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4x8 double oval layout in ho scale

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4x8 double oval layout in ho scale
Posted by biggnogg on Saturday, November 22, 2014 12:29 PM
Is it possible to design a double oval on a 4x8 layout in ho scale?, sorry for the newbie question.
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Posted by cacole on Sunday, November 23, 2014 10:21 AM

If you mean one loop inside the other, yes, it's possible but your inner loop's curves are necessarily going to need to be rather tight for some locomotives and rolling stock to negotiate.

In order to keep the outer track at least an inch from the edge of the layout, it will need to be in the neighborhood of a 22 inch radius, and the inner loop will need to be 18 inch radius.

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Posted by Beach Bill on Sunday, November 23, 2014 10:21 AM

Clearly the answer is yes.  The majority of HO market locomotives run on 18" radius, which is 36" diameter.  If that is the interior oval, there would still be space between that an the edge of the table (table being 48" wide) for the second oval, and there would be space for the cross-over between the ovals along the straights.

The difficulty is that this forces the track plan to run parallel to the edge of the layout.  It also compels a 18" radius, which limits the size and selection of equipment - if one uses small steam or diesel locomotives with 4-wheel trucks (known as B-B wheel arrangement) and freight cars that are a scale 40' length, then things can run fine.   Full-length passenger cars of a scale 80' length would have difficulties on those curves.

So, the image of two trains meeting on parallel tracks can be recreated on a 4X8, but there is a trade-off in terms of what else is then possible with that layout.  good luck

Bill

With reasonable men, I will reason; with humane men I will plead; but to tyrants I will give no quarter, nor waste arguments where they will certainly be lost. William Lloyd Garrison
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Posted by BroadwayLion on Sunday, November 23, 2014 12:03 PM

 

Welcome

Yes. You can even do it in 1:1

Both circles are now complet, the east loop (to the right is four tracks wide, the west loop is two tracks wide. Oil is trucked down that (dirt) street on the right, and transloaded into unit oil trains going east (mostly--but if China pays us more money for the stuff, we will send it west--try doing THAT with a pipeline.)

The BNSF main line cuts across the bottom of the picture, it is single track for the most part, but it is growing. With in 30 miles of where I am sitting (from west--the location shown--to east) we have:

1) A new diesel refinery, that second loop show above will be for diesel);

2) The Bakken Oil Express (the loop you are looking at);

3) Dickinson ND. It used to be a crew change point, but that no longer happens here, but so much of the industry near us needs switching that I am sure it will grow;

4) Gladstone Grain Cooperative, loading 100 car shuttle grain trains;

5) Haliburton is building a sand terminal here in Richardton, just west of town, that will have two loops plus some ancilliary tracks;

6) Red Trail Energy, an Ethanol plant (east of towon) has been operating for about ten years now. It has two locomotives of its own, and four staging tracks south of the BNSF main;

7) Richardton Rail Yards, is east of the ethanol plant, but on the same property, a new terminal being build by a consortium of interests, mostly trans loading oilfield supplies between train and truck. Pipe is a big commodity as are chemicals. There will be other industries here, I am told that a car cleaning and repair concern is among these;

8) Hebron Brick is one of the largest speciality brick manufactures in the country; and

9) There is a new Hebron Grain Elevator, again with loops like this. It is, I am told, owned by Asian interest and the grain travels West to the ports.

Most of this is all NEW industry, except for the Gladstone Elevator, and the Hebron Brick Plant all less than ten years old, and the Gladstone is only about 25 years old.

So, yes. make a loop, you can do a lot with it.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by riogrande5761 on Sunday, November 23, 2014 2:49 PM

biggnogg
Is it possible to design a double oval on a 4x8 layout in ho scale?, sorry for the newbie question.

Yes, but since the curves are pretty sharp, be prepared to run relatively short engines and train cars, bottom line.  A 4x8 can accomodate a double loop set up with 18 inch curves inside and 22 inch curves outside radius.

Many six axle diesels are manufactured to handle 18 inch curves, but they look pretty toy-like on such sharp curves.  Rolling stock used on 18 inch curves should be limited to 60' or you may have problems.

If you want to expand your running options for rolling stock, it's wise, if possible to increase to a 5x9 in HO to allow you to use larger radius curves.

If you must use a 4x8, its best to limit yourself to 4 axle diesels and shorter freight cars, 40' and 50' are best.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by cuyama on Sunday, November 23, 2014 3:24 PM

BroadwayLion
Yes. You can even do it in 1:1

Those prototype examples aren't really useful for anyone contemplating building an HO 4X8. They are unique loading or unloading situations for the most part and wouldn’t work as a layout without more space given over to staging tracks. And they are each massively larger than an HO 4X8 equivalent. So personally, I don't see how posting them helps anyone build a layout in a realistic space.

To answer the Original Poster’s actual question, yes, it is quite possible, like this double-track HO 4X8 that at least breaks up the racetrack ovals a little.

 

 

And of course, in the exact same floor space as an HO 4X8, a lot of neat alternatives will fit.

Tags: HO 4X8 , 4X8 layout
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Posted by rayw46 on Monday, November 24, 2014 9:07 AM

Do you mean two separate ovals or one oval that crosses over itself running two times around; I think its called a folded dogbone?

Ray

Shoot for the stars; so you miss, you are only lost in space.
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Posted by dknelson on Monday, November 24, 2014 9:44 AM

My first HO layout was two ovals (22" radius and 18" radius snap track, with snap switches for crossovers) on a 4x8.  I had fun with it but even back then I came to realize that since I was running just one train at a time, it would have been smarter to have just one oval, use the newly available space for sidings to switch and perhaps add some scenic factors such as creeks and roads, and not have the oval be a perfect geometric oval but work in some variety, more bean shaped.  I would have learned more about using flex track, and building structures, and perhaps even wiring had I been more imaginative. 

