In article ,
(Jan-Martin Hertzsch) wrote:

David Bradley wrote:
... The document can be found at:
http://www.cyberpictures.net/WLTTbusSolution.doc

Being in Microsoft Word document format ...

... it may happen that some readers can not access this
document at all because they don't have a reader for this
format. Would you be so kind and translate it into HTML?
Then anybody with a web browser could read it.

I've made a PDF version. Anyone want it?

--
Colin Rosenstiel

In article ,
Jan-Martin Hertzsch wrote:
David Bradley wrote:
... The document can be found at:
http://www.cyberpictures.net/WLTTbusSolution.doc

Being in Microsoft Word document format ...

... it may happen that some readers can not access this
document at all because they don't have a reader for this
format. Would you be so kind and translate it into HTML?
Then anybody with a web browser could read it.

pdf is the preferred and most commonly used format for this sort of
document on the web.

David

On Thu, 11 Nov 2004, Colin Rosenstiel wrote:

In article ,
(Jan-Martin Hertzsch) wrote:

David Bradley wrote:
... The document can be found at:
http://www.cyberpictures.net/WLTTbusSolution.doc

Being in Microsoft Word document format ...

... it may happen that some readers can not access this document at
all because they don't have a reader for this format. Would you be so
kind and translate it into HTML? Then anybody with a web browser could
read it.

I've made a PDF version. Anyone want it?

Perhaps you could suggest to Mr Bradley that he post it alongside the word
document.

tom

--
VENN DIAGRAM THAT LOOK LIKE TWO BIG CIRCLES EQUAL BAD PUBLIC POLICY.

On Thu, 11 Nov 2004 18:47:28 +0000, Tom Anderson
wrote:

On Thu, 11 Nov 2004, Colin Rosenstiel wrote:

In article ,
(Jan-Martin Hertzsch) wrote:

David Bradley wrote:
... The document can be found at:
http://www.cyberpictures.net/WLTTbusSolution.doc

Being in Microsoft Word document format ...

... it may happen that some readers can not access this document at
all because they don't have a reader for this format. Would you be so
kind and translate it into HTML? Then anybody with a web browser could
read it.

I've made a PDF version. Anyone want it?

Perhaps you could suggest to Mr Bradley that he post it alongside the word
document.

tom

Please go to www.trolleybus.net At the bottom of the green panel on
the left an option is there to send me an email. Please use this to
attached a PDF version of the word document. Once received I would be
happy to place the pdf on the web site. It will have the URL of:
www.cyberpictures.net/wlt.pdf - Can't say farier than that can I?

David Bradley

In article ,
(David Bradley) wrote:

Please go to www.trolleybus.net At the bottom of the green panel on
the left an option is there to send me an email. Please use this to
attached a PDF version of the word document. Once received I would be
happy to place the pdf on the web site. It will have the URL of:
www.cyberpictures.net/wlt.pdf - Can't say farier than that can I?

OK, but not before Saturday evening now.

--
Colin Rosenstiel

David Bradley wrote:
I thought that newsgroup readers might like to see the Electric Tbus
Group's analysis of the West London Transit sceeme using 'rubber tyred
electric trams', ie. Trolleybuses, as submitted to TfL. The Group
found that it would be possible to wire into Ealing Hospital, into
Ealing Broadway Station and avoid all diversions of 'other' traffic on
to side streets (page 4).

Trolleybus overhead is lighter than tram equivalents and despite
having 2 wires, has generally less visual impact.

The document can be found at:
http://www.cyberpictures.net/WLTTbusSolution.doc

Moving on from some of the distribution issues, it's an interesting
response that the group as produced and worth discussion. Although it
would do well to consider trolleybuses instead of trams (especially
given that some residents are against a tram but would not necessarily
be against a trolleybus, considering audience reactions at People's
Question Time in Acton Assembly Hall last night), I think there are some
concerns over trolleybuses.

