Re: SAMRA and New Ideas

["Ira Schneider" <ira_schneider@iname.com>]

Thoughts about the proposed bridge module

If the bridge is fixed (i.e. does not open or lift) I don't see the point, except as another scenic module.
We would still have to crawl underneath it to get in or out of the layout.  I would object to the club
financing such a module.  Of course, an individual can build any module he desires, as long as it
follows the club standard for size, track layout, and size.  A model of the loop 360 bridge would be great!

If the bridge is movable, it would have some use.  I am not sure I see us stopping the trains on all four
tracks every time someone wants to enter or leave the layout.  Personally, I would probably still
crawl in and out rather than disrupt the running trains.  If the bridge is simply kept open during setup
to allow us easy entry and exit, I am not sure it is worth the trouble.  We currently leave one module
out until we lock them up.

Having the bridge automatically interrupt power to the mainlines when it is open is technically possible
but I don't think it is practical.  From past experience, we would have to interrupt the power for a long
distance from the bridge (i.e. several modules on each side) for it to be effective.  This is partially because
cars with double rollers (like long lighted passenger cars) will carry the current across the fiber pins
from the active track to the inactive track.  Potentially, this means that we would have to interrupt the power
for the entire length of a train.  We would have to not only build the special bridge module but modify
several modules for use on either side of it (a minimum of two modules, probably four or six).  I don't
think this is practical.  Also, if we interrupt the power, conventional mode engines might go into neutral.
When the power is restored, they would not resume moving.  We could also have trouble with some
engines if the power is cut while the operator is blowing the whistle (horn) - the engine could interpret
that as a "lock direction" command (which the operator is unaware of).  Another consideration is the
sudden loss of power when a train is crossing one of the turnouts, crossovers, or UCS sections might
cause a derailment.

I am also not too keen on using the Halt push button on the CAB-1 controller when we are going to
open the bridge.  That could affect other layouts in the same room.

Don't get me wrong.  I think the idea of a full-length, full-width bridge module would be great.  I just
don't think it will help us enter or leave the interior of the layout.


Ira