Hi All,
I’m currently doing some layout planning for my HO scale RR empire. I’ve been looking and have asked several of my RR friends, but they don’t know also. My question is what is the minimum radius you can model for a in city, downtown turn? I am modeling the steam era, so the most likely rolling stock would be a 40’. I figure a 0-6-0 could be used on these tracks. As for Diesels, perhaps a RS-3, VO-660, SW-7, or GP 7. Any clue would be of great help to me.
Check this page http://www.nmra.org/standards/rp-11.html on the NMRA site. It gives recommended radii for various types of equipment in several scales.
Enjoy
Paul
Hawk, just for the info, in ‘96 for one of my projects at the Chicago plant of Golden Grain I was involved with Indiana Harbor Belt RR and got their specs for a new spur into the plant. Their MINIMUM for a single track was 12 1/2 degrees which is 459 feet. In HO this works out to (are you sitting down?) 63.3"
Have fun but make up a few temporary set-ups and try different radii down from 18" by 1" increments. A small switcher and a 36-40’ car may be able to get down to 15" consistently. Any smaller is probably asking for an occasional derailment. John Colley Port Townsend WA
If you’re careful about how you lay out the curve and add just a touch of easement on either end, you can probably milk that curve to about 12". A 15" curve will do the job just as well, though–either the ol’ Atlas snap-track type or a smooth, no-joint flextrack curve.
Trolleys go around sharper curves, of course–but even tight-corner industrial belt lines have to work with much wider standards. And as rolling stock wider than 40’ became common on such lines, so did derailments…
I would say somewhere between 15" and 18"
But if your talking trolleys, I don’t know
hope this helps
12" BUT as an exception rather than a rule. Most east coast rairroads had tracks into docks at harbors that were really tight. the B&O has a famous 0-4-0 tank engine designed just for this service. The PRR in Philadlphia had 0-4-0 engines with slope back tenders and would pole the cars into the docks rather than be connected with couplers. They would pull them out with chains sometimes because of the tightness. now if you are talking trolleys you can go down to 9" for street running if they aren’t pulling trailers but again it is the exception and you should stay to 12" for trolleys for the most part.
Maybe in O scale…if you’re running single-truck Birneys, 4" or 5" in HO is enough. For smaller two-truck trolleys, 6-7" can work, even those cheap Bachmann Brills (with a little work.) Interurbans or trolley freight with radial couplers, 10-12".
I’m sure Hauckra ISN’T talking trolleys, which is why I suggested 15", or maybe 12" if done carefully.
Hey Guys,
I want to thank you for your valuable input on the track radius. Heck! I even learned a few things (most valuable for this old dog). It looks like I will be going back to the drawing board on making the radius larger. I was hoping to get away with tight turns since it was inside the city. But I am more interested in doing it more prototypically than toy like. I’ll stick with 15" as minimum, use 12" only if left with no choice.
Hauckra
The other day I got a chance to look at a city plat featuring a railroad spur to a large local newspaper. UP drops off large rolls of paper there pretty regularly, and the map just happened to list the actual real-world radius of the curve. I did a little mental math, and found that if modeled exactly in HO it would be a 48" radius curve! Of course, that is for modern equipment (60’ boxcars) but it’s definitely good to keep in mind that even the sharpest real-world curves (except trolley curves, which really DID get down to the equivalent of 6-8"-in-HO radius curves sometimes) were pretty broad by model railroad standards.
That being said, model railroading isn’t strictly representational–and 15" in HO makes for a good very-sharp curve without being impossible to scoot 40-50 foot boxcars around…
Jetrock,
By any chance would this city be listed on the net, and if so, where? I’d like to really take a look at this. I had in mind a newspaper that had it’s paper delivered by rail.
When I moved to Marysville CA , 20 years ago, the newspaper had a spur. A track connected to the Western Pacific ran (west-east) on the alignment of 2nd Street (unconstructed) and ended between F Street and E Street (2nd Street was constructed west of F Street so part (less than one block) of the track was in pavement. The spur to the printing plant on the north side of 3rd Street ran (south-north) along an alley (Maple? Street). I saw a single box car (all there was room for) there once in a while. There is a (food?) warehouse on the south side of 3rd Street that was probably served served from this trackage at one time. The newspaper has moved their plant and the tracks are gone.
My memory is that the spur was a switchback movement from the WP. The 1981 Track Charts confirm this. They also show that the 2nd Street track and part of the spur belonged to the Sacramento Northern.
To Jetrock, I see you haven’t posted on the SN Board lately. What’s the latest on the Modular Traction Group?
Hauckra: Unfortunately, no. However, here is a link to a 1920’s map of downtown Sacramento (the city I live in and model) showing rail lines including quite a few industrial spurs.
http://sacramentohistory.org/admin/photo/578_1240.pdf
The modern-day railroad is the Sacramento Bee, and the spur is fairly recent–the building has only been there around 20-25 years. Prior to that, a brewery stood on the site, which was also serviced by rail. Those spurs are visible on the map at 22nd and R Streets.
The spur is a 90-degree turn off the mainline (on the map, the spur is off what used to be the WP mainline between 19th and 20th at S Street, turning right onto R Street and ending between 22nd and 23rd Street.) There is a switchback long enough for a car or two and a locomotive, which leads back to a free-standing, covered loading dock where big spools of newsprint are unloaded.
The alley where the spur ran was Orange Street. Located between F and G.
I’ve been kind of busy with a couple of other projects. Interest in the Modular Traction Group was very, very limited, and I really don’t have enough time to try to drum up a bunch of support for it and still pursue the rather large and unwiedly number of free-time-consuming activities I find myself engaged in. Heck, I haven’t even had a chance to work on my own layout in a couple of weeks.
Thanks for asking, though…
I was intriqued by the truncated ground floor building featured in MR recently to allow a spur to negotiate a 90 degree street intersection in a harbour belt. How common was this solution in north America ?. I will probably try this in a future layout. Has anyone else tried this feature.
We had similar problems when we discussed starting a HO modular group (steam/diesel) in Marysville/Yuba City about 15 years ago.
I was considering going to some of your meeting, but between health problems and the fact that I didn’t see your notices soon enough to plan for them, I didnt make it. I’m not in HO traction though, I model '70s WP in N scale and am planning an O scale electric/diesel SN /WPswitching layout based loosly on R Street. (I have a SN #651, a WP SW, and a 44 tonner (so far undecorated) to operate on it.
It sounds like we have fairly similar objectives, but different scales–while a modular club would have been nice, right now I’ve got my hands full with my own layout. I keep stumbling across WP/SN diesel motive power that works wonderfully on my Sacramento belt line layout, although what I really need right now is more layout to run all this lovely motive power on! And power lines above the track, of course…
R Street is undergoing drastic renovation right now–Sacramento’s redevelopment forces are focused on it. I have to make some photography trips up there to photograph the last remaining bits of evidence of the SP and WP industrial lines down there that still remain…much of it won’t be there for long.
lyctus: Not sure what photo you’re referring to, but one thing I have seen in Sacramento (off of North B Street) were brick warehouses built with round walls, to allow railroad track to curve around a corner tightly up against the building.
When Varney first came out with 0-4-0 dockside HO engine baqck in “47” they advertized it
by running it around a Silver Dollar which is about 3/4 inch radius.
MIke