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In lugnet.trains, Mike Poindexter writes:
>
> Is 44 long enough for 8 wide stock? That translates to a 55 foot long car.
> I would have though 64 studs (80 feet), or at the minimum 56 studs (70
> feet). What is the longest train car that could be considered very common?
> You would have to worry about both the interior of the curve where the car
> hangs over and also the outside of the curve where the nose might stick out
> if the trucks are set back a bit, like they are on many locomotives.
Good point. Perhaps instead of setting a length standard (although that is
useful when calculating siding capacity) the standard should speak to the
envelope of clearance that must be provided. (there must be 4 studs clearance
from the edge of the tie at all heights above 2 bricks above rail, 2 below
that, or something similar)
Then if a large articulated can fit, it doesn't matter how long it is.
Conversely I bet I can make a (pathological) 44 stud long 8 wide that won't
pass the nominal standard. I'll just put the wheels in the very center,
ensuring that the ends swing out and swipe everything.
If you see what I am saying.
Nevertheless speaking in terms of a length that's allowed is an easy way
as measuring clearance envelopes is rather tedious work.
> When this is agreed on for length between wheel sets and length in front of
> the front wheelset and behind the rear one, I will add the clearance
> requirements to the standards.
Precisely what i was getting at, guess I should have read to the bottom. These
lengths matter. Perhaps we need a standard "clearance car" that has to fit.
Anything else is fine as long as it doesn't exceed the loading gauge/clearance
envelope the "clearance car" defines.
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Larry Pieniazek wrote:
> Precisely what i was getting at, guess I should have read to the bottom. These
> lengths matter. Perhaps we need a standard "clearance car" that has to fit.
> Anything else is fine as long as it doesn't exceed the loading gauge/clearance
> envelope the "clearance car" defines.
Hmm, interesting, can one come up with a single car?
One thing I immediately wondered is if the clearance specs define a
maximum distance between wheelsets (actually between truck pin) and a
maximum extension beyond this point, would you get different, non
overlapping envelopes between a short car with a long overhang, and a
long car with little overhang. Fortuanately, I realized that the longer
wheelbase is going to push the overhang further out on a curve than a
shorter wheelbase (think of the "angle" the car is making with the track
at each truck, the longer the wheelbase, the sharper this angle, and the
sharper that angle, the more the overhang sticks out).
Of course this degenerate (extremely long) car will actually produce
more clearance than is strictly necessary, but it never hurts to have a
little too much clearance.
One issue though, one probably will want to have a tunnel portal
situated in the middle of a reasonable straight section, otherwise it
could look real ridiculous (of course if your curve has straight
sections interspersed, it will allow tighter clearances).
--
Frank Filz
-----------------------------
Work: mailto:ffilz@us.ibm.com (business only please)
Home: mailto:ffilz@mindspring.com
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Frank Filz wrote:
> Larry Pieniazek wrote:
> > Precisely what i was getting at, guess I should have read to the bottom. These
> > lengths matter. Perhaps we need a standard "clearance car" that has to fit.
> > Anything else is fine as long as it doesn't exceed the loading gauge/clearance
> > envelope the "clearance car" defines.
>
> Hmm, interesting, can one come up with a single car?
Sure - since the specs are being set, a ClearanceCar can be defined. Anyone
building a layout that doesn't allow it to clear gets a wedgie ;-)
All you need are LWH, and pivot point distances from the ends for the center of the
trucks, and each person can mock one up quickly enough.
> One thing I immediately wondered is if the clearance specs define a
> maximum distance between wheelsets (actually between truck pin) and a
> maximum extension beyond this point, would you get different, non
> overlapping envelopes between a short car with a long overhang, and a
> long car with little overhang. Fortuanately, I realized that the longer
> wheelbase is going to push the overhang further out on a curve than a
> shorter wheelbase (think of the "angle" the car is making with the track
> at each truck, the longer the wheelbase, the sharper this angle, and the
> sharper that angle, the more the overhang sticks out).
>
> Of course this degenerate (extremely long) car will actually produce
> more clearance than is strictly necessary, but it never hurts to have a
> little too much clearance.
Right. But you don't want 3/4 of the module to be clearance space either. Doesn't
leave much space for environment.
--
| Tom Stangl, Technical Support Netscape Communications Corp
| Please do not associate my personal views with my employer
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