PDA

View Full Version : When Easements and How Much?


Xiong
07-21-2011, 02:31 AM
I don't have a lot of space and I'm starting to wonder if easements are always taken seriously. Given limited real estate, I might sometimes think it better to make a simple 60" radius; rather than use up that space with an easement and a tighter radius. That tighter radius has a knock-on effect, requiring increased clearance from adjacent tracks and structures.

Notice XtrkCad does not even want to create easements when joining tracks at slight angles. With two straight sections meeting at 2 degrees, I cannot get an automatic easement regardless of easement settings or how tight or broad I make the join: the application just draws a simple, single-radius curve.

It gets worse when considering reverse curves. If I ease the curves at both ends of the required 12" straight then (effectively, for layout purposes) it's no longer a one-foot straight; it's a foot and a half. I'll be burning up all my plywood on easements.

Searched hard on the topic of easements; no joy. Free-mo standards (http://www.free-mo.org/standard) say nothing directly about easement. NMRA S-8 (http://www.nmra.org/standards/sandrp/s-8.html) talks about "eased... for a distance... consistent with the class equipment used"; this is not really a useful standard for a module designer since I must anticipate all kinds of foreign stock on my road. NorCalF (http://www.norcalfreemo.org/) says "All mainline curves should include easements..." but not how long they are to be.

Just saying that a transition should be eased does not seem to impose a rational requirement. I can ease from tangent to 18" radius in a half inch and say "I eased" but it won't do much good. I can join straight track directly to a 192" radius and someone might, logically, say, "You have no easement there".

There are many discussions of how to draw an easement, from country common sense to arcane surveying rituals. But I have a good math background and drawing is the least of my worries. I've read good arguments in favor of why easements should be used.

But I cannot find much discussion of when to put in an easement or how long it should be under which circumstances. I'd really appreciate pointers to good resources.

tjcruiser
07-21-2011, 10:21 AM
Xiong,

Your first attempt at posting this thread was "trapped" by our auto spambot ... I approved that post, then saw that you had this second attempt here. Sorry for the inconvenience.

TJ

Xiong
07-21-2011, 10:59 AM
Oh. I thought I'd just hit the wrong button and my post was lost. Should I just never link from within my posts? It seems polite to cite sources and points of reference.

tankist
07-21-2011, 11:53 AM
i would say easement is good before approaching tight curves. as you already found it reduces side-swing between the cars. an eased r18 will have less side-swing then non eased 22r.

standards? i'm sure real life railroad builders have formula but for us there is no set of rules i'm aware of. for my easements (HO) i was simply using short sections of R22 before getting down to R18 curves, and lightly bending the flex-track before hand as well.
FYI, anyrail software allows for easement planning

when to use? up to you really, some don't even bother. i'd say everywhere you can (and space permitting) before tight curves.

Xiong
07-21-2011, 02:05 PM
Thank you, tankist. Your post convinces me that we're not all speaking the same language. When I read about easements, I think writers (in HO) are thinking, as you do, about 18" radius curves, maybe 24" -- perhaps loops of a full circle, or at least a quarter circle.

But I'm planning to HO Free-mo standard, a switching module consisting, very generally, of a number of roughly parallel tracks. I try to avoid curved track and get most of my changes in direction from turnouts -- #6 or #8, only #8 on mainline. Free-mo requires 42" radius on mainlines with 48" preferred; NorCalF insists on 30" radius even on spurs.

Seems as though I should pretty much ignore the easement "requirement".

By the way, very impressive control panels.

tjcruiser
07-21-2011, 02:53 PM
Should I just never link from within my posts? It seems polite to cite sources and points of reference.

In theory, there's nothing wrong with including a link in one of your posts. However, the spambot has a mind of its own, and on occassion, it erroneously tags something as "fishy".

If you ever submit a post, and then don't see it, it may be that the spambot has put it off to the side for review. Us Mods usually check for these a few times a day, and approve any that are genuinely OK.

Cheers,

TJ