23Track geometries for 00-Gauge Hornby SeTrack

I have recently returned to mod­el rail­way­ing after a hiatus of over a dec­ade. Since I last mod­elled, things have changed con­sid­er­ably, with the wide avail­ab­il­ity of mod­el­ling soft­ware which allows lay­outs to be care­fully designed in advance — ensur­ing the design will fit in the space, and that the required track is avail­able.

In terms of track, most mod­el­lers now recom­mend Peco Stream­line track for a range of reas­ons includ­ing: it is believed to be bet­ter run­ning, the point radii are more suit­able for high speed run­ning of large locos, and there is a wider range of pre-made track pieces avail­able. With all that said, I still have a large col­lec­tion of SeTrack so I decided to design my lay­out to work with this track to avoid the cost of repla­cing it with new­er Stream­line.

Build­ing a basic circle with SeTrack is simple enough, but more com­plex lay­outs can become tricky, and so I decided to look on google for some stand­ard geo­metry lay­outs to help me. Hornby provide a fairly basic lay­out them­selves which is par­tially use­ful for curved points, but I was unable to find any oth­er geo­metry sites that included a com­pre­hens­ive set of cor­rect geo­met­ries. The best I man­aged to find was FreeTrackPlans.com which was a very use­ful start­ing point, but sadly includes sev­er­al examples which don’t actu­ally fit very well togeth­er.

Below are a large set of track geo­met­ries I have designed in Any­Rail 5. The Any­Rail plan is also avail­able. I should note that there are some examples below that tech­nic­ally don’t fit per­fectly — how­ever I have restric­ted these imper­fec­tions to instances where the prob­lem is caused by a straight piece which is frac­tion­ally too short. I believe that in a real world mod­el this error is so small that it wont mat­ter, and fur­ther­more that a mod­el­ler could eas­ily cor­rect them by using a longer straight piece and cut­ting it to length. Such very minor mis­matches are high­lighted in pink at the joint in ques­tion. All such imper­fec­tions are with­in the Any­Rail tol­er­ances — as their manu­al says: “Some­times you can make the track fit by using the play (wiggle room) in the track. While this can be con­sidered cheat­ing, some­times you don’t even notice that you’re doing just that when lay­ing real track”.

You may notice a lot of level-cross­ings at the ends of each geo­metry — these are present to demon­strate that the track at the ends is equal in length and the cor­rect 67mm par­al­lel sep­ar­a­tion for SeTrack.

Where shown the grid lines illus­trate 50cm squares for scale pur­poses

One last thing to note are the fol­low­ing spe­cific­a­tions for HO and OO gauge track stand­ards. The geo­met­ries below are for 67mm Hornby/SeTrack, not for 50mm Peco/Streamline

4mm OO Gauge track geo­metry — Hornby Stand­ard, Peco Setrack, & Bach­mann Branch­line

  • Track gauge: 16.5mm
  • Track spa­cing: 67mm (centre-to-centre)
  • Track spa­cing: 37.5mm (sleep­er edge-to-edge)
  • Track width: 16.5mm (rail-to-rail)
  • Rail heights: code 100
  • Turnout angle: 22.5°
  • 1st curve radi­us: 371mm
  • 2nd curve radi­us: 438mm
  • 3rd curve radi­us: 505mm
  • 4th curve radi­us: 571.5mm

4mm HO Gauge track geo­metry — Peco Stream­line

  • Track gauge: 16.5mm
  • Track spa­cing: 50mm (centre-to-centre)
  • Track spa­cing: 20.5mm (sleep­er edge-to-edge)
  • Track width: 16.5mm (rail-to-rail)
  • Rail heights: code 100, 83 or 75
  • Turnout angle: 12°
  • 1st curve radi­us: 371mm*

*Stream­line track does­n’t come with fixed curve pieces, how­ever, Peco advert­ise their Setrack as 100% com­pat­ible with Stream­line code 100.  Any curve with a radi­us less than 371mm is likely to cause derail­ments for many RTR mod­els.


  • 24-Sept-2015: Added 15 new geo­met­ries, mostly of sta­tions
  • 9‑Mar-2017: Added 8 new geo­met­ries
  • 19-June-2020: Cla­ri­fied stream­line track curves

Hornby 4 track loop standard dimensions


Standard parallel turnout geometries


Express parallel turnout geometries


Angled turnout geometries


Curved turnout geometries


X‑crossing and Scissor-crossing geometries


Y‑junction and T‑junction geometries


Basic Station geometries


Major station geometries


Curved station geometries


Terminus station with turntable geometries


Turntable geometries


4‑way junction geometries


Other geometries


Geometries by request

Please post any requests for oth­er lay­outs below.

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Inter­est­ing thanks, but note that Peco Stream­line do not do curved track so can­not have radii except a min­im­um for the flex­ible track, and those radii are not 50mm apart.

Curve radii for points are ‘small’ at 610mm / 2 foot, ‘medi­um’ at 914mm / 3 foot and ‘large’ at 1524mm / 5 foot.

