New Measurement. Techniques and Applications 
in Engineering Control 
Dr. N.J. Eales 
Longdin & Browning (Surveys) Limited 
ABSTRACT 
Recent developments in engineering and surveying 
have resulted in more rigorous dimensional con- 
trol. More often we find specialist surveyors 
monitoring construction work while the engineers 
are left to supervise materials control and pro- 
ject planning. 
The use of specialist surveyors has encouraged 
the development of new measurement techniques, 
which exploit the recent developments in elec- 
tronics. 
Two examples are discussed: the first involves a 
digitized stereocomparator and a programmable 
desk calculator in a photogrammetric technique 
for measuring steel fabrications; the second 
involves EDM tacheametry and a personal computer 
in a new technique for checking the alignment of 
railway tunnels. 
l. INTRODUCTION 
In engineering today, there is a demand for more rigorous 
dimensional control procedures. 
Correcting mistakes in large construction projects, involves 
considerable expenditure in resources of manpower and 
materials. 
Comparatively small errors in the critical path may delay 
completion of a project and incur enormous consequential 
costs. 
Where tighter tolerances can be achieved, design engineers 
may be able to plan more economical structures. 
Pre-fabrication techniques, for example, can make for fast, 
economical construction, but they require strict dimensional 
control. The final assembly stage is commonly on the critical 
path, and remedial costs can be especially. high.