Second Life Railroad/Rail Community/2011-06-10

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This page contains the transcript and information about the the Rail Community meetings in SL from 2011-06-10 The meeting was hosted by the Beware Hax for the benefit of the SL Rail Community as a whole.


  1. The universal height reference on rail track needs to be the top of the rails: because it's what the wheels of the train rest on. so it's the visually most fixed point. it's also the universal height reference of rails IRL. rail track may be embedded into a street, the depth of the track bed may vary.
  2. The height of the guide rail needs to be chosen to represent what exists so far: the height of the guide rail varies on the SLRR. variances cause sensor driven trains to float in the air, or to sink into the track. if the bottom of the guide rail is measured compared to the top of the rails (point 1), i've seen variances on the SLRR between being 0.04 m below, to 0.16 m above, but typically it's around level (0 m). the wiki currently defines the bottom of the guide rail as being 0.15 above the *track bed*. this is a standard that's not followed in SLRR construction. in new SLRR track (bay city) the guide rail is very low (0.07 m below), and it's 0.08 m above the track bed (street). this looks like a drift in the height of the guide rail: it's moving down over time.
  3. The height of overhead catenary wire needs to be defined more precisely, and needs to be committed to: according to the wiki it "should be about 6 meters above the track". i'm building overhead catenary on my own. needing something to go on, i interpreted this as: 6 meter above the top of the rails. i've also seen an electrical train on the marketplace, which was too big (both loading gauge and catenary height), and i asked the creator to make it conform to SLRR standards. the resulting train expects the catenary wire on 6 meter above the top of the rails. i'd like a clarification/more unambiguous definition, so that people can safely build to the standard.

Transcript for Friday June 10, 2011

[13:31] Beware Hax ok i made up some agenda points
[13:31] Beware Hax both in text, and in visuals
[13:31] Beware Hax gave you SLRR community meeting 2011-06-10 - agenda points.

[13:32] Michael Linden It's still rezzing ... or whatever it's called for text.
[13:32] Michael Linden there it it.
[13:32] Beware Hax loading, perhaps
[13:32] Beware Hax hi
[13:32] Radioactive Rosca hi
[13:33] Radioactive Rosca hi Beware, Hi Michael, hi Stryker
[13:33] Stryker Jenkins Hi !
[13:33] Stryker Jenkins Radio
[13:33] Beware Hax radio?
[13:34] Beware Hax i planned this meet on a way too short notice. i just started by asking michael if he could attend this friday. and he could
[13:34] Beware Hax anything people isn't my strong point
[13:35] Michael Linden I've only got about half an hour. But I think I can comment on some points right away:
[13:35] Stryker Jenkins I would say go for it
[13:35] Beware Hax yes
[13:36] Michael Linden On agenda point 1: I certainl agree, not sure how it came to be from "roadbed".
[13:36] Beware Hax for whoever is logging,
[13:36] Beware Hax for clarity, i should paste the agenda point relevant
[13:36] Beware Hax 1: the universal height reference on rail track needs to be the top of the rails: because it's what the wheels of the train rest on. so it's the visually most fixed point. it's also the universal height reference of rails IRL. rail track may be embedded into a street, the depth of the track bed may vary.
[13:36] Stryker Jenkins ah... well that had to do with the simple fact there was nothing else...
[13:37] Radioactive Rosca and that is compatible with the several tracks, from the LL ones to the ones made by several residents
[13:37] Stryker Jenkins so it is a more or less arbitrary point we picked. Taking into account the minimum distance of 0.1 m needed for Physical trains
[13:38] Michael Linden We changed the rail design, by the way: most of the older rail are simple textures prims; but much of the SLRR uses a set of sculpted rails.
[13:38] Beware Hax im aware of that
[13:38] Stryker Jenkins and we are talking about centimeters here. well within the tolerance of what is out there now
[13:38] Beware Hax i wonder why someone with any affinity with rail (or so i hope) doesn't think of the top of the rails
[13:39] Stryker Jenkins excuse me...
[13:39] Beware Hax go on
[13:39] Michael Linden (cough) the Lindens originally laying rail weren't rail enthusiasts! (cough)
[13:39] Radioactive Rosca lol
[13:40] Beware Hax are plans to define the top of the rails as the height reference possible?
[13:40] Beware Hax hi
[13:40] Radioactive Rosca i used at my railway station, a more sophisticated methode. Used the yellow loco from Stryker and adjusted the level of the guides
[13:40] Radioactive Rosca hi Perdita
[13:41] Stryker Jenkins I am a bit confused... are point 1 and 2 of the agenda not the same?
