Author Topic: A fish that (finally) works  (Read 21183 times)

0 Members and 1 Guest are viewing this topic.

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
A fish that (finally) works
« on: October 16, 2010, 03:09:38 PM »
Hi Folks,

I wanted to build my own towed fish for a long time and finally made it when I came back from Afghanistan in August.

My idea was to build the fish as heavy as possible to get it as deep as possible when scanning at 6 km/h. 6 km/h turned out to be the best speed for getting good and detailed pictures when scanning.

So I started to search for the needed materials and found most of it on a scrap yard in the next town. I got 1,5 meters of 3 inch steel pipe. On the same spot I found a box with brandnew 6mm steel cables in various lengths between 30 and 50 meters. The price tags on the cables were still readable and read 40 - 50 Euros a piece. I got three of them for 5 Euros a shot! The steel pipe nearly ruined me when I had to pay 10 Euros for it  ;D.

I ordered 50 meters of CAT 6 cables at a shop which were another 60 Euros. My old transducer that came with the 981 last year should provide the hard ware for the signals from the fish to the display. I cut out most of the original cable because the resistance was higher than then CAT 6 cable and started to solder. After the transducer cable was extended to 40 meters I started to get the fish ready with the help of my friend Heli who is a lock smith master.

Here's my first drawing:

ila_rendered

When we started to cut the pipe and prepared it for welding, I decided to place the transducer at the rear end of the pipe. Getting the pipe cut and then a holder for the transducer welded into the pipe looked too much hassle since one end of the pipe was already closed by a plate. This plate provided enough space to get the transducer mounted with the original mounting hard ware.

Heli had made a solid iron nose for the fish on the lathe in his shop. Holy smoke that thing IS heavy: 6 kg (approx 12pounds)!! And I was happy to have it that way. Much weight on the front end meant that I can hook up the fish in the first quarter of the pipe and get it more stable while dragging it.

The pipe
ila_rendered
« Last Edit: October 22, 2010, 02:55:08 PM by Jolly Roger »
YES,......
WE SCAN!


Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that doesn't work......
« Reply #1 on: October 16, 2010, 03:15:36 PM »
The nose:

ila_rendered

The stabilizers:

ila_rendered

YES,......
WE SCAN!

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that doesn't work......
« Reply #2 on: October 16, 2010, 03:22:50 PM »
After we had all the materials Heli started to weld:

ila_rendered

After two hours, we got this: 25 kg of cool looking steel, hehe.

ila_rendered

When I loaded the fish into my car, first doubts about the weight started to come to my mind. 25 kg (approx. 50 pounds) felt not too heavy, but there will be some weight added when the steel cable will be attached.
Hm, should be no problem.......
YES,......
WE SCAN!

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that doesn't work......
« Reply #3 on: October 16, 2010, 03:42:17 PM »
OK, the fish seemed ready, now the cables were due to be mounted.

I thought about getting a big cable drum and get both cables winded up on it. But then I would need some way of control over the drum to get the cable in and out from the boat. Because I had no clue how I can get this arranged, I decided to store the cables in a plastic box. To have control over the cable, I decided to attach steel eyes every 5 meters into the steel cable. With the eyes I can get the fish out from the boat in 5 meter steps, which seemed a reasonable length.

To get the whole thing arranged, I put some long nails 5 meters away from each other into the ground and led the steel cable down.

ila_rendered

When the steel cable was in place the eyes were to follow. I placed shrink tubes at the spots were the cable has to go around the eyes, to avoid that the steel cable will splice up and the wires will stick out to sting my fingers

ila_rendered

Looked good so far.......

YES,......
WE SCAN!

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that doesn't work......
« Reply #4 on: October 16, 2010, 03:53:35 PM »
The transducer cable followed after the steel cable was ready. Quick ties in different colours seemed a good idea. With the different colours I should be able to know how much of the cable is extended.

ila_rendered


After some correspondence with Rickard and others here in the forum (big thanks to all of you!) the cable went into the box in a figure eight.

ila_rendered

Now every thing was ready to go and I went out for a test.
YES,......
WE SCAN!

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that doesn't work......
« Reply #5 on: October 16, 2010, 04:57:30 PM »
My hopes were disappointed when the fish was deployed and the runs didn't show any decent pictures.

ila_rendered

ila_rendered

The runs were made at the position of a known wreck, but there was no wreck showing up on the display.

I thought that I can get better pictures if I extend the full length of the cable and drove to a deeper part of the lake. There a bad surprise was waiting. The picture on the display didn't improve at all. I tried different speeds and different revolutions on the engines, even stopped the engines to see if the alternator or ignition might be the cause of the problem.
I changed the frequencies, the side range sensivity and tried all what I could imagine, but there was no way to get a clear picture to the screen.

