3 Unknown Bridge Inspection Facts:
- Fact 1 – The Federal Highway Administration mandates that all U.S. bridges must be inspected at regular intervals not to exceed two years.
- Fact 2 – As of 1989, more than 40% of the nation’s total (231,389 bridges), were judged deficient by the FHA.
- Fact 3 – Experts believe that in almost every case, bridge damage could be prevented with early detection.
Underwater Inspection, Design, and Construction – Designing a bridge or other marine structure is a complex and exacting job, which requires the skills of highly trained professional engineers. But just as important as the initial design is the routine inspection and maintenance of every marine structure. What may appear to be a perfectly sound structure on the surface, may not be safe where it really counts, underwater. Because a damaged marine structure can be as dangerous as one that was improperly designed, underwater inspection must be viewed as an engineering function and not merely a diving task left to non-technical personnel.
As an engineering company specializing in structural underwater inspection, W.J. Castle & Associates has the experience and qualifications to ensure a comprehensive and accurate inspection of every type of marine structure.
A safe and accurate inspection takes teamwork.
Each member of the Castle crew plays a key role in ensuring a safe and accurate inspection. The boat operator and tenders navigate and keep the boat in position during the dive, and assist and communicate with the diver while he’s in the water. The tenders are also responsible for monitoring the diver’s air supply and critical underwater lifeline, or rigging, as needed. While a dependable inspection team is crucial to the success of every inspection, state of the art diving equipment is also required to assure precise inspections.
Based on water current speed, weather conditions, and wind velocities, an appropriate boat is selected for the dive. Another primary consideration is the type of air supply to be used. While many companies use scuba gear, Castle & Associates emphasizes the use of surface applied air. The primary advantages of this system include direct communication with the diver for more accurate documentation, longer dive times for more thorough inspections, and greater surface control for increased diver safety.
W.J. Castle uses the finest diving equipment available and carefully trains each crew member in pre-dive procedures to ensure successful inspections. Pre-dive preparations include rigging the air supply lines and checking pressures as well as wiring and testing the communication system. One of the many customized devices used by Castle & Associates is the diver to surface communication system. A small microphone and speaker are built into the diver’s helmet. A communication line, interwoven with the air hose, is run directly into the control console so the diver’s report can be permanently recorded as he conducts the inspection.
This system guarantees that no detail is forgotten or left unreported. A multilayered diving suit, including an underlayer of clothing for warmth, an airtight Viking dry suit, outer layer coveralls, and an airtight diving helmet protect the diver from inclement water conditions or possible exposure to pollution. Additional equipment such as diving gloves, swim fins, weight belt, and diving harness, also assist the diver during the inspection.
In rare instances, such as when a diver may need special assistance, scuba equipment is also utilized. However, scuba is almost always used as a backup or emergency equipment. With this equipment, The W.J. Castle team can conduct inspections under virtually any conditions, regardless of the diving environment surrounding the structure. From icy rivers to polluted bays, W.J. Castle will get the job done.
During the inspection, Castle divers carefully clean and test substructures using a variety of inspection tools. Removing marine growth is essential to expose the substructure for detailed inspection. When required, Castle divers will use ultrasonic devices, water blasting cleaning equipment, and core sampling tools for accurate, highly detailed, follow-up inspections.
Preparing for Inspection – Underwater Inspection Design and Construction
To ensure a thorough and comprehensive inspection, the Castle team spends hours preparing a pre-dive plan. First, they determine boat access to the inspection site and measure water currents and velocities. In many cases, tidal changes are the most critical factor. The diving team must carefully plan entry time into the water at slack tides. During these slack tide intervals, the tidal direction is changing and the currents are at their slowest. When diving in a river, however, there will always be currents. So the boat must be securely anchored and a lifeline must be run from the boat to the diver in order for him to maintain his position and conduct an accurate inspection.
Prior to the inspection, the Castle team collects and reviews as-built drawings of the structure and maps out a game plan for the dive. Any reports from previous inspections are also collected and reviewed to determine if any additional deterioration has occurred.
Once all necessary information has been gathered, the Castle team is ready to begin the actual inspection. While each inspection must be approached differently, general inspection guidelines are followed. After positioning the boat based on anticipated tidal changes, numbers are assigned to each pier or substructure. This not only provides an organized system for documentation but also serves as verification that the foundation is as shown in the supplied as-built drawings. The diver can now enter the water and begin the inspection.
For your marine structure needs, call someone you can trust.
Underwater Inspection, Design, and Construction – For accurate underwater inspections, contact W.J. Castle & Associates by phone 800-644-4713, or email firstname.lastname@example.org, the professional engineers with commercial diving experience.