[13:41] Beware Hax i don't know about a yellow loco. i'd like to see that one. but using it as a reference assumes that that loco is a good reference
[13:41] Beware Hax no, they're related however
[13:41] Perdita Muggins hello, all :)
[13:41] Beware Hax point 1: the top of the rails should be used as height reference. for really anything
[13:41] Michael Linden Hello Perdita.
[13:42] Beware Hax point 2: the height of the guide prims is a mess. and new definitions and builds have a significantly lower guide prim than old official and resident owned tracks
[13:42] Beware Hax (i put up a lot of pictures of that)
[13:42] Michael Linden In regards to point 2:
[13:42] Stryker Jenkins ok...
[13:42] Michael Linden Nobody, not even the SLRR, is required to use the standard.
[13:42] Stryker Jenkins if you allow me I would like to read out a text we prepaired on the subject earlier
[13:42] Michael Linden But if we have a standard, trains will tend to look better.
[13:42] Michael Linden Sure, Stryker,.
[13:43] Radioactive Rosca concour, Michael
[13:43] Stryker Jenkins may take some time... it's rather a long text
[13:43] Stryker Jenkins Measurement of Distances between Guide Rail, Metal Rail and Trackbed by Stryker Jenkins VRC
[13:43] Stryker Jenkins Spreadsheet of measurements (37 data points):
[13:43] Stryker Jenkins
[13:43] Stryker Jenkins Image of SLRR tracks design accompanying the spread sheet:
[13:43] Stryker Jenkins
[13:43] Stryker Jenkins that's just for reverence later
[13:44] Stryker Jenkins The object of this discussion, if I read it right, is to come to a unified / fixed height between Guide and metal Rails. This is a purely theoretical exercise! The tracks in Second Life will probably not be changed. And even if they will be changed a greater accuracy when building is hard to accomplish due to multiple factors, like terrain undulation and the need to smooth the guide rail out as well as possible.
[13:44] Beware Hax thanks for these measurements. this is what i need. it does agree with my own findings.
[13:44] Stryker Jenkins The current SLRR tracks vary a lot when it comes to placement of the Guide rail vs. the Top of the metal Rails. The measurements taken clearly show that the average deviation between the bottom of the Guide rail and the top of the metal Rails is a mere + 0.024111 meters. In other words 2.4 centimeter. However the individual measurements show a much greater variation.
[13:45] Stryker Jenkins Even the size of the primmed Rails and the sculpted metal Rails differs. A primmed rail is 0.198 meter high and the sculpted version only 0.140 meters.
[13:45] Stryker Jenkins There is also the need of physical trains to consider. Apparently they need an additional clearance of 0.1 meter between them and the guide rail v.s. non-physical trains that do not need that.
[13:45] Stryker Jenkins Changing sizes or heights at this point in time does not change the older trains that are out there. I.e., the ride height of those vehicles will stay the same. And therefore the look of the trains will not change. They are either a little bit too low or too high above the metal Rails.
[13:45] Michael Linden And we may have "finer physics" someday.
[13:45] Stryker Jenkins In my experience building tracks there is no real need to change the current height the guide rail set in the wiki. This is set at 0.15 meter above the trackbed / floor. Setting this to the top of the metal rails, i.e. 0.198 or 0.140 meters above the trackbed is only handy if you build the trackbed with metal Rails separate from the Guide rail. When you build them as a linked set and unlink them afterward you don't need to move any of the linked parts in a Z direction.
[13:46] Radioactive Rosca :-)
[13:46] Stryker Jenkins In a few locations inworld the Guide rail is much higher than the average. This causes people to "trip" or get "stuck" when they try to walk over them.
[13:46] Michael Linden Well, there are a lot of tracks without any trackbed.
[13:46] Stryker Jenkins Trackbed or road surface
[13:46] Michael Linden Along roads and streets, mostly.
[13:47] Stryker Jenkins All this leads me to conclude that:
[13:47] Stryker Jenkins 1) there is no real need to change anything on the wiki page about SLRR standards.
[13:47] Stryker Jenkins 2) there is no real need (apart from in a few locations) to change the current SLRR tracks inworld.
[13:47] Michael Linden On roads and streets, rail upper surface should be level with the pavement, more or less.
[13:47] Stryker Jenkins 3) this whole exercise is a waste of time.
[13:48] Michael Linden heh, you're not the one who has 9 kilometers of track to look at!
