Since 2017 we have performed a number of tunnel inspections for major players in the Norwegian hydroelectric powerplant market. Our technology is shown to be fit for purpose and provides an long awaited service for our clients.


On all our projects projects so far, we have sucessfully provided value for our customers by minimizing risk, cutting expenditure and gather the neccessary data needed to condition monitor and perform evaluation of their assets. 


Being true to our value: Reliable Innovation, we are proud of our achievements of providing safe and cost-effective inspection and documentation of underwater tunnels

Operating under difficult conditions with narrow access and lack of supporting infrastructure


We prepared for this job with a long period of product development, practically reinventing the whole NOTUS ROV, now reincarnated as NOTUS D.


After going through extensive testing, involving numerous modifications in the

months before the job was to commence, we where quite confident on our equipment. But there is always a certain doubt that we have forgotten to take a

important aspect into consideration or for something unexpected, unforseen to occur. 

Duge Pump-Station


Scope: 12km tunnel inspection with special consideration to sandtraps and rockslides

Hydroelectric Powerplant Tunnel Inspection

ROV ready for launch 

Tunne Inspection with ROV

Ready to enter tunnel and start inspection 

The matter a fact that we where so bold that the very first job we took on with the newly developed NOTUD D, was probably the longest single run tunnel inspection ever to be done by a ROV, added a certain thrill to it....

With good help from hired personell from Agder Dykk, all aspects of the operation went smooth and we reovered the ROV before estimated time. The client was happy and we where reliefed as we domobilized the equipment and headed back home

Tunnel Inspection ROV

11727 meter of tunnel inspection well done

Needless to say, we are quite satisfied with the performance of the new ROV-design.

There is still some aspects to improve and details to make better, but we can now say that the product is proven and can hereby move forward with great confident when taking on job like this

Successful recovery of ROV

Safe recovery after completed mission


Saurdal Junction Crossing

Scope: 3km tunnel inspection to assess a know rockslide

A job that involved complex planning due to narrow and difficult access to the tunnel. Special rigging arrangement had to be engineered and a custom solution to fly around corners with the tether had to be made due to a 90 degree angle between gate shaft and tunnel

The rockslide was observered several years ago with during a manual inspection with drained tunnel. The cient was concerned that the there was more rockslides in the area or that the masses had be relocated further downstream, potentially obstructing or damaging vital parts of tunnel-infrastructure.

Special rigging arrangement

Launching the ROV through narrow gate shaft

We where able to successfully inspect the rockslide, giving our client vital data need to further operate and plan maintenance of their tunnel.

The output of this inspection was giving to client as videofiles synced with sonar-registrations, giving their engineers a valuable tool to measure all dimesions of the rockslide and evalaute further measures when in comes to maintenance.

Our NOTUS A ROV proved to be fit for purpose, but it came clear during this job that design modifications was needed to take on longer tunnels


Blåsjø Interconnection

Scope: Short tunnel inspection to assess obstruction or potential rockslide

The Blåsjø-reservoir is the biggest in Norway measured by energy-potential and consist of 14 dams and numerous lake tunnel-interconnections. 

These are of interest to inspect in order to make sure proper integrity and give a valid dataset for use in hydralic calculations.

A short, but important tunnel for us to take on as it was a good opportunity to test our system

HydropowerTunnel Inspection ROV

Launching the NOTUS ROV. ready for tunnel inspection

Tunnel Inspection Hydropower Plant

The NOTUS ROV flying towards tunnel opening

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