Aqua Dakk CCTV
Successful exam in a confined space
The bridge is 17m long, 1.2m wide with a water depth of 1m, and a clearance from water level to soffit of 1.2m. A man entry confined space exam was previously attempted but disturbance of the bed sediment released high levels of methane so the examination was aborted and Inspire (Structures) were asked to carry out the exam using a floating CCTV system. Therefore, removing the need for man entry to the structure and causing minimal disturbance to the bed sediment.
Aqua Dakk is a fully steerable dual propeller robotic unit, it features 2 cameras, one pan and tilt that gives views above the unit and one tilt camera that views below. This system incorporates the standard camera and control box used in all the Dakk crawlers but has the addition of directional control and data feedback via a laptop. Wi-Fi allows footage to be viewed on 2 separate screens, one used by the operator and one by the examiner.
To carry out the examination a team of one STE4 examiner and one operator was used. The operator piloted the robot through the culvert whilst the STE4 carried out the examination.
The exam revealed a number of defects including dropped bricks and missing timber laggings (see photos). This resulted in an engineer’s recommendation for repair works to be carried out.
Aqua Dakk is a bespoke tool that was developed to be used in this type of situation. The client was provided with a detailed examination of the structure without the need for an expensive dewater/desilt scheme or alternatively using a BA confined space team and introducing risk factors.