When everything failed, I decided to get the fish back to the boat and call it a day. But when I wanted to get the fish back in it was nearly impossible to get the fish back up to the surface. The sheer weight was a problem and pulling up the cable was impossible with bare hands. Fortunatelly I had my dive gloves with me. Without them, there was no way to get the fish back up.

I have a transducer switch mounted and could change between the fish and the transom mounted transducer. The transom mounted transducer delivered perfect pictures, so I think that the cable is the source of the trouble.

Lessons learned:

30 kg of fish and cable isn't a set up that can be handled without a winch.

Small quick ties to attach the transducer cable to the steel cable don't work.


Next steps:

I'll try to sort out where the problem in the cable is. I think either the soldering wasn't good or a insulation problem occured when I sealed the soldering with shrink tubes.

I wrote to Humminbird if they would produce transducers with extended cables. The are considering the idea and I hope that we can get the transducers soon.  I posted the idea in the wish list as well.

A new fish will be made from lighter material. If I can get a winch, I will use the heavy fish for further experiments.

Transducer and steel cable will be seperated. Additional eyes will be attached to the steel cable so I can give out the steel cable in 2,5m steps. 2,5 meters is the width of my stern. Carabine hooks on each sides of the stern will be the hook points for the steel cable and the transducer cable will follow out on its own from the storage box.

I hope I can come back with better results next time.


Best regards / Harry
« Last Edit: October 22, 2010, 03:00:46 PM by Jolly Roger »
YES,......
WE SCAN!

Offline kron

  • Jr. Member
  • **
  • Joined: May 2009
  • Location: Sweden
  • Posts: 41
  • Unit(s): 997c SI
Re: A fish that doesn't work......(yet)
« Reply #6 on: October 17, 2010, 09:57:56 AM »
Hi Harry! I´m not sure i can give you reliable advices regarding your fish, but i´m pretty sure that Rickard have some solutions. But I have some thoughts though.

25kg seems to be too heavy to be handled manualy as you already experienced. And it can´t be neccesary either. My fish weighs aprox 12kg(built with PVC-tube and a steel nose-cone(~7kg). 50m of 3mm steel wire and CAT-7 cable). With 3,2knots and 20m of cable the fish goes 12-15 meter below the surface.

Is the cable a PIMF(Pairs in Metal Foil) type?
Did you connect it the way Rickard showed in a previous post?

I´m wondering if your steel cable can cause some interference with your CAT 6 because the big diameter of it?

By mounting the transducer in the rear i think you will get a lots of turbulence which may represent the white spots on the screen.

Best regards.

//Daniel

 
« Last Edit: October 17, 2010, 10:01:36 AM by kron »
Daniel

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
A fish that works now
« Reply #7 on: October 17, 2010, 05:50:26 PM »
Thanks for advice Daniel
and you're right in two ways:

Rickard had advice and the transducer in the rear appeared to be the problem.

Rickard told me that the fish body might have some resonance and that there might be other noise causing interference.

Since I had to move the boat from the buoy to the harbour today, I packed fish and cable and gave it another try. To eliminate the above mentioned problems I placed 4 layers of bicycle tube rubber between the fish body and the mounting bracket of the transducer. I also tied the shackles and extra cable with qiuck ties to the body to avoid any rattling et voila:

ila_rendered

That's the wreck that should have showed up in the first pictures. It's down on 20 meters and I wrote about it on my personal page here in the forum:

http://forums.sideimagingsoft.com/index.php?topic=240.0

I decided to drive over to the deeper part of the lake where I had a contact in 41 meters last year. This contact was the initial reason why I decided to build a fish:

ila_rendered

I thought that I might have the chance to take a "closer" look at this contact now.....
« Last Edit: October 22, 2010, 03:04:19 PM by Jolly Roger »
YES,......
WE SCAN!

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
A fish that works even in bigger depth
« Reply #8 on: October 17, 2010, 06:27:00 PM »
Here's the contact from a closer perspective:

ila_rendered

ila_rendered

Looks interesting, but I have to get more runs on it to decide if it is worth a dive. 40 meters are no walk in the park and take some preparation.
We'll see.....


Regards / Harry
YES,......
WE SCAN!

Offline kron

  • Jr. Member
  • **
  • Joined: May 2009
  • Location: Sweden
  • Posts: 41
  • Unit(s): 997c SI
Re: A fish that doesn't work......(yet)
« Reply #9 on: October 18, 2010, 04:52:33 AM »
herzlichen glückwunsch Harry! Das sieht ja sehr gut aus.

Have you estimated how deep your fish is going with E.G. 20m?

