Model railways have long been a beloved hobby in the UK, offering a blend of craftsmanship, nostalgia, and engineering. One of the most important aspects of the hobby is understanding gauge—the distance between the rails—and scale, the ratio of the model to the real-life train. Let’s explore the most popular model train gauges in the UK, their history, and how they compare.

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OO Gauge (1:76 Scale, 16.5mm Track Width)

• Most popular in the UK
• Uses the same track width as HO gauge but with a slightly larger scale
• Known for its wide availability and community support

🕰️ Historical Note:
Introduced by Hornby in the 1930s, OO gauge became the UK standard post-WWII due to Hornby Dublo’s success. Despite its scale-to-gauge mismatch, it remains the go-to for most British layouts.

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N Gauge (1:148 Scale, 9mm Track Width)

• Perfect for compact layouts
• UK-specific scale (1:148) differs slightly from international N (1:160)
• Offers impressive detail in a small footprint

🕰️ Historical Note:
N gauge rose in popularity during the 1960s and 70s as miniaturization improved. It’s now a favorite for those with limited space.

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O Gauge (1:43.5 Scale, 32mm Track Width)

• Large and highly detailed
• Ideal for collectors and display layouts
• Requires more space and investment

🕰️ Historical Note:
O gauge was the dominant scale in the early 20th century. It was eventually overtaken by OO due to affordability and space efficiency.

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 TT:120 Gauge (1:120 Scale, 12mm Track Width)

• A modern middle ground
• Offers a balance between size and detail
• Gaining popularity thanks to Hornby’s 2022 revival

🕰️ Historical Note:
Originally developed in the US in the 1940s, TT scale had limited UK adoption until its recent resurgence as a more accurate alternative to OO.

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Gauge Comparison Table

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Visual Comparison

 

Less know Guages in the UK:

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G Gauge (1:22.5 Scale, 45mm Track Width)

• Used for garden railways
• Large, durable, and weather-resistant
• Often represents narrow-gauge prototypes

History: Introduced by Märklin in the 1960s, G gauge became the standard for outdoor layouts. Its size allows for impressive detail and rugged construction.

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Gauge 1 (1:32 Scale, 45mm Track Width)

• Smaller than G but still large
• Used for both indoor and outdoor layouts
• Popular with live steam enthusiasts

History: Dating back to the early 1900s, Gauge 1 was once a mainstream scale before OO and HO took over. It’s now a niche for high-end collectors and live steam modellers.

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SM-32 Gauge (1:19 Scale, 32mm Track Width)

• Represents 2ft narrow-gauge railways
• Common in garden railways
• Often scratch-built or kit-based

History: Developed in the UK for modellers of British narrow-gauge lines, especially Welsh railways like the Ffestiniog.

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NG7 Gauge (1:43.5 Scale, 16.5mm Track Width)

• Narrow-gauge modelling in O scale
• Represents 2ft gauge railways
• Uses OO track

History: A newer niche gauge for modellers wanting narrow-gauge realism in a manageable size.

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On30 Gauge (1:48 Scale, 16.5mm Track Width)

• O scale narrow-gauge using HO track
• Popular in the US and gaining UK interest
• Great for freelance or industrial layouts

History: Developed by Bachmann in the 1990s to make narrow-gauge modelling more accessible.

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P4 Gauge (1:76 Scale, 18.83mm Track Width)

• Most accurate UK standard gauge
• Requires precision modelling
• Used by the Scalefour Society

History: Created by British modellers seeking exact scale fidelity. P4 is the pinnacle of finescale modelling.

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HO Gauge (1:87 Scale, 16.5mm Track Width)

• World’s most popular scale
• Rare in the UK due to OO dominance
• Ideal for European and American layouts

History: Developed in Germany in the 1920s, HO became the global standard by the 1950s.

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HOn3 Gauge (1:87 Scale, 10.5mm Track Width)

• HO scale narrow-gauge
• Models 3ft gauge railways
• Popular in the US

History: Used to model Colorado and other American narrow-gauge lines. Rare in the UK but used by enthusiasts of US prototypes.

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HOe Gauge (1:87 Scale, 9mm Track Width)

• HO scale on N gauge track
• Represents 750mm or 2ft narrow-gauge lines
• Compact and versatile

History: Popular in Europe for modelling Austrian and German narrow-gauge railways.

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HOm Gauge (1:87 Scale, 12mm Track Width)

• HO scale for metre-gauge railways
• Used for Swiss and European prototypes

History: Developed for accurate modelling of metre-gauge lines like the Rhätische Bahn in Switzerland.

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EM Gauge (1:76 Scale, 18.2mm Track Width)

• Improved OO gauge
• More accurate track width
• Requires custom wheels and track

History: Created in the 1950s by British modellers dissatisfied with OO’s compromises.

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TT:120 Gauge (1:120 Scale, 12mm Track Width)

• Newly revived in the UK
• Balance between OO and N
• Gaining popularity thanks to Hornby

History: Originally American, TT was reintroduced in the UK in 2022 to address OO’s scale/gauge mismatch.

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OO9 Gauge (1:76 Scale, 9mm Track Width)

• Narrow-gauge in OO scale
• Uses N gauge track
• Ideal for industrial and Welsh layouts

History: Popularised in the 1980s for modelling British narrow-gauge lines like the Lynton & Barnstaple.

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Z Gauge (1:220 Scale, 6.5mm Track Width)

• One of the smallest commercial scales
• Ideal for micro-layouts and novelty displays

History: Introduced by Märklin in 1972, Z gauge is a marvel of miniaturisation with a dedicated niche following.

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Gauge Comparison Table (Largest to Smallest)