CLOSE-RANGE PHOTOGRAMMETRY - TWO CONTRASTING | 
INDUSTRIAL APPLICATIONS 
Neil W T Chisholm 
University College of Wales, Aberystwyth 
Introduction. 
In 1969 a survey was carried out by Fairey 
Surveys Ltd of the north face of Edinburgh 
Castle Rock by terrestrial photogrammetry 
an account of which has.been given by 
Cheffins and Rushton (1970). Since that 
time many other commercial projects involving 
ground-based camera stations have been under- 
taken but the two examples to be discussed 
here owe something to that original work. 
Both were fairly extensive projects and were 
completed around the same period of time and 
each was connected with an advanced technology 
industry but, as the title of the paper 
indicates, they exhibit a degree of contrast 
in several important aspects. 
If up to 300m is taken as the object distance 
criterion for close-range photogrammetry, both 
applications fall within this limit albeit at 
different ends of the scale and the following 
descriptions of each project will bring out 
significant differences in, for example, 
instrumentation, accuracies and date present- 
ation. 
Application 1 Survey of the external 
surface of nuclear reaction chambers. 
Background. In 1975, during construction of 
the Heysham A Nuclear Power Station in north- 
west England, measurements were required on 
spherical dome-shaped roofs of the two 
cylindrical reaction chambers. Each dome 
was divided into two sub-areas - an outer 
area of uninterrupted surface and an inner 
(penetrated) area with an 11.4m diameter 
which, as its name suggests, was not an even 
surface. A regular array of 324 stand pipes 
(diameter 330mm) and 52 control rods (diameter 
250mm) would pass through this surface and 
would control the rate of reaction in the 
chamber beneath (Fig. 1). The area above 
the surface of the dome was itself enclosed, 
the distance from the highest point of the 
dome to the horizontal roof being 1.6m. 
Both stand pipes and control rods would pass 
through this roof. 
  
       
   
  
ababdedbdbdededo 
  
   
     
   
   
  
000000 0000000090 
odbededbdbdedbdbdbden | 
SIERT 
C 
SEHR ds dB 6 
O QOQO 
dedo 
Qe 
QQ 
O 
   
  
  
  
Fig 1 Arrangement of Stand Pipes (o) and Control 
Rods (o) within the penetrated Area. The two Basic 
Types of Cruciform Sections are indicated (a) and (b). 
The surface of the reactor vessels, between 
stand pipes and control rods, were to be 
fitted with insulation comprising 27 layers 
of stainless steel packs forming a laminate 
70mm thick (Fig. 2). These stainless steel 
insulation sheets were required to fit 
precisely round the pipes in their installed 
positions which, of course, did not necessarily 
conform to the design positions. Because the 
pipes protruded vertically and were, there- 
fore, not normal to the surface it followed 
that the areas to be insulated varied in size 
and shape according to their position on the 
dome. Thus accurate definition was required 
of the size and shape of each cruciform 
section formed between stand pipes and control 
rods so that templates could be produced for 
the subsequent manufacture of the insulation 
laminates. There were 68 type (a) and 140 
type (b) cruciform sections plus 88 assorted 
polygonal shapes on the periphery of the 
penetrated area which required accurate 
definition. 
  
hrm birt) 
| 
€ Inner (P. ) area Outer area 
| Proposed Insulation Pack 
    
| 
| 
| 
sh ; : Control Rod Nozzle | 
3| sem, secl | 
| | 
| 
| 
  
SECTION A - A' 
  
  
  
Fig 2 Showing the nature of the: dome through & cross- 
section A-A^