Minimum Radius

[ebtbob]

Good Morning All,

     This is a follow up posting to one currently in the HO section about the possible making of the Pennsy Q-2 2-4-6-4.   There is a supposed posting on the Broadway site showing the veriations of the engine and a stated minimum radius of 22 in or better.
      I responed to the post - referring to the minimum radius.   I have worked for over 13 years in an all train store in the suburbs of Philadelphia and have seen the anger and frustration of people who bought engines from other sources than us.   The engines do not work on the stated minimum radii and customers want to know why.
      Let me give you some advice and thougths based on customer expericence and my own.
      When a person wants to know if their engine is going to operate on a specific radii,  the first thing to do is see if the engine will actually fit on the track.   In the case of a steam engine,  once that is seen,  does the cab roof come close to or make contact with the tender?   It can happen.   In the case of a diesel,  ones like the BLI RSD15 are soooo long that using it on anything smaller than 24 in radii or thru tight turnouts such as #4s will cause it to pull cars off the track.
     Speaking of diesels,  manufacturers such as Athearn recommend that any radii under 22 in,  should be used with engines  with 4 wheeled trucks and those with 6 wheel trucks need 22 inch or better.


   

[rustyrails]

ebtbob,
Thanks for this thread.  The truth of what you say is reflected in the large number of posts here that ask something like, "Will my Acme Locomotive Works 6-12-6 run on 15 in radius curves?"  Back in the old days when we built more and bought less, I think we had a better understanding of the relationship between locomotive size, track radius and coupler offset.  24" radius curves were considered "conventional" when I was building my first layout, and I knew not to run anything much bigger than a Pacific and "shorty" passenger cars.  Today, as houses have gotten smaller while costing more and prefab track has become the de facto standard, 18" radius curves have become the norm.  I really don't think that the hobby industry serves us well when it makes beautiful 4-8-4's that will lurch around 18" radius curves like a drunken caterpiller.  The end result is a "pseudo-scale" locomotive that doesn't run all that well and tends to fall off the track a lot.   I wonder what the tin-plate guys and gals think about this conversation.  They've been happily lurching around curves for years.  LOL  No offense.      
Rusty

[adari]

ebtbob,
Thanks for this thread.  The truth of what you say is reflected in the large number of posts here that ask something like, "Will my Acme Locomotive Works 6-12-6 run on 15 in radius curves?"  Back in the old days when we built more and bought less, I think we had a better understanding of the relationship between locomotive size, track radius and coupler offset.  24" radius curves were considered "conventional" when I was building my first layout, and I knew not to run anything much bigger than a Pacific and "shorty" passenger cars.  Today, as houses have gotten smaller while costing more and prefab track has become the de facto standard, 18" radius curves have become the norm.  I really don't think that the hobby industry serves us well when it makes beautiful 4-8-4's that will lurch around 18" radius curves like a drunken caterpiller.  The end result is a "pseudo-scale" locomotive that doesn't run all that well and tends to fall off the track a lot.   I wonder what the tin-plate guys and gals think about this conversation.  They've been happily lurching around curves for years.  LOL  No offense.     
Rusty

6-12-6 post a picture. but you guys are right about radius. the Q2i think willl only work on at least 24-16" at the minimuim
Adam

[rustyrails]

Adam, there is no 6-12-6 nor Acme Locomotive Works, either, as far as I know.  I used that as a figure of speech to represent any manufacturer and any large engine.
Rusty

[jward]

ebtbob,
 I wonder what the tin-plate guys and gals think about this conversation.  They've been happily lurching around curves for years.  LOL  No offense.      
Rusty

i doubt tinplaters see operation in the same way we scalers do. as you said they are happy lurching around impossible rates of speed. i would guess they do very little backing of trains, or switching manoevers. so alot of the problems we try to overcome don't affect them.

[adari]

Adam, there is no 6-12-6 nor Acme Locomotive Works, either, as far as I know.  I used that as a figure of speech to represent any manufacturer and any large engine.
Rusty

Sometimes im weird.