Firstly, and primarily for me, a severe problem is ride quality. Trams
generally have a highly-superior ride quality to buses, and I can't see
that any amount of guidance or suspension will equal the playing fied -
steel rails are just much smoother than tarmac (and tarmac will wear
down a lot more quickly).

Secondly, the trolleybuses mentioned are 25m long, whereas a tram is 40m
long, and the trolleybuses are also narrower due to government
regulation. Therefore to maintain an appropriate capacity, a higher
number of trolleybuses are required. In the analysis of Cross River
Transit, both trams and trolleybuses were considered, and whereas trams
met demand at 40tph, trolleybuses or bendybuses would have required
100bph - one every 36 seconds!
(http://www.tfl.gov.uk/tfl/pdfdocs/crossriver.pdf)
The response says that needing a higher frequency to provide the same
capacity is a benefit; that may be so for off-peak journeys where
waiting times would be reduced, but in the peak, it could lead to
excessive bunching and problems accessing transit stops. Higher
frequency of heavy vehicles will also wear down the road surface, making
the ride quality poor. It will also offset any weight advantage the
trolleybus has - instead of suffering from heavy vibrations every 6
minutes, residents along the Uxbridge Road will suffer from lighter
vibrations every 3 minutes.

Thirdly, I'm not convinced by some of the advantages of the trolleybus
over the tram in the comparison of restrictions at junctions. Obviously
since the stops are shorter, you can put them in more places, but some
of the banned turns introduced by the tram are to prevent build-up of
traffic which eventually would block the tram's passage (because unless
a right turn lane is long enough, an increasing queue will eventually
block the tram). I appreciate that the trolleybus is more manoeuvrable
so it may be able to squeeze around the end of some queues.

I'm also not convinced about routing Tbuses via "new roads" to reach
Ealing Broadway station.

Finally, your figures come out quite differently to TfL's ones for the
trolleybus when it made its initial Uxbridge Road Transit report. TfL
found a benefit:cost ratio of 3.48:1 for the tram and 2.58:1 for the
trolleybus - partly because trolleybus installation costs were quite
high. (http://www.tfl.gov.uk/tfl/pdfdocs/uxbridge.pdf)


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

On Fri, 12 Nov 2004 15:54:12 +0000, Dave Arquati
wrote:

David Bradley wrote:
I thought that newsgroup readers might like to see the Electric Tbus
Group's analysis of the West London Transit sceeme using 'rubber tyred
electric trams', ie. Trolleybuses, as submitted to TfL. The Group
found that it would be possible to wire into Ealing Hospital, into
Ealing Broadway Station and avoid all diversions of 'other' traffic on
to side streets (page 4).

Trolleybus overhead is lighter than tram equivalents and despite
having 2 wires, has generally less visual impact.

The document can be found at:
http://www.cyberpictures.net/WLTTbusSolution.doc

Moving on from some of the distribution issues, it's an interesting
response that the group as produced and worth discussion. Although it
would do well to consider trolleybuses instead of trams (especially
given that some residents are against a tram but would not necessarily
be against a trolleybus, considering audience reactions at People's
Question Time in Acton Assembly Hall last night), I think there are some
concerns over trolleybuses.

Firstly, and primarily for me, a severe problem is ride quality. Trams
generally have a highly-superior ride quality to buses, and I can't see
that any amount of guidance or suspension will equal the playing fied -
steel rails are just much smoother than tarmac (and tarmac will wear
down a lot more quickly).

Secondly, the trolleybuses mentioned are 25m long, whereas a tram is 40m
long, and the trolleybuses are also narrower due to government
regulation. Therefore to maintain an appropriate capacity, a higher
number of trolleybuses are required. In the analysis of Cross River
Transit, both trams and trolleybuses were considered, and whereas trams
met demand at 40tph, trolleybuses or bendybuses would have required
100bph - one every 36 seconds!
(http://www.tfl.gov.uk/tfl/pdfdocs/crossriver.pdf)
The response says that needing a higher frequency to provide the same
capacity is a benefit; that may be so for off-peak journeys where
waiting times would be reduced, but in the peak, it could lead to
excessive bunching and problems accessing transit stops. Higher
frequency of heavy vehicles will also wear down the road surface, making
the ride quality poor. It will also offset any weight advantage the
trolleybus has - instead of suffering from heavy vibrations every 6
minutes, residents along the Uxbridge Road will suffer from lighter
vibrations every 3 minutes.

