Micro – Mini ROV’s – the debate!

[James McLauchlan]

In another topic on dam inspection a member asked what might be the best vehicle for that type of inspection. There were a few suggestions, mainly Micro/Mini ROV types, but it became apparent that a debate was needed on this class (Micro/Mini ROV’s) as a whole to give people a better overview of their uses in general and not purely for inspection of dams. At the suggestion of another member I have started this new thread.

So:

• What type of Mini/Micro ROV do you have direct experience of?
• What were you using it for?
• What were it’s pro’s and cons?

[JL Schnabel]

i’ve had experience with a sub known as ‘LBV’ manufactured by Seabotix… one could easily carry it under one of one’s arms. we used to joke and call it => little bastard vehicle.

it gave us a lot of hassles.
maybe it was only this particular ROV but we noticed ingress after every dive – flying it was rather erratic.

we used it 90 degrees to the work.class sub when landing the stack.

[c]

Ive had some experience both good and bad with Seabotix LBV’s in OZ. On the whole weve always got the job done with it, but not without dramas. Early on our two systems were a complete pain in the arse. Always burning out underpowered thrusters, dodgy umbilicals, and dodgy wiring etc.

They seem to be a lot better these days especially with the FO umbilical, however recently I received a system straight from the workshop that didnt even fire up. It was all repairable in the field (mostly internal leads in the console wired incorrectly or not plugged in at all) but the point is it left the service department not working!

They are overly fiddly to pull apart in my opinion (especially compared to commercial Oceanographic equipment) with a bizarre o-ring setup on the main acrylic houising for the electronics and cameras.

The overall design with the layout of thrusters and the dual tilting cameras and lights along with the HUD is really good. The new smaller umbilical has made a huge difference to performance. The simple manipulator is very handy, Ive used it to recover equipment weighing in excess of 200kg (by swimming down a recovery line)

Personally I think theyd do an excellent dam inspection job. Especially as they are light, and if the drop from the wall was excessive they can be easily lowered in a cage, or better still deployed from a small boat which would be my first choice anyway. Ive used them from a 3m boat. And theyre limiting factor has always been current speed for us so a dam would be fine. If vis is really poor you can use usbl or sonar on them.

I really like the way they pack up into 2 pelican cases too. Hope this helps.

[Bill Bulloch]

Good input Dugong, sorry never got to sending you a PM as yet, still offshore.
What I was trying to do on previus posts was to open up the discussion rather people just chucking in comments good or bad.
Quick question regarding the LBV fibre’s. I understand that there is a potted copper to fibre switch in the tether, obviously this negates the need for bulkhead FO connectors to the vehicle. Do you have any details on what they use to change the coax video to fibre int he umbilical and topside?
Mini-micro ROV’s are mainly dominated, in my opinion, by the AC-ROV, LBV and the VideoRay. Defining which is best for a particular project is a matter of ‘horses for courses’. For example, an AC-ROV has vectored thrust, excellent when inspecting laterally across a hull for example. The VideoRay only has fore/aft and vertical thrsters, however it can be fitted with a sonar. AC-CESS, the manufacturer of the AC-ROV have a comparison chart available from their website on all 3x mini/micro ROV’s mentioned.

[c]

Hi Rovdo, I know a guy that works for Seabotix on and off, I’ll track him down and see if I can get you some specifics. Are you interested in a specific part ie laser, detector, modulator or just the switch as a whole? Ive sent you a pm about other business too. cheers dugong.
ps agree with vectored thrusters, the lateral is excellent.

[Craig Thorngren]

I’ve used an LBV and a VideoRay and in my opinion the difference is night and day. A large part of my business is very short notice i.e. "How soon can you get here". With the VideoRay it’s a matter of making my airline reservations and going. With the LBV we had, the weight of the system became an issue. The case with the FO tether and reel weighed in at over 70lbs (150m of tether). Several US airlines won’t let you check in anything over 70lbs, it has to go freight. So now were limited on what airlines we can use.
The next biggest issue is service… Our LBV was in for repairs probably 35-50% of the time over a 1 1/2 year period. The initial time it went in was definetly our fault. The issue was after it was returned. There were still problems and Seabotix was willing to fix it on our dime. We had it shipped back three times, once we even had our sales manager hand carry it to them and it still wasn’t fixed. Now what bothered me most was that we had to keep paying for shipping both ways. If an item is under warranty and you have a policy of the client pays for all shipping that’s fine and dandy. But when they pay for shipping, it better be fixed. If it isn’t, then they shouldn’t pay for shipping.

