Deep Trekker has released a guide to help identify the features/benefits of each of the company’s Remotely Operated Vehicle (ROV) model/package and interpret which option is best suited.
When it comes to any large purchase, it’s important to weigh out all the variables before deciding which option fits your needs the best. Purchasing an ROV is no exception. Understanding each model’s subtle differences and how they benefit specific projects can be a complicated process, but it doesn’t have to be.
Considerations
ROVs are incredibly versatile devices, capable of a wide range of tasks. Because of this, there are a variety of features and add-ons that can be extremely beneficial for some industries, and lackluster for others. For example, using an ROV for storage tank inspections in a controlled still-water environment would have drastically different needs than an open water Search and Rescue (SAR) Team.
- Intended Tasks – Evaluate what features are most important to your industry’s daily tasks. ROVs are capable of equipping addons such as environmental sensors, thickness gauges, positioning systems, sonar, cleaning tools, and more. Identify what is needed for your particular project, and then select the most cost effective appropriate model/package to fit those needs.
- Portability – Depending on the amount of travel or operational maneuvering, such as carrying an ROV to the top of a water tank, it’s important to consider the form factor of an ROV. Mini ROVs can fit into a single case for air travel as a checked bag, and are light enough to be carried while climbing a ladder. Larger observation or work class ROVs may come with additional features, but could be completely unusable for remote work environments.
- ROV Control Through Current – Still water environments like water tank inspections will have little to no current, making it ideal for mini ROVs to conduct inspections. For offshore or high current situations, more advanced observation class models are required for enhanced control through stronger currents.
However, it’s not just size or power alone of the ROV that determines its ability to work in current. An ROV that utilizes sensor fusion and will maximize its positioning capabilities through its intuitive software. Just like people, ROVs can work smarter, not harder.
- Water Clarity – Ideally an imaging sonar would be on every ROV. It’s an incredibly helpful tool for most missions as it helps identify large objects from distances up to 120m (394ft), and provides clarity on objects through murky water. The reality is that imaging sonars can cost upwards of $20,000+, and not every project or application needs a sonar to be effective. In clear water, or if operations are in an enclosed area where it is easy to get visual references (such as under the hull of a ship or in a water storage tank), then you can likely conduct a successful mission without sonar.
- Depth Rating – Working at depths? Always check the ROV depth rating before committing to a purchase. If the main goal of an ROV is to inspect or retrieve deep sea assets like seismic nodes, ensure that the depth rating is adequate for the mission. Deep Trekker offers ROVs up to 305m depth rating and tethers up to 700m. Large Work Class ROVs can work to 11,000m. The company’s fiber optic tethers can extend up to 850m for pivot and revolution.
Choosing the Right ROV for Your Industry
- Aquaculture – Typical usage within aquaculture includes net / mooring inspections and maintenance, mort pushing, and environmental sampling. Simple inspections can be completed with a basic mini ROV setup, but adding USBL positioning or heading/depth sensors will help provide location information for points of interest. This creates a more robust inspection system and cuts down on dive times by offering exact positioning on breaches or other points of interest.A grabber arm can also be implemented for object retrievals, or be used to utilize tools like net patch kits, mort diggers, or water quality sensors to build a dissolved oxygen profile. The DTG3 and PHOTON BASE packages are commonly used as cost-effective and reliable solutions for these tasks.
- Infrastructure (civil engineering) – For dam, intake, bridge, and piling inspections, it’s important to understand the typical operating water clarity. If the water is relatively calm and clear, a general visual inspection can be completed using a mini ROV such as the DTG3.If these inspections require more significant structure detail, or are being conducted in challenging environments (high current/murky water), it may be beneficial to purchase a more powerful ROV with sonar functions. The DTG3 Package or PIVOT Expert with M3000 sonar are most commonly purchased for civil engineering applications.