Thirdly, I'm not convinced by some of the advantages of the trolleybus
over the tram in the comparison of restrictions at junctions. Obviously
since the stops are shorter, you can put them in more places, but some
of the banned turns introduced by the tram are to prevent build-up of
traffic which eventually would block the tram's passage (because unless
a right turn lane is long enough, an increasing queue will eventually
block the tram). I appreciate that the trolleybus is more manoeuvrable
so it may be able to squeeze around the end of some queues.

I'm also not convinced about routing Tbuses via "new roads" to reach
Ealing Broadway station.

Finally, your figures come out quite differently to TfL's ones for the
trolleybus when it made its initial Uxbridge Road Transit report. TfL
found a benefit:cost ratio of 3.48:1 for the tram and 2.58:1 for the
trolleybus - partly because trolleybus installation costs were quite
high. (http://www.tfl.gov.uk/tfl/pdfdocs/uxbridge.pdf)

A response to the many issues raised will be posted later but
meanwhile I have to give an immediate response to suggestions that
ride quality of trams will always be superior to that of trolleybuses.

A recent visit to the Nottingham system showed that the trams were
spacious and have comfortable seats. They have completely level flat
floors. On the negative side, the ride is awful, particularly on
curves where the vehicles seem to go round in crab fashion on a series
of straights rather than in an elegant curve. This jolts standing
passengers quite badly. The ride is far worse than Croydon, Machester,
Sheffield or Birmingham. It is not immediately obvious why this should
be so and whether its the track or the vehicles or both. As the track
wears, the likelhood is that this will get worse. Despite your
fanactical statement about 'smooth riding trams', it would be very
easy to get air suspension trolleys riding far better even on the most
mediocre road services.

Do have a look at this documentation, particularly the Committee
Verdict at the end:
-----------------------------
http://www.london.gov.uk/assembly/tr...tyResponse.rtf

"There is widely held scepticism among local residents and the
Committee that the tram is the only viable solution to meet the
growing demand for public transport along the Uxbridge Road corridor.

The Committee acknowledge the considerable public concerns about the
proposal. We would be interested in a further exploration of guided
bus technology to understand its costs, its ability to overcome those
concerns, even though it would appear to require similar degrees of
segregation to the tram, and whether such a system can provide the
capacity that TfL's projections suggest is required.

The Committee would welcome the opportunity to comment upon such work
before TfL's scheduled application for a Transport and Works Order in
the Spring of 2005."
-----------------------------

Unfortunately there seems to be a belief that trolleybuses and guided
technology go hand in hand; this is simply not true neither is it
impossible to have level boarding, as at stops/stations Kassell kerbs
would be used.

David Bradley

My friend has given me a more detailed response on this issue.

Comments are interlaced with the previous contribution to this
disccussion and are prefixed with ***

Moving on from some of the distribution issues, it's an interesting
response that the group has produced and worth discussion. Although it
would do well to consider trolleybuses instead of trams

*** especially given that some residents are against a tram but would
not necessarily be against a trolleybus, considering audience
reactions at People's Question Time in Acton Assembly Hall last night

I think there are some concerns over trolleybuses.

Firstly, and primarily for me, a severe problem is ride quality. Trams
generally have a highly-superior ride quality to buses, and I can't
see that any amount of guidance or suspension will equal the playing
field - steel rails are just much smoother than tarmac (and tarmac
will wear down a lot more quickly).

*** I might once have agreed with this, provided that the rails were
maintained in very good condition (a big if), but I fear that he is
now out of date. The ride quality of stub axle low-floor trams is
awful and far worse than many buses even on Britain's indifferent road
services. The truth is now that a low floor trolleybus on an even half
decently maintained road is far smoother than a low floor tram with
stub axles on rails. For comparison try a new low-floor Amsterdam tram
against an Arnhem trolleybus.

