If you owned a lake.......

[Paul Evans]

..... I don,t, but i know a guy who does

So this is the problem, at the edge of the lake (20 Acres), British acres, ( I don,t want to get into the metric - imperial debate again).
There is a 30 degree bank down to water level, No problem.

From there the lake decends at 1m in depth for every 2m in distance from the shore.

So it would be ideal at 4m depth to practise GS entry, this is 8m out :11:

How do I build a pier from the bank 8m out, which has to stable (for students) and long lasting.

This is my idea

1. construct 8ft * 8ft scafollding frames, deck with scaffolding planks and float each on 1ft thick polystyerene blocks

2. Keep doing this until you are the correct distance, or greater, out from the bank.

3. the first landing stage would be custom made on posts to acommadate the bank and connection to the first floating frame.

Anybody see anything wrong with this????

 

[weekender]

you should be talking to your lawyer then an insurance agent. i imagine your liability insurance would be rather high. even in the UK. i would never even consider it in the US. IMO the premium would be so high you would have to run a full time operation to make enough money to pay it. of course im not a lawyer. i do sleep with one, though, and she is always talking me out of ideas just like this one.

 

[DBailey]

Might be better off buying a pre-engineered one. That would alleviate (sp?) some of the liability.

 

[Paco]

Oh, what the heck; go for it and let us know how it turns out. I don´t see and problems.

 

[Paco]

Oh, and if you´re looking for a lake to buy:

http://gordonjohnson.com/Quarry/

 

[Ber Rabbit]

You could probably practice GS entries in 3m, that's about how deep most pools are anyway. A pre-engineered dock would probably cost you less than all that lumber if you bought one that wasn't wood. My inlaws have one that's about 1m wide for the pier part with a 2m x 3m dock at the end. It's some sort of plastic I believe, can't exactly remember what it's made of but it's not wood. It's removable so the ice doesn't destroy it in the winter, you just pull the metal legs out of the fittings you sink in the lake bottom. We've had quite a few divers on there at once and never had a problem.
Just my .02
Ber :lilbunny:

 

[Paul Evans]

There isn't a great demand for this sort of thing "Of the shelf" in the UK, the American market is much bigger. If we imported it from the States the cost would be to high.

Liability is not a problem, permission would have to be granted by the local council and HSE, all plans would be submitted to them.

The lake is one of a group of three, the others are dived now and the entrance platform in the traing lake is made of scaffolding and is covered in scaff boards, fixied in 1m of water, with steps down into lake :11: very slippy as the steps are submerged. so useing the the same materials should not be a problem?

 

[Groundhog246]

I don't see anything wrong with your design. I will mention that polystyrene is NOT waterproof and over time will absorb water and lose flotation. Extruded (around here it somes in 2' X 8' sheets to insulate a house) is much better than expanded (the "white stuff" that looks like small pellets fused together). The marina we sail out of is in the process of repalcing all the foam floats on the finger docks (doing about 30 fingers @$60K a year they're a little more than 1/3 of the way through the project). What they're using is a polyethylene tube, looks like the stuff they use around foundations only about 2 feet in dia. sealed in 6" sections (each rib).

I've seen some very nice docks built using blue plastic barrels used to transport foodstuffs. They're not allowed to reuse for food and around here can be picked up failry cheap. I've also seen 45 gal steel drums used. They do rust (paint em before you launch), but have the advantage that you can weld fastenings to them. Visit http://www.divegilboa.com/ and there are some shots of their excellent platforms.

One tip for the steps. Get some manila rope (the old brown non synthetic stuff), 3/8" to 1/2". Route 3 or 4 grooves about 1/2 the depth of the rope end to end of the steps and use construction adhesive to bed the rope in the grooves. Gives great traction even after being submerged for.

 

[DBailey]

Well, here are my two cents then...

1. Linking multiple 8*8 modules together might lead to chain-like effect (segmented movement). Something like a piece of unistrut running down each side should stiffen it up without adding too much wieght.

2. Using the 1ft thick polystyerene blocks is my concern (versus a fixed dock). How many fully loaded divers can stand at the end without "sinking" the dock to an uncomfortable level (slope, bounce after someone enters, etc.)?

3. I would look into some metal grating steps or step inserts. Anything smooth will always develop a slick film on the top of it. Anything with traction will wear out the gear a little faster, but would make egress safer.

 

[DA Aquamaster]

Locally, the preference is to use surplus 55 gallon drums for floatation. You can fairly easily make a dock section consisting of a warren truss on each side with cross bars at the ends and between each of the drums. The sections can be 8 to 16 ft in lenght and can be pinned or bolted together. The end result is a stable dock that won't flex or bounce and that will support a lot of weight. Ice is also not an issue as if it is in a lake with little or no current it will survive winters frozen in the ice with no problems.

You could make the sections out of wood and secure the bits and pieces with deck screws, but welded steel tube works better and lasts longer with minimal maintenence.