50Track 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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Hi Jon, fan­stast­ic resource thanks for pro­du­cing this. I’m strug­gling with try­ing to get a R8074 to run into a par­al­lel through sta­tion. For example try­ing to use Ropley on Mid Hants Rail­way as example. Is it pos­sible? I can get close if i use R8077 and a R600 + R628.

SBSimon Buckley

Dear John would be able to offer some advice. I would like to mod­el Brad­ford exchange sta­tion in the 1930’s par­tic­u­larly around the the St Dun­stans junc­tion which is a tri­an­gu­lar loop. If I can cre­ate the space I would like to include the ham­mer­ton junc­tion and the run back down to the Adol­phus street goods station

JSJon Scaife

Hi Simon

I recom­mend look­ing for old maps of the area, import­ing them into any­rail as an image, and then lay­out out track over the top — that is how I cre­ated the lay­outs for the shef­field sta­tions that I have shared. If you need spe­cif­ic advice about any­thing do ask


Hi there, some really good points and graph­ics here.
My ques­tion is.

I want a low level non-scen­ic return loop. I believe I can use 2nd radi­us curves. My biggest loco is a B12 4−6−0 with a max­im­um train length of 3 thompson carriages.

I also want to hold a train there, while a second one passes through. Or hold either one, while the oth­er moves off. I have a length of just under 8ft, as my lay­out is just under 8ft by just under 10ft.

This will be a low level affair so I can have a double track main level with an upper level branch. Hope you under­stand my ques­tion thanks

JSJon Scaife

Hi Scott

I recom­mend try­ing Any­Rail or an equi­val­ent track lay­out tool as you can then exper­i­ment your­self with what will work.


Hi Jon
I have a OO gauge Hornby Fly­ing Scots­man R1167 (code 100) set and a HO gauge Life-Like Uni­on Pacific T8608AA (code 83?) set.
Is it feas­ible to join them to use in two loops or will the change in track height cre­ate problems?
This idea is more about util­ising the track I have than run­ning both OO and HO loco­mot­ives together.
Appre­ci­ate your suggestions.

JSJon Scaife

Hi Monique
There is a good chance you’ll have prob­lems run­ning the code 100 loco on code 83 track as older mod­els often have deep­er flanges on the wheels. The HO loco will almost cer­tainly run fine on code 100 track if it runs on code 83 track.
I’d highly recom­mend test­ing the Fly­ing Scots­man on code 83 track before com­mit­ting to any­thing as it may well “ride on the ties” or have issues with turnouts and frogs. If you find it works reli­ably then there is no reas­on you can­’t mix track for use with both locos. If you have old rolling stock that does­n’t like the code 83 track it is easy to switch the wheels to ones with smal­ler flanges. I would­n’t want to try swap­ping wheels with locos though, it would prob­ably involve a lot of pre­ci­sion DIY.
There are products out there that will allow you to join code 83 to code 100 track without an issue, e.g. Atlas rail join­ers with product code 551. If you have code 75 track then Peco make a track join­er for code 75 to 100 too.
Assum­ing everything does work then I would recom­mend using code 83 on scen­ic sec­tions and code 100 for fiddle yards as the code 83 will look more realistic.


I attemp­ted to recre­ate the angled turnout geo­metry (the smal­ler of the three) and for some reas­on it does not appear to fit. the R614 cros­sov­er com­bined with the R8072 switches do not pre­serve the dis­tance between tracks to match the R636 Level Cross­ing both on the straight and angled areas. I am using SCARM though and not Any­Rail (I assume you used that one) so the two pro­grams may have dif­fer­ent dimen­sions for the indi­vidu­al pieces but I don’t want to invest in the actu­al pieces or com­mit to the design only to find out they won’t fit on final assembly.

JSJon Scaife

Hi Tony
The pink dots are where there is an imper­fect but very small mis­fit. This would eas­ily be accoun­ted for by using a piece of flexitrack — it is small enough to not mat­ter I believe


A tip picked up from Mod­el Rail is the Hornby 2nd radi­us 14 curves can be used with the Y points to give a longer straight and min­im­al 50mm between centres.
ALL the Hornby radii can be used to cre­ate a diminishing/increasing radi­us curve which can be use­ful inform­a­tion when link­ing scen­ic and non-scen­ic sec­tions of a layout.
Hornby Large radi­us R8077 & R8078) and Y points (R8076) can be used in com­bin­a­tion for release roads at ter­min­al sta­tions, with the Y con­nect­ing to the diver­ging of the large radi­us points.
Any single Hornby 45degree curve R1 — R4 will con­nect to the diver­ging branches of short Hornby points (R8072 & R8073) the infin­ite radi­us link being formed by a cut length of R621 Flex a use­ful fix when work­ing in O‑16.5 and oth­er light/tramways were odd point-work arrange­ments were used to access water tanks or provide loco stabling off of the single mainline.
Sim­il­arly and half curve (22.5degrees) will work in sim­il­ar fash­ion in com­bin­a­tion with large radi­us points.
Any­rail is use­ful to set out the basic prin­ciples of what sec­tion works with which com­pon­ent to con­struct your needs.
Sec­tion­al track gets a bit of an iffy press BUT it can also provide a work round due to it’s con­stant arc be it 11.25, 22.5 or 45 degrees.

JSJon Scaife

Hi Stu­art

That’s really good info thanks.

For any­one new to mod­el­ling I would­n’t gen­er­ally recom­mend SeTrack any­way, it’s just there is a lot of it out there that is still per­fectly usable and for “toy train” lay­outs as opposed to “mod­els” it’s quick­er and easi­er to get a work­ing layout.

RNRichard Noble

Awe­some­ness inform­a­tion Sir!!
Could you pos­sibly post the most eco­nom­ic for point space, a 16 road mar­shalling yard please??

