View source for OO9

{{Short description|Model railway scale}}
{{For|other uses of "009"|009 (disambiguation)}}

{{Infobox Model Rail Scale
| name = OO9
| image_filename = 009 Gryndene Halt.jpg
| image_caption = Gryndene Halt, a station on the fictitious ''Evaleight Light Railway'', by the Sussex Downs 009 group
| widthpx = 275px
| scale = 4&nbsp;mm to {{cvt|1|ft|mm|0}}
| ratio = 1:76
| gauge = {{Track gauge|9mm}}
| prototype_gauge = [[Narrow gauge]], approx {{Track gauge|2ft3in|lk=on}}
}}

'''OO9''', often also denoted as '''009''' or '''00-9''' and commonly pronounced as '''Double-Oh Nine''', is a [[model railway]] scale and gauge combination of [[4mm scale|4&nbsp;mm scale]] and {{Track gauge|9mm}} gauge tracks, which models a [[Prototype#Scale modeling|prototype]] track gauge of {{Track gauge|2ft3in}}. It is a common choice in the [[United Kingdom]] for the modelling of [[narrow-gauge railway]]s whose prototype gauges lie approximately between {{Track gauge|2ft|lk=on}} and {{Track gauge|2ft6in}}. The {{Track gauge|9mm}} track gauge is used by [[N gauge]] model railways, a common commercial scale, which means that a selection of wheels, track, and mechanisms is readily available.

{{Track gauge|2ft}} gauge railways were common in Britain, but the gauge implied by 9&nbsp;mm at 4&nbsp;mm scale - {{Track gauge|2ft3in}} - was quite rare - today only the [[Talyllyn Railway|Talyllyn]] and [[Corris Railway|Corris]] railways in the UK use this gauge. However at 4&nbsp;mm/foot scale, the differences to gauge required to correct this are barely perceptible by eye, and the wide use of 9&nbsp;mm gauge in the modelling community is generally accepted to be an appropriate compromise. For example, the correct gauge for a 2-foot prototype would be 8&nbsp;mm, but the resulting 1&nbsp;mm difference from the OO9 standard is usually treated as insignificant by most modellers.

The 009 Society exists to connect modellers, issues a monthly colour newsletter ("009 NEWS"), commissions its own range of kits, and provides a popular second hand resale service.

There is a growing range of commercially available ready to run support for OO9, with a number of manufacturers announcing ranges of products, and small manufacturers making limited runs of models from time to time. 

In November 2012, Peco announced the launch, during 2013, of a range of ready to run 009 coaches and wagons, based on prototypes of the [[Lynton and Barnstaple Railway]].<ref>[http://www.peco-uk.com/page.asp?id=009wagon Peco new product announcement ''(retrieved 29 November 2012)'']</ref> This was followed in the March 2013 edition of [[Railway Modeller]] Magazine, by Danish manufacturer [[Heljan]] announcing an 009 locomotive based on the Lynton and Barnstaple Railway Manning Wardle 2-6-2Ts. Peco have since released ready to run carriages for the [[Glyn Valley Tramway]] (GVT), Ffestiniog Railway slate waggons and other general stock such as V tipper and 4 wheel flat wagons.

In July 2014, [[Bachmann Industries|Bachmann]] announced a range of ready to run 009 products, starting with a [[Baldwin Class 10-12-D]] locomotive and a number of wagons, primarily used by the British War Department during [[World War I]].<ref >[http://www.bachmann.co.uk/details_archive.php?id=188 Introducing Bachmann's Narrow Gauge range ''(retrieved 23 December 2014)'']</ref>  To date a range of Baldwin liveries have been released including models representing prototypes from the WHR, [[Ashover Light Railway|Ashover]], [[Snailbeach District Railways|Snailbeach]], GVT and [[War Department Light Railways|War Department]]. These have been launched alongside a range of wagons and a 'might have been' fictional Lynton and Barnstaple Baldwin locomotive named ''Sid''. Further Bachmann models representing Quarry Hunslet locomotives, small industrial diesels alongside further coaches and wagons are expected to arrive in the next couple of years after announcements in Bachmann catalogues. In 2015 Bachmann also introduced an OO9 line (marketed as "HO Scale on N-gauge track") based on the Skarloey Railway from their [[Thomas and Friends]] line. As part of their Skarloey line, Bachmann has introduced ''Skarloey'' and ''Rheneas'' products based on the [[Talyllyn Railway]]'s two [[Fletcher, Jennings & Co.]] locomotives (''[[Talyllyn (locomotive)|Talyllyn]]'' and ''[[Dolgoch (locomotive)|Dolgoch]]'' respectively) along with a ''Peter Sam'' model based on the Talyllyn's ''[[Edward Thomas (locomotive)|Edward Thomas]]''. A 3rd party industry emerged to offer replacement parts to convert the Bachmann locomotives into their real world inspirations, and Bachmann has announced plans to release modified tooling for a more realistic Talyllyn.<ref>[url=https://dundasmodels.co.uk/webstore/index.php/search/product/6052-talyllyn-railway-no-2-dolgoch-conversion-kit-for-use-with-bachmann-rtr-rhenaus-locomotive ''(retrieved 28 June 2021)'']</ref> 