Also sug­gest adding point angles, 22.5° for Hornby, 12° for Peco S

gravatarJon Scaife

Thanks Bill. I have added a cla­ri­fic­a­tion on the curve radii and also added your sug­ges­tion on point angles.


Thanks for the very use­ful inform­a­tion just start­ing out again at the grand old age of 64 Ive finally got the space and the time. now.

gravatarJon Scaife

I’m pleased to hear it. This peri­od of being stuck at home at least has the upside that it’s a great time to get back into mod­el­ling.

gravatarstuart moon

Jon, Is it safe to assume the grid used for the illus­tra­tion is set at 12″ (305) if not what scale did you employ?

gravatarJon Scaife

Hi Stu­art. As a former phys­ics teach­er I’ve very much adop­ted the met­ric sys­tem (and I believe Any­Rail soft­ware is from Ger­many) so the meas­ure­ments are all met­ric. Where they are shown the grid lines illus­trate 500mm squares.


Excel­lent resource! Even using flex­track you need to know suit­able dimen­sions and a load of oth­er­wise use­less rusty old bits of track can be used as a tem­plate to give the shape for the new track to fol­low. Thank you.


Holy grail for quick ref­er­en­cing of con­fig­ur­a­tions. Very much appre­ci­ate the amount of work put in and thank you for shar­ing.


Great site very help­ful in giv­ing basic design inform­a­tion, thanks for your efforts. I have a ques­tion ?
I’m try­ing to visu­al­ise if it is pos­sible to have two circles of track side by side joined with 4 curved points so the circles can be run sep­ar­ately or switched with the points to cre­ate a fig­ure of 8. In oth­er words repla­cing an X cross­ing with points. Thanks for any guid­ance.

gravatarJon Scaife

It’s cer­tainly pos­sible with a single track loop. A double track loop would be more com­plic­ated. I’ve added an image of a single track figure‑8 / double loop lay­out


Thanks for these. I would sug­gest mov­ing the curved cros­sov­er to its own dia­gram.
Is there a geo­metry that allows a 2nd radi­us curve in a 3rd or 4th radi­us circle? Some­thing to allow points with the curve on a 3rd radi­us circle.

gravatarJon Scaife

I’m not sure which “curved cros­sov­er” you are refer­ring to.
I’m also not quite cer­tain what you mean by a 2nd radi­us curve in a 3rd or 4th radi­us circle? So here are sev­er­al pos­sible answer
(1) The stand­ard hornby circle shows a 2nd radi­us to 3rd radi­us curved turnout geo­metry.
(2) I’m not aware of any way to do a 3rd to 4th radi­us on a curve without using flexitrack. With flexitrack it can be done.
(3) If you mean is it pos­sible to use 2nd radi­us curves to enable space to fit an inward turn­ing point into a 3rd or 4th radi­us turn then yes it is — you could just modi­fy the stand­ard Hornby loop to do this, or it is pos­sible to do it in a more com­pact way.
I’ve added 2 extra geo­met­ries to show how to do (2) with flexitrack and (3) with a 3rd radi­us, altho it isn’t an abso­lutely per­fect fit it will be close enough real world.

gravatarTim Blake

We are build­ing a child friendly lay­out to raise funds for a loc­al chil­dren’s char­ity from largely donated com­pon­ents, so your inform­a­tion was par­tic­u­larly use­ful for design­ing the lay­out using setrack curves.

gravatarJon Scaife

That’s great. Thanks for your feed­back. We always wel­come ‘advert­ising’ for any­thing char­it­able, so feel free to let us know more about it.


Jon, thanks for your work, shame I only dis­covered after start­ing to lay down my track. Your work, how­ever, has been use­ful in cor­rect­ing my track lay­ing mis­takes.


Thanks Jon, This has been really help­ful… I’m now going to side down and digest much of this and then try in Any­Rail to cre­ate my own solu­tions based on the ones you’ve provided here! 🙂


What size is the full 4 track lay­out please use­ing the 4th radi­us ?

gravatarJon Scaife

The radi­us of 4th radi­us is 572mm — so the total dia­met­er will be 1144mm (1.15m or 45 inches). That is to the track centre, so you’d need to add on a small amount for the phys­ic­al space required. I’d sug­gest adding on half a track width at either side, and half a track spa­cing at either side. That gives a grand total of 1228mm of space needed (1.23m or 48 13 inches). I’d want a little mar­gin for error on top of that myself.

gravatarBob Goodsir

Being a novice at this can you con­firm the appx over­all size of the board i.,e. 1.3m x 1.3m etc.for the Hornby stand­ard 4 loop track.
Thanks a lot.

gravatarJon Scaife

The grid squares are 50cm x 50cm so the stand­ard 4 track loop is approx 1.4m x 2m.
To be more pre­cise I meas­ured it in Any­Rail — with reas­on­able track clear­ance it could be fit­ted as shown onto a board 1.25m x 1.9m.


Super item, Jon. Sorry if I’ve missed it here, but when you men­tion track spa­cing, e.g H0 as 50mm, how is that space meas­ured? Is it the space between the edges of the sleep­ers of two tracks or say, from track centre to track centre?


Thank you for doing this, it has helped me real­ise what can be achieved.