81 



Inspection 



It should 1k' obvious that specifications and inspections should be co-extensive. 

 The best specification is comparatively \alueless unless inspectif)n is both thorough 

 and of sufficient scope to insure that the specification has been complied with. 



DURING CONSTRUCTION 



ITnder present conditions, in which workmen are for the most part comparatively 

 untrained in the intricacies of preparing and handling substructure materials, the only 

 means of securing successful results is through painstaking supervision by those who 

 understand the problems. Careful specifications should be prepared to cover all phases 

 of the work and constant inspection should be established to see that they are followed. 

 Timber, its protections and treatment methods, cement, and concrete aggregate, all 

 involve special requirements which must be made the subject of specification and of 

 inspection check. The Committee believes that the best insurance of right results in 

 respect to the furnishing of creosoted piling is to have inspection for final acceptance 

 done as it hangs in the driver gins, where every defect may be seen and examined. 

 On the practicability of such a requirement see further under The Problem of Work- 

 manship (p. 82). Similar attention must be given to the placing of materials in position. 

 Piles must not be prematurely damaged by over-driving; protective shells tor timber 

 piles must not be liroken or ]ienetrated; concrete must be properly mixed and placed. 



.\fti:r construction 



When a structure is completed it commonly is allowed to continue in service with 

 little or no attention until it gives evidence of failure. Yet through inspection the life 

 of the structure can often be prolonged, sometimes greatly, whereas otherwise it ma>' 

 fail suddenly, with loss of life and propert>-. Where timber piling is involved, the 

 effect of borer attack should be closely watched; if the timber protection is only carried 

 to the mud line, a periodic investigation should be conducted to make certain that 

 the mud has not been removed below the protection; if flaws develop they should be 

 repaired as quickly as possible, because of the numerous influences which are ready to 

 hasten deterioration. Inspection by ordinary means can be effectively made only 

 above low water level. Under specially favorable circumstances this may suffice to 

 indicate conditions. However, where property of critical importance or magnitude is 

 involved, the inspection should be made by a diver to give accurate information of 

 conditions down to the mud line. W'hen such an inspection is made in a structure 

 involving a great number of similar piles or other supporting units, it may only be 

 necessary to select certain representati\e units, to determine the average or general 

 condition. 



test blocks 



Where unprotected timber piling is ser\ing in water in which an infestation by- 

 marine borers may occur, especially in isolated structures where no attack has been 

 experienced, a particular hazard is involved. Procedures should be adopted to note 

 the advent of the borers and to observe the degree of their attack. This offers some 

 difficulties, however, for the reason that when such action begins it is not readily 

 detected and may escape a casual inspection. Surface erosion by Limnoria is ^•ery 

 minute and gradual, yet destruction may occur in the period between inspections if 

 the first attack is missed. The presence of Teredo and Baiikia is particularh- hard to 

 observe because of the microscopic size of the holes in the pile surface through which 

 they enter the timber and destroy the interior. This condition is often further ob- 

 scured by liarnacles and shell fish adhering to the surface. Since the degree of attack 



