9Track 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
  • 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
  • 1st curve radi­us: 371mm
  • 2nd curve radi­us: 438mm
  • 3rd curve radi­us: 505mm
  • 4th curve radi­us: 571.5mm


  • 24-Sept-2015: Added 15 new geo­met­ries, mostly of sta­tions
  • 9-Mar-2017: Added 8 new geo­met­ries

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



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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! 🙂

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.