The other issue is the cost of repairs. A new tether cost around $4K from Seabotix. You can send it back for retermination, but you lose tether length i.e. if it was a 150m tether and you cut it at the 75m point, then all your going to have is 75m of tether. With the VideoRay, if you break or cut the tether, you can have it reterminated by them for around $400 and you only lose a foot or two of tether length. I know of two instances when VideoRay has put a person on a plane with replacement parts and it was all covered under warranty. Not a dime was paid for by the client. Now that is excellent customer service!

I’ve done, hull inspections (looking for parasitic devices, running gear inspections and UWILD inspections), pier/berthing sweeps, recoveries of items lost overboard, diver monitoring, dam inspections, evidence recoveries and the list goes on. My VideoRay hasn’t let me down and it’s always allowed me to bill the customer for the job 😀

Chief

[c]

I have to agree chief, ive had a lot less hassles with the video ray and the one i was using was one of the originals. Its biggest let down was lack of thrust but i believe the newer ones are much better. Throwing it on a plane is great too.

[Subhuman]

I am in the process of looking to buy a small ROV and I am having a hard time making my mind up about which one to get. As most of the work I will get with it will be salt water I will need something that can do cable survey, hull survey and search and recovery. I have been looking at the LBV150-e5 with the track[4 tires] option, AC- ROV, and Video Ray.
As I have never been involved with the billing end of this industry I do not know what the going day rate is for a small ROV and what one should charge as a day rate or hourly rate? Any info on this could help me in my selection. Also is it better to rent/lease Sonar and LBL for navigation, or buy it?

🙄

[Craig Thorngren]

Subhuman,
I’ll try and answer some of your questions, but to truly answer your questions, your going to have to give us more information.

The first thing you need to decide is what depth you are going to be going to. All of the manufacturers will tell you what a system is depth rated to. Once you decide that, you can cross off the systems that aren’t going to be able to go to that depth.

The second thing I would recommend is what type of repairs are typical for each system and what does it cost to get them repaired. Some salesmen will tell you "it never fails or has any problems", in which case you should just scratch that company right off the list. All systems require some sort of maintenance (some a lot more than others). If your not willing or able to do the repairs yourself ask them what it would cost to repair/replace a motor. Keep in mind that most systems come with spare/repair parts. Don’t fall for the "Oh it comes with a spare thruster" line, because if you replaced it once, you’ll need to replenish your spares for future failures. Don’t forget to add in the shipping costs if you have to send it back to the maker. Some don’t charge shipping and some do, Ask them what their policy is.

Ask others what they are using and whats been their experience with the unit. Don’t get a list from the manufacturers (you’ll only get their "happy with the system" people), but rather look on the web for people who are using the various systems in a way similar to what your looking to do and call or email them.

Then there is the all important actual purchase cost of a system. Looking on the web here’s the pricing I found for the LBV150-SE5with the crawler skid (tires). You can expect to pay around $74,000 (USD) plus shipping. Without the skid, the vehicle is around $42,500 (USD) plus shipping. A VideoRay ProIIIXE GTO system would cost you a little under $28,000 (USD) plus shipping. I’ve done quite a few hull inspections and haven’t had the need for the wheels. I guess it’s a novel idea, but for what it cost’s to what your getting I don’t see the benefit when you can easily do an inspection without it. I mean why would you want to crawl when you can fly 😀

I haven’t been able to find any pricing on the AC-ROV, James can you supply that?

As far as buying or leasing a sonar or posisitioning systems… I guess it depends on what your budget is. What I would do is make sure your system comes ready to integrate sonar and positioning systems on them. Make sure it isn’t something you have to send back for an upgrade (some times the "upgrade" to use a good sonar can be as high as $13,500 USD)

What’s the going day rate??? It’s going to vary. Tell me all the details of the job and I can quote you accurately. There’s a lot that goes into pricing yourself competitively. Everything from travel, to paying your operator and your overhead costs. There’s also (in my case) a Short Notice Deployment Premium. If I’m on the road or flying within four hours of you calling me, I charge you for that (I may call it Short Notice Deployment Premium, but in reality it’s better known as Keeping the wife happy pay 😀 ).

I hope this helps. If you have any more questions, please feel free to PM me with your email and i’ll answer your questions as soon as i can.

Chief

[James McLauchlan]

Chief…… Very informative and balanced response.

To fill in the AC-ROV gap a little…..

