Page 46: of Marine Technology Magazine (May 2014)

Products - Remote Sensing A remote control boat equipped with a SonTek M9 Acoustic Doppler ProÞ ler (ADP) was employed with HydroSurveyor software to create a 3D map of a damaged (and still sub-merged) ß ood barrier, following seri- ous damage that took place last De-cember. Data from the survey enabled the Environment Agency to act swiftly and effectively to repair the damage and thereby protect local industry and residents.Extreme weather conditions and the highest tide for 150 years resulted in serious damage to a ß ood bank at Seal Sands near Billingham in the North East of England. A large hole, approxi- mately 60 to 80m across, was scoured from the barrier and enormous quan-tities of seawater ß ooded into an area of marshland, which is an important wildlife habitat. However, this area is also adjacent to a number of high value industrial as- sets, so this breach in the ß ood defens- es represented a serious threat. Initial-ly, military helicopters were recruited to help drop boulders into the hole, but it soon became clear that greater volumes were required so a temporary road was quickly constructed along the barrier so that Þ ll material could be delivered by truck. Unfortunately, the extent of the dam- age to the submerged ß ood bank was not visible, even at low tide, so it was necessary to be able to survey the dam- age in order to be able to calculate the type and volume of material that would be necessary for the repair operation. Traditionally, such surveys would have been conducted manually from boats using gauging poles, but the En- vironment Agency now employs re- mote control boats that have a range of 200m, so operators are able to remain on the bank.The M9 ADP on-board the remote controlled ARC-Boat is a 5-beam depth sounding and velocity proÞ ling device that scans the bed as the boat is guided across the waterÕs surface. Recorded data are analyzed in real-time by the SonTek HydroSurveyor software to produce accurate depth and velocity measurements in addi- tion to 3-D maps of the water body. The AgencyÕs Chris Train said, ÒThe operation of the ARC-Boat was a great success; we were able to conduct a complete survey during about one hour of slack water at the top of the tide. As it happened, this was under- taken at night, but we attached navi- gation lights to the ARC boat, so the timing was of no consequence. ÒThe HydroSurveyor software cre- ated a superb map of the damage and demonstrated that the hole was signiÞ -cantly deeper than we had anticipated, so this data was essential in helping us to plan the remediation work. ÒThe main advantages of the ARC- Boat/HydroSurveyor system are the speed with which a survey is under- taken, the quality of the data, and im- proved safety because it is not neces- sary for staff to work on the water.Ó Product Spotlight Remote Control Boats The ARC Boat and (inset), navigating the ARC Boat. May 201446 MTRMTR #4 (34-49).indd 46MTR #4 (34-49).indd 465/12/2014 2:17:07 PM5/12/2014 2:17:07 PM