Step Back in Time – Article 20

This weeks article is from the New Zealand Railway Observer Volume 28 , No 1  –  Autumn/Winter 1971 and is:

An Introduction to Railway Signalling in New Zealand by T.A. McGavin 

Article 20, Volume 28, No 1

Each week a new Article from early issues of the New Zealand Railway Observers will be featured. Previous articles can still be viewed via the Publications Tab and then Historical NZRO Articles (the bottom option under this tab).