News and views on Greystones harbour and marina [SEE MODERATOR WARNING POST 1187]

Blanchflower

Dunphus wrote: »

According to the eurocodes structures are designed with an intended design life based on their design working life category, the concrete mix is then designed on an exposure class and there is a specific class for seawater structures which is based on corrosion due to chlorides. A structure like this would have a design life for at least over 100 years.

The report you have given is from 1973, I'm confused as to how this is applicable? Has there been talk of the concrete not being suitable? I did hear that some of the columns had cracked but that isn't related.

Listen Dunphus, concrete exposed to seawater is susceptible to its corrosive effects. The potholed concrete boulder manufactured in the batching plant on the north beach is evidence of this for all to see.

You see Dunphus my friend above the water surface, mechanical damage occurs by erosion by waves themselves or sand and gravel they carry, and by crystallization of salts from water soaking into the concrete pores and then drying up and Portland cement is not very good in a sea environment as sea water corrosion contains elements of both chloride and sulfate corrosion.

Alas I am compelled to report that the concrete constructed breakwater structures at Greystones Harbour are doomed. Doomed I tell you.


If only they had used granith to build the breakwaters instead of cement!

Jimjay

Blanchflower wrote: »

Listen Dunphus, concrete exposed to seawater is susceptible to its corrosive effects. The potholed concrete boulder manufactured in the batching plant on the north beach is evidence of this for all to see.

You see Dunphus my friend above the water surface, mechanical damage occurs by erosion by waves themselves or sand and gravel they carry, and by crystallization of salts from water soaking into the concrete pores and then drying up and Portland cement is not very good in a sea environment as sea water corrosion contains elements of both chloride and sulfate corrosion.

Alas I am compelled to report that the concrete constructed breakwater structures at Greystones Harbour are doomed. Doomed I tell you.


If only they had used granith to build the breakwaters instead of cement!

Oh well. In 25 years the harbour will look just like the old one and everyone will be happy.

Btw, the Romans used concrete to build harbours and some are still there today.

dr ro

Jimjay wrote: »

Oh well. In 25 years the harbour will look just like the old one and everyone will be happy.

Btw, the Romans used concrete to build harbours and some are still there today.

But the Romans hadn't technologically advanced to the stage of reinforcing their concrete with steel! Which causes faster erosion and degradation. Especially in coastal areas. According to my sources.(Life After People-History Channel)

Blanchflower

dr ro wrote: »

But the Romans hadn't technologically advanced to the stage of reinforcing their concrete with steel! Which causes faster erosion and degradation. Especially in coastal areas. According to my sources.(Life After People-History Channel)

Spot on dr ro! Your sources are indeed correct. I myself have read widely on this particular topic and would thoroughly recommend acquiring a copy of the excellent book "Corrosion of steel in concrete: prevention, diagnosis, repair" by Luca Bertolini, Bernhard Elsener, Pietro Pedeferri, Rob B. Polder. It really is a sobering read in the context of the harbour development.

Jimjay

Blanchflower wrote: »

Spot on dr ro! Your sources are indeed correct. I myself have read widely on this particular topic and would thoroughly recommend acquiring a copy of the excellent book "Corrosion of steel in concrete: prevention, diagnosis, repair" by Luca Bertolini, Bernhard Elsener, Pietro Pedeferri, Rob B. Polder. It really is a sobering read in the context of the harbour development.

Have you any evidence that the structural engineers and marine architects that design harbours don't have your advanced knowledge on the subject. Perhaps it may be wise if they hired your good self as an advisor to deal with the harbours demise over the next few years. It's a shame they didn't learn or read that book while studying for their degrees.

Blandpebbles

Ooooh it's an engineering nerd dance off!

Alan_P

Blandpebbles wrote: »

Ooooh it's an engineering nerd dance off!

No it's not. On the one hand you have Sisk, who have been been in business for 150 years, and whose civil engineers (who are actually professionally qualified in this stuff), know their company is going to be sued into bankruptcy if they get this wrong and the Greystones harbour (melts, is it?) in 20 years.

On the other hand, you have some random people on the internet, who are proposing various frankly bizarre theories about the longevity of concrete.

dr ro

Alan_P wrote: »

No it's not. On the one hand you have Sisk, who have been been in business for 150 years, and whose civil engineers (who are actually professionally qualified in this stuff), know their company is going to be sued into bankruptcy if they get this wrong and the Greystones harbour (melts, is it?) in 20 years.