The AC-ROV:

• Rated to -75m (246ft)
• Four vectored horizontal thrusters + Two vertical thrusters.
• ROV itself weighs 3KG (6.6lbs) in air.
• Total system weight of 18Kg (40lbs) including one hand carry case.
• Easily carried and operated by one person.
• Cheap/Easy to ship by plane or chopper.
• Ideally suited to operating in remote locations.
• Power the AC ROV system from 90-260VAC single phase mains power or from a small portable generator (e.g. small 1kw Honda unit)

Options available for Retro-fit:

• USBL Positioning & Tracking
• Wall Thickness Sensor
• Laser Scaling
• Rear View Camera
• 2 Function Manipulator
• Slip Ring

Limitations:

• Max -75m depth
• Max 120m tether length.
• No Compass/Heading(yet)
• Won’t take a sonar (yet)

System Example
Basic system (without options or recommended spares package)
System [€Euro 8,813.20]
Tether [€Euro 815.67] – utilising 52m 50/50 tether (other tether options to 120m available).
Total: € 9628.87 (approx USD $13,122.00) + shipping.

[For more accurate pricing please supply delivery address and request a formal quotation]

best regards
James Mc

[James McLauchlan]

What I do like about the LBV is that a standard unit is rated to 150m which is pretty handy. (AC-ROV -75m – VideoRay Scout -76m, VideoRay pro 3E 152 m – 500 ft.)
I believe the new LBV’s come with 100m tether as a basic supply (within the system price). If you want more than that (eg 150m) then you’ll be looking at extra costs.

The LBV BE system is not as portable as Seabotix might have you imagine as the basic system comes in two cases.
Case 1: Weight: 28.5 kg – 62.8 lbs
Case 2: Weight: 27 kg – 60 lbs
LBV BE (-150m): Two cases – Total transport weight: 55.5kg (122.8 lbs)

The Video Ray has the same penalty as the LBV in that it also comes in 2 cases, although it is somewhat lighter than the LBV.
VideoRay total Transport weight:(for examples used in this post)
VideoRay Scout (-40m): Two cases – 32 kgs (70 lbs.)
VideoRay Pro 3E (-152m): Two Cases – 40 kgs (90 lbs.)

The AC-ROV comes in one case and weighs less than either of the other two systems.
The AC-ROV Total transport weight:
AC-ROV (-75m): One Case – 18Kg (40 lbs).

A small case system (Up to 52m tether) comes in one case.
Anything over 52m tether will mean that you’d be looking at what AC-CESS designate as a ‘Large case system’ to accommodate the larger tether & larger reel.
With a 120m tether the system still remains a ‘one case system it just weighs more (if memory serves me correct the ‘large case system’ with a 120m tether and reel comes in at around 30kg) – still in the one case.
Note: The AC-ROV manufacturer (AC-CESS Co UK Ltd), do it a little differently on pricing. They offer a standard AC-ROV system with no tether. You then add the tether that suits your requirements/pocket.

Single Small Case system: Tether lengths up to 52m
Single Large case system: Tether lengths 53m-120m

I think that between the Micro ROV/Mini ROV market the units mentioned in this thread are the three main choices.
I tend to view the LBV and VideoRay as Mini ROV’s and the AC-ROV as a Micro ROV. I suppose my view is based on size and system weight.

In my mind a Micro ROV comes in one hand carry case and as such you get the benefit of easier/cheaper to transport.
The mini ROVs comes in two cases or more, more to lug around and more expensive to transport (by air for example) but potentially more capable at the work-site, although as has recently been seen a reduction in sensor sizes is reducing the gap between the two classes on that score.

As mentioned before, often, it will always boil down to your own needs and funds available as to which system you select.

Hopefully this thread will continue to give some insight into the choices available in the Micro/Mini ROV market and enable those that are interested to make an informed decision when choosing a system to suit their needs/budget.

best regards
James Mc

[DJansen]

Many moons ago I was working with a seacat.. We were doing an inspection job at the local pool.. Trouble was the sub just coun’t cope with the current …

😛

[captpaul]

This thread has been very informative and helpful. We’ve also been in the market for a mini/micro ROV and have so far looked at systems by SeaBotix, VideoRay, AC-CESS, Outland Tech, and GNOM. From a buyer’s perspective (limited or no hands on, just from what we’ve learned from either the dealer, a happy customer, or in dealing with the companys involved) here are the pro/cons that we’ve assembled. I’d be interested in what comments actual users might have on these:

VideoRay:
Good portability, wide selection of ROV models.
Limited maneuverability in cross current due to no lateral thruster.
Limited performance in stronger currents due to thicker umbilical.
Only Pro and above expandable, cheaper models not expandable and some lack sensors.