In late 2019 Peco announced a new joint venture with Japanese manufacturer Kato, together they plan to release models of the [[Ffestiniog Railway]] [[Festiniog Railway 0-4-0TT|England]] and [[Fairlie locomotive|Double Fairlie]] locomotives. Peco are also planning to release Ffestiniog rolling stock including bug boxes, quarrymens coaches and larger bogie 'Bowsider' coaches.

The modeller can also choose from a wide range of plastic, white metal and etched brass kit manufacturers such as Dundas Models, Meridian Models, Mercian Models, GEM, Rodney Stenning, Worsley works, Light Railway Stores, Nigel Lawton etc. Many of these companies attend narrow gauge focussed exhibitions - a diary of events is available to all on the OO9 society website (link below).

Some modellers also adapt models originally made for [[OO scale|OO]] or utilise [[scratch building]] techniques. Many OO9 modellers also use H0e equipment, which although built for 3.5mm scale, not 4mm, is often close enough to work alongside OO9.

Standard H0e 'bemo' style loop couplings are most often used. A slimmer alternative also with a loop is the Greenwich coupling which is compatible with these standard couplings and can be magnetically operated. Some modellers use chopper couplings or repurpose couplers made originally for other scales such as DG couplings. MicroTrains or [[Kadee]] couplings intended for N gauge can also been used.

==Related scales==
Using N gauge 9&nbsp;mm track to model narrow-gauge prototypes is also popular in [[HO scale]] model railways. In [[Europe]], this is known as [[H0e scale|H0e]] while in the [[United States]] this is called [[HOn30]] or HOn2{{frac|1|2}}. As the latter indicates, 9&nbsp;mm in HO scale is {{convert|783|mm|abbr=on}} in the theoretical prototype, closer to {{Track gauge|2ft6in|lk=on}} gauge.

{{Track gauge|3ft|lk=on}} gauge lines (common in Ireland and the Isle of Man) are generally modelled in 4&nbsp;mm scale but with {{Track gauge|12mm}} gauge track, which is known as [[OOn3]].

==Manufacturers==
*[[Nigel Lawton 009]] – Industrial narrow-gauge rolling stock kits and micro motors
*[[Dundas Models]] – Locomotive and rolling stock kits
*[[Peco]] – 009 narrow-gauge style track, rolling stock and accessories
*[[Worsley Works]] – Rolling stock and loco 'scratch aid' kits
*[[Bachmann Branchline]] – Locomotives, rolling stock and buildings
*[[Heljan]] – Locomotives
*[[Fourdees]] – Locomotives and rolling stock

== See also ==
* [http://www.009society.com/ 009 Society] UK 009 modelling society and publisher of the 009 NEWS newsletter.
* [[HOn30 gauge]] and [[HOe gauge]] narrow-gauge railways in HO scale on N (9&nbsp;mm/0.65 in) gauge track in 1:87 scale ratio
* [[Rabbit warren layout]]

==References==
{{Reflist}}

==External links==
{{Commons category|00-9 scale|OO9}}
* [http://www.009Society.com 009 Society]
* [http://www.narrowgaugenorth.org.uk Narrow Gauge North]

[[Category:4 mm scale]]
[[Category:30 inch railways and modelling]]
[[Category:Narrow-gauge railway modelling]]