More layout tips

Thank you all so much for your kind mails after the last post. I really do appreciate them.

There were more comments about Stephen than Todd’s question, so I thought I’d lead with this today:

“Hi Al,

I endorse the multitude of comments that were posted in support of your emails. However in looking through them I did not see a complete answer to Todd’s questions.

Q1 How do I know if a curve is too tight?

A. Experience of rolling stock de-railing.
Manufacturer’s recommendations.
Tips form others who model in your scale.

Q2 What’s too tight?

See answer to Q1. The consensus of results from the emails on Al’s site would suggest a minimum radius of 27 -30 inches or 70 – 75 cm for the metric minded.

Q3 How do I measure the radius of a curved section of track?

Regards Rev John.”

Hi Al.

I’ve attached a photo of a simple conversion to turn an ordinary wooden clothes peg into a really useful clamp.

I know this has been around for a while but there’s always new people coming in to the hobby and also those who’ve forgotten this simple tip. The main problem people have when the try is that they change the position of the two peg halves. If you look at the photo you can see that the peg itself hasn’t changed, but the spring has been reversed and moved to the middle notch. Although its not necessary you can make two little grooves for the repositioned spring and enlarge the middle notch. Even without this the clamps are very effective and useful model building tools.


“hello – here is some pics of my layout im working on i have actually 3 tables linked altogether the first one is a mountain table i converted to a army base theme then the second table was created for passenger trains and residential theme basiclly i have some big boy trains and needed to create a layour they would run on the radious of first table was too tight so then i started the second table.

i have built a suspension bridge to link the mountain table to the yard table (almost completed)

then i will finish up with ballast and street lamps with telephone poles on middle table

i get great ideas from other peoples pics and layouts so i hope everyone can give me some feedback or any helpful hints my project has been on the works now for about 8 months and work on it in my spare time

thanks again for looking


And have you been on the ebay cheat sheet lately? It’s still going strong – have a look – latest one is here.

Keep ’em coming.



21 Responses to More layout tips

  1. Lovely layout – it would be nice to see the track plan.

  2. Al.

    have you obtained any video`s of loft layouts with tunnels using woodland scenics,and if so could you put them on your web site.

    I`ve with help relayed my layout 11 foot x 8 foot x11 x8, with 4 lineson flat boards,but it looks bare.

    I want something to make it look better,if it can be done.

    Thanks. Mike M

  3. Al, there appears to be a bit missing from this explanation of calculating curve radii by Rev John. Could you possibly make the explanation a bit clearer? Thanks and keep up the hints and tips as I find them very useful and informative.

  4. Hi Al,
    I was out of internet reach for the last week and saw this post first before your last marathon commentary filled one! All I can say is that you have received a near 100 percent vote of confidence, so just keep this email blog as it is – very user-friendly for all your friendly users! You’re on the right track!

  5. Hi Doug:
    If you happen to have a piece of curve track handy, perhaps a section of Atlas snap track for example that has a fixed radius, you can test this formula.

    Notice that measurements are taken from the centerline of the track piece.
    An example would be a 12″ long curve piece measured from it’s centerline from end to end with a ruler. This is W(the tangent). With the ruler still in place, now measure up from the 6″ mark on the ruler straight up to the middle(centerline) of the curve, that is “H” in the formula.. For simple numbers just say that that measurement is 1″. Now put the 1″ in place of the H’s and the 12″ in place of the W’s and finish the math.

    R=1/2 + 12×12/8×1. R= 1/2 + 144/9. R=1/2 + 16. Radius = 16.5″
    Hope this helps.

    This is very handy in Garden scale as the track is so large.

  6. My thanks to Ken for a new way to use clothes pins. I am one of the new (to modeling) guys, Thomas your cable stayed bridge is great. Cable Stayed bridges are my favorite bridges to model. I have 9 completed & 2 more in progress. Al keep them coming.

  7. I have used the peg clamps for many years but it is not untill someone puts them in a book and everyone reads that the idea is spread. Plus cant they get into such a tight space.

    Dont forget that you can thin them down to almost a point for very difficult places or soldering something in place!!!

    Ok it had to be done…My daughter 6 1/2 talked about a model so out came 3 metres of lining paper and several hours later a Southern Railway line emerged just ready for the mass of RTR models in 00 gauge to run on?
    And here am I building a Pannier, Prairie and a Bulldog when I get the time!

    David in Reading.

  8. Thanks Ken (and Al); for sharing the tip for converting clothes-pegs into useful modelling clamps. At 75 yrs, I’ve been into modelling, airplanes and RR layouts for many years, and had never previously seen this handy suggestion. I only hope that Ken and other RR modellers, will continue to share even the simplest of tips. Most of us are like damp sponges, ready and willing to soak up all the available help from anyone who cares to share. I’ve always considered every day that I learn something new is a great day; so, I’ve just now raided the laundry basket, and built myself a few clamps.

  9. Regarding the radius of curved track I think the easiest way to determine the radius is to use a drafting compass and draw segments of circles with different radius. The most common radius sections I am familiar with for HO are: 15 inch, 18 inch, 22 inch and 24 inch. Draw 1/4 circle for each radius and lay the track section on each curve. Note the radius of a track section is measured at the center of the track.

