152 



C. W. DARLEY. 



For convenience of description these thirty-nine Reservoirs may- 

 be divided into nine types, a representation of each type being 

 shown on the plans exhibited with this paper, in most cases a 

 section and half plan only are shown, these being considered suf- 

 ficient to illustrate the general construction of the Reservoir. 



Type A., Plate xiv. — Of this type two have been constructed by 

 the Department, and one, namely the Woollahra Reservoir, by 

 the Sydney Council ; Crown Street and Paddington Reservoirs 

 also come within this head, but particulars of cost not being avail- 

 able, they are not included, these have square or slightly rect- 

 angular vertical brick walls, roofed over with brick arches of 

 about sixteen feet span, carried on cast iron girders resting on 

 brick piers ten feet apart. The side walls being carried up, coped 

 over, and the enclosed span filled in over the arches and spandrils 

 with earth ; this form of structure is most substantial, but is 

 amongst the most expensive of all the types of large Reservoirs 

 referred to. The size and cost of the three being as follows : — 



No. 



Dimensions. 



90'x79'x 12' 



120' x 95' x 15' 



110' x 100' x 18' 



Available capacity 

 in gallons. 



501,500 

 1,030,000 

 1,000,000 



Cost per 1,000 

 gallons. 



£14 Is. 9d. 



£9 5s. 9d. 



£12 0s. Od. 



Type B., Plate xiv. — Circular, vertical brick walls, stopping at 

 level of springing of arch, covered over with coke concrete annular 

 arches fifteen to sixteen feet span. Arches carried on cast iron 

 ring girders resting on brick piers about eight feet apart, top of 

 arches covered over with soil, vent pipes or a valve room only 

 being visible on top. 



Of this type, three have been built, the sizes and cost being as 

 follows : — 



No. 



Dimensions. 



100'diam.20'deep 

 80' 5" „ 15' „ 

 45' „ 14' „ 



Available capacity 

 in gallons. 



1,087,000 

 464,000 

 134,100 



Cost per 1,000 

 gallons. 





£8 17s. 9d. 





£7 3s. 7d. 





£11 Is. Od. 





