C-WW Like most of us, I'm in the midst of designing a layout, and I have a few questions about curves..... Realistically, what's the minimum curve radius for a Rivarossi Big Boy? Is it different on flat land than on grades? How about in a helix? I'm hoping 24" or 22" is adequate. I'm freelancing the UPRR in mountains, and it wouldn't be complete without one of those beasts..... For switching in sidings, is a #4 adequate, or should a #6 always be used? A larger one? Again, I'll have some larger engines and stock to worry about. I have one area where I want the main line to be going between a a siding area, with two or more sidings on each side. Does anybody know of a "three-way" switch, to select between the through track, the east sidings, or the west sidings? Your input will be appreciated.... Mark [ March 29, 2006, 03:52 PM: Message edited by: watash ]
Mark, your Rivarossi will actually go around an 18" radius curve because they are designed for the trade where all new engines have to retrofit to existing track sold over the years. It will be about like a toy Lionel going around one of the 1939 curves that Lionel put in with their train sets for children. When the HO size hobby went to ready to run rolling stock, the industry had to furnish already put together track to go in train sets made for childern, so adopted the 18" radius secional (9") track molded into plastic tie strips. If you do not have the space to allow 30" minimum radius curves, then of course you will have to either give up your dreams of owning a railroad empire, or compromise. So, oft times we use "Selective Compression", (Compromise) (Cheat). The same is with switches (turnouts in the real world), or turnouts (where a switch in the hobby world is an electrical thingy for wiring). A #4 turnout was made for 0-4-0 steam and diesel engines and short cars. Your 4-8-8-4 will usually hang up on the electric solenoids that throw the turnout points. #6 sometimes but have to go slowly or the pilot wheels will pick the frog and derail. #8 is OK although not prototypical, but works and look OK. #10's through 20's are prototypical and do not give any problems. Now you know the facts, as they are in a rigid sense. Somewhere in between you can enjoy hours of fun if you pay close attention to lay and maintain really good track. Everything else will fall into place. My experience over the years has lead me to now use #6 for logging etc, #8 in yard tracks, #10 &14 on main line sidings and passing tracks. I have used 18"R curves on logging, 26 on industrial, and no less than 30" on mainlines (60" only on one layout that was big). It depends on the space you have. An 0-4-0 switch engine will couple onto an 84 foot diner on a 30" radius, but not much less than that. See? This is only my opinion, Not written in stone from God.
Mark, and Watash, I own 4 EM-1's for the B&O that were customized to a 2-8-8-4 from a 4-8-8-4 Big Boy. I run my ex. Big Boys on 24 inch radius maxium, and 22 inch radius minimum. And they all run well without problems or an exceptally bad over hang. I use #6 an #8 turnouts #8's on my main line and #6's in yards and sidings etc... And again run well. And as you both know most times you find someone with a Big Boy 4-8-8-4 its made by Rivarossi. And yes all 4 of my customized Rivarossi 2-8-8-4's were in fact 4-8-8-4 big Boys and all I changed was the pilot guide wheels from a 4 set of wheels to a 2 set of wheels I never cut the body itself down of the boiler to shorten it so Mark your Big Boys are exactly the same lenght of my 2-8-8-4's. And as I said of the radius I run I have no problem at any speed running them. Matter of fact Watash *I got some strange happenings with a few of my loco's since I switched from 18 inch radius to 22 and 24 inch radius!!!!!!!! I got a few EL CHEAPO'S from Life-Like that are in fact 0-4-0's and they hate me I swear to the fact!!!!! They ran like scared jack rabbits on the old 18 inch radius I used to have before I got my mallets and then I changed to 22 and 24 inch radius and now my 0-4-0's won't run the way they did!!!!!! And i've checked the wheel gauge with a NMRA "HO" standards gauge and everything is right on the spacing on my wheels, and then I went and checked the spacing of my rails and that was right, so I started thinking that the wheels may have been dirty or something that was causing the problem on my curves. So I gave the wheels a good cleaning and polishing, still does the same thing, but only on curves. I run code 83 track in curves and for the straight a ways I use code 83, 3 foot flex track. And I went as far as to see if the wheel flange was catching the simulated spike heads and it clears them by 1/32 of and inch. So I don't think thats doing it. No traction bands on the wheels of this little EL CHEAPO either. I looked to see if a band was dry rotted and their are no bands!!! I went as far as to make sure the wheels weren't binding up and turned freely and they were. I mean to tell you I tried everything I could possibly think of and still those 0-4-0's of mine not just the Life-Like but others too I got the Mantua "Goat" 0-4-0 "Camelback" and it does it too but no where near as bad as the Life-Like ones do though. But anyway all the 0-4-0's I have do this on the curves only. What else could it be that i'm over looking or I have no clue what could be causing it to happen????? Oh I forgot one thing... I have 2 of the C-16 0-4-0T Rivarossi Switchers, the "Little Joes" that Rivarossi made now they don't do that on curves they run exceptionally well over all. It seems as if the Life-Likes are hanging up pulling. I mean the boiler and cab wobbles, and the wheels just spin like crazy and thats at less then half throttle too. But once they get on a straight they don't wobble or anything but fly *ZIP* right by till it gets on the next curve. I thought at first a wheel was not in its quarterly fasion like they have to be to run right so I even checked the quartered side rods to make sure. And I even noticed that since i've been in trainboard I looked to see if the plastic spokes warped from any type of heat and they come out plumb. But when I got these 0-4-0's and still had 18 inch radius curves they didn't do this but since I went to 22 and 24 inch radius curves, they have. And I bought pre fab 22, and 24 inch radius curves (rigid) at 9 inch sections so I know it shouldn't be modeled off curves. I mean bad craftsmansship in manufacturing them. They have the swepping to the curve without kinks. Then I even got to thinking about how I put the joints together, I soldiered them on the out side of the rail not on the inside and I checked that with NMRA gauge and at the joints the gauge don't hang up so what else could it be??????? I'm stumped on this one. [ 15 March 2001: Message edited by: 7600EM_1 ]
John I suspect the flange is running hard against the outer rail on 18"r making good contact, trying to climb over. That right hand front wheel is probably the pickup wheel. There is almost no strain to go around the 24"r, which makes me think, maybe the front axle is not parallel to the rear axle. Some quality of contact is lost on the 24" when the engine teeters on the two diagonal wheels because the right front flange is not tring to climb over. If it isn't that, maybe the wheels are plated, and the pickup brushed have worn through the plating on the inside of these wheels.
