An unfortunate/fortunate accident

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An unfortunate/fortunate accident

Postby john_lewberg » Tue Mar 15, 2005 10:24 pm

While searching for the sea chest on the underside of an oil tanker, the VideoRay suffered an unfortunate accident. The operating environment was very poor, visibility was only about 3 inches, and the current ranged from
2-6 knots. We initially deployed the ROV from the pier perpendicular to the ship but soon discovered the current was too strong. Next, we staged the ROV from our smallboat at the stern of the ship, inline with the current and upstream so that we could control the position of the ROV with the tether.
Although the positioning issue was somewhat resolved, visibility was so poor that I could not focus on the hull even when the ROV was up against the ship, in fact I could barely see the manipulator arm when used as a point of reference.
We decided to wait till slack tide and try again from the side of the ship.
The coxswain had the bow of the smallboat against the ship and the engines engaged to maintain a stable position. Even though the tide had slacked somewhat, the ROV drifted underneath the bow of our smallboat. While trying to regain my bearings, I found the edge of the ship hull and started to make my way back to the initial drop point. The next thing I saw was the hull of our smallboat and all appeared to be well... Unfortunately the suction created by our props pulled the ROV towards the engines and the next thing I knew, bits of yellow foam were floating to surface of the water... Image

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An unfortunate/fortunate accident

Postby scott_bentley » Wed Mar 16, 2005 11:16 am

We're almost finished repairing this unit here at VideoRay. The amazing thing is that the number of parts to repair, and the technician time, were both very low. This unit is on our Comprehensive Support and Maintenance program, so there will be no charge to the end user. However, since the user immediately rinsed the salt water off the completely-flooded ROV (note the end of the light dome was sheared off,) we saved ALL of the interal cameras and camera movement parts, and all internal electronics. Our retail expenses to repair this unit would have been roughly $1500 USD plus shipping.

Scott Bentley, President, VideoRay LLC
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An unfortunate/fortunate accident

Postby thomas » Sun Mar 20, 2005 12:00 pm

We once experienced a small leak when diving at -92meters, off coastal Ecuador. 2 out of three boards were damaged. How do you recommend to "rinse" the salt water?
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An unfortunate/fortunate accident

Postby mcgurney » Tue Mar 22, 2005 9:36 am

Thomas,

Removing the board set from the ROV takes about 10 minutes.

When the board set is removed from the ROV it can be rinsed with deionized water. If that is not availed tap water will do.

After you rinse the PCB, let it air-dry.

As always, it is preferable that while handling PCBs, that you are grounded.

Bill McGurney, Manufacturing Engineer, VideoRay LLC
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An unfortunate/fortunate accident

Postby tanku » Tue Mar 22, 2005 3:56 pm

It also helps to rinse any electronic equipment with Pure grain alchohol (PGA) because it allows for fast dry time and leaves no residuals. It is no specialty item and can be found at most liquor or package stores.
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An unfortunate/fortunate accident

Postby deveshp123 » Sat Feb 04, 2006 11:09 am

Hi, actually i wanted to know about where can i get the best training for as in a ROV Technician , I am looking for a ROV technician course that is recognised worldwide, Plz help..
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Rapid ascents and descents with the Video Ray

Postby dehshaw » Wed Mar 28, 2007 10:06 am

When I first started using the Video Ray I found that it was sometimes difficult for me to change my depth if time was critical. I had read that a rule of thumb was 1000 feet in 10 minutes at 1 knot, but when I was on location I would sometimes need to cover 60 or 70 meters in the water column in just a minute or less. What I started doing was using the natural responsiveness of the sub to actually dive at full speed by using the back thrusters. I tilt the Rov through using the vert. thruster and/ or tether orientation, but once I am pointed the right direction I rarely use the vert thruster after that.

Has anyone else used this approach and did I explain it well?
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