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Dolosse – a South African invention used over the world

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Re: Dolosse – a South African invention used over the world

#21

Post by Robotbeat »

markdown wrote: post #17
nusq wrote: post #15

Finnally something I have knowledge of. Dolosse were invent in South Africa many years ago, but they are only one type of concrete block for wave dissipation and protection. Many others exist and some of them are patented and require the payment of royalties to be used. Anyway, in Portugal we do not use dolosse ever. We used it once in Sines deepwater breakwater, which suffered a catastrophic collapse in 1979. The pr…

> reinforcement with rebar is almost always a bad idea in ocean conditions While a little more costly, 316 stainless steel should work just fine.

Or composite rebar. Basalt fiber is sometimes used. Way cheaper than stainless and just as rust proof

Re: Dolosse – a South African invention used over the world

#23

Post by paduc »

kamma4434 wrote: post #22

The article is embarassing. Basically it says nothing but links to wikipedia. I’m saving you a click: https://en.wikipedia.org/wiki/Dolos

The blog article mentions 80 tons while the wiki article mentions 8 tons. Are they using the same definition of a ton ?

Re: Dolosse – a South African invention used over the world

#24

Post by nephihaha »

Cthulhu_ wrote: post #9
liotier wrote: post #8

Save yourself the blogspam, go directly to https://en.wikipedia.org/wiki/Wave-dissipating_concrete_bloc... and enjoy the whole collection !

A bit rude, this doesn't come across as spam but a genuine human sharing something interesting they came across. Peak old internet (2000s) content. The wiki article is very short and doesn't actually have more or better pictures.

Some people here think if it's on Wikipedia it's authoritative. Yours truly has written many Wikipedia articles, some translated into ten or more languages. I've seen how ugly it is behind the scenes there.

I miss blogs. They are omitted from searches now but are among the best internet search content. Threadinburgh is one of the best online resources about Edinburgh by far.

Re: Dolosse – a South African invention used over the world

#25

Post by lazide »

markdown wrote: post #17
nusq wrote: post #15

Finnally something I have knowledge of. Dolosse were invent in South Africa many years ago, but they are only one type of concrete block for wave dissipation and protection. Many others exist and some of them are patented and require the payment of royalties to be used. Anyway, in Portugal we do not use dolosse ever. We used it once in Sines deepwater breakwater, which suffered a catastrophic collapse in 1979. The pr…

> reinforcement with rebar is almost always a bad idea in ocean conditions While a little more costly, 316 stainless steel should work just fine.

‘a little more costly?’ Lulz.

316 is an order of magnitude more expensive than the crap used in rebar.

Re: Dolosse – a South African invention used over the world

#26

Post by sgt »

cookiengineer wrote: post #16

Not sure why Dolosse are so special? There's lots of different forms and shapes of wave breakers, like the Tetrapods [1] that you can find over here across pretty much every coast in Europe. Maybe I'm just not getting it why the Dolosse shape is superior? [1] https://en.wikipedia.org/wiki/Tetrapod_(structure)

Apparently the Dolosse works a lot better for high energy wave environments like coastline of SA etc. They are used here, and I am sure they considered Tetrapods and there was a reason they weren't suitable.

Re: Dolosse – a South African invention used over the world

#27

Post by bix6 »

Havoc wrote: post #19
walski wrote: post #4

In Germany (on the island Sylt) they recently removed all of these structures again after decades of them being a staple on Sylt's beaches. They were found to have no positive effect on protecting their shores. I'm having a hard time to find a good source to quote but look for: "sylt tetrapoden" if you want to dive deeper.

I find it hard to believe they have not protective effect. You can throw pretty much anything hard with an irregular shape down and it’ll help scatter energy

They don’t prevent erosion though which is the primary issue

Re: Dolosse – a South African invention used over the world

#29

Post by bix6 »

These are cool shaped but they don’t actually work; coastal armoring in general does not work as it does not prevent erosion. Sand replenishment is increasingly the path taken. Australia has an amazing pumping system (a jetty blocked longshore sand transport so they pump it around to the other side).

We could just stop building so close to shore…

Re: Dolosse – a South African invention used over the world

#30

Post by PaulDavisThe1st »

nephihaha wrote: post #24
Cthulhu_ wrote: post #9

Earlier quoted context omitted.

A bit rude, this doesn't come across as spam but a genuine human sharing something interesting they came across. Peak old internet (2000s) content. The wiki article is very short and doesn't actually have more or better pictures.

Some people here think if it's on Wikipedia it's authoritative. Yours truly has written many Wikipedia articles, some translated into ten or more languages. I've seen how ugly it is behind the scenes there. I miss blogs. They are omitted from searches now but are among the best internet search content. Threadinburgh is one of the best online resources about Edinburgh by far.

> They are omitted from searches now but are among the best internet search content

I use google search with &udm=14 to remove all AI elements in the results presentation.

Searching for "dolosse", the HN item is the 3rd link, and TFA is the 4th. They are preceded by Wikipedia, and a dolosse-manufacturer's page.

Not sure why you think "blogs are omitted from searches now".

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