[13:48] Radioactive Rosca eheheh
[13:48] Stryker Jenkins 4) if put simply the Guide bottom should be the same as the top of the metal rails... seen the small change that really is... I would have no problems with that on the wiki
[13:49] Radioactive Rosca but with clear rules, that's better for the residents.
[13:49] Stryker Jenkins (not that it matters all that much anyway)
[13:49] Beware Hax i'd like to see #4 done
[13:49] Michael Linden I think Stryker's statement has a certain easy-to-comprehend value to it.
[13:49] Radioactive Rosca indeed
[13:49] Beware Hax stryker's observations agree with mine. stryker's points #2 and #3 are only valid if you decide to not care.
[13:50] Stryker Jenkins we ARE talking 2 centimeters here...
[13:50] Radioactive Rosca that's nothing
[13:50] Stryker Jenkins 90% of rail users will NOT notice it
[13:50] Michael Linden I'll talk with the railway-oriented moles about track. For the Mainline, we'd probably have to look at an automated relaying system.
[13:50] Michael Linden But we can still pretty easily fix the track in Bay City.
[13:50] Beware Hax or give me a $1 contract, and i'll do it for you
[13:50] Stryker Jenkins you not seriously considering changing the current SLRR track Michael?
[13:50] Michael Linden Yeah ... not gonna happen, alas.
[13:51] Michael Linden Not really on the Mainline, Stryker.
[13:51] Michael Linden But if and when we build or rebuild any track, we're happy to watch the standards page.
[13:51] Stryker Jenkins how ever... there are a few spot where the guide rail is so high they block people from walking over them
[13:52] Beware Hax so can there be an agreement on point #4?
[13:52] Michael Linden Oh, that reminds me: Bay City track has phantom Guides for now.
[13:52] Stryker Jenkins lol... pushy...
[13:52] Michael Linden Easily changed back if there's a howl of protest.
[13:52] Radioactive Rosca yep... and it's ok for several locos
[13:52] Stryker Jenkins there will not be any protest ... atleast that's my thinking...
[13:52] Stryker Jenkins because it's only on the wiki at this point in time
[13:53] Michael Linden I have to say, on most curves and changes in grade, the Guide is not gonna be that close to the standard anyhow.
[13:53] Radioactive Rosca that's the tests i did for Sylvan Mole, Michael
[13:53] Stryker Jenkins however... You may want to consider asking Sylvan to make a new standard track version for the mole mart Micheal
[13:53] Michael Linden Cool, thanks. Have you passed this to Sylvan, too?
[13:53] Michael Linden Good point, Stryker.
[13:53] Radioactive Rosca yes
[13:54] Beware Hax ok i'd like to briefly bring up agenda point 3 before michael leaves
[13:54] Beware Hax 3: the height of overhead catenary wire needs to be defined more precisely, and needs to be committed to: according to the wiki it "should be about 6 meters above the track". i'm building overhead catenary on my own. needing something to go on, i interpreted this as: 6 meter above the top of the rails. i've also seen an electrical train on the marketplace, which was too big (both loading gauge and catenary height), and i asked the creator to make it conform to SLRR standards. the resulting train expects the catenary wire on 6 meter above the top of the rails. i'd like a clarification/more unambiguous definition, so that people can safely build to the standard.
[13:54] Michael Linden So: underside of Guide to be, as closely as possible, level with the upper surface of the visible rails ... just to be clear.
[13:54] Stryker Jenkins hmmm there is currently no height defined I think
[13:54] Michael Linden Hmm.
[13:55] Perdita Muggins that sounds good
[13:55] Beware Hax michael: yes.
[13:55] Michael Linden I don't currently expect any of the SLRR Mainline to provide catenary lines.
[13:55] Beware Hax i don't, either
[13:55] Stryker Jenkins well No Michael... according to Beware it should be "exact"
[13:55] Beware Hax but i think it's good if there is a standard for builders to adhere to
[13:55] Radioactive Rosca too many prims, perhaps...
[13:55] Michael Linden Not enough prims in many places.
[13:55] Radioactive Rosca yep
[13:55] Beware Hax stryker: as close as possible. i like exact, but it has to be possible
[13:56] Michael Linden Heh, and the standards for double-stacked containers conflict with the height for catenaries.
[13:56] Michael Linden In real life, too.
[13:56] Beware Hax true.
[13:56] Michael Linden There's a reason not too many western US railways don't have catenary, heh.
[13:56] Beware Hax in real life, there's variances in height due to double stacked containers.
