How to safely conduct under wharf inspections using Trendspek and photogrammetry

Main wharf structures are constructed with concrete elements that are subject to environmental corrosion, making asset maintenance key for their continued use. However, inspecting underneath wharves comes with specific challenges, from tides to low visibility.

The main challenge is sending people physically underneath a wharf structure to inspect in small spaces, in low light, working with the tides and swell and recording accurate information for reporting and reference.

With hundreds of metres of the structure to look at, and a race against time to conduct the inspection, it can be very challenging for inspectors to correctly record and report the location of defects. Typically, generalised reporting occurs over larger parts of the wharf and can result in less accuracy.

Leading port organisations are turning to advanced data capture and 3D modelling software Trendspek for a complete view of hard-to-reach areas of a wharf. This enables comprehensive condition assessments, and ensures that every defect is captured.

What are the challenges with inspecting under wharves?

Limited access space: The primary challenge is the constrained space between the underside of the wharf and the water's surface. This restricted area makes it difficult for personnel to physically access and inspect the underside of the structure.

Tidal and Swell Variations: Inspections must be timed carefully to account for tidal changes and swell conditions.

GPS Denied Environment: The area under wharfs often lacks GPS signal, making it challenging to track the location accurately during inspections. This can affect the precision of data collection and the ability to create accurate 3D models.

Low Light Conditions: Underneath wharfs, there is limited natural light, which can result in dark and poorly lit environments. This can lead to high ISO settings on cameras, resulting in noisy or grainy images that may affect the quality of inspection data.

Corrosion and Saltwater Exposure: Wharfs are exposed to saltwater, which can lead to corrosion of concrete elements. Inspecting for chloride content and corrosion risks in such an environment requires specialized equipment and expertise.

Structural Complexity: Wharfs can have intricate structural designs with various support elements and features that need to be thoroughly examined. Navigating and inspecting these complex structures can be challenging.

So... how do you capture data underneath a wharf?

Trendspek works with leading data capture partners to overcome the issues associated with under-wharf inspections, such as small confined spaces, tidal swells and low lighting. We process this integrated data into a Precision Reality Twin — an exact 3D replica of the asset — to make it easier to identify defects of large maritime structures without needing to make repeat site visits.

Hoverscape's Chief Remote Pilot Danny Elassad shares the steps to safely inspecting underneath a wharf:

1. Integrated Data Capture: We start with an integrated capture survey of the entire wharf structure. High-resolution imagery and videos captured from above can provide an overview of the entire area and identify potential problem areas. To inspect the underside of the wharf, we use a low-lying boat (like a tinny) to navigate the tight spaces beneath the structure. We equip the boat with cameras, sensors, and GPS equipment. These devices will capture high-quality imagery and spatial data.

2. Data Processing and 3D Modelling: Once we’ve collected the data, including images and spatial information, this can be processed into a high-fidelity 3D Precision Reality Twin in Trendspek’s software to create an exact replica of the entire under-wharf area. The integration of GPS data ensures accurate georeferencing of the model.

3. Chloride and Corrosion Analysis: Once the 3D model is created, asset owners and engineers can conduct a detailed inspection of the wharf’s structural elements on-screen, including support columns, beams, and any potential signs of deterioation or corrosion damage to the concrete. This analysis can help identify areas that require maintenance or repair.

4. Tying with Aerial Data: We can combine the under-wharf 3D model with the above-deck drone data captured in the initial aerial survey. This integrated approach provides a comprehensive view of the entire wharf structure, both above and below the waterline.

5. Asset Management and Reporting: Asset owners can retrospectively refer to the inspection data to create reports that highlight maintenance priorities and recommendations. This information can aid in informed decision-making for asset management and repair strategies.

By utilising advanced data capture and Trendspek's 3D models, inspectors can conduct a comprehensive and accurate assessment of a wharf's condition, allowing for proactive maintenance and ensuring the continued safe and efficient operation of maritime infrastructure.

How technology can help you achieve WSCAM compliance

After identifying a need for a repeatable approach to the inspection and condition assessment of wharf structures, the Wharf Structures Condition Assessment Manual (WSCAM) was introduced in 2014 by Ports Australia port and maritime operators to follow.

Since then, the manual has become widely recognised as a best-practice methodology, providing a consistent framework and guidance on inspecting wharves, piers, jetties, walkways, breakwaters, revetments, embankments, and other fixed assets.

Trendspek's customisable fields allows asset owners to set templates to meet WSCAM criteria, from condition scaling to colour-coded outcomes. Learn more about how you can achieve WSCAM compliance with Trendspek.

Want to learn more about how Trendspek can help you conduct detailed condition assessments of maritime structures? Book a call to speak with us.

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