Ski pole for tube attachment

Sparike

Seaman Apprentice
Joined
Aug 29, 2019
Messages
38
I've read where it has been done with no issues, I've read where it is the worst thing to do, but I've never came across a thread that explains why, or someone that has had bad experience. All I want to do is get the rope out of the water so it's not spraying in the kid's face
 

jbcurt00

Moderator
Staff member
Joined
Oct 25, 2011
Messages
23,477
Tube submarines and either the tow rope snaps or the ski pole does. Neither projectile is passeger friendly....
 

rallyart

Lieutenant Junior Grade
Joined
Jun 7, 2008
Messages
1,150
There are a few options to keep the rope out of the water. The best might be a spinner float in the line from the boat. Booster Ball is one type of these. You could use a tow pylon but it must be a very good one that is supported and braced almost to the attachment point, or one on a competition style tow ports boat. Anything less and it will fold, which really messes up your watersports day. The third option is attaching the tube to a tower which will probably not fold but will tear the top deck apart on your boat as you put a few thousand pounds of force at the top of a five food lever.
A tube submarining can stop your boat and break a 2500 pound tow rope. It's much more load than a competition slalom skier can put out. My advice is to start with the assumption that tubing is a 'wet' sport and that is it's purpose. Tow them slow over huge bumps and watch the riders fly straight up. There is a certain joy in punishing your friends and kids in this simple way.
 

Superchief

Cadet
Joined
May 13, 2013
Messages
20
a few ski boat towers have been damaged by a submarining tube, the main pole/pylon in the middle of a Mastercraft can take the hit, the rear tow hook is also supposed to. Ultimately it's the boat owners/drivers responsibility to always watch the rider through a mirror.

I inform anyone that rides a tube behind my boat, that tubing is not for your entertainment, its for mine. If you don't like it learn to ski.
 

ahicks

Captain
Joined
Sep 16, 2013
Messages
3,323
a few ski boat towers have been damaged by a submarining tube, the main pole/pylon in the middle of a Mastercraft can take the hit, the rear tow hook is also supposed to. Ultimately it's the boat owners/drivers responsibility to always watch the rider through a mirror.

I inform anyone that rides a tube behind my boat, that tubing is not for your entertainment, its for mine. If you don't like it learn to ski.
No truer statement ever spoken!!! If you aren't entertaining enough at our current speed, I'll bet I can find a speed where you will be! Kidding of course. But the tuber behind my boat doesn't need to know that.... -Al
 

Scott Danforth

Grumpy old guy who plays with boats
Joined
Jul 23, 2011
Messages
34,872
its simple physics

a skier will put a maximum of 400# of force on what ever a ski rope is attached to. that is the maximum strength that someone can exert holding onto the rope before the ski handle is pulled from the hands. so if a skier dumps and hits the water and holds on, the rope is pulled from their hands and no damage to the rope or tow boat.

when a tube submarines (not if), it becomes an underwater parachute and instantly comes to a stop. it will put up to 4000# of force instantly onto what ever the rope is attached to because that is the breaking strength of the rope. the transom hook is designed for about 2500# of pull. the two transom eyes are designed for over 3X the boats weight.

boats with wake board towers have been pulled over by tubes

wake board towers have been ripped off boats by tubes

wake board towers have collapsed onto people by tubes

transom tow hooks have been pulled out or bent by tubes

ski pylons have been bent and ripped loose from the boat by tubes.

I have been in boats where a skier cuts and tips the boat on its side just from the 400# side pull. that was enough to scare the pooh out of me (literally) to the point where I did the calculations

I have been at the scene of the accident when the boat with the wake board tower is pulled over.

I only use the bridle attached to the transom for the tube. the wake tower is for skiers and wakeboards only

if water is spraying in the kids face, either your rope is too short, or you are over the 20mph recommended limit for pulling tubes
 

oldmanram

Recruit
Joined
Jul 30, 2020
Messages
5
Yes it is physics , and mechanical engineering,
this is the inside of my installation , 1/8" carbon graphite reinforced composite ( epoxied to fiberglass ) to spread the load out , plus where the tow hook was originally (an additional 1/8' thick stainless bar stock on top of the composite to spread the load out even more . At 20.5" to the tie point on the pylon (fulcrum) , with 8" from fulcrum to the bottom plate. This gives a mechanical advantage of 2.5:1 , 4,000lb X 2.5:1 = 10,000lbs of force. You can see why I added the Stainless Steel plate !! This setup has a season on it , and I submarined the tube once , at low speed. But it got my attention, however the pylon suffered no permanent damage. I am however contemplating cutting another 4-6" off , 2 reasons
1) To reduce the mechanical advantage
2) The tube rides a little high in the front , I use a 3 person tube, and when going into the wind it CAN or DOES get a little light in the front , cutting the pole down a little will reduce this.

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