The New Zealand Railways Magazine, Volume 12, Issue 3 (June 1, 1937)
Signalling Practice in Various Countries
Signalling Practice in Various Countries.
Train signalling forms a most important branch of railway working, and it is surprising how signalling practice varies in different lands. In a report prepared for the forthcoming International Railway Congress, by Mr. W. A. Fraser, Engineer (Scotland), L. & N.E. Railway, it is stated that in Great Britain upper-quadrant, mechanically-operated semaphore signals are now standard, except on the Great Western. Large numbers of lower quadrant signals are still employed, however, both types operating through angles varying from 45 to 60 degrees. Canada, South Africa and the United States also employ upper-quadrant signals, while in Japan both three-position upper-quadrant and two-position lower-quadrant signals are favoured. Among other railway systems retaining the lower-quadrant type, the most common angle of operation is 45 degrees. In Great Britain and Ireland, 5,280 feet is the maximum distance at which mechanical signals are erected from the cabin. This compares with the New Zealand figure of 4,500 feet, the Indian 3,000 feet, and the South African 4,000 feet. The maximum length of track circuit under favourable ballast conditions varies on the Home railways from 2,400 to 15,840 feet. For India the figure stands at from 1,800 to 2,500 feet, and for the United States from 4,000 to 7,000 feet.