I found an interesting trackplan that I like that is in O scale. I model in HO. Since HO is roughly half the size of O, would that mean that an an HO track plan would take up half the space as the same plan in O scale? Also would scaling N scale plans up to Ho be as easy as multiplying by 2? Thanks for the help everyone.
Dave
In general, yes. The exact factors are a little different, but as a rule of thumb, you’ve got it. But, there is a catch, especially when scaling down (O to HO, or HO to N). While the railroad scales down nicely, the real world doesn’t. So that aisle that is three feet wide on the O scale plan becomes 18" wide on the HO plan, and you have an unworkable situation. So, unless you hare talking about an aisleless plan, you will probably have to do some “adaptation” to get a real, workable, plan out of a plan drawn in a larger scale. Going the other way, the aisles get larger, but so does the distance you have to reach, so you have to look out for that.
Yes and no. The linear dimensions are halved (roughly) but the space or area required is only one fourth the size. For example an O scale layout that is 20x20 is 400 sq ft. In HO at 10x10 it is 100 sq ft. This a double car garage vs a spare bedroom.
When going from a smaller scale to a larger watch the reach. An easy to reach across 2 ft in N becomes 4 ft in HO.
When going from a larger to a smaller watch the aisles. You may also find the layout narrower than what you expect as the 2 ft across in O becomes 1 ft in HO.
Enjoy
Paul
Just a thought - I haven’t worked on too many O gauge layouts so I might be out in left field. Be careful of turn radius when scaling down. If the O is 60" radius then 30" in HO is fine, but if the O is only 40" then things might turn out a bit tight for large rolling stock or engines.
HO is actually slightly larger than half O, roughly 10% larger. This might or might not be significant depending on what you are scaling down. The structure that fits in the O scale plan might not fit in half as much space in an HO plan. Also, as pointed out, the radii might not scale down as well. O scale plans tend to have tighter radii because of their large scale. It is likely you will have to make some adjustments other than just reducing the plan by half in both dimensions but you should be able to work it out.
The actual size ratios for O, HO and N scale are 48:87:160, but that isn;t the most important consideration. Models can be scaled up or down, but people come in a single scale, 1:1. Thus, if part of that O scale plan is an aisleway or operating pit, that part has to be kept the same width even if the scale is reduced to N. In this respect, directly scaling up results in wider aisleways, so a 24 inch aisleway for N scale would result in an aisleway 80 inches wide if taken directly to O scale. A 24 inch aisleway (John Armstrong standard?) in O would only be 13.27 inches wide in HO - not good for anyone bigger than a junior elite gymnast.
Also, as mentioned, direct reduction may lead to minimum radius problems.
The best mathematical answer, then, seems to be to reduce the size of the O scale plan by the acceptable ratio between the O scale minimum radius and your desired HO minimum, then add back 11 inches for each aisleway. Not a simple, elegant single digit, but more likely to result in a layout that can be built and operated enjoyably.
Good luck
Chuck
Being one of the more anal retentive people around I would answer your original question as follows:
O scale to HO conversion: 0.5517
N to HO conversion: 1.8391
Then, as someone very well pointed out in one of the previous responses, you have to go through the adjusted layout plan and make sure the spots you have to fit 12" scale human bodies through (aisles, pop-up holes, etc.) are adequate.