I am fortunate to have a large basement that I only have to share with the house mechanicals. For that reason I established broad standards for curves and turnouts, 36" radii and #8 turnouts on the mainline, and 30" radii and #6 turnouts everywhere else. Then I got to my industrial area where I have a number of large structures in a fairly tight area. No matter how I tried, I couldn’t configure it to get all the structures in place without bending the rules. I’m going to have at least two #4 turnouts and I actually bought a pack of 18" radius sectional track to make the tight turns necessary.
I think this is justifiable given that nothing longer than a 40’ box car and SW7 switch engine will be traveling down these tracks. I’ve also read that in the real world, prototypes used extremely tight curves on their industrial spurs. Like the prototype, I’ll do what I have to do to make it fit.
Well John, there are no “rules”. The only rule I use is to use the MAXIMUM radius and turnout that will fit in the area. Outside curves on larger layouts can be 36 inches and even 48 inches sometimes and at least no. 6 or no. 8 switches should be used wherever practible.
Many railroads had street running in industrial districts with very tight curves into alleys or front of building loading docks so no. 4’s will only work there. Nothing wrong with that. I try to keep stub end yard ladders to no. 6 because pushing even 40 ft scale cars through no. 4s can be VERY problematical. In prototype practice sharp curves require severe speed restrictions impacting service.
In an industrial area this is perfectly prototypical. To fit tracks in between buildings and so forth, even the real railroads have to go with relatively tight curves in places. In the good old days, the big road engines would not have to traverse this trackage, so it was no big deal. Smaller switchers and smaller power used on local switch jobs were the only things that would rin in these places. Look around some time at places that still have rail service, or that show evidence of former rail service, you will see the tight curves used.
John, the savvy organizations impose “guidelines” on themselves, and if they must deviate now and then, it is most often rubber stamped and the work gets done. I began my current layout with a hard rule, “No mainline curves smaller than 28!” As I began to encounter all the issues that tend to accumulate in their effect over linear trackage, I think I had to squeek down to 26" in a couple of places, one for sure. My reasoning was that I had used curved #7.5’s from Walther’s/Shinohara which I quickly determined needed surgery in order to meet their advertised radii. I absolutely could not have inside curves to my longest siding shorter than 24" because my PRR J1 2-10-4 with coal drag was going to hold up there while the Twentieth Century Limited behind an NYC S1b roared past on the main. The stated mins for the BLI J1 is 24", although it can squeel through 22" at a walk.
In the end, it was the mins on the sidings and in the yard, the latter of which I had never had on a layout, that was the absolute minimum, so #6’s and 24" curves were successfully managed everywhere that it mattered.
Besides, in every photo posted by a good modeler that I have seen, #4’s are everywhere, and their smaller locos and boxcars look just right negotiating tight alleys, around building corners, diagonally across narrow streets, and so on.
Do it, and don’t give it a second thought. You can always ponder a fix in later months as time permits, if a fix is in the offing.
Many prototypic industrial areas have #4 turnouts and tight curves. There was one area in downtown Omaha where the track from one side of the street turned the corner into an alley. And at that it wasn’t even a fixed radius corner. It began and ended with a turnout and had a wye turnout in the middle! That is when I went in and started measuring. The end turnouts were about 4.2, the wye was a 2.6, and I believe it ended up being equivalent to a 20" radius curve in HO scale.
In my factory district, I could have gone with #4s. However, I wanted to send the occasional 50 or 60-foot car…so I went with #6s instead. I suppose the #4s would have permitted slightly longer sidings at the loading docks…but I’m happy with how things turned out.
Seems to me there are two different kinds of minimum radii here, cosmetic and operational.
Having curves that can only be traversed at minimum speed, or are embargoed to certain cars and locomotives, is not uncommon in the prototype world. Supertight curvatures drove the B&O to build the “Little Joe” 0-4-0T “Dockside” locomotive, probably the most overmodeled prototype design ever. (There were only four, compared to 25 Big Boys, and Varney had been producing their version for a quarter of a century before Tenshodo built the first 50 Big Boys for PFM. Since then the original Varney design has been reproduced by several toy and scale manufacturers, with a total production of thousands.)
Industrial areas, especially older areas in established cities, were laid out to nineteenth century standards - radii and clearances set when 40 foot cars were considered oversize. Thus, they aren’t going to look anything like mainline curves (or even modern industrial areas.) The contrast actually adds to the cosmetic realism, and the operational requirements as well.
As long as the curves can be traversed by rolling stock that ISN’T embargoed, that’s all to the good.
Chuck (who has an entire railroad that’s embargoed to long cars and most locomotives - interchanging with one that isn’t)
I really like this reply because the solution I came up with incorporates 2 wyes end to end so they form a portion of a curve that is part of the main trunk of the industrial belt. The other leg of the wyes feed into #4 turnouts or 18" radius track. The fact that I also grew up in Omaha makes this seem like it is a good omen
What this illustrates is that you have to carefully consider a number of factors before deciding to fudge on standards. In my case, I model the transition era when 40’ boxcars were the rule so going with the tighter curves shouldn’t be a problem. I’ll probably be able to even get away with spotting a 50’ car on occasions but we’ll see how it works out. The bottom line is your track must be able to accomodate the largest equipment that will pass over it and in this speciifc case, I think I can get by with #4 turnouts and 18" radius track.
Yeah, I got one of those docksiders. Rivarossi’s version sold under the AHM label. Still sits on the shelf sporting its horn hook couplers dreaming of the day I will retrofit it with a decoder. It will have a long wait.
I recall reading in a John Armstrong book that sometimes breaking your rules can be very bad in the long run. He said that if you change the rules once, you will be more likely to do it in the future, which could cause serious problems.
I am in no way saying what your doing is wrong, just tossing that out there…
Mr. Armstrong was no doubt referrring to the mainline, is what I’m thinking, in the quote you’re citing.
He, like many other modelers, saw no harm in using sub-standard trackage to meet special needs in industrial districts or to visually seperate branchline, industrial, or narrowgauge trackage from the higher standards on the main.
I’ve often found that you can break the rules, as long as you thoroughly think through what new restrictions you’ll impose on your plans if you do. The industrial area described sounds like it was that place. I can’t see any downside, unless there’s a later shift in era that puts all the traffic to those industries into modern longer cars.
And there is plenty of precedent around for such restruictions keeping older rolling stock in service specifically to service track that is not up to the latest standards. One example is all the 40’ boxcars kept aroound for grain service much longer than they would have been, except for the need to serve the light branchlines that couldn’t handle modern grain-hauling covered hoppers.
An era shift is one of the factors I had considered but decided to go with the tighter curves and turnouts anyway. I reasoned that this probably was an issue in the prototype world as well and the real railroads would have had to face this problem. I’m guessing the choices would have been to reconfigure the track if possible and if not, restrict the size of equipment allowed. In any event I think it is unlikely I will have to face these choices. If I do decide to go with an era shift, I will probably go backwards from my transition era to the pre WWII period.
This was right downtown on 14th street between Jackson and Jones Steets. The track was in use until 1987 or so, and paved over around 1990. I was so glad I got pictures when I did. I believe the location still has a building that has a corner clipped off where the curved track went (south east corner of the 14th & alley intersection). Last time I was there (six years ago?) it was still a tire store.
P.S. It also had about a 3% grade east to west down the alley, and another south to the main tracks.