Drawbridge style pier (fishing jetty)

[Primus983]

Hi!

So i got an idea for a spring project, and that is a riversyde fishing cottage with a drawbridge style pier. Because it is a huge and fast flowing river it is imposible to install poles for a pier and a floating pier would just be washed away. So i came up with a drawbridge style pier. I never build something like that so i need some good advice and if someone could come up with a blueprint that would be awesome. I drew up something fast to get an idea of what imtalking about, here is the drawing.

P.S.: The pier messurments are like 3m lenght and 1,5m width.

What do you think? Your input about messurmentsis and other info is highly requested

Thank you!

 

[Brigade77]

Why a drawbridge type arrangement & not just a solid, well built platform on the bank?

If you really need to, lots of canals in the UK have ingeniously simple cantilever & swing type bridges whose designs could be adapted.

 

[Primus983]

A solid is out of the question because its a river deep 4m+ with a solid drop, and a lot of debry starts going when they open up the dam, also with a flow rate of 100m3 per sec plus and a huge tide variation it would be destroyed in secunds. Also the area is accessible by boat or a 2km hike.

 

[Primus983]

About the bank platform... I would dig out a foundation and fill it with concrete. Size 2x3m and build a small cottage on top of it.

 

[Brigade77]

Doesn't make any sense to me.

 

[Tigercubrider]

You will need a lot of winch power or counterweight to make it easy to use

It is easier to have the vertical post near the pivot and then a horizontal beam pivoted at the top, holding the end of the drawbridge up by chains or cable. The rear of the beam extends outwards towards the bank, short enough to allow the horizontal beam to go vertical. Adding weights to the land side of the beam allows a balance to be obtained so that the effort to move the bridge is minimal

Obviously one beam and weight each side, braced to form a structure

 

[Primus983]

Doesn't make any sense to me.

So how would you do it? With no machinery to place the poles into the water? Also to prevent the giant logs that the river carries and the tides to destroy/flood the pier?

 

[Brigade77]

You will need a lot of winch power or counterweight to make it easy to use

If he were to use an electric motor for the winch mechanism then you can get approx 3hp max from a 240v supply. Would it be better to use 3 phase or a generator?

 

[Primus983]

You will need a lot of winch power or counterweight to make it easy to use

It is easier to have the vertical post near the pivot and then a horizontal beam pivoted at the top, holding the end of the drawbridge up by chains or cable. The rear of the beam extends outwards towards the bank, short enough to allow the horizontal beam to go vertical. Adding weights to the land side of the beam allows a balance to be obtained so that the effort to move the bridge is minimal

Obviously one beam and weight each side, braced to form a structure

I drew it realy fast and not in detail, but o get what you are saying. I intended to place 2 poles bound with a traverse on top and for stability a cable fixated from the bottom to the to top or maybe 2 diagonal legs for each pole. For a minimum effort to lover and rise the bridge i would use a counterweight (sand or gravel sack) the pier would be minimal weight because of the wood. But please, draw up a design and upload it here

 

[Primus983]

If he were to use an electric motor for the winch mechanism then you can get approx 3hp max from a 240v supply. Would it be better to use 3 phase or a generator?

I thought about that also. But that would be unnecesarry because if i use a counterweight its childsplay to lower and riste the pier. I think it would weigh like 250 to 300kg. The wood i intend to use is preety light. Its not hardwood

 

[Brigade77]

So how would you do it? With no machinery to place the poles into the water? Also to prevent the giant logs that the river carries and the tides to destroy/flood the pier?

I would first of all have to question my sanity. Why do I want a retractable platform over the water where it can only be accessed by boat or a 2km hike?

 

[Brigade77]

I thought about that also. But that would be unnecesarry because if i use a counterweight its childsplay to lower and riste the pier. I think it would weigh like 250 to 300kg. The wood i intend to use is preety light. Its not hardwood

Ditch the whole drawbridge concept. Have you considered some sort of rope bridge?

 

[Primus983]

I would first of all have to question my sanity. Why do I want a retractable platform over the water where it can only be accessed by boat or a 2km hike?

Its all for the fish my friend. The area is known to have 2.5m catfish and 1.2m pike

 

[Primus983]

Ditch the whole drawbridge concept. Have you considered some sort of rope bridge?

I need solid ground for fishing. Fighting monsters is hard worl and you need the footing

 

[Tigercubrider]

counterweight drawbridge

https://www.roadtraffic-technology.com/projects/fort_l/attachment/fort_l3/