Secondly, the trolybuses mentioned are 25m long, whereas a tram is 40m
long, and the trolleybuses are also narrower due to government
regulation

*** only 0.1 metres narrower 2.55 m. compared to 2.65 m. - that's only
3 inches in old money and is not significant

Therefore to maintain an appropriate capacity, a higher number of
trolleybuses are required

*** Quite true but you need the demand to justify the intense
frequency of trams along the Uxbridge Road. TfL have never proved this
case.

In the analysis of Cross River Transit, both trams and trolleybuses
were considered, and whereas trams met demand at 40tph, trolleybuses
or bendy buses would have required 100bph - one every 36 seconds!

*** We are not discussing CRT but WLT. The maths is also a bit off.
Taking an exact ratio of space you only need 64 trolleybuses per hour
not 100. I presume the 100 was based on 18 metre artics not 25 m.
double artics

(http://www.tfl.gov.uk/tfl/pdfdocs/crossriver.pdf) The response says
that needing a higher frequency to provide the same capacity is a
benefit; that may be so for off-peak journeys where waiting times
would be reduced, but in the peak, it could lead to excessive bunching
and problems accessing transit stops.

** Two by 25 metres trolleybus bunching only equals 50 metres, not
much more than TfL are planning for every journey of the tram without
any bunching (40m). Bunching of trams is likely to be less often but
still quite frequent on the TfL proposed tram service and this then
gives an 80 metre blockage on a fixed path. This I would suggest would
completely block up junctions and generally clog up the street

and Higher frequency of heavy vehicles will also wear down the road
surface, making the ride quality poor.

*** Main roads are built in the UK to 11.5 metre axle loads to allow
for the heaviest HGV's. The DfT officially regard the wear and tear
due to all other traffic (including buses) as zero due to the massive
disparity between the axle loads of such traffic and that of HGV's.
The trolleys will not of course be using the exact same width of road
all the time except at low speed for approach to stops. Tram track
also wears out of course as a ride on the well used Blackpool -
Fleetwood tramway will testify!

It will also offset any weight advantage the trolleybus has - instead
of suffering from heavy vibrations every 6 minutes, residents along
the Uxbridge Road will suffer from lighter vibrations every 3 minutes

*** The comments about the road construction again apply. Generally
unless the road has been allowed to badly deteriorate, there is no
noticeable vibration from vehicles with the axle loads of buses or
trolleybuses. The heavy mass of trams concentrated into the small
wheel contact on the railed surface does of course cause considerable
vibration despite the best efforts of rubberised dampeners in the
track mountings etc. This will be particularly so with the 40 metre
monsters proposed for WLT. It is regular and frequent vibration from
trams or no noticeable vibration amongst the general traffic from
trolleybuses in reality.

Thirdly, I'm not convinced by some of the advantages of the trolleybus
over the tram in the comparison of restrictions at junctions.
Obviously since the stops are shorter, you can put them in more
places, but some of the banned turns introduced by the tram are to
prevent build-up of traffic which eventually would block the tram's
passage

*** Because unless a right turn lane is long enough, an increasing
queue will eventually block the tram.

I appreciate that the trolleybus is more maneuverable so it may be
able to squeeze around the end of some queues.

I'm also not convinced about routing Tbuses via "new roads" to reach
Ealing Broadway station.

Finally, your figures come out quite differently to TfL's ones for the
trolleybus when it made its initial Uxbridge Road Transit report. TfL
found a benefit: cost ratio of 3.48:1 for the tram and 2.58:1 for the
trolleybus - partly because trolleybus installation costs were quite
high.

*** We all know that the trolleybus figures were distorted upwards by
deliberately including unnecessary total route guidance. No appraisal
has ever been done by TfL of an unguided 25 metre trolleybus option.
Ours is the only one. It is worth noting that the original tram
benefit cost ratio has been reduced several times by TfL since the
heady 3.48 of the original report and at maximum tramway cost now
stands at only 1.5, even with TfL's vastly over inflated usage
estimates!

