Hi guys, I need to install floating pontoons along a non tidal stretch of river. 1000mm wide on plastic floats. All galvanised using open grid flooring as the top. Pontoons will be fixed to scaffold poles or similar with a ring to allow up and down movement. Has anyone had any experience with this type of thing?

I made some pontoons that were 1500mm wide and 10m long. 100x100x6mm angle iron, Kennedy grating and hot dip galvanised. Floatation was 205ltr plastic drums.

Did you need to ballast the drums for stability?

No. The structure was wide and heavy enough to be stable. I had left enough room to get at the drum-tops in case they needed a bit of ballast but my sums worked out fine!!

Do you think 1000mm is wide enough? We need 60 of these along a river!!

What sort of boats will be tied-up? Any services (electric/water?)on the pontoon? Will folks be leaving stuff on the pontoon? Will they be open to the public? Or locked for 'members only'? Can you ensure that some pillocky-tit won't decide to tie his 40t barge alongside? Any current?

[Edited on 5/7/14 by owelly]

Private moorings for members only, service bollards for electric and water. These will be mounted to the pontoon, possibly on a steel plate bolted to the side. The river is an inland waterway with very little current. There will be some 45ft plus narrowboats being moored.

I'd suggest you get someone who knows how to calculate relevant loadings etc to do the sums for you. Fine to chuck a couple of scaffold poles in if its for personal use, but sounds a bit more than that

ATB

Simon

I'd say 1000mm may be a bit too narrow. Imagine two folks tying to pass each other. Worse if they are carrying something. And worse still if they are manouvering the service bollards...... People also tend to dump stuff off their vessels onto the pontoon. Bags of rubbish, trolleys for moving stuff, water and fuel drums etc. Even though they're only there temporary, it's long enough to cause a problem on a narrow walkway!
Would mounting the service bollards to the outside of the pontoon make them vulnerable to damage from clumsy boat-folks? Are these for 'permanent' users?

Had similar job and scaffolding poles are far too light. You need HD 4inch poles filled with concrete.

I may have to consider using 205litre plastic drums, I could increase the width, would you mind sharing your design with me? This is a personal project Oma small budget!

It was over 15 years ago so I doubt I'll have any drawings floating (pun intended) about.
They were very basic frames with the drums fitting up inside with stainless straps under them. 'My' pontoons were designed to be floated up to the piles and then frames bolted to the side of the structure to hold it whilst still being able to move up and down with the tide.
I used the steel stock-holders weights to work out how heavy the structurs were, and basic school physics to work out how much air was needed to keep them afloat.
If there may be liability issues, make sure all your figures are correct or get a grown-up to approve them!!

Plastic drums? 4" poles? Galvanised angle iron?

What's wrong with a bit of concrete?:

http://en.wikipedia.org/wiki/Mulberry_harbour

What a pain in the bottom! Built a ladder frame, 6mx1m, it rolled straight over! .....shallower floats....floated fine, very unstable to stand on. Thinking of increasing width to 1500mm and running floats cattermeran style??????

how about adding some bottom ballast by part filling drums with water

quote:

---

Originally posted by dilley
What a pain in the bottom! Built a ladder frame, 6mx1m, it rolled straight over! .....shallower floats....floated fine, very unstable to stand on.

---

quote:

---

Originally posted by adithorp

quote:

---

Originally posted by dilley
What a pain in the bottom! Built a ladder frame, 6mx1m, it rolled straight over! .....shallower floats....floated fine, very unstable to stand on.

---

This thread is useless without video...

---

quote:

---

quote:
Originally posted by adithorp
quote:
Originally posted by dilley
What a pain in the bottom! Built a ladder frame, 6mx1m, it rolled straight over! .....shallower floats....floated fine, very unstable to stand on.


This thread is useless without video...



Preferably shot from a head mounted GoPro with audio

---

God! Is there nothing in the world that locostbuilders is not a wealth of knowledge on!

Stephen Hawking should become a member. Those big questions posted on here would be solved in minutes!

For the record, I did have a swim yesterday!