New 13x7 Indoor Live Steam Layout,Ready to secure Astroturf and G Scale Track

[dunnyrail]

The term thunderbird is a railway term;

Railway Rescue Locomotive (UK)

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• Definition: A locomotive kept at a key location on the network to quickly rescue failed passenger or freight trains.
• Origin: The nickname comes from the 1960s television show Thunderbirds, which featured a high-tech rescue organization.

There was an article years ago in garden railways about a person buying a loco for that purpose on his live steam layout it was heavy which why he used it.

I think Virgin Trains (remember them?) first coined the name introducing a sub class of class 47 diesels with the necessary gubbins to attach to their trains for rescue in case of failure. They were all named after characters in the show.

British Rail Class 57 - Wikipedia

en.wikipedia.org