- Energy – For nuclear power, internal tank inspections are often in clear water. Due to the inherent potential hazards when working with nuclear energy, having a precise visual is integral. Implementing high quality zoom cameras and enhanced 4K cameras are the key to successful nuclear inspections. Deep Trekker’s REVOLUTION ROV equipped with a 4K camera and zoom lens is a popular system for these types of inspections. For Hydroelectricity, inspecting intakes or sluice gates for proper function may just require a basic visual. Mini ROVs such as the DTG3 can accomplish the inspection and can be the preferential option for working in tight spaces. Some dams with higher flow and murkier water conditions would be better suited for the more powerful REVOLUTION or PIVOT equipped with sonar. The DTG3 Package or PIVOT Expert with M3000 sonar are the most commonly purchased models for Hydro.
- Search & Rescue (SAR) – Target search and identification missions are far more effective with an imaging sonar. Having a ROV that can also tilt the sonar is a huge advantage. This allows the operator to change the angle and optimize the field of view to fit any situation. However if budget constraints are an issue, an ROV without a sonar is still a helpful tool for missions, as it still provides a method to quickly deploy eyes underwater.Beyond the search and verification of a drowning victim or evidence thrown overboard, ROVs can also assist with victim recovery. Using an ROVs grabber claw, the operator can latch onto and retrieve the target by pulling back on the tether. The ROV pilot also has the option to place a carabiner with a line onto the target. For more sensitive retrievals, teams can also have the ROV hold in place on the target, and deploy divers to follow the tether down for extraction.The REVOLUTION or PIVOT Expert with M1200 are excellent ROV options for SAR missions. The M1200 sonar offers high quality imagery at ranges up to 30m (98ft). Experienced operators do not identify targets from further than 30m away from the target. This vindicates the limited range of the M1200 in comparison of the M750 and M370 sonars, since the tradeoff is enhanced clarity for superior identification. The interlocking jaws (small and large) are also useful addons for victim recoveries, as they are better suited for sensitive retrievals in comparison to the teeth of the grabber claw.
- Commercial Diving – Vessel inspections, ship husbandry, and naval damage control are all common uses of ROVs in commercial diving. Whether it’s for emergencies, security, or maintenance, the first consideration during ship hull inspections is the strength of the opposing current. Mini ROVs may struggle in currents that observation ROVs such as the REVOLUTION and PIVOT can handle. Sonar can be a beneficial add-on for murky water conditions, or on larger ships to identify large defects or welded foreign objects. Common packages differ depending on the desired scenario of the inspection:
- For quick easy inspections: DTG3 Package or PHOTON BASE Packages.
- For thorough inspections: REVOLUTION with M3000 Imaging Sonar, Cygnus Thickness Gauge, CP Probe.
- Bonus tool – DT640 MAG Crawler with M3000 Imaging Sonar is an excellent tool for hull inspections, since it is attached to the surface it is inspecting, it does not face effects from strong currents, and is a great complement to an ROV.
ROVs are an effective method to add or enhance streams of business for a dive company, as some of their customers may prefer the ensured safety of ROV inspection. Having an ROV on hand provides more diverse service options to offer and market.
Many projects for commercial dive teams require pre-inspections, bid surveys to evaluate the budget for the project, or can benefit from having another pair of eyes for dive monitoring. A simple mini ROV like the DTG3 can be a useful asset in this case.
ROVs can also be used to identify unexploded ordnance and mines underwater. Using a ROV that has an imaging sonar is key, similar to SAR. These missions can cover long distances, so utilizing USBL for position tracking and autonomous capability is extremely helpful. The PIVOT NAV and REVOLUTION NAV with M750 imaging sonars are most popular in these cases, due to the long distance sonar capabilities and in-depth navigation features.
Deep Trekker offers a comprehensive lineup of ROVs to suit all of the above industry tasks on nearly any budget. With predesigned packages plus customizable addons, it’s easy to build the perfect ROV to fit specific needs.
The article goes on to discuss the following:
- How much to spend on an ROV
- The difference between Deep Trekker ROVs
- Deep Trekker Universal Product Features
Read the full guide here, or visit the Deep Trekker website to find out more.