On the other hand, you have some random people on the internet, who are proposing various frankly bizarre theories about the longevity of concrete.

The fact that it may be a theory you're not familiar with doesn't necessarily make it bizarre. I've no doubt sisk have dealt with the old disintegrating concrete issue. Regardless though, do you really think they'll still be around to be sued in twenty years if they haven't. Let's just hope they didn't use the fairy liquid as morticiser trick!

Jimjay

Jees, can we just concetrate on getting the darn thing opened in the next few months and worry about repairing it in 25 years time a bit further down the road?
If in 25 years it is a fully working harbour with exclusive appartments and yacht clubs then it wont be a problem repairing the odd bit of concrete.

Dunphus

Jimjay wrote: »

Have you any evidence that the structural engineers and marine architects that design harbours don't have your advanced knowledge on the subject. Perhaps it may be wise if they hired your good self as an advisor to deal with the harbours demise over the next few years. It's a shame they didn't learn or read that book while studying for their degrees.

That's what I was going for, I don't think it's fair to the engineers who designed this to claim that their structure is going to fall down after 25 years.

Alan_P

dr ro wrote: »

The fact that it may be a theory you're not familiar with doesn't necessarily make it bizarre. I've no doubt sisk have dealt with the old disintegrating concrete issue. Regardless though, do you really think they'll still be around to be sued in twenty years if they haven't. Let's just hope they didn't use the fairy liquid as morticiser trick!

Please forward me, by PM if you prefer,verifiable details about your qualifications in civil or materials engineering. As regards your 20 year question :- did you miss the part about Sisk being 150 years old ? They've been around that long and are still in existence after the worst crisis to hit their industry ever. Yeah, I reckon they'll be around in 20 years.

micandre

I've just carried out some googling. The revetment works of the harbour was carried out by Ashleigh Contracts. They look like they have a long history of Marine Civil Engineering.

Precast concrete looks like an industry standard.
http://precast.org/precast-possibilities/products/marine-products/
http://www.cpsprecast.com/cps/Home.html

disclaimer: I'm not a civil engineer. ;-)

Fiachra2

With all respect folks this discussion is probably a bit academic as the thing is built.
The information on its longevity (or lack therof) came from a very reliable source but one which cannot be disclosed. However it is done now. If it falls down in 25 years time it will be just another example of the incompetence of Wicklow County Council. There is not a lot we can do about it and its probably better to focus on getting the thing open to the public.

I would agree however that it would be interesting to have somone who is truly independent to give an informed opinion on the lump of concrete on the North beach!

dr ro

Alan_P wrote: »

Please forward me, by PM if you prefer,verifiable details about your qualifications in civil or materials engineering. As regards your 20 year question :- did you miss the part about Sisk being 150 years old ? They've been around that long and are still in existence after the worst crisis to hit their industry ever. Yeah, I reckon they'll be around in 20 years.

No need for PMing, I've already revealed my sources as being a documentary on the History Channel. I didn't realize qualifications in civil or materials engineering were necessary in order to comment in this thread. I was merely picking up on a point made previously concerning Roman construction methods. As regards my 20 year question and your repeating your sisk being 150 years old and still around after the worst crisis etc, first of all, it's not "after" yet, and secondly, being 150 years old doesn't mean they'll be around next year let alone in 20 years. Of course I'm very likely wrong as I've no experience in construction or construction companies other than being aware the construction industry is currently on it's knees, and several other large construction companies have gone under. What makes you so confident? Are Sisk too big to fail?

Dunphus

Fiachra2 wrote: »

With all respect folks this discussion is probably a bit academic as the thing is built.
The information on its longevity (or lack therof) came from a very reliable source but one which cannot be disclosed. However it is done now. If it falls down in 25 years time it will be just another example of the incompetence of Wicklow County Council. There is not a lot we can do about it and its probably better to focus on getting the thing open to the public.

I would agree however that it would be interesting to have somone who is truly independent to give an informed opinion on the lump of concrete on the North beach!

It seems like it would be SM Morris biting the bullet if anything did go wrong seeing as they batched the concrete (Which is GGBS not sulfate resisting concrete which has been all but replaced by GGBS - http://www.ecocem.ie/index.php?p=technical&q=durability). Clearly I'm skeptical about the whole thing and without knowing the source I think it is just rumor and speculation.

