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37 Special inspections, often involving material sampling or inspections. France defines both underwater inspections and NDT applications, occur as needed. underwater investigations. Investigations are thorough, arms- length examinations, and include measurements, sampling, or Inspections of the Highways Agency's 10,000 bridges are testing as needed. done by consulting engineers. Inspections for approximately 100,000 bridges controlled by local road agencies are either done by local agency staff or by consultants. Germany In Germany, underwater inspections are done every 6 years as part of each Major test. If there is known damage, under- UNDERWATER INSPECTION--FOREIGN AGENCIES water inspections are performed during Minor tests as well. Dive inspections usually involve a diver with a video camera Intervals for underwater inspections are listed in (Table 52). directed by a civil engineer at the surface. Inspections are by sight and by touch. Denmark South Africa The Road Directorate sets no fixed interval for inspection by divers. The regional bridge inspector selects the bridges and Few South African bridges require underwater inspection by intervals for dive inspections. Inspections are done by con- divers. There is no policy on interval or intensity of dive in- sultants. Inspection by wading and probing, if appropriate, is spections. No SANRAL bridges cross navigable waterways performed during principal inspections. The underwater and there is no hazard resulting from vessel collision, other inspection affects the condition rating for the "underpassing" than small craft. feature. Sweden Finland In Sweden, underwater inspections employ divers at sub- merged foundations of bridges. Divers use sight and touch to Underwater inspections by divers are done at 5-year intervals inspect structural components and probe at foundations for for Finnra. Scheduling is determined by the district bridge scour holes. Video cameras are sometimes used. The channel engineer. Seasons with high water or ice in streams are profile may be measured at the discretion of the inspection avoided. Finnra guidelines provide detailed lists of the com- team. Underwater inspections usually occur at 6-year intervals. ponents to inspect and the observations to make. Condition ratings of substructure components are affected by observa- tions from underwater inspections. United Kingdom For the Highways Agency, underwater inspections are usu- France ally performed at 6-year intervals; however, area structures managers can set different intervals. The Highways Agency In France, dive inspections are sight and touch inspections of requires that all surfaces of a structure be inspected. This may submerged components with probing at foundations for scour be accomplished by divers or by other means. Area structure holes. Dive inspections are performed at 6-year intervals. Un- managers review and approve inspection plans submitted by derwater inspections are separate from IQOA and detailed maintenance contractors. TABLE 52 UNDERWATER INSPECTION INTERVALS--FOREIGN AGENCIES Country Type Interval Notes Denmark Dive None When ordered by regional bridge inspector Wade 6 years Performed during Principal inspection Finland Dive 5 years Schedule set by district bridge engineer France Dive, 6 years Arms-length inspection Intensity 1 Performed separately from other inspections Dive, None Includes measurements and material sampling Intensity 2 Performed as needed Germany Dive 6 years Performed during Major test South Africa Dive None Few bridges require inspection by divers Sweden Dive 6 years Channel profile None At discretion of inspection team United Kingdom Dive or wading 6 years Highways Agency Area Structures Manager reviews/approves contractor's proposed method(s) for underwater inspections