Towing

[calibra]

Hi

I need to tow a 21ft Speed boat in my 3.6m SIB

The Sib has a Johnson 2 stoke 1999 15hp engine on it.

The SIB is PVC.

Do you think I should glue on some D-Rings at the back of each tube and attach the speed boat to those?

Thanks

[Poly]

Originally Posted by calibra

Hi

I need to tow a 21ft Speed boat in my 3.6m SIB

The Sib has a Johnson 2 stoke 1999 15hp engine on it.

The SIB is PVC.

Do you think I should glue on some D-Rings at the back of each tube and attach the speed boat to those?

Thanks

How far are you planning to tow it?
What fixings do you have?

[Pikey Dave]

Without knowing all the details, my gut reaction would be eyebolts in the transom


.....sh1t happens.......

[calibra]

• The engine on the 21ft speed boat has failed.
• The boat is located in a tidal river
• I need to tow it about qtr or half mile closer to the mouth of the river so it can come out of the water
• I would like something that in future I could use again if the need arises. Chances are it won't.

I have brought some patches as shown in the attachment. If you look at the picture you will see where I plan to attach them (Red squares)

I did think about the transform, but the load combined with the weight of my engine worries me.

Thanks

James

[calibra]

Adding image

[Pikey Dave]

If that's all you want to do, I'd hold it by hand.


.....sh1t happens.......

[calibra]

Yeh, your probably right. It's actually more like a mile looking at the map lol.
I thought it might be easier as I'll be in the sib and dad will be in the speed boat.

[Wightdiver]

•The boat is located in a tidal river

Wait for the tide to go in the right direction and drift/paddle, use the sib as a safety boat.

[jyasaki]

Tie the speedboat side to side to the SIB. You want the back of the SIB to be about even or just forward of the back of the speedboat.

Go slow, and test out steering before you need to be accurate about placement - you may need to alternate forward and reverse power to get the speedboat to go where you want. Make sure you have someone on board the speedboat with a boat pole to fend off whatever you don't want to hit.

Towing in tandem is fine for open water, but you can't really steer worth a damn.

jky

[Poly]

Some eye bolts on the transom are very handy things to have. I’d much rather tow with them than patches on tubes. Jky talks sense about an alongside tow. A mile is quite far for that but if you take your time you will get there. Keep your engine completely astern of the broken down boat or you will get no steerage. Going with the tide and wind would obviously help reduce the effort involved too.

If it is a one off, you could try just physically holding it alongside (just with ropes) in calm conditions. I’d rather have some springs though – something like this:

[kelson]

Two forged eye bolts at the transom along with a tow bridle like the one pictured make for a good towing set up. I would not want to attach the tow line to the tubes. Go with the strongest part of the boat! At least some of the forces from the outboard will be in direct opposition to the tow loading.

The forces applied will ramp up quickly with speed. Go slow says Mr. Obvious

Nice art Poly!

[Nick Hearne]

In my experience towing a hard boat with a Sib is not very successful as you do not have much sib in the water to add steerage!
I would just hold or use a bridle attached to the transom NOT the tubes, or can you not stick the Sibs outboard on the hard boat?

[kaman]

Plus one for eyebolts.

[ShinyShoe]

I've alongside towed about 2miles it works OK. (For a one off tow thats what I'd do). I prefer to be towed on a bridle but would prefer that to be through eye bolts than attached to the toobs. I've never towed in a SIB just a RIB but Practical Boat Owner did a series last year with a SIB type tender moving a yacht about in a marina and everyone in the test was surprised how effective it was.

[Landlockedpirate]

Alongside towing works well, I towed my 28ft sportscruiser from about 2 miles offshore with the Zodiac 240 slat deck and 3hp Malta tender strapped alongside.

Steerage was a bit hit and miss, but using the leg on the sportscruiser helped a lot.

[Fenlander]

As others have said if you tow then put eye bolts in to the transom, that doesn't increase the load as such just gives the most direct pull from where the force of the outboard is being applied. Using the ring patches will load their glue attachment to the point they might pull off.... or cause stress to the transom to tube joints.

Use several larger (30mm dia or more) penny washers on the inside of the tow eyes.

Finally go carefully avoiding snatch loads. How much stress you give the SIB might also depend on its transom. For example the Honwaves have lovely thick fibreglass & wood sandwich transoms.... leisure Zodiacs like my 340 air floor have very thin plywood transoms.

BTW I agree alongside could be good... quite a pro way to do it with springs as Poly shows. Your 15hp will have the power to move it all... just set up similar to Poly's diagram for best steerage.

I always fit towing eyes on my SIB transoms and carry my own home made tow bridle. This for emergencies only and I'm thinking more about helping with a canoe, board, other SIB or small sailing dinghy than anything larger.

[treerat]

I'd be putting the engine onto the speedboat of at all possible, if not alongside will work well with a line tow the last option.

I used to tow on my sib by placing a nice wide bridle around the front of the sib, through the carrying handle / painter clip and then back along the sides, through a pair of eyes for guidance, not weight bearing.

This gave the boat a wrap around (for want of a better explanation) and worked really well.

[otilly]

And what about tying a rope to the outboard itself? A bit down low the leg? As I understand the bottom of the outboard is pushing and the top of the outboard is pulling at the transom.
Is it possible to even out the pulling (speedboat) and pushing of the outboard if you tie a rope to the outboard itself?

Just thinking.

[Richardnhunt]

Alongside, slow speed and anticipate the tidal flow rather than fight it.

Just keep the rear of the power /steering boat as the rearmost part of the setup to keep steerage

Don't forget the 270 around the tow may be easier than 90 tow around tug

Rich