"Richard J." wrote in message
...

To accommodate tides of 7 metres or more, you would
need ramps totalling 90 - 100 metres long (to limit maximum
gradient to the DfT guideline maximum of 1 in 12),
and sufficient of them to cope with large passenger
flows. It's not impossible, but it's a significant constraint
on the design, and may limit potential capacity just
because the piers would take up so much room.

You could have a narrow zigzaggy ramp (or even a lift?) for the few, and
wide steps for the many.

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes

John Rowland wrote:
"Richard J." wrote in message
...

To accommodate tides of 7 metres or more, you would
need ramps totalling 90 - 100 metres long (to limit maximum
gradient to the DfT guideline maximum of 1 in 12),
and sufficient of them to cope with large passenger
flows. It's not impossible, but it's a significant constraint
on the design, and may limit potential capacity just
because the piers would take up so much room.

You could have a narrow zigzaggy ramp (or even a lift?) for the
few, and wide steps for the many.

How can you have steps or a lift when the pier is afloat, rising and
falling by up to 7 metres twice a day?
--
Richard J.
(to e-mail me, swap uk and yon in address)

Richard J. wrote:
Aidan Stanger wrote:
Richard J. wrote:

Brimstone wrote:
I accept that a different design would be needed for commuter
(compared to the current leisure) levels of traffic but why would
they be more difficult to design?

To accommodate tides of 7 metres or more, you would need ramps
totalling 90 - 100 metres long (to limit maximum gradient to the
DfT guideline maximum of 1 in 12), and sufficient of them to cope
with large passenger flows. It's not impossible, but it's a
significant constraint on the design, and may limit potential
capacity just because the piers would take up so much room.

So obviously you just ignore the DfT guideline maximum! 'Tis not a
problem when your vehicles are crew operated...

Are you suggesting the boat crew would assist passengers up, say, 50
metres at 1 in 6?

Not quite that much, but (at the less busy piers) that's the general idea.

That would increase dwell times even more.

Only when the tide is very low.

Anyway,
personal service like that is impracticable for a mass transit system.

It would be if many people needed it, but I doubt that would be the case.

"Jeremy Parker" wrote in message
...

To arrive at Heathrow, and be met by your own canal barge,
seems like a neat service to offer frazzled foreign tourists.

Where is the navigable waterway at Heathrow?

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes

"John Rowland" wrote

To arrive at Heathrow, and be met by your own canal barge,
seems like a neat service to offer frazzled foreign tourists.

Where is the navigable waterway at Heathrow?

It's the Grand Union Canal, close to the railway. I regret that I
can't remember the name of the car park organization. It's been some
time since I left my car at Heathrow when on a trip, and I can't find
the leaflet.

Jeremy Parker

On Sun, 27 Mar 2005, Richard J. wrote:

John Rowland wrote:
"Richard J." wrote in message
...

To accommodate tides of 7 metres or more, you would need ramps
totalling 90 - 100 metres long (to limit maximum gradient to the DfT
guideline maximum of 1 in 12), and sufficient of them to cope with
large passenger flows. It's not impossible, but it's a significant
constraint on the design, and may limit potential capacity just
because the piers would take up so much room.

You could have a narrow zigzaggy ramp (or even a lift?) for the
few, and wide steps for the many.

How can you have steps or a lift when the pier is afloat, rising and
falling by up to 7 metres twice a day?

The lift would have to have a variable top or bottom point. I've never
come across a lift like this, but i don't see why it couldn't be done.

There are a couple of ways you could do the steps. The first would be to
have the steps fixed to the bank, so that the bottom ones are sometimes
underwater, and have the pier slide up and down the steps (ie diagonally).
This would be pretty simple, but would mean the steps would be a bit
muddy. Perhaps a cunning mechanism on the lip of the pier could clean them
up as it descended. The other would be to have flexible steps - so that
when the tide was higher, they were shallower and flatter, perhaps even
becoming a flat walkway at high tide.

Getty any of that past the HSE, though ...

tom

--
an optical recording release. copyright digitally mastered. .,

In article , John Rowland
writes
"Jeremy Parker" wrote in message
...

To arrive at Heathrow, and be met by your own canal barge,
seems like a neat service to offer frazzled foreign tourists.

Where is the navigable waterway at Heathrow?

4 kilometres due north of the bus station - at West Drayton. (The Grand
Union). With work, the River Colne could be canalised and connected to
the Grand Union, giving canal access to Terminal 5.
--
Steve
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