David Bradley

Dave Arquati wrote:
Moving on from some of the distribution issues, it's an interesting
response that the group as produced and worth discussion. Although it
would do well to consider trolleybuses instead of trams (especially
given that some residents are against a tram but would not necessarily
be against a trolleybus, considering audience reactions at People's
Question Time in Acton Assembly Hall last night), I think there are some
concerns over trolleybuses. ....

Secondly, the trolleybuses mentioned are 25m long, whereas a tram is 40m
long, and the trolleybuses are also narrower due to government
regulation. Therefore to maintain an appropriate capacity, a higher
number of trolleybuses are required. In the analysis of Cross River
Transit, both trams and trolleybuses were considered, and whereas trams
met demand at 40tph, trolleybuses or bendybuses would have required
100bph - one every 36 seconds!

Uxbridge Road is planned for 20tph or every 3 minutes at peak times.
Troleybuses would need to be every 1.5 minutes, which seems close. But
they'd travel something like 700m on average in 1.5 minutes, which
seems adequate spacing.

It also has the advantage that off-peak you're not shifting so many
empty seats around to maintain adequate frequency.

Finally, your figures come out quite differently to TfL's ones for the
trolleybus when it made its initial Uxbridge Road Transit report. TfL
found a benefit:cost ratio of 3.48:1 for the tram and 2.58:1 for the
trolleybus - partly because trolleybus installation costs were quite
high. (http://www.tfl.gov.uk/tfl/pdfdocs/uxbridge.pdf)

I suspect the real reason for TfL preferring the tram is that it is
easier to give it its own space, not shared with other traffic. The
Uxbridge Road design gives the tram segregated space wherever
possible, reducing capacity for other traffic. This makes the trams
faster than trolleybuses, but frightens residents, who assume that all
the existing traffic will remain and find a way through somehow. In
fact, when road capacity is reduced, some traffic evaporates -
especially if a high-quality alternative is being provided at the same
time.

Colin McKenzie

David Bradley wrote:
My friend has given me a more detailed response on this issue.

Thanks for the detailed replies! May I respond to both you and your friend.

David Bradley wrote:
( Ride quality of trams vs trolleybuses)
A response to the many issues raised will be posted later but
meanwhile I have to give an immediate response to suggestions that
ride quality of trams will always be superior to that of trolleybuses.

A recent visit to the Nottingham system showed that the trams were
spacious and have comfortable seats. They have completely level flat
floors. On the negative side, the ride is awful, particularly on
curves where the vehicles seem to go round in crab fashion on a series
of straights rather than in an elegant curve. This jolts standing
passengers quite badly. The ride is far worse than Croydon, Machester,
Sheffield or Birmingham. It is not immediately obvious why this should
be so and whether its the track or the vehicles or both. As the track
wears, the likelhood is that this will get worse. Despite your
fanactical statement about 'smooth riding trams', it would be very
easy to get air suspension trolleys riding far better even on the most
mediocre road services.

I wasn't trying to be fanatical about trams; I personally like them,
although lack of flexibility does have me concerned on a 100% on-street
route. However, my impression from the few trams I've ridden on has been
positive - Croydon seemed pretty smooth to me (more so than a bus).

My highly unscientific test would be to see how well you can write on a
bus versus a tram. It seems to me that it's much easier on a tram - but
then again, it's difficult on the District line, so I guess it depends
completely on the rail condition.

If an air suspension system gives a ride quality, what stops this being
used on new diesel buses? (just wondering)

Do have a look at this documentation, particularly the Committee
Verdict at the end:
-----------------------------
http://www.london.gov.uk/assembly/tr...tyResponse.rtf

"There is widely held scepticism among local residents and the
Committee that the tram is the only viable solution to meet the
growing demand for public transport along the Uxbridge Road corridor.