[13:56] Stryker Jenkins I like the idea on some location for a catenary... but not on the SLRR due to the fact it would interfear with the view of the camara when driving a train
[13:56] Beware Hax im not asking for catenary to be placed anywhere. don't get me wrong.
[13:57] Michael Linden Yah. I think we put a number in the wiki just as a "placeholder", more or less.
[13:57] Beware Hax i'm asking for a defined height, so builders can build for that
[13:57] Stryker Jenkins anyway... Michael has defined the Clearance on the wiki as 9 meter...
[13:57] Stryker Jenkins I think that is a bit much for the current SLRR... I would stick to 7 meter...
[13:57] Michael Linden We try to, Stryker! Heh, I'm not sure the whole Mainline has 9m clearance the whole length.
[13:57] Beware Hax 6 meter was stated for overhead wires, on the wiki, up to now
[13:57] Stryker Jenkins again for the same "camara positioning" reason
[13:58] Michael Linden Different real countries use different heights ... trolley vs. mainline, etc. ...
[13:58] Beware Hax yes
[13:58] Radioactive Rosca yes
[13:58] Michael Linden 6 meters above the rail upper surface sounds "round" and easy to remember.
[13:58] Beware Hax there's a variation on real railways between about 4.7 m and 5.7 m
[13:58] Beware Hax then calculate SL scale
[13:58] Stryker Jenkins SL is NOT RL
[13:58] Beware Hax i know
[13:58] Michael Linden A lot of SL content looks better done larger than RL.
[13:59] Beware Hax things in SL are bigger than in RL. i know that
[13:59] Michael Linden For interior spaces, I use 1.4 x larger.
[13:59] Perdita Muggins bew likes standards and wants especialy for over head things, with the camera you don't want too much intereference
[14:00] Radioactive Rosca i only have 1 minute felf
[14:00] Radioactive Rosca left
[14:00] Stryker Jenkins anyway... I think no addition definition for overhead line heights on the wiki is needed at this point in time because there are no plans, if I read it correctly, to implement it on the SLRR
[14:00] Michael Linden I'm not committed to any particular catenary height, myself ... I don't know what current building/systems exist that we should accomodate.
[14:00] Beware Hax but what about 3rd party builders, land owners, etc? aren't they allowed to interoperate on this?
[14:00] Beware Hax i know about nothing existing, tbh
[14:00] Michael Linden Hmm, important point: catenary systems should probably be phantom!
[14:01] Beware Hax i went and took the standard i saw
[14:01] Beware Hax yes they should be
[14:01] Stryker Jenkins they can do what they like...
[14:01] Beware Hax if people can do what they like, there can be no interoperation
[14:01] Michael Linden the overhead line in Nova Albion is a huge physics problem.
[14:01] Stryker Jenkins the Standards page was more a guide line than a rule book anyway
[14:02] Beware Hax yes, it's a guide, in that violating it does not violate the TOS or anything, of course
[14:02] Michael Linden Ah: let's say: phantom catenary lines will reduce problems with different build sizes.
[14:02] Beware Hax but if there's a guide, people can build for it, and things can fit together
[14:02] Michael Linden Plus: less physics = better.
[14:02] Radioactive Rosca and are less laggy
[14:02] Michael Linden Hmm, is anyone getting crazy enough to want to build a catenary-tracking trolley pole?
[14:02] Michael Linden Or: should the actual catenary current-carrying cable have a consistent name?
[14:02] Beware Hax i think a standardized height would make life easier
[14:03] Beware Hax there *is* a standard for that. a phantom prim with a standard name
[14:03] Beware Hax so one *could* track it
[14:03] Stryker Jenkins well lets set the height at 7 meter...
[14:03] Michael Linden "Catenary" is at least a word that won't appear too often in other objects, heh.
[14:04] Stryker Jenkins and call the wire... hemmm... Cantenary?
[14:04] Michael Linden I have no objection to 7 meters.
[14:04] Beware Hax so far,
[14:04] Radioactive Rosca i think it's more important to implement phantom guides at SLRR than the catenaries, but it's only my oppinion
[14:04] Beware Hax there is a standard set name for the prims
[14:04] Stryker Jenkins what are they?
[14:04] Beware Hax "Catenary Wire"
[14:04] Michael Linden Heh, fancy scissors-type overhead pickups can change their height to match the cable height!
[14:05] Beware Hax they could perhaps be scripted to do so
[14:05] Stryker Jenkins lol... I would prefer simple names... like "Wire"... but I don't care...
