190. The table produced below shows the individual types and quantities of work carried out during the year but does not include the area of surface patching work undertaken by the directly employed labour or by the maintenance contractors.
Type of Surfacing.
Areas in square yards Island Mainland Total 8″ cement concrete 30,704.81 45,514.57 76,219.38 6″ cement concrete 18,108.24 95,087.84 113,196.08 2½″ granolithic 39,913.12 66,872.56 106,785.68 4″ tarmacadam 15,415.53 28,065.55 43,481.08 3″ tarmacadam 34,268.62 12,995.50 47,264.12 4″ dry macadam 1,841.75 73,444.71 75,286.46 3″ dry macadam 5,422.22 5,258.73 10,680.95 2″ tartops 14,180.92 3,140.33 17,321.25 1″ tartops 149,473.17 345,752.77 495,225.94 Tarpainting Bottoming Cement concrete in cu. ft. 25,873.34 56.11 25,929.45 788.15 17,230.19 18,018.34 70,919.58 80,953.62 151,873.20:
191. A considerable amount of work was carried out during the year at Kai Tak Airport. The access track to the R.A.F. dispersal area which consisted of a 7″ thickness of stabilized earth surface failed under heavy traffic and was reconstructed with a 6″ vibrated concrete slab on 3″ hardcore. The hard-standing area was improved by the reconstruction of a further section in 6″ of concrete. Owing to the poor bearing value of the subsoil the re-construction of the 13/31 runway extension entailed the laying of a 3′-0″ depth of combined foundation and wearing surface. This runway extension was reconstructed half width at a time, the excavation being taken down 3′-0″