//Daniel
« Last Edit: October 18, 2010, 05:02:38 AM by kron »
Daniel

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that doesn't work......(yet)
« Reply #10 on: October 18, 2010, 06:17:12 AM »
Danke schön Daniel!

I wasn't paying attention to that yet, but for the first runs on the 20 meter contact I had 25 m of cable deployed and ran at around 6 km/h. I varied the height above ground by going slower, but found out that that it's quite tricky to go real close to ground by varying the speed (had couple of "touch and gos"  ???).

At the 41 m target I had all the cable out and the fish was about 12 meters above ground when I ran 6 km/h. To get closer I had to slow down to 2 - 3 km /h as you can see on the pictures.

I will do more runs to get a feeling what speed at what cable length gives the best results.

Rickard said that it's a of lot trial and error that I will face. Well, if the pictures are coming out that good, I will take the errors with a smile, hehe


Best regards / Harry
YES,......
WE SCAN!

Offline kron

  • Jr. Member
  • **
  • Joined: May 2009
  • Location: Sweden
  • Posts: 41
  • Unit(s): 997c SI
Re: A fish that doesn't work......(yet)
« Reply #11 on: October 18, 2010, 12:18:09 PM »

Rickard said that it's a of lot trial and error that I will face. Well, if the pictures are coming out that good, I will take the errors with a smile, hehe


Hehe.. Yeah that´s so true as it can be. My fish has ufortunately already tasted the seafloor.

I guess you are using another transducer/sonar on your boat so that you can see how deep it is beneath it. If not, i would recomend it. I use a simple Humminbird piranha sonar and sets the depth alarm on it so it will warn me to take the fish up. I think it has saved the fish a couple of times.


//Daniel
Daniel

Offline sonar2000

  • Chief
  • Global Moderator
  • *
  • Joined: May 2009
  • Location: Kerr Lake NC
  • Posts: 5970
  • It is not lost ...it has been misplaced.
  • Unit(s): (1) 1197 (1) 1198
  • Software: 6.6
  • Accessories: Tow Fish
Re: A fish that doesn't work......(yet)
« Reply #12 on: October 18, 2010, 01:19:30 PM »
That is a good idea.   Could the depth alarm be set on the fish also so that it alarms when it gets close to the bottom.  Maybe have the fish sound at 5 feet and the second unit sound at 3 feet.
Or some other determined depth.   Sounds like a really good idea that will save many a fish later. 
Chuck

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Rickard is THE MAN!!!
« Reply #13 on: October 19, 2010, 08:48:59 AM »
I ain't kiddin'!! Check this:

ila_rendered

That's a close up picture made with the fish yesterday evening.

Here's a picture from last year of the same target with the transom mounted transducer:

ila_rendered

Is this a difference or what???

Yesterday when I was out I was thinking what else might have caused the interfences in the beginning. In other words: What did I do when I did the first unsuccessfull test and what is different now?

OK, as already mentioned, the bracket and fish body are "uncoupled" by the rubber layers and the shackles and excessive cable are tied down to avoid rattling. But another thing came to my mind:
During the first test, I had the laptop hooked up to the 981 via a PC connection cable to get the NMEA data for the navigation from the unit's antenna directly to the laptop. The laptop has its own GPS antenna, but I wanted to use the same GPS data like the unit.
Rickard adviced to have the unit completely separated from any electronic / electric of the boat. I thought I had that done, but the PC connection cable IS a connection to other electrical circuits of the boat: The laptop is hooked up to a 12V socket. On the successfull test I had the laptop NOT connected.

I use a 100ah battery for the unit. It's not connected to the alternator / generator and the unit is completely on its own power source.
If this battery runs out of juice, I can exchange it with the auxiliary battery. Both have the same capacity. And if the starter battery should be down I have a second (actually a third) chance to fire the engines up. All three batteries are 100 ah.

Another thing I noticed yesterday: I have a 12V neon light mounted underneath  the engine hood in case I have to work on the engines at night. Yesterday evening I did a quick visual engine check when I was out and the unit was already running. As I switched this neon light on, a white bar ran over the screen for a second. The first moment I thought I had caught a fishing net or ran over one, but when I checked astern, there was nothing to see (luckily). I wondered what the white bar was all about and I realized that it showed up up when I had turned the light on. I switched the light off and on again: BINGO! The white bar showed up again. I took a closer look at the screen and saw that the screen was slightly lighter after the bar appeared and the light was on. I switched the light off and the screen went normal again. Note: The distance between the neon light and the fish cable was more than 1m!

