Re: Lift out bridge

If we are going to seriously consider building some kind of "entry way" we
should first discuss the Requirements for this structure.

I know it is much more interesting to design and build something than it
is to discuss requirements. However, I have seen too many products
designed and implemented without considering who will be using it
and the way it will be used. (Can you say "Windows Vista?")

Please let us discuss the requirements for the module before we work on
how to build it.

Here are some topics for discussion: (Note: I will refer to the entry way
as "module" in these topics.)

- What problem does this module solve?
- What are the benefits for this module? Is there a tradeoff between
   benefits (i.e. ease of entering and exiting the layout) and cost
   (i.e. continuous operation of trains during an event)?
- Who will use this module? It it intended for only people to enter and exit
   the layout or is it also for dollies and/or carts?
- When will this module be operated? Is it intended only to be used when
   trains are not running (i.e. during setup, teardown, before the event opens
   to the public, or after the event is closed to the public) or is it intended to
   be opened at any time? If so, how often will we allow it to be opened
   (e.g. any time, once an hour, etc.) and how long may the module be opened
   (e.g. 30 seconds, 5 minutes, etc.)
- What impact can this module have on the design of a layout? Should we
   restrict this module to a 4' length or can the total size be a multiple of 4'?
   For example, could it be constructed from three 4' sections or two 6'
   sections?
- Is there a width restriction to this module? Does it have to be the same
   width as a standard module (i.e. 2') or can it be wider? If so, can it
   extend inside, outside, or on both sides of the layout?
- Is there a weight restriction?
- Should this module automatically affect the operation of nearby trains
   (i.e. should we consider having the module turn off the power to
   nearby tracks)? If so, what impact will this have on conventional engines
   (which will take the power off as a signal to cycle their e-units), and
   command controlled engines (who might take the power off as a signal
   to revert to reset or neutral state)?
- Will the module be stored in the trailer? If so, should it fit in one or more
   standard module slots or will we stand it up somewhere else in the trailer?
- Should the module use the standard leg configuration or can it have
   integrated legs? If the legs are permanently attached to the module (or
   part of the bench work) what is the height requirement for the roadbed?
   Should there be a mechanism to adjust the height of the module to
   meet the height of the adjoining modules?
- Should this module be one of our standard configurations (ABCD or ABCE)
should it be a "universal" module (ABCDE) like the corners, or should the
   module be some nonstandard configuration internal to the module?
- Is there a budgetary restriction (i.e. is there a maximum amount of money we
are willing to pay to build this module)?
- We keep referring to it as a "Lift out bridge." Is there a requirement that the
   module contains one or more railroad bridges or can it be just a standard
(flat) roadbed which opens?
- What are the horizontal and vertical clearance requirements for the tracks
   on this module? For example, if it contains actual bridges, what is the
   minimum track spacing (if not 4-1/4") and what is the minimum vertical
   clearance under the bridges?

I am sure many of you can contribute more topics of discussion. These topics
should be related to why we want to build this module and any restrictions
on the module, not how to build it.

Please consider these types of questions before discussing how to build
this module.

Please let us know you opinions on the requirements for this module, either by
proposing answers to some of the above questions, discussing these topics,
or by suggesting other topics about how the module will be used (as opposed
to how we will build it).

Thanks.

Ira

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TTAT members reflector.