Dave Nelson

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Posted by carl425 on Monday, November 24, 2014 9:47 AM

rayw46

Do you mean two separate ovals or one oval that crosses over itself running two times around; I think its called a folded dogbone?

Ray

 

The layout design you're talking about is a "twice around" - assuming you're willing to accept John Armstrong's definitions.

A "dogbone" is where the sides of the oval are squeezed together to simulate a double track main. This leaves a turnaround blob on each end.  The "folded dogbone" is when you fold the dogbone around so that the two turnaround blobs are stacked one on top of the other.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by BroadwayLion on Tuesday, November 25, 2014 2:50 PM

Welcome

 

Certainly. If you use sectional track you can us 18" for the inner oval and 22" for the outer oval. If you are just using 18" radius curves you can drop a 6" straight track on the outer loop to make it fit in the middle loop.

 

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by jjdamnit on Tuesday, November 25, 2014 11:37 PM

Hello all,

I find it interesting that all the suggestions have been in two-dimensions. No mention of elevations and I’m not talking a figure eight with an elevated crossover.

My 4x8 pike is a small inner oval connected to an outer oval with a 3% curved grade to an elevated siding with a coal trestle that ends in bridge over the inner oval to a 360º loop that connects back to the inner oval just under the bridge.

If that weren’t enough I’ve added a Wye on the inner oval along with an elevated supply track parallel to one leg of the Wye; between the Wye and the loop.

On the opposite side of the elevated coal trestle there is a siding running the length of the 8-foot side; outside of the inner loop on the same level, with two single crossovers to the inner loop. Just to make things interesting I added a siding, on the inside of the loop, with a single crossover.

Before converting to DCC there were 16 power blocks with dual cab control via two transformers. With DCC I now control the locomotives not the track.

Currently there are 13 turnouts and one Wye turnout. The paired crossover turnouts and the turnouts to the Wye are wired parallel so one switch throws both sets of points. The turnouts are divided into two blocks that are powered by separate capacitor discharge units fed by a single 16V AC transformer.

The Wye (see “How to wire a Wye for DCC” post) uses an Auto Reversing Unit drawing power from the inner oval outside the legs of the Wye.

Yes, all of this on a 4x8 layout.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by rayw46 on Wednesday, November 26, 2014 9:55 PM

jjdamnit

Hello all,

I find it interesting that all the suggestions have been in two-dimensions. No mention of elevations and I’m not talking a figure eight with an elevated crossover.

 
Many model railroaders, although very intelligent, are like Khan; they think in only two dimensions.

Ray

Shoot for the stars; so you miss, you are only lost in space.
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Posted by riogrande5761 on Thursday, November 27, 2014 10:53 AM

rayw46

 

 
jjdamnit

Hello all,

I find it interesting that all the suggestions have been in two-dimensions. No mention of elevations and I’m not talking a figure eight with an elevated crossover.

 

 

 
Many model railroaders, although very intelligent, are like Khan; they think in only two dimensions.

Ray

As aptly pointed out by Captain Kirk

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by BroadwayLion on Thursday, November 27, 2014 12:36 PM

jjdamnit
I find it interesting that all the suggestions have been in two-dimensions. No mention of elevations and I’m not talking a figure eight with an elevated crossover.

A 4x8 layout really does not have enough space for a proper elevation. That said, LION has indeed designed a SUBWAY layout for a 4x8 form factor. Remeber that subway stations are 4' long (if you use a six car train). Well on a 4x8 I'd have to use a 4 car train which is how the equipment is sold anyway.

On an upper level the train leaves the terminal station across a double crossover swithc and begind its decent. on the opposite side of the table is a subway station which nonetheless is still 2" above the table surface. The next half turn gets you down to the 0" level directly under your terminal. You can either build another terminal, or I wouldl suggest a return loop back to the middle station. You could keep three trains moving at once on such a layout just by controlling the interlocking plant at your termijnal

 

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by jjdamnit on Thursday, November 27, 2014 1:21 PM

Hello all,

On a 4x8 layout there is plenty of space for elevations- -what is consider proper is debatable.

With a 1-inch foam base you also have that inch to depress the tracks for additional clearance, just as prototypical railroads have done.

If you doubt this just look at the Woodland Senics River Pass layout in HO.

Felines can’t perceive the complete color spectrum, I guess that’s why some things get lost in plain sight.

meow.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by BroadwayLion on Thursday, November 27, 2014 1:33 PM

jjdamnit
With a 1-inch foam base you also have that inch to depress the tracks for additional clearance, just as prototypical railroads have done.

Actually, my design does go up and down. Go back to the middle station on the 2" level. NOW if you like, you can call that the 0" level, and it goes to a -2" level under the terminal; and to a +2' Level at the terminal.

jjdamnit
Felines can’t perceive the complete color spectrum, I guess that’s why some things get lost in plain sight.

I'm am having trouble with your eye chart, could you bring it into my den where I can see it better...

Thanks

 

 

ROAR

 

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by mactier_hogger on Thursday, November 27, 2014 4:42 PM

[quote user="BroadwayLion"]

 

 
jjdamnit
With a 1-inch foam base you also have that inch to depress the tracks for additional clearance, just as prototypical railroads have done.

 

Actually, my design does go up and down. Go back to the middle station on the 2" level. NOW if you like, you can call that the 0" level, and it goes to a -2" level under the terminal; and to a +2' Level at the terminal.

 

Good comeback Broadway!!

 

 

 

 

Dean

30 years 1:1 Canadian Pacific.....now switching in HOSmile

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