VARIOUS TYPES OF BREAKWATERS. 



177 



In designing works of this class, facility of repair should be 

 kept prominently in view ; and inaccessible parts, such as bracings 

 and through ties, should be made of the most durable materials, 

 as in the case of the breakwater just referred to. A typical 

 drawing of a timber-framed rubble breakwater is given in 



Fig. 28? 



Harbour 

 Side 



Frames lo/eet apart. 



Ends of rails returned 

 round face of pile. 



V V v V 



FIG. 28. Type section of timber-framed breakwater with rubble hearting. Intermediate piles, spaced 

 2 feet 6 inches centre to centre, carried to full height on seaward side, and up to the level indicated 

 at X on harbour side. 



The description of timber to be used for the piles, etc., will 

 depend much upon the presence, or otherwise, of sea-worms in 

 the locality, reference to which was made in Chapter VII., 

 Section 5, p. 131. 



2. Breakwaters with Side Walls of Concrete Blocks or Masonry, 

 and Hearting of Dry Rubble. 



This class of breakwater, like the one we have just been con- 

 sidering, is only suitable for sites where the exposure is small. 

 In some such situations, especially where extra width is required 

 for quay space, it may be adopted with advantage. 



Examples of breakwaters of this type may be seen at Peter- 

 head (old harbours), Whitehaven, Kilrush, Seaham, and many 

 other places. 



The Kilrush pier, a section of which is given on the next 

 page (Fig. 29), is a good example of this class of work. 



N 



