Dredging at depths of over one hundred meters without being able to see what's being excavated demands a level of precision that few tools can offer. The submarine electrohydraulic orange peel grab has become the reference equipment for marine construction wherever conventional dredging cannot operate with the accuracy required.
Why Deep Dredging Needs a Different Kind of Equipment
Shallow dredging can be handled with suction dredgers and other conventional systems. But beyond one hundred meters, the challenge stops being just about reach: what comes into play is the need for extremely precise position control, minimal turbidity in sensitive marine environments, and the ability to extract very different materials, from soft soil to large rocks and riprap. The submarine electrohydraulic orange peel grab is designed precisely for that scenario, where the margin for error is minimal and the cost of a failed maneuver is high.
Applications in Marine Construction
Beyond port dredging, the submarine orange peel grab is used across three areas of marine construction that share the same technical demands:
Preparing the seabed for coastal pipeline installation, where controlled material extraction avoids damaging existing or future pipelines. The construction of new ports, extracting rocks and riprap from the seabed with millimeter precision. And, increasingly, the foundation work for offshore wind farms, where monopiles and jacket structures require a seabed prepared with exact precision before installation.
Sealing and Position Control: What Sets a Submarine Orange Peel Grab Apart
An electrohydraulic orange peel grab designed to work underwater is not a minor adaptation of a land-based unit. It requires a sealing system verified to operate at depths of up to one hundred meters, with IP-68 multipolar electrical connections and a dual safety system to prevent snagging on the seabed. On top of that, an automatic position self-correction system keeps the maneuver precise even when currents or limited visibility make manual control difficult.
This level of technical rigor is certified by leading external bodies in the naval sector, such as Lloyd's, TÜV, DNV, and Bureau Veritas, a standard Stemm already applies in the development of its amphibious clamshell grabs for hostile environments, and one that becomes even more critical for the submarine orange peel grab given its working depth.
Controlled Turbidity: An Environmental Requirement, Not Just a Technical One
On projects near coral reefs or sensitive marine ecosystems, generating turbidity during dredging can jeopardize the entire project, regardless of any technical considerations. The submarine electrohydraulic orange peel grab enables dredging with far more limited turbidity than other conventional dredging systems, making it the preferred option whenever the environmental setting is part of the project's actual conditions, not just a regulatory checkbox.
A Real Case: The Port of Safi
Stemm has applied this technology in real marine construction projects, such as the new port of Safi, in Morocco, where submarine orange peel grabs were installed on vessels equipped with peripheral vision and lighting systems to dredge from depths of one hundred meters and beyond. This experience also extends to deep-water applications in Australia and Norway, involving the excavation of thousands of cubic meters of both hard and soft soil.
This ability to adapt to the working environment, whether due to depth, temperature, or the nature of the material, is the same approach Stemm applies to the design of its equipment operating in hostile environments, tailoring each component to the actual conditions of the project rather than starting from a generic design.
Stemm, Submarine Precision for Every Marine Construction Project
Deep dredging and marine construction leave no room for trial and error: every maneuver underwater has to be calculated in advance. Stemm's submarine electrohydraulic orange peel grab is designed to deliver that precision wherever direct visibility and access aren't possible, whether in preparing a new port, installing coastal pipelines, or laying the foundation for an offshore wind farm.
If you have a dredging or marine construction project and want to find out which equipment fits your needs, you can do so through our online configurator.
