Douglas stinky beach

[Happier diner]

56 minutes ago, Dirty Buggane said:

What happens when the beach gets to the level of the new wall ?. Extension and then when it gets to the hight of the new new wall admit defeat and clear the beach back

The beach can only get to the peak sea level. That's where nature will leave it. If these was no wall the beach would be on the prom. Yes you can pull it back but it will inexorably find its level again. 

[Kopek]

You forgot the Dlas beach Tractor? That will save lower Dlas!!!

[2bees]

Surely this wasn’t something they thought up without getting advice from people who actually know about this stuff, mariners and engineers, those sorts of people? 

[John Wright]

13 hours ago, Dirty Buggane said:

What happens when the beach gets to the level of the new wall ?. Extension and then when it gets to the hight of the new new wall admit defeat and clear the beach back

 

12 hours ago, Happier diner said:

The beach can only get to the peak sea level. That's where nature will leave it. If these was no wall the beach would be on the prom. Yes you can pull it back but it will inexorably find its level again. 

I think you’re both wrong, mainly because you’re conflating two issues.

First, let’s get rid of the nonsense that the Douglas beach level has risen due to the breakwater extension. Sure, any artificial structures built into the bay, piers, wharf’s m breakwaters, promenade walls and groynes, will change current flow and sand and stone drift. But if you look at photos of Douglas bay/beach over the last 170 years the beach height has varied cyclically.

The height of the sand and stones on the beach has no effect on the level of the sea.   It doesn’t increase over topping because the sea is higher. The level of the sea is changed by atmospheric pressure, wind direction, melting ice caps, tides.

The sea level is rising due to melting ice caps, due to global warming, and it doesn’t matter whether that’s human, natural, cyclical or a combination. That is also having an effect on the weather, pressure, winds, storms. BUT, ever since we’ve had promenades and sea walls there’s been overtopping.

Over topping can be water, from waves - and barriers or sea walls will reduce that risk, as will storage ponds to intercept the water before it gets to Strand Street, think sunken gardens, or stones, sand and debris thrown up by wave action. It’s probable that debris is more prevalent with a raised beach. And as they’re thrown up they can go higher than mean high water. You only have to look at the stepping at Point of Ayer.

The stepped sea wall, like Blackpool is an interesting one. It actually demonstrates the physics theory of waves dissipating their energy on a rising beach, artificial or not. In other words a higher beach is better for sea protection.

[Dirty Buggane]

Please show me where I mention or  indicated the depth of the tide, I am basically stating the beach will keep  on building up as and when the weather decides to throw up more sand/shingle/stones against any barrier placed in front of it. I am not conflating any issue.

[CrazyDave]

1 hour ago, John Wright said:

 

I think you’re both wrong, mainly because you’re conflating two issues.

First, let’s get rid of the nonsense that the Douglas beach level has risen due to the breakwater extension. Sure, any artificial structures built into the bay, piers, wharf’s m breakwaters, promenade walls and groynes, will change current flow and sand and stone drift. But if you look at photos of Douglas bay/beach over the last 170 years the beach height has varied cyclically.

The height of the sand and stones on the beach has no effect on the level of the sea.   It doesn’t increase over topping because the sea is higher. The level of the sea is changed by atmospheric pressure, wind direction, melting ice caps, tides.

The sea level is rising due to melting ice caps, due to global warming, and it doesn’t matter whether that’s human, natural, cyclical or a combination. That is also having an effect on the weather, pressure, winds, storms. BUT, ever since we’ve had promenades and sea walls there’s been overtopping.

Over topping can be water, from waves - and barriers or sea walls will reduce that risk, as will storage ponds to intercept the water before it gets to Strand Street, think sunken gardens, or stones, sand and debris thrown up by wave action. It’s probable that debris is more prevalent with a raised beach. And as they’re thrown up they can go higher than mean high water. You only have to look at the stepping at Point of Ayer.

The stepped sea wall, like Blackpool is an interesting one. It actually demonstrates the physics theory of waves dissipating their energy on a rising beach, artificial or not. In other words a higher beach is better for sea protection.

Are you honestly suggesting that if the sand and stones were returned to where they were 30 years ago that the seawall which is already there wouldn’t do a better job of dissipating the energy, keep the actual swell off the walkway and reduce the amount of debris being lifted over in the area from Broadway to the Empress?

[Happier diner]

2 hours ago, John Wright said:

 

I think you’re both wrong, mainly because you’re conflating two issues.

First, let’s get rid of the nonsense that the Douglas beach level has risen due to the breakwater extension. Sure, any artificial structures built into the bay, piers, wharf’s m breakwaters, promenade walls and groynes, will change current flow and sand and stone drift. But if you look at photos of Douglas bay/beach over the last 170 years the beach height has varied cyclically.

The height of the sand and stones on the beach has no effect on the level of the sea.   It doesn’t increase over topping because the sea is higher. The level of the sea is changed by atmospheric pressure, wind direction, melting ice caps, tides.

