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Large Scale Trains to Ride
In general, the broader you can lay out your curved track, the better. 1"scale diesels and 40' freight cars will easily negotiate a 15' radius turn, whereas some streamlined passenger cars and larger steam locomotives (such as 4-6-2s or 4-8-4s) with their longer wheelbase may require as much as 30' or 40' radius curves.

Despite the large size of these models, you do not require an estate to have a home track. A standard suburban lot is plenty big enough for a track that circles the house.
4.5 gauge layout
Click image for 4.75" gauge layout