Re: More tech than sci Q -- best size for community

On Tue, 02 Dec 2003 08:18:44 GMT, Coridon Henshaw
<(chenshaw<RE<MOVE>@(T<H+ESE)sympatico.ca)> wrote:

>Wildepad <[EMAIL PROTECTED]> wrote in
>news:[EMAIL PROTECTED]: 
>
>> The townlets are grouped into pods, an ellipse with 12 inhabited
>> townlets (six spaced along each side) and two workplace townlets (one
>> at each end). The pods are arranged in concentric circles connected by
>> spokes.
>> 
>> Line 1 is local -- stops at every townlet within a pod. 
>> Line 2 is express -- picks up at an inhabited and goes straight to the
>> workplace. 
>> Line 3 is reserved -- used only in case of accident or tie-ups on
>> another track.
>> Line 4 is pod jumper -- stops at every workplace.
>> Line 5 is bulk delivery.
>> Line 6 is police/emergency line.
>
>This is just for intra-pod travel, with inter-pod services around or across 
>the concentric circles using different trackage, correct?

Yes, and no.

The high-speed lines (on the circles and spokes) are a separate
system. 

Except for line 4 (which goes from pod to pod), it's all meant to be
used intra-pod, but the actual cars travel much longer routes -- if
you wanted to, you could get on a local on the inner circle and ride
it, with a stop at each and every townlet, all the way to the outer
circle. 

>Four tracks will handle this scenario very easily.  12 tracks yields an 
>ultimate, crush-loaded, capacity in the ballpark of a million passengers 
>per hour using off-the-shelf 75' subway cars operating on 90 second 
>headways.  Doing the math here, if everyone in the pod decided to get on 
>the RTS at once, they'd use less than one percent of its capacity.

Well, efficiency was never a priority. :)

>Even just the three passenger tracks running at capacity could move several 
>orders of magnitude more people than a pod's population in an hour.

The idea is to overcompensate service so that the citizens never have
even a hint of a reason to complain about the lack of other forms of
transportation.

>> Under this scenario, there is no track switching at all required, unless
>> there is an emergency which requires traffic to be temporarily
>> reassigned to track 3.
>
>Crossovers to allow both emergency tracks to be used bidirectionally 
>without the need to wrong-rail will require a minimum of 24 switches. 

? I'm not doubting your figure, I just don't know what you mean.

> If 
>you've got one of these arrangements per townlet that's 336 switches that 
>must be maintained and protected against damage.  Using the crossovers will 
>ruin throughput, however.  A worst-case reroute to put a train on track 12 
>onto track 3 (wrong rail) would involve closing tracks 4-11 for several 
>minutes.  If an express or emergency train needs to go through in the mean 
>time, too bad.

There is no need for crossovers. Lines 2 and 4 don't need to corss
anything. Lines 1 and 5 will either pass over or under the inner
tracks to get to 3 (I never envisioned line 1 and 2 to be on the same
level anyway.). Yes, it'll take a lot of space, but these lines can
easily be several hundred feet apart between the townlets, and even
the stations are 300 feet wide.

Line 6 will never have to be switched between towlets because if it
goes down, the vehicles are put onto line 3 at the hospital/police
headquarters/rescue center.    

>One of the advantages of having fewer tracks is that it becomes practical 
>to use flying junctions to allow for reroutes without fouling other main 
>lines.

'Flying junctions'? 

>Wildepad <[EMAIL PROTECTED]> wrote in 
>news:[EMAIL PROTECTED]:
>
>> The beauty of 12 lines is that collisions are easy to avoid -- all you
>> need is a system to prevent one car from rear-ending another. 
>
>Every switch and crossing in a rail network represents the possibility of a 
>collision and every tight curve represents the possibility of a derailment.    
>In the network you have described, there will be switches to access the 
>reserve tracks, switches for expresses and freights to access their off-
>line platforms, and switches to connect to the replicated rail yards.  

A switch which can only be used one-way is much simpler than one which
needs to be used bidirectionally, and that no switch is needed at all
for a train to merge onto a track from a siding /if/ there will never
be a train coming from the opposite direction (in which case the setup
acts as a derailer). These are not used with rw railroads because
someone, sometime, will want to run a train in the other direction,
but material handling tracks sometimes use these methods. 

In this system, there are no crossings. 

The bulk carrier lines do not need to switch at the station since
there is only one set of cars on the line at one time.

>> Replacement of the track can be done one at a time without the users
>> even knowing it -- line 3 is reserved for times when another track is
>> unusable.
>
>The passengers will certainly notice when their train gets rerouted over a 
>different track after leaving the station.  Even if the cars have no 
>windows they'll be able to feel the difference.
>
True, but if the switching is done near the stations, before they pick
up speed, it should not be an inconvenience.

>>>Human Blockage: What if a mob of people decided to block all the
>>>tracks (at some location) as a protest?  
>> 
>> Fine. You simply block off that pod's access to the lines running to
>> other pods and stop all traffic within that pod.
>
>A blockage in community B of the chain A-B-C would increase A-C trip times 
>from minutes to just under the whole-ellipse, or just under an hour.  Shut 
>down the tracks and everyone in the rest of the pod will be so severely 
>inconvinenced that the mob will have won.

Or everyone will be so inconvenienced that they will takeout their
rage on the nearest available target, which is the mob.

>The solution in most totalitarian countries would simply be to run the 
>trains over the mob.  However, since you have reseve tracks you can just 
>run trains through lesser-known routes that can't easily be blocked.

I actually prefer the 'vandals broke open a natural gas line in the
rail tunnel' news release and picking up the bodies rather than having
to wash all the blood off the cars. :)

>> This is exactly the type of thing that I needed to know and why I
>> asked the original question -- I now see the need for the distribution
>> centers to have a supply of batteries so that they can operate their
>> cars on the bulk delivery line even if the rest of the system is shut
>> down.
>
>You mean 'locomotives,' 'generators' or 'fuel cells.'  Moving a rail 
>vehicle, particularly a freight carrier, requires far more energy than 
>batteries can provide at tech level you're using.

I used to run a forklift putting pivot irrigation systems onto
semi-trailers. I don't know the weight, but I could do six a shift on
one charge.

>> The townlet's garbage truck is basically a small electric pick-up with
>> compactor hydraulics and a flatbed for the container which it packs
>> the trash into. It can be pressed into service for the ocassional
>> delivery of a sofa or piano.
>
>Something similar will be needed for a firetruck.  Hauling fire hoses 300' 
>from the emergency track exhaust the firefighters before they even got to 
>the fire and cost too much time.  A dual mode (hirail) firetruck that can 
>ride on the tracks, then dismount and drive on wheels through the townlet 
>to a fire would be ideal.

I was thinking more on the lines of one on a flatbed that can drive
off onto the platform.

I don't see fire as a major threat -- all the buildings are reinforced
concrete, so spread will be minimal, and there will be an officer on
patrol 24/7 to spot an outbreak. A small quick-response unit in each
townlet should be able to handle 99% of the problems. A Cushman could
do the job. Also, there's no reason that instead of just having a
plain fire hydrant, it could be a short booth containing a  couple of
basic tools and a suitable amount of hose on a reel.