The sea level is rising due to melting ice caps, due to global warming, and it doesn’t matter whether that’s human, natural, cyclical or a combination. That is also having an effect on the weather, pressure, winds, storms. BUT, ever since we’ve had promenades and sea walls there’s been overtopping.

Over topping can be water, from waves - and barriers or sea walls will reduce that risk, as will storage ponds to intercept the water before it gets to Strand Street, think sunken gardens, or stones, sand and debris thrown up by wave action. It’s probable that debris is more prevalent with a raised beach. And as they’re thrown up they can go higher than mean high water. You only have to look at the stepping at Point of Ayer.

The stepped sea wall, like Blackpool is an interesting one. It actually demonstrates the physics theory of waves dissipating their energy on a rising beach, artificial or not. In other words a higher beach is better for sea protection.

Conflating? Me? I think you need to read your own post.

You have disagreed with me and then written 5 paragraphs that I agree with👍

[Happier diner]

1 hour ago, CrazyDave said:

Are you honestly suggesting that if the sand and stones were returned to where they were 30 years ago that the seawall which is already there wouldn’t do a better job of dissipating the energy, keep the actual swell off the walkway and reduce the amount of debris being lifted over in the area from Broadway to the Empress?

No it wouldn't. JW is correct. Its about sea level and not where the sand level is. The friction of the sand actually reduces the chance of over topping and protects the sea wall.

[John Wright]

1 hour ago, CrazyDave said:

Are you honestly suggesting that if the sand and stones were returned to where they were 30 years ago that the seawall which is already there wouldn’t do a better job of dissipating the energy, keep the actual swell off the walkway and reduce the amount of debris being lifted over in the area from Broadway to the Empress?

 

18 minutes ago, Happier diner said:

No it wouldn't. JW is correct. Its about sea level and not where the sand level is. The friction of the sand actually reduces the chance of over topping and protects the sea wall.

There are two recognised ways of dissipating wave energy, and trying to ensure over topping doesn’t happen. Both are used with sea walls of a location specific height.

1. bullnoses to reflect the wave energy back on itself.

2. a long sloping approach to the sea wall so the wave slows naturally. This can be sand, stones or concrete steps.

often various combinations/pick n mix are used.

 

[CrazyDave]

1 minute ago, John Wright said:

 

There are two recognised ways of dissipating wave energy, and trying to ensure over topping doesn’t happen. Both are used with sea walls of a location specific height.

1. bullnoses to reflect the wave energy back on itself.

2. a long sloping approach to the sea wall so the wave slows naturally. This can be sand, stones or concrete steps.

often various combinations/pick n mix are used.

 

I agree.

30 years ago we had a sea wall with a bull nose and a long sloping approach.

Now we have an approach which is steeper in the last 20m than it used to be, and which completely covers the bullnose making it useless.

I remain to be convinced that exposing the wall again wouldn’t be of some benefit.

[Happier diner]

16 minutes ago, CrazyDave said:

I agree.

30 years ago we had a sea wall with a bull nose and a long sloping approach.

Now we have an approach which is steeper in the last 20m than it used to be, and which completely covers the bullnose making it useless.

I remain to be convinced that exposing the wall again wouldn’t be of some benefit.

There would be some benefits yes. I think there would be less debris washed onto the prom that's for sure. Rocks dont tend to float very well and therefore lifting them 10m up and over a wall is less likely than pushing them over a small lip.

However there are drawbacks. A high seawall will take the full force of the waves hitting it. Consider when you look at waves breaking on a beach. As the wave runs up the beach it gets smaller until it eventually becomes nothing. This is a combination of the friction of moving the sand and the increasing level.

In high sea the effect is the same. Pushing all that sand and pebbles up the beach takes energy. All energy has to balance and therefore it is a given that this energy comes from the waves, thus reducing their energy in the process.

[The Phantom]

Rising sea levels would have a very small effect.  We're talking about a few cms and bearing in mind we have 7m tides, the  effect would negligible. 

What I will say is that there have definitely been more Easterly blowing storms the last few months than normal.  They're usually pretty rare, maybe a couple per year.  We've had them more or less constantly for the last few weeks.   These will have much more of an effect on the central Douglas Prom, rather than just at the North end which usually takes the brunt of the predominant SW. 

[TheTeapot]

Slightly odd to choose to start this project in January really, you'd have thought giving it a couple more months before starting might make a little more sense. Be pretty funny if we get a belting storm 2 weeks in and it washes all their work away.

[The Phantom]

13 minutes ago, TheTeapot said:

Slightly odd to choose to start this project in January really, you'd have thought giving it a couple more months before starting might make a little more sense. Be pretty funny if we get a belting storm 2 weeks in and it washes all their work away.

Tricky one.  It is likely to take a battering mid construction and I would imagine it will be fairly grim most of the time for the guys building it.  However, the GMP are likely to moan about it obstructing views and such like much less during the winter. 

[Fred the shred]

The GMP will moan whenever it is built the moaning has already started plus 101 different theories as to why, which and whatever especially with the current weather making people grumpy anyway.    It is refreshing to have something new to discuss it may even keep us going until Christmas.