SeaBotix:
Thinner umbilical, better performance in stronger currents (less drag).
4th lateral thruster for cross currents, maneuvering.
Decent portability.
All models expandable and have sensors.
Pricey.

AC-ROV:
Excellent maneuverability.
Questionable performance in current due to square shape and large umbilical.
Limited expandability, no compass (can’t even mount a dive compass externally as there is a magnetic thruster directly over camera).
Very affordable.

GNOM:
Smallest ROV and umbilical.
Difficulty in getting technical assistance, support, repairs, or parts?
Lowest price

Outland Tech:
Good expandability.
Least portable of all those evaluated (not really a mini-ROV, but more like a small observation class ROV).
Seemed to be the only system designed for day to day, industrial use of those we evaluated.
Reasonably decent pricing.

Again, these are just impressions that we got from looking at these systems and asking around. I’d be interested in hearing from those who actually use them to learn how far off the mark we might be.

[Craig Thorngren]

VideoRay:
Limited maneuverability in cross current due to no lateral thruster.
Limited performance in stronger currents due to thicker umbilical.

SeaBotix:
Thinner umbilical, better performance in stronger currents (less drag).
4th lateral thruster for cross currents, maneuvering.

I’d be interested in hearing from those who actually use them to learn how far off the mark we might be.

Capt. Paul,
Since you asked 😀

I don’t agree with the "limited manuberability in cross currents due to no lateral thruster." I’ve got to examples for you. Go to YouTube and type in "KONDARI" (sorry, i don’t have the URL). The video show’s a VideoRay ProIIIGTO model in a flood tide threading a shackle with a tag line. The entire operation took about 11 minutes, but it’s been edited down to about 2. The current was around .5 to .75 knots. Then search "VideoRay Shotgun" This was a recovery in over two knots of cross current. I guess what I’m trying to point out is most of these units turn on their own axis and a good operator know’s their limits and their systems limits and how to work within those.

Also, with the Pro4 model from VideoRay, there is the option of Quad Thrusters (4 omni directional thrusters). There are several reasons why this is a better arrangement than a single lateral thruster. The first is that the lateral thruster isn’t centered in the vehicle. If you move laterally, you’ll notice your actually going in a circle. Also if your moving into a current head on, you have two thrusters. Now turn side ways, you have 1 thruster but twice as much mass going into the current (front profile vs. side profile).

"Limited performance in stronger currents due to thicker umbilical." I think that the weight of the tether in the smaller systems is more important than thickness of the tether. I’m not 100% sure, but I believe the thickness difference is less than 2mm. What’s even more important is the ROV’s ability to pull it’s tether. Now each manufacturer is going to have their own say in bollard pull strength or what ever to make their system seem better. I like a good old fashion Tug-of-War. This shows me which system is better able to pull it’s own weight and that of a tether…

Chief

[James McLauchlan]

AC-ROV:
Excellent maneuverability.
Questionable performance in current due to square shape and large umbilical.
Limited expandability, no compass (can’t even mount a dive compass externally as there is a magnetic thruster directly over camera).
Very affordable.

………..I’d be interested in hearing from those who actually use them to learn how far off the mark we might be.

A little more on the AC-ROV’s manoeuvrability.
Yes, the AC-ROV has always been very manoeuvrable. In addition a recent (Q1 2009) improvement to the thruster (prop) design has been introduced.
Any AC-ROV with the white props fitted is using the later more efficient design.
For existing system owners the latest props can be ordered and swapped out with existing props.
Rather than fit a complete set to an existing AC-ROV it makes economic sense to swap out the four vectored thruster props only (as a full set) and keep the old ones as spares, for future vert prop replacement, until they run out. Then finally order the white props to replace them.
I would not recommend replacing just one or two props with the new design as the thrust would likely become unbalanced.

Yes, it’s a cube however you need to bear in mind that the AC-ROV has a full set of vectored horizontal thrusters which is the same configuration as work class ROV’s.
For that reason, combined with a roughly equal surface area on all faces, it will operate in current (approx. 1.5kts s the best reasonable estimate) at the same speed in any direction, including laterally.
With two vertical (fore and aft) thrusters it also has the same thrust capability up or down.

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