Lesson learned:
  • Get the unit insulated from all other electrical stuff on the boat
  • Keep the cables / wires of the unit as far as possible away from other cables and wires of the boat

The good thing about the initial failure: It wasn't my soldering, he he  >:D

Regards / Harry
« Last Edit: October 22, 2010, 02:14:20 PM by Jolly Roger »
YES,......
WE SCAN!

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that doesn't work......(yet)
« Reply #14 on: October 19, 2010, 10:38:57 AM »
Hehe.. Yeah that´s so true as it can be. My fish has ufortunately already tasted the seafloor.

I guess you are using another transducer/sonar on your boat so that you can see how deep it is beneath it. If not, i would recomend it. I use a simple Humminbird piranha sonar and sets the depth alarm on it so it will warn me to take the fish up. I think it has saved the fish a couple of times.//Daniel

Hi Daniel,

I have a transducer switch mounted to switch back and forth between the fish and the boat. Works quite good so far.
I also set the depth alarm to 2m, but I have to admit that I'm not experienced enough to keep the fish that close to the ground  :o. Yesterday I had some "touch and gos" of the harder version, but Heli's "Hard-core-heavy-duty-and-A-bomb-safe" welding ("if an A-bomb will hit this thing, you, the whole boat and half of the lake will be on a dumpster truck, but this fish will still be scanning") payed off.
Yesterday I used a soft "touch down" to recover the fish when I had the whole cable length deployed: I drove to a shallow place and "landed" the fish there to pull it back up. OK, 25 kg still are 25 kg, but I didn't have to lift the whole cable weight then.......

I hope I don't run into an underwater obstacle with this SOP. But on the way to the shallow spot I used the boat's transducer to look for trouble ahead.

Here are more shots from yesterday. This target starts looking real interesting!

ila_rendered

ila_rendered

Best regards / Harry
« Last Edit: December 26, 2010, 04:02:36 PM by Jolly Roger »
YES,......
WE SCAN!

Offline sonar2000

  • Chief
  • Global Moderator
  • *
  • Joined: May 2009
  • Location: Kerr Lake NC
  • Posts: 5970
  • It is not lost ...it has been misplaced.
  • Unit(s): (1) 1197 (1) 1198
  • Software: 6.6
  • Accessories: Tow Fish
Re: A fish that (finally) works
« Reply #15 on: October 19, 2010, 11:05:17 AM »
Looks like you are on to something Harry.  Keep those picture coming. And let us know what you find.
Humminbird should build a fish and take out the troubles we have in doing it ourselves.
Chuck

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #16 on: October 19, 2010, 12:20:28 PM »
Your wish is my order Chuck,

Things start looking more clear now. This is the first time DI really helped:

ila_rendered

Looks like I need a dive buddy. No solos in 40 meters  8)

Regards / Harry
YES,......
WE SCAN!

Offline sonar2000

  • Chief
  • Global Moderator
  • *
  • Joined: May 2009
  • Location: Kerr Lake NC
  • Posts: 5970
  • It is not lost ...it has been misplaced.
  • Unit(s): (1) 1197 (1) 1198
  • Software: 6.6
  • Accessories: Tow Fish
Re: A fish that (finally) works
« Reply #17 on: October 19, 2010, 01:45:41 PM »
DI looked good Harry.  Wish I could get over an dive with you.  This has been one of our busiest summers EVER.  As you can see by the little time I have spent on the site lately. I hope that you can get out to the site and dive before winter is here.  This seems promising target to explore.  Good picture on DI.
Chuck

Offline Rickard

  • Hero Member
  • *****
  • Joined: May 2009
  • Location: Mariefred, Sweden
  • Posts: 512
  • Unit(s): 999, 981, M37, LowBird-1, LowBird-2
Re: A fish that (finally) works
« Reply #18 on: October 19, 2010, 01:48:48 PM »
Harry,

I can recognize your satisfaction now! The quality of the images is the best possible, I think, congratulations! And thanks for the flattering words on me... a bit embarrassing, perhaps, but it's a relief to see your results since I couldn't keep my mouth/keyboard shut and interfere with your plans. I could have  been wrong, you know.... :-\

It seems now as the electrical insulation thing is the most important factor. Then there is the fish height over the seafloor. Those who have failed with their systems should take a very close look on the electrical situation, they may be in the possession of excellent systems without knowing about it! The neon lamp issue shows how noise sources may lurk anywhere. The new LED lamps can be even more noisy. That's why they are not approved for safety related applications like lanterns (that was at least the situation in Sweden recently).

I suspect the heavy fish will taste some water the few days left of your boating season  ;) It's a win win situation, lovely scanning and bigger muscles at the same time!

Rickard

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #19 on: October 19, 2010, 02:41:08 PM »
Embarrasing???
No need for that Rickard!