[jward]

you are not alone. take a look through this warped web page. it's amazing what photoshop can do......
http://home.att.net/~Berliner-Ultrasonics/bwrkapg1.html

[az2rail]

ebtbob,
 I wonder what the tin-plate guys and gals think about this conversation.  They've been happily lurching around curves for years.  LOL  No offense.      
Rusty

i doubt tinplaters see operation in the same way we scalers do. as you said they are happy lurching around impossible rates of speed. i would guess they do very little backing of trains, or switching manoevers. so alot of the problems we try to overcome don't affect them.

No offense taken, but you guy's might want to try reading an O guage forum some time. O gaugers/scaler's have the same problems HO'ers do. Only on a larger scale. This goes for all scales.

Bruce

[jward]

my comments were in no way directed at o scalers. o scale and tinplate are 2 dirrerent beasts. one achieves a level of detail we in the smaller scales can only dream of, the other has standard curves tighter than an HO 18" radius curve. tinplate equipment sacrifices scale proportions in order to run on those curves. i believe you when you say o scalers deal with the same problems as other scale. they also deal with space constraints much more than we do. i'd love to do o scale, i just don't have the space......

[bobwrgt]

I am a collector as well as a runner of HO. When i purchase a new loco i like to know if it will run. When i started i only had room for 18in radius curves but 24 feet of one wall.
I have since added an overhead line with 22in curves about 6 feet off the floor all around the room.
I never pay attention to what manufactures  say about tight curves or radius needed. If i did i would not have purchased half my engines.
That is why people ask real users if the engine will make it.
My 18in radius is level and true. Good track work is needed.

I do run BLI GG-1, M1a, 4-8-4 Santa Fe, RSD-15, N&W j, and Hudson all on 18in radius at all speed and pulling a 21 car freight. I also run Bachmann Heavy and Light Mountains, Niagara and 8-40cw"s. With no problems. The trick to pulling cars is to put a long shank coupling on the first freight car for swing.
I also have several Kato and Life-Like SD70's that also do fine.
This may not look the best to some but on my railroad it works.
Again i stress good track work and proper placement of wires between engine and tender.

Bob

[Woody Elmore]

My godfather had a basement filled with Lionel trains. He ran them on outside third rail and had five foot radius curves. I have fond memories of one of his GG-1s pulling a train of Madison cars. He ran them slowly and they looked great.

My best advice to people starting out is to use the largest possible radius. Unfortunately, when they start with sets, people get locked into whatever radius track that comes with the set.

[jward]

large radii are good, but model railroading is a compromise. you try to get the railroad you want into the space you have. ideally, i'd like to have 30 or at the least 24 radius. but if the situation calls tfor the use of 18 i won't let that stop me from having a railroad. i just put my larger engines and cars away.

[rogertra]

Speaking of HO "scale" model railways, Vs rtr set track layouts the general view seems to indicate that 30 inches is about the ideal minimum visible radius as it gives the minimally acceptable realistic look to scale length  coaches and large steam.

Of course, there are many people who don't have the space for larger radius curves so they have no option but to use a tighter curve.  In this case, the recomendation is to use smaller steam, 2-8-0s for example, B-B first and second generation diesels, 40 foot freight cars and shorter passenger cars so that the equipment doesn't look too "odd" going around tight curves.

But then, there are those people who like to run their 4-10-10-10-6 around 18" curves while pulling a train of full length 80+ foot TOFC cars and if that's how they get their fun, more power to them but don't call it a "scale" model railway.

[rustyrails]

The best way to get away from the requirement to use small radius curves is to break free of the idea that a layout has to be an island, ie: 4X8 sitting in the middle of a room.
Rusty

[grumpy]

This thread has offended me and I am sure others who participate in this forum . There sure is a lot of pomposity in some of the comments . I am a railroad modeler who does it for my pleasure . .Because space limitations my whole layout is 18" curves. I have a 4-8-4 and it does not lurch around curves . I have a 2-10-2 and it also does not lurch around curves , also a Challenger that looks great around 18: curves Just as you have insulted me I will insult all you pompous rivet counters who dare set the standard by which you measure the rest of us
Don