The Committee acknowledge the considerable public concerns about the
proposal. We would be interested in a further exploration of guided
bus technology to understand its costs, its ability to overcome those
concerns, even though it would appear to require similar degrees of
segregation to the tram, and whether such a system can provide the
capacity that TfL's projections suggest is required.

The Committee would welcome the opportunity to comment upon such work
before TfL's scheduled application for a Transport and Works Order in
the Spring of 2005."
-----------------------------

I am extremely sceptical about guided buses - they would seem to offer
many of the disadvantages of buses with the disadvantages of trams.
Didn't a guided bus system operate between Charlton station and the
Dome, extremely unsuccessfully? (although the route is to be
incorporated into Greenwich Waterfront Transit).

Unfortunately there seems to be a belief that trolleybuses and guided
technology go hand in hand; this is simply not true neither is it
impossible to have level boarding, as at stops/stations Kassell kerbs
would be used.

Although guided buses have the disadvantage of a fixed route, I can see
how it would be an advantage in guiding them to the edge of transit
stops. How would a non-guided trolleybus be any improvement for level
boarding compared to a current bus? They must have the same difficulties
reaching the kerb without hitting it. An unguided driver can only drive
to a certain level of accuracy.

Comments are interlaced with the previous contribution to this
disccussion and are prefixed with ***

Moving on from some of the distribution issues, it's an interesting
response that the group has produced and worth discussion. Although it
would do well to consider trolleybuses instead of trams

*** especially given that some residents are against a tram but would
not necessarily be against a trolleybus, considering audience
reactions at People's Question Time in Acton Assembly Hall last night

That was my original comment! :-)

I think there are some concerns over trolleybuses.

Firstly, and primarily for me, a severe problem is ride quality. Trams
generally have a highly-superior ride quality to buses, and I can't
see that any amount of guidance or suspension will equal the playing
field - steel rails are just much smoother than tarmac (and tarmac
will wear down a lot more quickly).

*** I might once have agreed with this, provided that the rails were
maintained in very good condition (a big if), but I fear that he is
now out of date. The ride quality of stub axle low-floor trams is
awful and far worse than many buses even on Britain's indifferent road
services. The truth is now that a low floor trolleybus on an even half
decently maintained road is far smoother than a low floor tram with
stub axles on rails. For comparison try a new low-floor Amsterdam tram
against an Arnhem trolleybus.

Is that an offer?
To be honest I've never used a trolleybus - but should I expect ride
quality to be much different to the buses which I use regularly in London?

I was always under the impression that ride quality is one reason why
people view trams in a much better light than buses. Even if this
perception is incorrect, the public see rail-based systems in a light
that they will never see any kind of bus in.

That's not a good reason to reject trolleybuses if they can indeed offer
a good ride quality, but it would certainly affect traffic projections -
reducing its benefit:cost ratio.

Secondly, the trolybuses mentioned are 25m long, whereas a tram is 40m
long, and the trolleybuses are also narrower due to government
regulation

*** only 0.1 metres narrower 2.55 m. compared to 2.65 m. - that's only
3 inches in old money and is not significant

Point taken.

Therefore to maintain an appropriate capacity, a higher number of
trolleybuses are required

*** Quite true but you need the demand to justify the intense
frequency of trams along the Uxbridge Road. TfL have never proved this
case.

TfL forecast demand of around 5500 passengers per peak hour in the
eastbound direction between Southall and Acton (I think). Using a very
rough calculation, if a tram has a capacity of 300 passengers for 40m of
length, then your 25m trolleybuses have a capacity of around 190
passengers, right? The tram would meet demand at 19tph but the 25m tbus
would need 29tph.

Of course this depends on TfL's forecast of demand.

In the analysis of Cross River Transit, both trams and trolleybuses
were considered, and whereas trams met demand at 40tph, trolleybuses
or bendy buses would have required 100bph - one every 36 seconds!

*** We are not discussing CRT but WLT. The maths is also a bit off.
Taking an exact ratio of space you only need 64 trolleybuses per hour
not 100. I presume the 100 was based on 18 metre artics not 25 m.
double artics

Quite probably - let's ignore CRT.