Honestly, I was so frustrated and disappointed when I saw the pictures at the first test, that I had no plan to pursue this thing any longer. "Damned piece of Aaaaaargh!! After all the soldering and fiddling around with the cables. Screw it! Something for winter........" I thought.

But when I heard your thoughts and I was looking at your pictures, I thought again and tried to narrow down the issue. OK, you could have been wrong, but then I had at least tried to solve the problem.

Talking about the neon light: Guess what? I'm pretty sure that the light was on and I had the box with the cable placed right on top of it! Next time I go out, I'll try to replicate the situation and post the results.


Thanks again Rickard, I owe you!!

Regards / Harry
« Last Edit: October 22, 2010, 02:51:44 PM by Jolly Roger »
YES,......
WE SCAN!

Offline keizerh

  • Full Member
  • ***
  • Joined: Mar 2009
  • Location: Wildervank
  • Posts: 201
  • Unit(s): none
  • Accessories: ASHH and VC cable
Re: A fish that (finally) works
« Reply #20 on: October 22, 2010, 01:51:03 PM »
Harry,

GREAT!!!!!!

I''m waiting for Navico to built their CHIRP transducer with a long towfish cable.

hendrik

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #21 on: October 22, 2010, 02:47:51 PM »
Yeah Hendrik,
Finally  ;)!

Here are two more shots in Down Imaging. Looking real good.

ila_rendered

ila_rendered

I scheduled a dive for Monday. Andi will come along and bring his video camera. With luck, we'll have some real pictures of the target then.

Regards / Harry
YES,......
WE SCAN!

Offline keizerh

  • Full Member
  • ***
  • Joined: Mar 2009
  • Location: Wildervank
  • Posts: 201
  • Unit(s): none
  • Accessories: ASHH and VC cable
Re: A fish that (finally) works
« Reply #22 on: October 22, 2010, 04:48:17 PM »
Pity for me that:

1 there is no Navico to Humviewer converter.
2 Mr humview ;-) is very busy.
3. the Humminbird 098 black box is not ready.

Maybe Danny can use his influence on this on the Lowrance side or Greg will ask delvelopment on the Humminbird side.

Otherwise I have to buy an extra Geonav unit, that I will check out on Mets Amsterdam next month.

 
Harry,
I would build a simple PVC fish at fairly no costs like mine and try again.
Happy hunting nezt week, and don't forget to make a close-up of your last year wreck.

when will you try Windemere?
hendrik
« Last Edit: October 22, 2010, 04:50:23 PM by keizerh »

Offline abraquelebout

  • volunteer rescue diver, surfer, publicist
  • Sr. Member
  • ****
  • Joined: Apr 2010
  • Location: france
  • Posts: 263
  • Unit(s): 898, 1198, helix G2
  • Software: deep,,drdepht,reef.
  • Accessories: towfish lowbird /LSS2-hdsi, 60mcable
Re: A fish that (finally) works
« Reply #23 on: October 22, 2010, 06:00:57 PM »
 ;)congratulation
yes rickard is the men !
when i see the first problem i wonder if i  construct another towfish in fiberglass??
my towfish is working but he is in aluminium.
tomorow i'm going to dive on river,
whe find lot of target and i hope that's antique...next dive must be interresting. ;)

Offline RGecy

  • Administrator
  • *
  • Joined: Mar 2009
  • Location: Beaufort, SC
  • Posts: 1981
    • SideImagingSoft.com
  • Unit(s): 1197c SI, 997c SI & 785c2
  • Software: 4.950 & 4.510
  • Accessories: Interlink & GRHA
Re: A fish that (finally) works
« Reply #24 on: October 26, 2010, 12:09:01 PM »
Harry,

Great work!  The images look awesome. 

What we need is for Humminbird to market a transducer with a preinstalled 150' low-impedance cable.  This would drastically reduce any interference or connection issues.  They have successfully made these at the factory with the HB connectors installed.  No splices!  Now we just need them to make some to sell!

Hope you are doing good!

Robert
Humminbird Guru and Forum Administrator

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #25 on: October 26, 2010, 01:30:32 PM »
Yeah,
I hear you Robert.

I wrote to Humminbird and asked for an extended transducer.
The first response was way over my English capabilities, so I wrote them another mail.
The second response was that they will look into it and write back.

Here's one picture from yesterday. The wind was about 6 Beaufort and the waves quite annoying. It's one of the not so successfull attempts to keep the fish at two meters above ground: BANG!!!

ila_rendered

Now I even have the target torpedoed  >:D!

Regards / Harry
YES,......
WE SCAN!