If your source can't be named maybe there are legal implications and this sort of information shouldn't be up on a public board?

Either way I won't argue about it here. Perhaps at this point a thread in the engineering section would suit it better. Or Blanchflower are you a structural engineer? Feel free to PM me your reasoning in less layman's terms, and I don't mean that in any condescending way, I have a genuine interest in the matter.

As for the concrete block on the North beach, whereabouts is it? I'll have a gander at it to satisfy my curiosity!

vinpaul

Fiachra2 wrote: »

With all respect folks this discussion is probably a bit academic as the thing is built.
The information on its longevity (or lack therof) came from a very reliable source but one which cannot be disclosed. However it is done now. If it falls down in 25 years time it will be just another example of the incompetence of Wicklow County Council. There is not a lot we can do about it and its probably better to focus on getting the thing open to the public.

I would agree however that it would be interesting to have somone who is truly independent to give an informed opinion on the lump of concrete on the North beach!

What's this about the lump of concrete on north beach . Has it come from harbour. Won't be going up today for a look. It might be washed away after all this rain!!

Fiachra2

Its about 100Mts up the beach from the entrance. Just past the rock armour. I dont think it came off the wall. It was probably in with the rock armour and got washed away.

By the way we have no passed 1000 posts on this thread.

Annasopra

Could we all stop bringing in alleged stories with no source. Scaremongering through rumours and innuendo will not be encouraged. Also please don't backseat moderate by saying what should and shouldn't be acceptable. If you see a post you have a problem with then report it

pixbyjohn

North Beach, Greystones November 2007 by pixbyjohn, on Flickr

pixbyjohn

Greystones 25-10-2011 by pixbyjohn, on Flickr

pixbyjohn

Harbour Master's Office, Greystones Harbour 25-10-2011 by pixbyjohn, on Flickr

RosieJoe

Off topic, when you look at the pictures from today you would never think it was the day after such bad flooding!

pixbyjohn

RosieJoe wrote: »

Off topic, when you look at the pictures from today you would never think it was the day after such bad flooding!

Good point, at least the drainage on this part of the harbour is efficient.

darter

Walked past the harbour today. Back to sweet fa happening. Seems to me that the finished parts could be opened up right-bloody-now for the public to access. No idea why we're not permitted to walk along the sea wall of the south side of the harbour.

It's a case of greasing the squeaky wheel - when GUBOH is vocal and active, things happen, when not, then not.

Need another push.

Mullie

Does anyone else think the harbour looks like a POW camp?

pixbyjohn

Mullie wrote: »

Does anyone else think the harbour looks like a POW camp?

It does yes, the lack of boats in the marina and the emptiness of the boat pens doesn't help.

darter

pixbyjohn wrote: »

It does yes, the lack of boats in the marina and the emptiness of the boat pens doesn't help.

Why ARE the boat pens empty??? What's stopping them being used?

I've learned an Irish expression since moving here - "to put something on the long finger".

The harbour completion is on the long bloody arm, never mind finger...

Fiachra2

I cant speak for the other clubs but in the case of the sailing club we have not moved because:
A) its not open
our season is about to end this weekend

With regard to GUBOH being quiet we are affording the developers and council a reasonable amount of time to complete certain aspects of their plans. I appreciate that many will feel that the time taken is unreasonable (bear in mind it was to be open in mid september originally) but in a spirit of co-operation we have to afford more leeway than we might have done in the summer months.
We have not lost interest and are still very much on the case!

Fiachra2

Heres an interesting take on the situation by one local councillor


http://www.greystonesguide.com/articles/article/6961207/160716.htm


Of particular interest is the last sentence of the last slide. Quote:

"Delays happen. Dart campaign to 22 years."

This project has been going for 4 years. Can we infer that in the view of this councillor it wont be unreasonable if it takes another 18 years to finish?

danjo

Fiachra2 wrote: »

Heres an interesting take on the situation by one local councillor


http://www.greystonesguide.com/articles/article/6961207/160716.htm


Of particular interest is the last sentence of the last slide. Quote:

"Delays happen. Dart campaign to 22 years."

This project has been going for 4 years. Can we infer that in the view of this councillor it wont be unreasonable if it takes another 18 years to finish?

I also thought the following bullet point was interesting:
Greystones. Virtually no taxpayers money, new harbour built as Town ‘Icon’ and central feature.
I am to assume that a councillor does not view WCC funding of the PPP as spending taxpayer's money?