The big problem for London, created by parliament, who in their
wisdom, many times in the 19th century, wouldn't allow a London "central"
station to be built, is that most commuters come into the the south bank,
with a walk just to long to be convenient, to reach their city centre
destinations. So, the "Cross-River Tram Project". Since we can't change the
past at all, nor its consequences at a reasonable price, the logic of the
cross river tram plan is incontestable. But does it have to be trams?

What about belts? Their capacity is stupendous, and there would no
problem fitting them into the south bank nor onto the bridges across the
river. There would be some problems fitting them into the north side of the
river, but I think they could be overcome. Certainly I think their
potential should be investigated.

Here is a rather long collection from different authors in another
newsgroup.

Michael Bell

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Date: Thu, 9 Oct 2003 00:31:21 +1000
From: Dudley
Subject: [lrta] Continous belts and the Never Stop Railway

Sorry for the delay in replying - we have moved house!

Some further information extracted from "Passenger Conveyors" Tough
and O'Flaherty, Ian Allan, 1971. Please note that much of this is
direct quotation - but so mixed in with my text that it would be
unsatisfactory to keep inserting quotes and unquotes. My apologies to
Messrs Tough and O'Flaherty. Please refer to their book for further
details, diagrams, and references to original documents.

(A) Continuous belts

Two major installations have been built. The first was at the Chicago
Exhibition of 1893 - designed by Silsbee and Schmidt. Two moving
platforms were used, running at 3 and 6 mph. The slow platform was
720 mm wide, used only as a step to the fast platform. The latter was
1760 mm wide and carried transverse benches 1440 mm long (seating 3
people) at intervals of 910 mm. Total length was about 1310 m. The
belts were carried on four wheel trucks - the slow speed belt on a
cantilever from the truck frames, and the high speed belt on rails
running on top of the wheels.

This gave the 2 : 1 speed ratio. Total seating capacity was 4212
persons, and at the design speed the capacity was 31 680 persons per
hour past any fixed point. Every 35th truck carried 2 x 11 kW
motors, current collection by a trolley wheel from a third rail.
Return current through the running rails. Demand apparently never
exceeded 150 kW, and with a full load of passengers (about 300 tons)
and the tare of 500 tons, normal operation took no more than 78 kW.
Silsbee and Schmidt explained that should more intermediate platforms
be required, to get speeds greater than 6 mph, it could be done by
extending the truck axles and mounting addition larger flanged wheels
on them.

The second was at the Paris Exhibition of 1900. This was a larger
installation (the longest ever built) at 3360 m. This was an
improvement on the Chicago system as the motors were removed by the
fixed structure, and drive was from different sized traction wheels
bearing against the underside of a continuous rail mounted under the
axles of the trucks. In this case, the two belts were mounted on
separate sets of trucks. The slow platform was 900 mm wide, and the
fast platform 2000 wide. However, neither had seats. There were 172
motors employed, each of 3.7 kW. All motors were in parallel, but
the power distribution network was arranged so that half of the
circuit was in series with the other half. This meant that each
motor had only 250 V across it. Speeds were lower than in Chicago,
at about 3.6 and 7.2 km/h (2.2 and 4.7 mph). Starting was at 200 V,
with a current of 900 amps, but after normal operation was
established, between 300 and 400 amps at 500 V.

Power consumption did not exceed 209 kW when loaded. Capacity of the
fast platform was 26 800 persons (at 4 per m2), giving a capacity of
57 600 passengers per hour past any fixed point.

However, the daily average of passengers carried was only about 31
000, which meant there was quite a lot of standing room. It had an
excellent safety record, with 6 694 308 journeys in seven months, no
serious accidents, and only 40 minor accidents reported. Financial
operation was not good, each passenger paid 50 centimes, so the total
income of 3 347 154 francs was less than half of the construction and
operation cost of about 7.5 million francs (44.6%). (Note: this
'farebox return' compares well with most modern bus systems in
developed countries, though not as good as most light rail systems.
However, finances would have been substantially improved by the scrap
value after closure of the Exhibition, or if the systems had operated
for several years, instead of only 7 months).

