Subsea cable detection

Member Joined: May 24, 2007

Hi fellow rovers

Besides using TSS 340, 350, 440. Does anyone know any better equipment to detect buried subsea FO cable?

Thanks

ROVworld Webteam Joined: Dec 12, 2003

There's Smartrak and Ultra system from Innovatum, but I've never used any of their systems.

Member Joined: Mar 23, 2007

I used the Smartrak on my last job. It is small and lightweight - we fitted it to a Seaeye Lynx. The system seemed to work well - although Innovatum's t-shirts are poo Laughing

Member Joined: May 24, 2007

Thanks for the help. We are using the TSS440 which i learnt is a new system. To a certain extend it works but it is picking up lots of signal so not sure it is detecting the cable or metalic debris.

Member Joined: Aug 30, 2005 Location: Aberdeen

the 440 is a particularly sensitive system and needs carefull initial setup a bit more than the 340 does. never used it for cable although we did manage to detect 13" pipe at over 2mtrs.

beware. the cable penetrators for the coils are very sensitive (more so than the 340) to moisture and will give spurious readings. if you are in the med or somewhere warm a manual seawater comp is better than the pre-sets

Member Joined: Oct 08, 2005 Location: Inversnecky

Kaka.

Have you followed the updated TSS procedures for mounting the 440?

Supposedly, you have to earth bond every member on the sub first.

Then enure the 440 is mounted at least 1.25 metres from the sub.

And finally, ensure the whole thing is rigid - no raise/lower rams etc.

Had a survey rep insist we do all this a couple of years ago. The first two are a load of bull - get out of jail free cards for TSS when results don't match the 440's supposed capabilities( the old 'it's your sub, not our equipment' argument).

However, we did see a marked improvement when we fixed the coil array rigidly to the sub and then cross braced them. Seems the 440 is that sensitive after a background comp, that any movement in the coils then registers the sub as a target as it has been compensated at a differnent position.

All in all, a pain in the a**e compared to the old 340. and not really that much better in practical terms.

I'm waiting with bated breath for someone from TSS to take the hump now.

Member Joined: Jun 05, 2004

After sales was never their strongest point Very Happy

Member Joined: Aug 30, 2005 Location: Aberdeen

if your using the 440, deifinetly go for the training course even if your not using one do it anyway, not so much for the technical aspect but more for the operational as there is a lot of things to watch for as previously mentioned. If not the training course, there is always the manual Twisted Evil

regs the after sales service, personnally never had a problem they are always on hand to answer questions. Shocked

Member Joined: Jun 05, 2004

Member Joined: Jun 25, 2007

Hi there.
Experienced numerous problems with 340/440 in South African waters, pipeline survey. We could not calibrate the system and extensive checks by both myself and the ET proved the system to be functioning normally. The PARTY CHIEF (his grand holiness) summoned me to the bridge for a large portion of bollocking,Whilst this was going on I looked at the chart table----and guess what we were in a region known as a Magnetic Anomoly where the amount of nickel or iron in the seabed throws out conflicting feilds.
It is in this situation impossible to do a reliable survey .
POLO

Member Joined: Aug 09, 2007 Location: Thailand etc

Same thing happens onshore , i used to do telecomms surveys and installations for microwave transmission , we sometimes had line of sight but transmission of radio beam was crap due to magnetic anomalies which the planners had not taken into account as they did their planning from A/c offices in Montreal or Harlow using satellite maps.

wasted millions $ on useless equipment and relocation of towere over the years.

jerry

Member Joined: Aug 03, 2007

They also have a problem working in hot countries and the power supplies crapping out

using a 350 at the moment - vague as a chocolate walking stick.

Also if we thrust as we survey we pick up signal from the motors over the the tone generated by the cable - really annoying using tone freqs<30Hz as these are right in our rotor frequency range for staying stable at slacktides? Vehicle is really rather small so we can't just increase our separation from the triads as the thing wants to "COWP OWER".

Member Joined: Aug 03, 2007

Why not use a bigger ROV Confused

Member Joined: Jun 05, 2004

Or

Employ some large Toads that have worked out on steroids Very Happy

Pay them in insects ( a little bit less than the going rate in dollars at the momento ) Very Happy