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #26 on: November 02, 2010, 09:07:03 AM »
Harry,
I would build a simple PVC fish at fairly no costs like mine and try again.
Happy hunting next week, and don't forget to make a closeup of your last year wreck.

when will you try Windermere?
hendrik

I'll make a PVC fish in winter and I thought about a "wing" attached to the cable that should provide some down force to get a lighter fish deeper down.

The close up of last year's wreck is already here in the thread. I did the first test at exactly that spot.

Going to Windermere?
Hm, I took the boat out and put it in the winter storage on Saturday. Most of the winter preparation is done.....
I have to ask Kevin, if he can provide accommodation, he he. Would you join us?


Regards / Harry
« Last Edit: November 02, 2010, 09:09:55 AM by Jolly Roger »
YES,......
WE SCAN!

Offline keizerh

  • Full Member
  • ***
  • Joined: Mar 2009
  • Location: Wildervank
  • Posts: 201
  • Unit(s): none
  • Accessories: ASHH and VC cable
Re: A fish that (finally) works
« Reply #27 on: November 02, 2010, 02:13:42 PM »
Good Idea.

and here is your depressorwing.
Be carefull that it doesn't cut your cable

hendrik




Our use a hydrofoil for an outboard leg
hendrik
« Last Edit: November 02, 2010, 02:16:25 PM by keizerh »

IRC Kevin

  • Guest
Re: A fish that (finally) works
« Reply #28 on: December 08, 2010, 03:19:11 PM »
Congratulations, Harry and glad to see you got back from the 'Stan' safely.

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #29 on: December 09, 2010, 07:00:16 AM »
Thanks Kevin!

I'll propable go back south in March for a year. So there wont be much boating next season unless I pull out there for safety or family reasons.

The fish did a good job after solving the initial problems. Now I'm looking for the right PVC tubes and materials to build a lighter version. Not that I'm getting old, but getting the heavy fish out of the water and back on board is quite a challenge. Besides that, it's a safety issue as well: Getting caught by the cable and pulled overboard would be more then a party foul if I have to keep afloat with 25 kg of extra weight.....

Regards / Harry
« Last Edit: December 25, 2012, 11:34:12 AM by Jolly Roger »
YES,......
WE SCAN!

Offline Kimi

  • Jr. Member
  • **
  • Joined: Jan 2010
  • Location: Vanda-Ekenäs
  • Posts: 79
  • Unit(s): 798CXI 898 CXI
Re: A fish that (finally) works
« Reply #30 on: December 16, 2010, 03:13:15 PM »
Seems like a good project to start whit. Simple construction? Think I "steel" this concept.  ::)

By the way, here is an intresting towfish concept. http://www.starfishsonar.com/

Shows that a towfish do not have to be built like a sidewinder AA missile.

Kimi..
homepage: ( in Finish only) www.wreckdiving.yolasite.com

Offline Kimi

  • Jr. Member
  • **
  • Joined: Jan 2010
  • Location: Vanda-Ekenäs
  • Posts: 79
  • Unit(s): 798CXI 898 CXI
Re: A fish that (finally) works
« Reply #31 on: December 17, 2010, 11:05:57 AM »
Moved over from an other topic!

There are heavy duty cables on the market, but these cost way too much for a low budget fish.

That's what I'm worried about. And the day when the towfish get stuck, and the cable get broken, there is little to fix and repair. You need to buy a new one, or make it shorter.

For the stability in the water I think the longer the fish the more stability is has and wont "run away" to the sides. The hook up point of the fish is also critical. I guess the further forward the better. The trick is propably to find the right compromise between axial stability and position of the fish in the water while dragging.

Sounds like the same problems you have to solve when constructing an aircraft. Length makes stability, the body should be in balance, and the weightpoint as low as possible.

Another thing: I hope Humminbird will listen to our pleads and comes out with a tow fish transducer.......

In this case, whats the difference betwean an transducer placed on the surface, and towfish transducer?


Let's keep our fingers crossed!

Lets do that..

Kimi..
homepage: ( in Finish only) www.wreckdiving.yolasite.com

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #32 on: December 17, 2010, 09:30:38 PM »
About the tow fish transducer:

I put that up on the wish list and wrote to Humminbird for it. The difference would be that one does not have to extend the cable by himself. And that we could relay on a transducer originally made with a longer cable by Humminbird.

For the fish getting caught:

If you look at my drawing, you see that I have two hook up points on the fish:
One on the rail and one at the end. The one at the rail is the main drag point. If the fish would run into something and gets caught, the cable will (hopefully) break loose on the shackle of the tow cable. Then the fish will (hopefully again) swing around and be dragged free with its rear end first from the obstacle.

I hope this makes sense Kimi  ;D.

Harry
YES,......
WE SCAN!

