CHAPTER VIII. 



CONSIDERATIONS AFFECTING THE GENERAL DESIGN OF HARBOURS. 



No general rules for designing harbours can be laid down Preliminary investiga- 

 tion Survey Materials available for works Quarry and work-yard sites 

 Transport of materials Description of vessels to be provided for Beaching- 

 ground Spending-beaches Future development of port Degree of shelter 

 required Anchorage Good and bad holding-ground General requirements 

 of harbours of refuge Natural features of sites should be utilized. 



IN designing and constructing sea-works, the ability of an 

 engineer is perhaps best tested by the manner in which he 

 can adapt the materials at his command and the natural 

 features of the site to the particular circumstances of the case. 

 Each different locality has its own peculiarities ; therefore each 

 particular case must be considered and dealt with upon its 

 own merits. 



It will thus be seen that no general rules can be laid down 

 for the construction of harbours ; neither can it be said that one 

 type of breakwater is better than another, or even that one way 

 of constructing breakwaters of the same type can always be 

 adopted with equal advantage. 



The only safe course for an engineer to pursue, in designing 

 a sea-work, is for him to carefully investigate the peculiar 

 circumstances of the locality, and, having made himself thoroughly 

 acquainted with them, to adapt the design to the conditions and 

 requirements of the individual case. 



The materials readily available for the work, as also the 

 important factor of funds, must always largely influence the 

 decision arrived at. 



Preliminary Investigation. An investigation, such as the 

 one just referred to, should embrace 



(a) A comprehensive and detailed survey, the limits of which 

 can be best decided after an inspection has been made of the 

 site and its general surroundings. 



