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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