JSJon Scaife

Hi Richard

I’m not sure exactly what you mean. I assume you don’t want to con­struct a cas­sette or slid­ing sys­tem — you’re look­ing for a 16-road fixed yard?

But I’m not sure what you mean by “eco­nom­ic for point space”?

Is this for a scen­ic area — i.e. a mod­el of a mar­shalling yard, or is it for an off-scene area?

Assum­ing it’s for an off-scene area you pre­sum­ably don’t care about pro­to­typ­ic­al oper­a­tion — you just want to max­im­um ‘stor­age’ in th emin­im­um space or with the min­im­um num­ber of points?

Are you want­ing some­thing double ended (i.e. with a through-track for a loop) or some­thing ‘dead-end’? How many tracks do you need lead­ing into each end?

RNRichard Noble

Hi ya
Many thanks for com­ing back to me!
The mar­shalling yard is a back­ground area.
I’m extremely pushed for space, in that I want to store 8 coach trains which is fine except that the points are tak­ing up to much space that I haven’t got? So basic­ally I need to get my 16 lanes in the shortest way pos­sible with the points over­all length
Hope that makes sense?
The less space wasted with the points length the better
Many Thanks again

JSJon Scaife

Hi Richard
That makes sense. It sounds like you want a ‘sta­ging yard’ specifically

Are you using Horny SeTrack or some­thing else (e.g. Peco Streamline)?
How many tracks do you have com­ing in? Just 1 or more? E.g. if you have 2 could you have 2 sep­ar­ate 8‑lane sec­tions. Or do you need to feed all 16 lanes into 1?
Is it just con­nec­ted at one end or at both ends — i.e. does it need to have a run through part?

Assum­ing a single track entry with no pass-through the shortest length I can see so far would have the points take up 1m of length before your straight sec­tions. 8‑coach trains would be about 2.5m long includ­ing a single-engine or a bit longer for MUs so you’d be look­ing at a total length of 3.5m and a width of ~1.6m. I’ve included a design below.

If you are tight for space you might be bet­ter with a tra­vers­er or elev­at­or. Have a look at https://modelrailwayengineer.com/fiddle-yards/ for dif­fer­ent pos­sible approaches

16-road staging yard model railway

RNRichard Noble

Hi ya Jon
This is per­fect for what I want to achieve, I can’t thank you enough!!
Thank you again
Kind­est Regards

JSJon Scaife

Hi Richard

After think­ing about this some more I came up with an improved design. The length is mar­gin­ally short­er but the main bene­fit is that the width is smal­ler (around 1m rather than around 1.6m) which means the fur­thest tracks will be much easi­er to reach. Note that the light blue parts are shown for design pur­poses but actu­ally form part of the roads them­selves, so the point­work is less than 1m long

If any­one has any thoughts on a more effi­cient design please let me know

JSJon Scaife

Hi Chris. Agreed — FreeTrackPlans.com is great. I’ve gen­er­ally tried to avoid duplic­a­tion of the info they provide so I can recom­mend a good look at the many plans they have

ISIain Smith

Hi Jon — really great site — thanks. I am new to using Any­Rail — and plan­ning first layout.Reference the ‘geo­met­ries by request’ sec­tion — top line — second from left — could you post the angle and radi­us of the vari­ous R621 sec­tions you are using, please? I am hav­ing a prob­lem rep­lic­at­ing the dia­gram on Any­rail. Would be much appreciated.

JSJon Scaife

Hi Iain

There are 4
The one next to the road-cross­ing on the R4 curve is r=54, a=17.5
The one below it on the R3 curve is r=56.5, a=17.5
The longer one on the R4 curve is a cus­tom adjus­ted smooth curve with rmin=52.68
The final one — at the bot­tom of the R3 curve is r=56.5, a=17.5

Hope that helps. If not I can send the .any file over, just let me know


Would it be pos­sible to incor­por­ate a R8075 point on a 4th radi­us R8262 so as to cre­ate a spur off and then to effect­ively have the inner curve back on align­ment (presently a com­plete 180 degree 4th radi­us curve) pos­sibly by hav­ing short R410’s pri­or to the point? Many thanks.

JSJon Scaife

Hi Jeff

I assume you mean on the stand­ard Hornby 4‑track loop or equi­val­ent 180 curve?

If so then yes, although not without cut­ting one of the R610’s short. I assume you mean R610’s?

You need to use R610 -> R8075 -> R610 -> R610 (cut short) -> R643. This will have the same start and end points as a 90 degree 4th radi­us corner. Note that it does include the 2nd radi­us R643.

If you wanted to achieve the same thing without the R643 you could use flexitrack to cre­ate a piece with a stand­ard 4th radi­us of 572mm and a curve of 11.25 degrees. It is a shame Hornby don’t make one of these as stand­ard as it would fit near per­fectly in a pat­tern of R610 -> R8075 -> flexipiece which would form a smooth­er curve also of 90 degrees and fit­ting into place of a 4th radi­us 90 degree turn

Of course, flexitrack is a good idea any­way as you can then include ease­ments which both look bet­ter and improve smooth running

IHIan Hunter

Can you tell me the thick­ness (under­side of sleep­er to top of rail) of Peco 00/H0 Stream­line Code 100 track? Every mil­li­metre counts as I attempt estab­lish the gradi­ents on a lay­out that I am planning!


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

JSJon 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.

JSJon 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.

SMstuart 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?

JSJon 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.

JSJon 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.

JSJon 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.

TBTim 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.

JSJon 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 sit down and digest much of this and then try in Any­Rail to cre­ate my own solu­tions based on the ones you’ve provided here🙂

JSJon 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.

BGBob 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.

JSJon 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.