    I am unaware of any rule regarding derailing based on car length and track radius, but as many have said the smaller the radius the smaller the car that can traverse a curve. Someone else also advised to look at the box the Engine or car came in for guidance regarding minimum radius. Train speed also affect derailing on a curve. If curves are in a yard tighter radius may be used than on an open section of track. 15 inch radius will only allow cars with short lengths. 22 and 24 inch track will handle nearly all cars. I haven’t found a car that derails if I use 22 inch radius.

  10. Hi Ken, Thanks for the peg tip, never knew that. I tried it and it works very well. Did you know you can use a peg as a return spring if you have manual wire operated points? I saw that tip on you tube, and I never knew that either.
    Barry, 66 and 3/4’s

  11. Replying to Barry Read, glad you liked my peg clamp tip, but can you direct me to the You Tube video on using a peg as a return spring for wire operated points? I couldn’t find it.

  12. Just wondering do peole draw there layout on paper first before you start to build it. I have got the base board made so i know the size

  13. All this work to get your radius correct, I’ve been in construction work over 50 yrs and I believe in kiss construction (keep it simple stupid) I took three pieces of per made track that had the curve already and I solder them together, I laid out my whole layout with this. No figuring and no math, works perfect

  14. Alistair,

    Just a quick point about railway turns. On the full sized rail lines turns start out gently, and within 10° of radius or so, the full radius of the rest of the turn is accomplished. This is called the “spiral” of the turn, and allows the locomotive and car trucks to adjust to the transition from tangent track to the turn. If we look closely we see model train cars wobble as they start into a turn laid out with no spiral. Using model railroad sectional track a spiral is not possible, however it may be desirable when designing layouts using flex track.


  15. Love the glowing bridge… How did you do it?

  16. In answer to the determination of radius of track here is an answer from a math degreed person.
    The perpendicular bisector of the cord of the arc of the circle will run thru the diameter. So, having said that here is how to apply that. Draw two different lines across the curve. Get a vertical bisector of both lines that you drew and (bisector means center) those lines will meet at the center of the circle.

  17. As for drawing out a layout ahead of time, I did that recently. I have a nice piece of building insulation board (2″ thick). I bought the pieces I needed from Bachmann (HO EZ track) and put together something I thought would be interesting. I then decided I wanted to try layout software, and so purchased AnyRail software (you can download it for free to try it out) The price for a licensed copy is £35 GBP or $59 USD. This works quite well, and has libraries of track from different manufacturers in many different scales. I was able to blow up just the part I wanted to turn into a diorama and print it out, and then the section next to it. That made transferring details to the layout very easy.

    Problem with using HO track for On30 is the rail is a nice size, but the ties (aka sleepers) are not the right scale (the difference between 1:87 and 1:48) PECO makes a On30 track that is much nicer and even colours the ties brown (a good start).

    Ken (in the States)

  18. Real nice layout Thomas. Looks like you know what you are doing ! Bill

  19. Hi Alistair

    I just read Bob’s letter about his depression and how your articles has helped him.

    I am a teacher and find myself in the same boat as Bob. I ended up in a psychiatric hospital in September 2014 due to stress and severe depression here at school caused by learners and management. I am 59 years of age and found it more and more difficult to cope with this problem.

    The good news is that during the workshops we had at the psychiatric hospital we were told to seriously get into a hobby that would stimulate our senses and that we would enjoy. Well as it was my life dream as a youngster to one day build a model train diorama I thought that it is time to get started and try my hand at it.

    My grandfather planted that dream into my mind. As a child from the age of four years old he would always buy me a train set or rolling stock to add. On the other hand my own father was very negative towards me ever since those years whenever I tried to start a layout. He was against the fact that it would cost a lot of money, money that might be needed for more important things in life. This caused me to be very afraid of even trying to do a complete layout.

    I mentioned that that the good news was to start a hobby. I must give praise when praise is due. Your emails and the positive way in which people reply have inspired me tremendously. I am much more relaxed and have found something that adds to make it worthwhile getting up in the morning.

    I began my layout in N-scale soon after I got back from the psychiatric hospital and all I can say is “WOW” what an experience it has been so far. I never knew that I could be so fulfilled with joy as with this hobby. I spend each and every moment I can, to work on the scenery. I cant wait to get to the next free moment just work on the layout again.

    So I want to thank you over and over again for the the great grand difference you and your email readers has made in my life.

    I do not think that people really know how much it means to people like me when they share their videos and pictures. So to all you guys and galls out there, thank you and please keep it up because I thrive in watching and reading your videos and articles.

    Yours faithfully
    Deon Joubert.

  20. With smaller layouts 22” plus curves won’t fit. So you do what you can with 18” curves: run shorter engines and rolling stock. But sometimes changing to a longer coupler can help avoid derailments on smaller radius curves. The wheels may bind a little and cause some drag with longer rolling stock but with slower speeds, they get through the curve.

    Jim AZ

  21. R=1/2 + 12×12/8×1. R= 1/2 + 144/9. R=1/2 + 16. Radius = 16.5″
    Hope this helps.
    In reference to this formula, isn’t 8×1=8 and not 9?

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