Using the Ski Pylon for pulling

[IDBoating]

That is what I use. The problem is somof these boats d-rings are below the swim platform.

The other problem is that using devices like that puts a HUGE amount of strain on those d-rings. As I've noted in other threads, this is a common mistake made in rock climbing when setting up a top rope anchor system. The lateral force applied to the anchor points can actually exceed the weight of the climber due to mechanical leverage. Then add in shock loads (from a falling climber in rock climbing, or jerking tubes in boating) and you have incredible forces being applied to your rings and transom.

Here's a nice intro to the concept. Read the first part of this page:

http://www.chetwynd.info/other/anchors.htm

Many climbers have been injured or killed by "two connected anchor" setups like that. I know the transom and those rings are supposed to be the strongest parts of the hull, but I don't want to subject my transom to abnormal, leverage-multiplied forces when it can be so easily avoided with a dedicated tow ring.

[ajholt7]

After installing my transom lights I know how thick the back of these boats are. I wouldn't hesitate to pull from anything bolted to the back of these boats.

[IDBoating]

After installing my transom lights I know how thick the back of these boats are. I wouldn't hesitate to pull from anything bolted to the back of these boats.

If you're using one of those "connector ropes" you could be microfracturing the gel coat or fiberglass. You could also damage the rings without damaging the fiberglass at first.

Example: I asked someone to connect my ATV's winch line to our dock ramp so we could winch it up the beach for winter storage. We've done this for years and it works great. But this time they ran the cable through both of the handles on the ramp and then clipped the winch line back onto itself, forming a triangle exactly like the one formed by these outboard tow ropes. Result: The ramp moved a little and then the galvanized steel handles bent out of shape TOWARD EACH OTHER (but not toward the ATV), and ripped themselves off the ramp! They were almost flattened. They looked like someone had intentionally pounded them almost flat with a hammer. There was some SERIOUS lateral load on those handles, and they weren't small.

If I needed a reminder of why not to use those outboard towing straps on my brand new wakeboat, that certainly did it.

YMMV!

[ajholt7]

I think the forces would be different with running the rope through the rings like you stared that you did, as opposed to the rope ends terminating at the rings. Running a rope through both rings would certainly try to pull the rings inward to each other.

[IDBoating]

I think the forces would be different with running the rope through the rings like you stared that you did, as opposed to the rope ends terminating at the rings. Running a rope through both rings would certainly try to pull the rings inward to each other.

Perhaps, but the climbing website I cited does NOT run the rope that way. Check out the drawing... the ropes terminate at the anchor points with no cross member.

I will not be subjecting my boat to those potential forces.

[talltigeguy]

The other problem is that using devices like that puts a HUGE amount of strain on those d-ring.....

As far as evidence of this happening on any of these boats...I have never heard of the D rings failing. They are way overconstructed for the job of pulling a tube. It is a nice theoretical concern because a harness will multiply the forces against the D rings, but it has never been reported. So there is even less evidence for that being a possibility than the ski pylon failing. Again, if anyone has pics of those failing in this manner, I would be happy to eat humble pie.

At least I have heard of a ski pylon that had more than gel coat cracks, but don't know what caused it. A friend of mine saw it at the dealership on a boat and did not take a picture. The boat was generally in trashed condition, so I suspect it was the result of abuse, but never knew what happened.

It is killing me to see the gyrations people are going through to prevent an extremely rare problem that would cost as much to fix as it would to prevent it. A pound of prevention is worth a pound of cure...in this case.

[ajholt7]

If I were climbing rocks I might be worried about this. Pulling tubes has never damaged a d-ring that I know of. They lift the boats by them. If they were worried about preventing latteral forces the d-rings would be on the top for lifting.

[zad0030]

I think any tournament slalom skier exceeds the forces on the pylon that a tube under normal circumstances would.

[skippabcool]

In reading the owners manual it points to the ski pylon on a v drive and refers to it as the "Water Sports Tow Pylon". On a direct drive it points to the post in front of the engine and calls it the "Water Sports Tow Pylon". My buddy with a dd uses that to pull tubes. What is the definition or water sports? Skiing only, if so why not call it the skiing pylon? It refers to the d hooks on the transom as stern eyes, nothing about towing.

Again the owners manual under towing safety it states that Tige is not responsible for damage to the boat or people from the use of a boom or extended pylon. I would interrput that as add on items that are not part of the boat like a barefoot boom, could be wrong. Then it says the transom towing hook is designed for normal water sports. There is nothing that is designated as a transom towing hook. Hook was not plural so it this a special hook? To me that means it is not referring to the stern eyes, again I could be wrong.


Looking at another manufactures owner manual it calls the ski pylon the watersports tow point. But there is a warning to use the pylon for water skiing only. DO NOT use for parasailing, kite flying or towing other boats. It never mentioned pulling tubes.


I know that tubes can have a lot of pressure but for pulling my kids around a slow speeds I think I will use the pylon making sure that it is always tight. I had to buy the socket after I bought the boat because when I got it the pylon was already loose. I do know that I have seen tubes pulled from lower points and as has been mentioned the rope tends to go into the wake and I have seen it pull the tube down causing it to flip or pull the cover off. It has happened to my littlest ones, not a positive experience.

[skippabcool]

Zad,

I like your signature. Common Sense is not so Common, very true. I think I see this everyday at work.

[Iwndr]

I think any tournament slalom skier exceeds the forces on the pylon that a tube under normal circumstances would.

I would think the same

[Ewok]

X3

[talltigeguy]

X3

I am just so cantankerous lately....

There is no way a slalom skier can put as much force as most tubes do. The weak link in a slalom skier is their capacity to hold onto the rope. Imagine yourself tubing and holding onto a ski handle instead of the rope tied to the tube. Try that next time you are out and you will see the forces on the tube rope are a lot more than a skier can generate. Then imagine a 2-3 person tube and it is even more. The people in the tube can be essentially seated into the tube where hanging on is not an issue and/or are in a lying position where they can put a lot more force on the rope than a skier trying to stay semi-upright.

It is not unusual for a tube to submarine as well.

[Ewok]

I am just so cantankerous lately....

There is no way a slalom skier can put as much force as most tubes do. The weak link in a slalom skier is their capacity to hold onto the rope. Imagine yourself tubing and holding onto a ski handle instead of the rope tied to the tube. Try that next time you are out and you will see the forces on the tube rope are a lot more than a skier can generate. Then imagine a 2-3 person tube and it is even more. The people in the tube can be essentially seated into the tube where hanging on is not an issue and/or are in a lying position where they can put a lot more force on the rope than a skier trying to stay semi-upright.

It is not unusual for a tube to submarine as well.

I see your point for a submarining tube but a regular tube with a regular sized person skipping across the top of the water seems like less stress. The slalom skier example is probably less than 1 full second of full stress but I guess this is an idea for the myth busters to prove or disprove. Anyone want to submit this idea to discovery or should I?

[Ewok]

My real world example of how I handle this situation is that I don't own a tube and I never offer to take people out tubing, so I have yet to pull a tube from my boat.

I did take the little ski pylon off my boat for the move and I noticed it is slightly re-enforced with that steel frame that surrounds the engine compartment hatch, it's not all fiberglass holding that on.