Offline Kimi

  • Jr. Member
  • **
  • Joined: Jan 2010
  • Location: Vanda-Ekenäs
  • Posts: 79
  • Unit(s): 798CXI 898 CXI
Re: A fish that (finally) works
« Reply #33 on: December 18, 2010, 01:33:21 PM »
I hope this makes sense Kimi  ;D.

Yes, that should be good enough. As long as Mr. Murphy don't come along!

In late October two guys tried to get a topshot of an old wooden wreck. Closer, closer,... until the fish got stuck in the wreck! The cable got broken. Ewen if it was cold and it was going dark, they decided to dive, and bring up the towfish, and so they did. The next thing that happend was that the anchor got stuck in the wreck. Diving again.

When they got back to the harbour the wind had gone nasty, and a snowstorm had begun. Later the two guys where satisfied to sitting in a warm car on their way home, they probably tough that after a bad day like this, nothing more could happend? Wrong! The road had frosen to ice, and they smashed the car.

Shit happens...  ;D
homepage: ( in Finish only) www.wreckdiving.yolasite.com

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #34 on: December 19, 2010, 12:15:18 AM »
Shit happens?????

In August I was exploring a wreck I found last year. It was a bit windy, so I decided to make sure the anchor sits well in the ground and pulled back for about 50 meters. Should be enough I thought and went for the dive.

Beautiful! The sight was great, the wreck looked nice and the dive went perfect. I came back up and I changed clothes. Than I tried to winch the anchor up, but couldn't get it up. I got all chain out and tried to drive the anchor out of the ground / obstacle heading the other way. No chance. Dammit!!

What the hell, I thought and changed bottles on the jacket to go down again and see where the anchor got stuck. When I tried to get the jacket on, the pressure meter got caught on the motor hood and the hose broke. Aaaargh!!
I dropped the jacket, shut the valve and checked: The hose broke right at the first stage, so all the compressed air went out of the tank.

I did an estimate: The tank was fully filled, so 210 bar were in. The hole in the first stage where the air blew off was quite tiny, so I thought that it would take about at least two or three minutes until the tank would be empty. Should be enough to go down and get the anchor free.....

I dressed up, jumped in, swam the the anchor chain at the bow, opened the valve of the tank and went down to the ground in twenty meter as fast as I could. I followed the chain until it disappeared in the muddy ground. There I reached into the mud and tried to find the anchor. Nothing? I reached further and further. Still nothing! After I was an arm length in the mud and still haven't got the anchor I called it a day and went up again. HOLY S§$&!!!!!!!!

There I was: The boat got stuck, I couldn't dive because both tanks were empty, now what??

I tried again for 45 minutes to get the anchor free with the engines, but had no success. OK, tool time. I let all the chain out, tied two buoys to it, crawled into the chain cabin and released the chain.

Next thing, I drove back to the harbor, moored the boat, jumped into the car and hauled ass to the dive shop to buy a new pressure hose and refill the bottles. After that I raced back to the boat, loaded the tanks to it and repaired the pressure meter.

When I finally reached the place where I ditched my anchor it was already dark. I could see lightnings in the distance as I caught the buoys and got the chain back on board. Looks like a thunder storm...better get the boat ready for bad weather. So I closed the tarpaulin and went to sleep after a beer.

I woke up, because I fell out of my bunk! What?????
It was kinda light already and I checked the clock: 8:00 in the morning and not really bright light??? I got up from the floor and looked outside. Storm, waves of about 1 meter and rain, rain, rain. I crawled back into the bed and stayed there until eleven. The wind lessened and I decided to go down and get that damned anchor free.

Down on the ground I started digging and after I had a hole of about 1 meter dug out, the anchor still wasn't in reach. Screw it!!!!
I got back up and thought I would have to let the anchor and the chain go again and come back with a bolt clipper to save as much of the chain as possible. But then the boat of the water police luckily showed up. The guys asked me what I was doing and I explained what my problem was.
They took my chain over to their boat and then put the pedal to the metal. Voila, the anchor came free!!

After I had the anchor back on the deck the anchor was bent, but repairable........


Lesson learned: Yes, shit happens!!!!!!!!!!


Harry
YES,......
WE SCAN!

Offline Kimi

  • Jr. Member
  • **
  • Joined: Jan 2010
  • Location: Vanda-Ekenäs
  • Posts: 79
  • Unit(s): 798CXI 898 CXI
Re: A fish that (finally) works
« Reply #35 on: December 19, 2010, 12:37:21 PM »
Yes. shit happens.. and usually at sea.  As old seamens use to say,  that it is better to be on dry land when you got involved in an accident at sea.

Did you ewer found out what the anchor was stuck on??