(B) "Never Stop Railway".

This was originally proposed by Lewis and Adkins for New York in 1905,
but not adopted. However, in 1922 they proposed it for the British
Empire Exhibition to be held at Wembley in 1924. A trial length was
constructed at Southend on Sea in 1923 - a single loop about 275 m
long, being two parallel lines with sharp turns at each end. The
Wembley line was 2.20 km, with 88 cars, each seating 18 and with a
further 12 standing. The spiral shaft was driven by some 14 motors,
with an input of 180 kW (Plate 8 shows 60 hp) for a speed range of 2
to 16 km/h (note that Plate 8, presumably contemporary, has a
notation stating 2 - 16 mph. this sounds more likely). A speed
range of 4.8 to 38.4 km/h is said to have been possible. The cars had
rubber tyred wheels, with horizontal rubber tyred guide rollers to
keep them on track. The railway operated for two seasons, 1924 and
1925; during the first season there were stoppages due to defective
equipment being supplied. There were no involuntary stops during the
second season. which operated free of charge as its operating costs
were so low. The railway carried some 2 million people without
accident in the two years. Lewis submitted the railway in a
competition organized by the Ville de Paris in 1920, and won the
prize in 1924 (jointly with 2 Frenchmen who had submitted a moving
platform scheme.) These were not built, nor was Adkins' and Lewis's
proposals when submitted for the Victoria Line in 1955.

Both systems could be substantially improved. There was apparently no
trouble with bearings with the Never Stop Railway (see below), but
apart from the sharp corners at the terminal points, the spiral drive
shafts would have presumably only permitted very large radii curves,
in both horizontal and vertical planes. (Plate 8 shows apparently
cars pushing each other round a tight terminal loop, another drawing
I have seen (I have lost the book but think it was B Richards - New
Movement in Cities, 1966) apparently showed cars being propelled round
the very tight curve by a four armed turntable). The original
diagrams do not indicate different gauges for front and rear wheels -
this would considerably increase the infrastructure cost but would be
practical. However, people generally do not seem to mind trams
tilting on reasonable slopes - note the 10% grade for the Kingsway
Subway northern ramp, and rather steeper grades used on tramways
elsewhere.

I put forward a modification of the NSR to the Brisbane Expo people
(which was not adopted either!). This would have used the spiral
drive shafts only for the acceleration and deceleration sections. In
between, automatic jaws would have clamped onto a steel cable,
operating very much as cable trams. With this, reasonable curves
could have been used, both in the horizontal and vertical planes. As
the cable would only have been used for constant speed sections of the
line, there would have been minimal stress on it, unlike those in San
Francisco, where the cable has to accelerate and decelerate very
heavy trams from rest to 9 mph and back. Steel flanged wheels would
have omitted the cumbersome horizontal rollers, and fibreglass and
aluminium would have made the cars far lighter than the wooden bodies
and cast steel trucks used in 1924. Doors could have been opened
automatically by a system of weights and levers at stations. Use of a
moving platform on the station would have enabled a substantial
increase in the minimum speed (keeping the same differential between
platform and vehicle) and hence a substantial increase in the top
speed.
Alternatively, use of a moving platform surface at the same speed as
the vehicles would make wheelchair boarding very easy, necessary now
in view of the Disability Discrimination Acts. This would, of
course, considerably increase costs! It is possible that the DDA
would prevent operation of any system using belts moving at different
speeds (other than the Biway system, where the fast belt operated at
constant speed and the other belt alternately stopped and accelerated
to the same speed as the fast belt).

Regards

Dudley

************************************************** ********************

Sent: Tuesday, 1 July 2003 9:32
Subject: Continous belts

Let me inflict on a you an essay I wrote some time ago.


