without passing through these junctions,
e.g. Poplar - Beckton) but was considered as highly inconvenient
to passengers.

Was this issue part of the reason why the takeover of the NLL was
considered, to provide a completely separate route on the
Stratford-Woolwich axis that doesn't require more trains to use the
existing single-track branch into platform 4?

Alan (in Brussels) wrote:
"Dave Arquati" a écrit dans le message de
...

big SNIP

Four-car trains were considered as part of the planning process but were
rejected at this stage as the infrastructure works would be
prohibitively disruptive. A light railway just isn't designed for the
sort of passenger numbers the DLR is now expected to deal with, and I
think these 3-car works are designed to plug the gap; the Woolwich
extension will make things worse, but hopefully the Jubilee signalling
upgrade and car addition will mitigate matters. Crossrail is needed.


Just why do you think "the Woolwich extension will make things worse"?
Surely, by providing another cross-river route further downstream, that
extension of the LCY branch will reduce the curent traffic demand on the
Lewisham extension, especially that coming from potential Crossrail
passengers. But, needless to say (?), all the station sites on the Woolwich
extension must be suitable for expansion to accommodate four-car trains,
even if fitted out for only two-car or three-car trains initially.

DLR passenger numbers are expected to soar once the Woolwich extension
opens; passengers won't just transfer from the Lewisham branch,
otherwise there wouldn't be much point building the Woolwich one.
The new passengers generated by the Woolwich branch will add to
congestion in the central area around Canary Wharf - although many may
opt to change to the Jubilee at Canning Town rather than use DLR all the
way.

All of the viaduct stations can probably be expanded easily; Woolwich
Arsenal is underground so that's a bit more risky. However, half of the
Woolwich trains will not be running through North Quay or Royal Mint
Street junctions - initially half will terminate at Canning Town, but in
future they will be extended via West Ham to Stratford International.
The signalling has been designed to accommodate 30tph which should
provide the necessary capacity for the near future solely using two-car
trains.

--
Dave Arquati
Imperial College, SW7
www.alwaystouchout.com - Transport projects in London

TheOneKEA wrote:
Dave Arquati wrote:

Whatever they can push through North Quay Junction, which is the
bottleneck for the entire network.

Frequency enhancement was considered through doubling of Bow Church
to Stratford and remodelling of North Quay and Royal Mint Street
junctions (to remove the conflict between northbound Stratfords
and southbound Canary Wharfs at the former, and between services
to/from Tower Gateway and eastbound Banks at the latter); however,
the cost was similar to the 3-car plan, but for only a 25% capacity
increase rather than 50%.

That implies that the network is already at the upper limits of
frequency in the peaks for any services passing through North Quay
or Royal Mint St. Curtailing some services has also been considered
(i.e having them terminate without passing through these junctions,
e.g. Poplar - Beckton) but was considered as highly inconvenient
to passengers.


Was this issue part of the reason why the takeover of the NLL was
considered, to provide a completely separate route on the
Stratford-Woolwich axis that doesn't require more trains to use the
existing single-track branch into platform 4?

It does provide that benefit for both Beckton and Woolwich services (of
the 10tph serving Stratford International via West Ham, 5tph will run to
Beckton and 5tph will run to Woolwich), but I'm not sure whether that
was a key factor in the decision to take over the NLL.


--
Dave Arquati
Imperial College, SW7
www.alwaystouchout.com - Transport projects in London

Dave Arquati wrote:
Ian Tindale wrote:

Stephen worheedatworheeddotf9dotcodotuk wrote:


Whilst were on about the DLR, the public enquiry into 'Capacity
enhancement' (upgrading to 3 car trains) started this week. DLR say
most
of the objections have been withdrawn, so it looks likely to go ahead.



I'd have thought that it'd be more cost-effective and more
satisfactory for
passengers to keep increasing the frequency of trains, instead of making
them bigger. What's the theoretical top limit for frequency of DLR
trains?


Whatever they can push through North Quay Junction, which is the
bottleneck for the entire network.

Frequency enhancement was considered through doubling of Bow Church to
Stratford and remodelling of North Quay and Royal Mint Street junctions
(to remove the conflict between northbound Stratfords and southbound
Canary Wharfs at the former, and between services to/from Tower Gateway
and eastbound Banks at the latter); however, the cost was similar to the
3-car plan, but for only a 25% capacity increase rather than 50%.

That implies that the network is already at the upper limits of
frequency in the peaks for any services passing through North Quay or
Royal Mint St. Curtailing some services has also been considered (i.e
having them terminate without passing through these junctions, e.g.
Poplar - Beckton) but was considered as highly inconvenient to passengers.


During rush hour trains seems to run within 2 minutes of each other.

Trying to increase that to just 90 seconds is probably going to cause
more problems with people trying to get on or off the trains themselves.