Dublo or OO is a peculiar British scale, acoss Europe and North America HO gauge is the most popular scale however here in Britain it is the slightly larger OO. How did this happen?

During the 1930's electric motor technology had moved on with motors becoming smaller. Ths lead to a new scale HO or half O. However British government locos where slightly smaller meaning that fitting the current motors was difficult. Manuacturers decided to slightly increase the scale from 1:87 to 1:76 however they kept the track gauge the same as HO meaning that OO trains have a narrower distance between their wheels than their scale.


Without Hornby's adoption of OO it is unlikely that the scale would have been a specialist scale, however with the backing of Hornby the scale grew to dominate British model railways.

Improving on O gauge the new scale saw locos and most rolling stock made from Diecast rather than tinplate. Nearly all all locos where electric powered by a 3 rail 12 volt system.

1938 in hindsite was not the best time to launch a new product. Wih World War II starting in 1939, development of Hornby Dublo would have to wait until the war ended in 1945


Production of Dublo post war started with a wimper rather than a bang, shortages meant that production did not start until 1947. One of the first releases was the 4-6-2 LMS loco the same Duchess of Atholl, promised prewar but never released.

As had happened after the introduction of O Gauge with the grouping so too there was changes to railways with nationalization in 1947, meaning that if models livery needed to be changed to keep up with current railway practice.

As things happened Hornby was given time from another war this time in Korea, ongoing shortages meant that after the Duchess of Atholl, no new loco was introduced until the 1954. However once production got going things moved on quickly, with several locos and rolling stock released all in British Railways livery. During the rest of the decade Hornby increasingly narrowed the gap between toys and models, in the early 1950's Hornby Dublo was considered a toy in other words a reprisentation of the real thing, but by the end of the decade and particularly after introducing plastic into some of its range they had become scale models.

1959 saw a major change with the introduction of 2 rail track and locomotives, ths further added to the fact of becoming more true to scale. Outside of South East England most railways are just two years rail. All new locos would be 2 rail with a 3 rail option, whist Hornby started to build a 2 rail version of its 3 rail locos. 3 rail however continued to be produced .

One outstanding new part the ring field motor was introduced in 1960 on the new Dublo loco Cardiff Castle a powerful and reliable motor that was quickly added to quite a number of locos.