[14:05] Beware Hax so, 6 m was made up earlier, and put in the wiki, but now considered to be too low?
[14:05] Michael Linden It's all copied, so you don't have to type "catenary" too much.
[14:05] Radioactive Rosca ok, i've to go. Thanks for inviting me. Good conclusion and i hope to see you all at SL8B
[14:05] Michael Linden Well, we could have two standards, aiee ... !
[14:05] Stryker Jenkins Bye Bye!
[14:05] Stryker Jenkins Radio
[14:05] Michael Linden Later, Radioactive!
[14:05] Radioactive Rosca bye
[14:05] Beware Hax i think 2 standards is a terrible idea
[14:06] Stryker Jenkins thaks for joining
[14:06] Beware Hax especially if they're 6 and 7 meter
[14:06] Perdita Muggins byebyeradioactive
[14:06] Beware Hax bye
[14:06] Stryker Jenkins nope... I would suggest 7 meters now
[14:06] Michael Linden Well, if you're all comfortable with 7 meters ... ?
[14:06] Beware Hax i don't know. i really have no idea.
[14:07] Beware Hax of course, i'm bothered by the fact that i asked someone to scale a train to 6 m
[14:07] Beware Hax (that train is sitting here)
[14:07] Perdita Muggins if htey can scale it once, they can scale it twice, bew
[14:07] Beware Hax interestingly, i made up 7 m long before that wiki page existed
[14:08] Beware Hax so, ok, 7 m. counting from the top of the metal rails
[14:08] Michael Linden
[14:08] Michael Linden A discussion of double-stack trains in Europe.
[14:09] Beware Hax IRL, in UK it's 4.7 m, in NL it's 5.5 m. those are the two extremes. so, 7 m sounds ok to me. i would not go higher.
[14:09] Stryker Jenkins nah... the 9 meter clearance is a bit much... even for SL standards
[14:10] Michael Linden 7 meters it is! Go ahead and change the wiki ... I'll poke in and put my name in their somewhere, to make it more official.
[14:10] Beware Hax double stack is not actually done in europe
[14:10] Beware Hax ok.
[14:10] Beware Hax then remove the 9 m
[14:10] Stryker Jenkins but if we stick to 1 measurement that would make the reading of the wiki easier too.
[14:10] Perdita Muggins yay
[14:10] Beware Hax and just leave 7 m *and* say: from the top of the metal rails
[14:10] Michael Linden Exactly the point of the forum, Beware.
[14:10] Beware Hax and i'll ask that japanese creator to again change everything
[14:10] Michael Linden Though someone might want to model a container yard, heh.
[14:10] Beware Hax and perhaps throw with some lindens
[14:10] Stryker Jenkins anyway... Beware... are you going to make the changes in the wiki or should I?
[14:11] Beware Hax stryker: good question
[14:11] Michael Linden I have to scuttle off to a Sekrit Projek meeting.
[14:11] Beware Hax i can try to make the changes.
[14:11] Beware Hax to be clear on what i would change:
[14:11] Stryker Jenkins Bye Bye!
[14:11] Stryker Jenkins enjoy Micheal...
[14:11] Beware Hax thanks michael for being here
[14:11] Michael Linden heh, we need committee/joint editing on wikis ...
[14:11] Beware Hax 1: the bottom of the guide rail is at the top of the metal rails
[14:11] Michael Linden "We, the undersigned ... "
[14:11] Perdita Muggins byebye Micheal :)
[14:11] Beware Hax 2: the overhead catenary wire is 7 meter above the top of the metal rails
[14:11] Stryker Jenkins lol
[14:11] Michael Linden Bye all!
[14:12] Stryker Jenkins overall clearance (i.e. remove the 9 meter)
[14:12] Beware Hax yes.
[14:12] Perdita Muggins so, nothing can be built over the railroad tracks that is under 7 m, did I get that right ?
[14:13] Stryker Jenkins anyway.... I will look at the wiki after your done editing with it... may tweak it a little bit for form... not content.
[14:13] Beware Hax perdita: that is called loading gauge. and i think you're right
[14:13] Beware Hax ok
[14:13] Stryker Jenkins yeah... that's the point of setting the 7 meter
[14:13] Perdita Muggins yay, that's great to know
[14:13] Perdita Muggins pleased I came
[14:13] Stryker Jenkins but building over the SLRR means building over LL land...
[14:13] Stryker Jenkins so you need their permission
[14:14] Beware Hax of course

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