UW-Tech is a service company specialising in underwater inspections, hydrographic surveying and seabed scanning. Our business concept is to provide the material that the client needs, plus a little extra. Hydropower plants, harbours, bridges, sea lanes, county councils and municipalities are some examples of our client base.
By using the two video cameras on the ROV we can record/photograph the entire inspection. All information such as depth, position, direction etc. is shown in both cameras.
The top camera is on top of the ROV, which means we can also inspect piles/quays etc. above the surface. The top camera can also help us to navigate because we can easily go straight up to the surface from an object and see the surrounding above the surface.
The main camera is in the middle of the ROV.
Real Time Sonar
The sonar allows us to see up to 100m in front of the ROV. 135° sideways, and 22° vertically. This sonar gives us a view of what is in front of us seen from above, it creates an “aerial view” of the bottom and this is what we navigate with to 99%.
We have, for example, scanned along quay edges before the rebuilding to make sure there are no surprises before the building starts.
Another example is that we can easily and without danger to life or limb monitor clearing with a grapple from a mobile crane at a power plant intake, we then see from a safe distance were the grapple is to clear and where it is fully cleared, very cost-effective!
We have the opportunity to get coordinates directly in the image on the ROV. In this way we can get the position of an object or damage directly in the image, and can easily find it later on.
We have equipment for making different sampling of bottom sediment.
We have the possibility to offer HD Video, although not with all the information in the image.
This can, for example, be used for inspection of fauna/flora.
It is possible to film with both cameras so that they can be synchronised afterwards to get the information that way.
Frequent inspections / work using ROV
Here we look for deviation in the concrete around the intake, the condition of the gates, the logs the gates sit in, the bolts holding the gates, the threshold and the surroundings upstream of the intake.
STOP LOG THRESHOLDS
The cost saving of doing an inspection of the threshold that the stop logs are to rest/stand on for some time before a closing is invaluable. In our capacity as divers we have encountered enormous amounts of material over the threshold on numerous occasions when the stop logs are to be lifted in place. This puts a standstill to all the machines and the crew while the clearing is carried out. We therefore strongly recommend a pre-inspection of the thresholds.
By using the grapple on the ROV we have on several occasions sealed gates with rags, which is very effective and sometimes it can be cramped for divers to get in to the outside of the gate without demolishing parts of the intake gates.
SALVAGE OF OBJECTS
Using the grapple on the ROV to go down and either grip the object, or with the help of the grapple and hook to ease the object into it and then pull it up to the surface. Effective and not dangerous in the event of a hazard.
Frequent inspections / work using ROV
One frequent type of inspection is for quays with pile constructions. This means that we hand over complete documentation of the condition the piles are in. In the event of any deviations/damage we can also provide a proposal for measures to take. This is of course individual, depending on what you as the client are interested to know.
SHEET PILE QUAYS
Very common. By using our real time sonar we can see if the pile line is still intact, or if there is some deviation. With the camera we can follow all the pile planking from the bottom and up, without having to think about diving time or pressure equalisation, all documented, and we can easily mark any deviations up on the quay and in the report.
OBJECTS WHEN RAMMING
When deep-ramming you can come across objects and with the ROV we can easily go down and see what it is. Could it be a car, or a wreck? What ever it is, it’s important with the camera and sonar to see what has interfered with the ramming.
The grounding of a quay can make it very difficult for divers to know how dangerous it is to inspect the damage. Pile planking can be under tension, some piles can have half collapsed, and some parts of the quay could be hanging loose, etc. For this reason it’s important to do the first inspection with a ROV. This is where we can easily film/photograph the damage and check that the divers will not be in danger.
MARINE CONDUITS: WATER SUPPLY AND SEWERAGE - ELECTRICITY
There are frequent inspections of marine conduits with ROVs.
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Sewers that might be too shallow, and which have been run into by a boat, are often inspected. Sewers that are too shallow need to be protected, or re-laid. Ice can drag conduits, anchored boats can pull conduits, etc.
It is therefore important to inspect conduits at regular intervals and to make sure they are protected and in good condition. A broken sewer is an immediate threat to health and the surroundings, and can often be prevented by annual inspections.
A lot of power companies are starting to keep an eye on their cables. This is because it is very easy to chart them and the surroundings.
In many places the cables can be “hanging”, and the rocking motion can cause them to break or become damaged. Another threat is anchors that have fastened on cables, even though anchoring is most often prohibited.
A fresh water conduit that, for example, supplies an inhabited island with water can lead to serious consequences if it stops working. One way of preventing damage to a fresh water conduit is annual inspections.
All data is available as XYZ files – also known as point clouds – that compile a 3D model of the scanned area. The file reading program provides you with accurate depths at each individual point, as well as extremely accurate coordinates.
Thanks to WASSP wireless, we can position ourselves in front of a vessel and perform a scan if you are unsure of the seabed’s formation, or if there are shallows. The vessel’s equipment/computer receives our scan in real time allowing you to feel fully assured that there is sufficient depth and there are no signs of any obstacles.
Presents hardness of the seabed which is excellent for example, prior to a dredging project,
XYA files (point clouds)
Diagnostic raw data (.WMBF files).
SIDE SCAN SONAR
Provides a more detailed picture of objects at the bottom, similar to a flight image.