(http://www.tfl.gov.uk/tfl/pdfdocs/crossriver.pdf) The response says
that needing a higher frequency to provide the same capacity is a
benefit; that may be so for off-peak journeys where waiting times
would be reduced, but in the peak, it could lead to excessive bunching
and problems accessing transit stops.

** Two by 25 metres trolleybus bunching only equals 50 metres, not
much more than TfL are planning for every journey of the tram without
any bunching (40m). Bunching of trams is likely to be less often but
still quite frequent on the TfL proposed tram service and this then
gives an 80 metre blockage on a fixed path. This I would suggest would
completely block up junctions and generally clog up the street

I suspect that bunching would be a much bigger problem at the two-minute
trolleybus frequency. Firstly, because it's a 50% increase in frequency
- bunching must be more likely. Secondly, I suspect the non-guided
trolleybus will take more time to gain level access to the kerbside
stops than a tram (which can have a steeper deceleration curve on its
approach as it doesn't need to avoid hitting the kerb).

and higher frequency of heavy vehicles will also wear down the road
surface, making the ride quality poor.

*** Main roads are built in the UK to 11.5 metre axle loads to allow
for the heaviest HGV's. The DfT officially regard the wear and tear
due to all other traffic (including buses) as zero due to the massive
disparity between the axle loads of such traffic and that of HGV's.
The trolleys will not of course be using the exact same width of road
all the time except at low speed for approach to stops. Tram track
also wears out of course as a ride on the well used Blackpool -
Fleetwood tramway will testify!

How much does a trolleybus weigh? (again out of interest) I appreciate
that it is not as bad as an HGV.

It will also offset any weight advantage the trolleybus has - instead
of suffering from heavy vibrations every 6 minutes, residents along
the Uxbridge Road will suffer from lighter vibrations every 3 minutes

*** The comments about the road construction again apply. Generally
unless the road has been allowed to badly deteriorate, there is no
noticeable vibration from vehicles with the axle loads of buses or
trolleybuses. The heavy mass of trams concentrated into the small
wheel contact on the railed surface does of course cause considerable
vibration despite the best efforts of rubberised dampeners in the
track mountings etc. This will be particularly so with the 40 metre
monsters proposed for WLT. It is regular and frequent vibration from
trams or no noticeable vibration amongst the general traffic from
trolleybuses in reality.

OK, I accept your point about the small contact area for trams making
them cause more vibration.

Thirdly, I'm not convinced by some of the advantages of the trolleybus
over the tram in the comparison of restrictions at junctions.
Obviously since the stops are shorter, you can put them in more
places, but some of the banned turns introduced by the tram are to
prevent build-up of traffic which eventually would block the tram's
passage

*** Because unless a right turn lane is long enough, an increasing
queue will eventually block the tram.

That was my comment again, and I'm still a bit concerned about it.

I appreciate that the trolleybus is more maneuverable so it may be
able to squeeze around the end of some queues.

I'm also not convinced about routing Tbuses via "new roads" to reach
Ealing Broadway station.

Finally, your figures come out quite differently to TfL's ones for the
trolleybus when it made its initial Uxbridge Road Transit report. TfL
found a benefit: cost ratio of 3.48:1 for the tram and 2.58:1 for the
trolleybus - partly because trolleybus installation costs were quite
high.

*** We all know that the trolleybus figures were distorted upwards by
deliberately including unnecessary total route guidance. No appraisal
has ever been done by TfL of an unguided 25 metre trolleybus option.
Ours is the only one. It is worth noting that the original tram
benefit cost ratio has been reduced several times by TfL since the
heady 3.48 of the original report and at maximum tramway cost now
stands at only 1.5, even with TfL's vastly over inflated usage
estimates!

I didn't read that TfL had assumed the trolleybus was guided, but I
might have missed it. I do think their trolleybus analyses generally
given a much higher cost than they should, given the decrease in the
amount of road-digging that needs to be done.

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