Special Order Geodetic Operations for a Canadian Pacific Railway Tunnel in the Canadian Rockies

Abstract

A brief historical account is presented of the Canadian Pacific Railway involvement in the Rogers Pass that led to the decision to build 34 km of new track in the area, including a 14.5-km tunnel through the Pass. The specifications to be met for each of the two phases of the survey are described. The first phase consisted of the establishment of a surface control network and was carried out by Nortech in the summer of 1983. The second phase is the underground alignment survey to be carried out during the period 1984–1988. The unique survey problems of Phase A encountered in such a mountainous area are described together with the methods used for their solution. The observations selected, which consisted of distances, directions, Laplace azimuths and spirit leveled heights, led to results that exceeded, in terms of accuracy, the objectives initially set. A discussion on the importance of each data type used is presented.