Kimi..
homepage: ( in Finish only) www.wreckdiving.yolasite.com

Offline Jolly Roger

  • Hero Member
  • *****
  • Joined: Mar 2009
  • Location: Germany, Lake Constance
  • Posts: 801
  • HB Addicted
  • Unit(s): 998Cx SI
  • Software: latest (mostly)
  • Accessories: AS GR50, custom towfish and: A boat!!
Re: A fish that (finally) works
« Reply #36 on: December 19, 2010, 04:56:13 PM »
No Kimi, I didn't find out what caused the incident. Actually I was so mad about the whole stunt that I stayed away from the spot  :-\.  But I'll take a look at it next year.
Who knows, maybe I fished a new wreck with my anchor, hehe.


Regards / Harry
YES,......
WE SCAN!

Offline sonar2000

  • Chief
  • Global Moderator
  • *
  • Joined: May 2009
  • Location: Kerr Lake NC
  • Posts: 5970
  • It is not lost ...it has been misplaced.
  • Unit(s): (1) 1197 (1) 1198
  • Software: 6.6
  • Accessories: Tow Fish
Re: A fish that (finally) works
« Reply #37 on: December 19, 2010, 04:59:35 PM »
Thank goodness for sonar....
Years ago we used anchors to find sunken boats that had wrecked.
Wow, what technology has done for the world of SAR.
Chuck(sonar2000)

Offline Kimi

  • Jr. Member
  • **
  • Joined: Jan 2010
  • Location: Vanda-Ekenäs
  • Posts: 79
  • Unit(s): 798CXI 898 CXI
Re: A fish that (finally) works
« Reply #38 on: December 20, 2010, 01:59:36 PM »
No Kimi, I didn't find out what caused the incident.

Yeah.. sometimes anchors just like to be stuck on bottom without a specific reason.
Happened early last summer. We where out at sea to check out a remaining of a wreck that might be a Hansa-kogg ship from 1468. The story tells that it had  about 15000 golden coin aboard, so of course I felt a little interest to expolore the seabed. The sea had been calm for days and the visibility was excellent. So no or newer was the day.

I located the wreck and dropped the anchor outside the wreck location at a deep of 20m. First I dropped a ROV in the water but couldn't see anything, so I tough it was something wrong whit it.
So we decided to dive. At the bottom the visibility was about 2 feet, so we accended. At the surface it seems like storm was rising up. So I decided to move to maineland. But the anchor was stuck. I jumped down to release the anchor but it wasn't stuck anywhere, just small rocks. And the visibility had got worse. I had a realy bad feeling down there. You could imagine that the 200 people that had drowned whit the ship, was happily waving hands to you somewhere in the abyss???  :-\
Back at the surface I comanded my mate to take up the anchor but it was still stuck. ??? Down again, and same story, anchor was laying on seabed stuck on nothing. So I took it up whit me, blow up my wings and drysuite and up we went while the divecomputer went crazy.
I had newer felt so bad during a dive before, and newer been so full of adrenaline. If someone had told me its ghosts down there I would probably had believe it.
We made two other dive the same day a mile from that place, and the visibility was brilliant, and weather was as nice as can be..

First time in my life that I have been afraid of something else than the taxdepartment, and russian sausages.

Well, I'm going back someday. Just have to put some first season OWD divers to do the first "tryout" dive!  >:D

Thank goodness for sonar....
Years ago we used anchors to find sunken boats that had wrecked.
Wow, what technology has done for the world of SAR.


Well the same techniques was using when searching for old wooden wrecks. The anchors made a lot of damages to the antiqueships. Nowday technology help us to to act respectfully at wrecksite areas. 

Kimi... ;)

homepage: ( in Finish only) www.wreckdiving.yolasite.com


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo

 

Related Topics

  Subject / Started by Replies Last post
5 Replies
3176 Views
Last post December 19, 2009, 10:13:47 PM
by capttim
10 Replies
5365 Views
Last post September 22, 2010, 04:25:00 PM
by Humminbird_Greg
4 Replies
6071 Views
Last post September 12, 2011, 12:43:36 PM
by lolar3288
1 Replies
2057 Views
Last post October 10, 2011, 10:43:01 AM
by Humminbird_Greg
3 Replies
2984 Views
Last post January 17, 2013, 12:11:30 PM
by sonar2000
8 Replies
3892 Views
Last post June 24, 2013, 04:01:41 PM
by Humminbird_Greg
8 Replies
4438 Views
Last post February 27, 2015, 08:42:43 PM
by Bob B
2 Replies
2549 Views
Last post March 04, 2018, 02:15:08 AM
by iceperch


SimplePortal 2.3.3 © 2008-2010, SimplePortal