Heavy Metal

[WIRiverRat]

After a few years of attempting to use a portable course in our river and it be destroyed by current, frequently changing water levels (changes of 7ft are common), and fishermen we got a group of skiers together to form a club, get proper permits and install a permanent course that will withstand the challenges of our river. I thought I would share some pictures of our installation from yesterday and will dare say we now have one of the most heavy duty slalom courses in existence.

 

A few details, each buoy is individually anchored by a 2in, 7ft long pipe. There is a steel weight inside the pipe that allows the buoys to move up and down with the changing water levels. The weight is attached to a stainless steel cable which attaches to a steel chain. The chain clips on to our subfloat which we put a machined aluminum plate on each end with a threaded rod through the middle so the sub floats will not get chewed up over the years from rubbing with wave action. The subfloat then goes to another stainless steel cable up to the bouy. If a buoy comes off the weight drops to the bottom of the pipe pulling everything down which we can easily retrieve with a magnet to the steel chain.

 

The course was installed off a barge using a vibro hammer on a excavator. We used GPS to place markers at the bottom of the river in the correct spot and had a diver place the anchor pipe on that spot so we could get the location correct to drive the pipe.

 

We began this project back in November and after many hours and countless meeting with the city/DNR to get our permits after that first pass was made I can finally say it was all worth it.

 

[DaveD]

That's awesome! That has to set the record for the most expensive course ever.

[skihart]

WOW! Now that is dedication to the sport! Very impressive. Nice work.

[Gar]

Totally bad ass!

[MISkier]

Awesome. Post a picture of the finished course and one with someone skiing.

[WIRiverRat]

I will have to get some pictures when we go out monday, already got our sets in today and tomorrow is supposed to storm. As for the price I am afraid to know what that really was, two of our members have a marine contracting business which is where all the support came from.

 

I will say this course has had an effect on skiing in the area in that when I moved to this area 4 years ago my wife and I were the only serious slalom skiers I could find, now we have a club of about 10 people, two of which have bought new pro stars, and I get calls from people all the time I have never even met wanting to come out and ski with us. If you build it on public water they will come...

[UWSkier]

Whereabouts on the river are you?

[klindy]

Wow! Hugely impressive!!

[PatM]

And I though us putting in a course through the ice was impressive. This is the mother of all course projects. Should give your number to Dr. Jim Michaels

[Andre]

That's definition of heavy duty right there!

I don't see a weak link or fuse to release the bouy if a prop would it them only SS cable.

Is there one ?

[WIRiverRat]

UWSkier, I am in La Crosse, come join us if you are in the neighborhood.

 

Andre, yes we put a weak link in to release in case of a major hit. We have a spring clip between the chain and subfloat. I think it is rated at 150lbs, would break away if someone were to really give it a tug.

[bishop8950]

That is impressive. That engineering! I had the same question on fuse link to protect boats, skiers and your beautiful underwater gear. Do you have one?

[bishop8950]

If it were me, the fuse would be on top of the sub float and there would be no metal from the sub float up.

[Gar]

Now it's time to surround it as needed to keep the waves out! (If you can!)

[UWSkier]

Nice. I'll definitely hit you up if I'm over that way. I'm in SE WI.

 

How much of the poles is above the river bed? Wondering how high you keep them to prevent sediment from building up over time.

[WIRiverRat]

The poles are just a few inches off the river bed. I don't have a good picture but we machined up some brass inserts the neck down the hole on the top considerably. We also flared the edges of that insert so the cable would not wear on it. The gentleman who helped me design this does work in bridges and dams for a living and was confident we would not have sediment issues. His bigger concern was getting minnows in the pipes. He said they have pulled up 12in pipes before that have full grown catfish living inside them that must have gotten in when they were small.