Topic: Kronīs towfish

[kron]

Hello!

I think it is time now, to show my/our towfish which was built a couple of years ago, 2008.

Specs:
Weight: 11,2kg
Length: unknown(approx 1,2m)
Material: Fish; PVC-tube, Nose cone; solid iron(for the weight)
fins; Plastic
Cable: CAT 7 pimf 50m.
Steel cable(50m) 2mm coated with plastic.

As you can see on the picture, I use aluminium and stainless steel to protect the transducer. In the former version it was only plastic on the sides. Unfortunately my fish tasted the seabed which resulted in only one plastic protection . The ducer got some scratches too, but it works fine after the grounding.

The reel on the picture is to a garden hose so it does not have any sliprings.



455KHz
depth: 5-8 meters

[Jolly Roger]

Nice work Daniel!

I'm looking forward to see some close up pictures of Northern Wrecks. So keep them coming  .  The garden hose reel is a good idea. Something I still haven't figured out is how I can get my cable reeled in and out.

Keep us posted!
Harry

[abraquelebout]

nice and biautifull
waintig for picture, good job
the reel of grden hose sim's a good idea

[Rickard]

Tjenare kandidat Kron!

Well done, you are my favourite student! Your fish is very much more elaborated than mine. Please tell folks about your fish-saving system and your breakthrough on the long cable issue. Everyone should know you are the young bright man who presented the first working solution on the issue with long cables for the HB transducers. And don't forget to tell you are my student, (even if that's in a very different area - Human-Machine-Interaction.  )

Ses i Luleå (See you in Luleå), perhaps for some ice-scanning at sea when the sun comes back?

Rickard

[kron]

Images on some of the northern wrecks will come, later on. Nowdays we really have to use Icebreakers to scan with boat.

About the SI image above: I weren't searching for stones, but that was almost everything what occurred. The real search was too find an completely new outboard engine, 25hp, 4-stroke. We did not find it though.

The image, under, shows the transducer better, and the fish has also an extra security system if it tastes the seabed anymore. As on the image, there is an extra steelcable going from the other steelcable(the one going to the surface) to an point at the rear of the fish. The reason is quite simple. If the fish get stuck in an stone then will the other cable(going to the rear) turn the fish around and hopefully get undamaged to the surface. The Idea is not new, and i didn't know about it before "Rickard" told it too me.

 

[Jolly Roger]

Very nice set up for the transducer Daniel!

If the ground isn't too muddy and the outboard wasn't sinking into it when it touched the ground, you will find the motor, no doubt. The other key is to have the right area to search in.

I've been out a lot of times to search for lost motors and other stuff. The deciding factor is to get a precise position where the item went astray. Otherwise you'll be driving for hours and don't find it.

A brandnew 40hp outboard really hurts to loose! A friend of mine had his lost with not even 10 hours on the clock and we found it within an hour (without sonar at the time). I was surprised when he showed up one day and gave me a voucher for a nice dinner with my girl, because I didn't know what the motor was actually worth. When he told that he had paid 6500 Deutsch Marks for it, I was a bit knocked off.  I enjoyed the dinner with a good conscience....... 

Regards / Harry

[sonar2000]

Daniel, searching for an object can at times be intense. And uses up some good fishing time.  

One thing we have found when searching for smaller objects, is to make runs in 90 degree plots.  For example if you ran north to south then also run the same area east to west.

Of course when on the smaller objects such as outboards then it is a good idea to make segments (recordings) of runs and then review the recording on humviewer or some external viewing program. 
You will be surprised at how much more you see on the playback in an external viewer.
More than a few times we have not seen the object on the sonar run but have found it on the viewer
Patience is the virtue and yields the best returns for your time...

Sorry if this thread got kinda of hijacked....I dont want to take away from your original pictures and efforts. 

Of course, just getting in the right area is challenging. It can be hard to pinpoint an exact place on the water by vision, so use some good judgement when told an object is right here. Be willing to expand the search area after you are sure you have covered the original spot and the object is not located...

For motors we rely on color as much as  a picture as the motors are often metal on a mud bottom...and will show a different color(hardness)

Chuck. 

[Jolly Roger]

Daniel,
Just out of curiosity: How did you attach the second cable which goes to the rear end of the fish to the actual tow cable?

I have the same "turn around" set up and have my tow cable attached to the rear end and the break away cable to the front tow point. I have the two cable connected with a shackle which should give the front end free if too much tension is applied to the tow cable. A stopper shackle is attached to the tow cable to stop the first (connecting) shackle from slipping along the tow cable (that's my theory and I hope it will work when it's needed).


Regards / Harry

[kron]

Hi Harry.

I have a picture showing that, not so good quality though, because the fish is far away. Anyway,I think the picture is saying more than words. The towing cable is attached to the fish with a ring from an keychain(because the breakage of that ring is less than the towing cable).

[Dale]

Daniel,

I'm quite impressed with the keyring as a shearpin. Have you had any pin failures while towing?

Dale

[kron]

Hi Dale.

No problem so far.