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mainline max lenght

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  • Member since
    February 2005
  • From: Southwest US
  • 12,914 posts
Posted by tomikawaTT on Saturday, April 17, 2010 1:30 AM

As far as just plain distance from power supply to the farthest end of track, I think the problem with analog DC would be voltage drop.  However, that is somewhat load related.

3 locomotives could be 3 modern coreless motors with a total power requirement measured in milliamps, or three 1960-era x-C+C-x catenary motors with two open frame power hogs per - guaranteed to pop the breaker on anything but a really serious power supply.  I doubt that the three EF-motors would be able to travel anywhere near as far as three ANYTHING with can motors, given equal-size feeders.

Someone with more knowledge than I have about power attenuation and waveform degradation of high frequency signals over distance might be able to cover the DCC side of this.

As for the practical side of running HO outdoors, I experimented with the idea when I moved into my present abode.  After a month of desert sunshine, gale-force winds and one rainstorm where the drops appeared to have originated as hailstones the only things salvageable out of the original stock (one length of Atlas code 100 flex and a train set box car) were two lengths of stick rail.  And it wasn't even high summer!

Chuck (Modeling Central Japan in September, 1964 - in a Mojave Desert garage)

  • Member since
    March 2007
  • 2,751 posts
Posted by Allegheny2-6-6-6 on Thursday, April 15, 2010 11:03 PM

 A plan doomed to fail, sorry for being a wet blanket but HO is not meant to be run outside and before too long you will see the problems with track being exposed to the elements and what problems will rear their ugly heads. First off unless yo plan to mount the track to some pressure treated wood or some other type of sub roadbed you will have problems right out of the shoot. I know the guy in the UK ran a 00 scale train for quite a long distance but that was only a one shot deal doing it on a permanent basis , I'll go with the other poster who mentioned going G scale but be careful there too as you need to run brass track out door on G scale not the stainless steel track you'll find in the cheaper Bachmann kits

Just my 2 cents worth, I spent the rest on trains. If you choked a Smurf what color would he turn?
  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Thursday, April 15, 2010 8:31 AM
Baghdad firefighter

What is the maximum length you can run a train 2-3 engines and 20 to 30 cars I was thinking about making a simple outdoor single or dual line in HO scale out in my kids play area Just something I can run while the kids are outside and bring in the engines and rolling stock when not in use I was looking at a mainline of between 300 and 800 feet and help would be great

Yikes, HO scale outdoors.  Dunno.  Even if you bring in the trains, how long will the track work hold up outdoors? 

Good point about straight line versus a loop.  I run 162 foot double mainline (indoors) with a 5 amp DCC powered system with no problems.  A 300 to 800 foot run may well require a booster.

 

Alton Junction

  • Member since
    July 2003
  • From: Metro East St. Louis
  • 5,743 posts
Posted by simon1966 on Thursday, April 15, 2010 7:18 AM

7 miles.

They did it for a TV show in the UK. You can see part one at this link http://www.youtube.com/watch?v=ZyIgwqhBZi0 and then watch the whole thing if you like.  It is really entertaining and fun to watch.  But it does show that if you provide sufficient power, there really is no limit.

It also shows some of the issues of running smaller scales (in this case OO, which is close to HO) outside.

Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum

  • Member since
    November 2002
  • From: Colorado
  • 4,075 posts
Posted by fwright on Thursday, April 15, 2010 3:09 AM

I assume this is not a straight line distance, but rather a total loop distance.  The length is unlimited provided you provide an adequate electrical path to prevent voltage drop.  A heavy bus system using say #12 wire in a loop following the track, tied to track feeders every 3 feet or so (every track length) would be adequate in DC.  Multiple, parallel links from the power pack directly to the bus could further mitigate voltage drop issues.

DCC - I don't know.  Specific actions may be necessary to prevent deterioration of the signal and/or reflections at such lengths.

You didn't ask, but I would be very dubious about the success of this proposal.  Successful, reliable (no derailments or stalling) operation of HO equipment requires very stable track with tight tolerances on allowable deviations in both vertical and horizontal rail alignment.  Maximum allowable deviations would be on the order of 0.020" within a 1-2" length - and even then rolling stock would be rockin' and rollin'.  Clean electrical contact between rails and wheels is also critical.  Both are nearly impossible to maintain over time in an outdoor environment.

Why not move up to equipment that is designed for outdoor operation - G?  The size has a lot more visual appeal for the kids, and demands on track tolerances are nowhere near as great.  Battery power and radio control solves the clean track and burying wires issues.  And even if you choose track power, the greater weight of G equipment helps break down oxidation very quickly.  Regardless of scale, bringing in the equipment when not in use will enhance its longevity.

my thoughts, your choices

Fred W

  • Member since
    November 2006
  • 41 posts
mainline max lenght
Posted by Baghdad firefighter on Thursday, April 15, 2010 2:03 AM

What is the maximum length you can run a train 2-3 engines and 20 to 30 cars I was thinking about making a simple outdoor single or dual line in HO scale out in my kids play area Just something I can run while the kids are outside and bring in the engines and rolling stock when not in use I was looking at a mainline of between 300 and 800 feet and help would be great

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