Michael Bell


Continuous passenger transport?

In the early 1960s New Scietist published an article on
continuous transport which has stayed in my mind.

The argument was that for short-distance travel in towns,
waiting time for the next vehicle to come along is a significant part
of the total journey time, and if waiting time could be reduced to
nothing, then moderate speeds would be competitive.

The writer put forward 2 ideas; The "Never-Stop Railway" amd
"Continuous Belts".

The never-stop railway consists of cabins for 6-8 passengers
which are moved along the track by a continuous spiral laid between
the tracks. The pitch of the spiral is fine at stations, so at the
stations the gaps between the cabins close up and the cabins move
slowly and the passengers can get in and out. As the cabins reach the
end of the station the doors close and when they leave the station the
pitch of the spiral coarsens so the gap between the cabins widens and
they pick up speed. The cabins can be slowed down to go round sharp
corners. The front and back wheels of the cabins run on different
rails so the cabins can go up and down steep slopes without tilting
them, in the way that steps on an escalator do. To be able to go round
sharp corners and go up and down steep slopes are important advantages
in fitting such a system into a town. The system was successfully
demonstrated at an exhibition in Wembley in the 1920s.

It seems a natural for linking close-together point sources of
traffic, such as the pairs of stations you often get in London which
are just too far apart for convenient walking, but it could be used in
all sorts of circumstances. In some cases the speeds could be quite
high. The drawbacks include the height necessary for the ability to go
up and down steep slopes and the huge number of bearings to be
maintained.

Continuous belts are altogether more radical. The idea is that
you have a series of continuous belts side-by-side, each moving faster
than the last. The writer said that it would only be possible to have
speed differences between belts of 1-2 mph, so it would need an
impracticably large number of belts to reach worthwhile speeds. but I
think he said this to tilt the balance to his own preference, the
never-stop. We can all walk at 4 mph (= 1M/sec), so I think 4 mph steps
would be acceptable, so 3 belts would get us up to 12 mph and 4 belts
would get us up to 16 mph. This is much faster than town buses and
after allowing for the time taken walking to the station and waiting
for the train, competitive with Metros.

The slow-speed belts would be at most 1 M wide, if the fastest
belt carried a long bench-seat facing the slow side it might be at
most 2 M wide, and there must be a stationary walkway along the full
length of the system. A 3-belt system with a 2M-wide walkway would be
at most 6M wide. Capacity is startlingly high, if all were seated on
this 3-belt system at 2 persons per metre, capacity is 43 000
passengers/hour, crush capacity is very much more. A 2-belt system
like this was demonstrated at an exhibition in Paris in the 1890s. It
was a very restful system to go on. With its vast capacity, passengers were
well spread out, they were quietly carried at constant speed past scenery
which it was in everybody's interests to make interesting. Here I think is
one of the systems's great opportunities, which the writer overlooked.

Building owners naturally don't want to have overhead
structures put up in front of their buildings taking passengers PAST
with no possibility of getting off - this is one of the big difficulties
with overhead transport systems. But surely building owners DO want people to
be brought past their buildings in a way which allows them to look, and to
get off and go to their shops, nightclubs, apartments, etc. Building owners
should actually be willing to PAY to have such a system brought past their
buildings, whether at basement level or first-floor level doesn't matter.

Of course, there are the practicalities to think of. Drive
would obviously be by linear motor, a new technology. Support is more
of a problem. Wheels work, but they wear out and the bearings need
servicing. They also take up height. Air-cushion is another
possibility, and so is magnetic levitation. Is that possible with permanent
magnets?

Raising our eyes from the technical details, we see that the
reasons why such project might or might not go ahead are political and
economic. Belts would create a wholly new townscape. They would lead
to massive concentrations of commercial activity and residential
occupation along their routes, in contrast to the way cars tend to
spread out activities and living places.



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