160 replies to this topic

[ocd]

Bettina

It doesn't inspire confidence when you know they've cocked it up so many times in the past. Dry stone construction is a dying art unfortunately, I hope they get it right this time.

regards

               ocd

[FourWinds]

It's hard to believe that this can get any worse, but it keeps on happening.

I shall be making some calls next week.

[Bettina]

OCD, Four Winds,

Thank you both for your support.

A local paper carried yesterday a small article stating that "the Office of Public Works insisted its "intervention" will not only considerably improve the future stability of the monument but also ensure safe public access to the site. The OPW said its conservation design team at the Grianan of Aileach site included specialist archaeological and engineering consultants and that all work was being overseen by an expert team from its Heritage Service branch."

Words used in a statement to the same paper in 2003, after this section of the wall collapsed only a few months after they had finished work on this particular part of Grianan Aileach.
I do not believe for one moment, that their specialists have no expertise to restore a dry stone monument to its original design or that those employed by the OPW are not aware of the most basic guidelines of bricklaying and have been unable to improve their skills over the years.
Recently the OPW has acquired a piece of land in Buncrana to build a new office for the Department of Family and Social Affairs under the decentralisation scheme. I have no doubt, that this building will have a foundation and the skills applied will be superb.

[discordian]

Dear All

As a regular visitor to Grianan and from observing the work carried out over the past few years, it is clear that Bettina is being disingenuous - the photos of gaps
inside the entranceway are sections that the OPW have not touched - these are areas that were either rebuilt by Bernard or sealed up sections leading into the passageway - they are not examples of shoddy OPW work. Having said that - the use of cement on the uppermost platforms and top course is not the most attractive. I can't comment on the success or otherwise of the use of cement inside the walls as I have no expertise of same.

Regarding the tar marked stones on the dumped pile - from my observations there are several of these stones displaced within the walls already - owing to obvious earlier intervention by the OPW over the past 70 years - it is likely that these come from the walls. The archaeological report on the recent works - available to the public at the DEHLG offices in Dublin - also state that cement was found on top of the passageways along with modern finds - indicating that very little of the work carried out by Bernard in the 19th century actually survived the 20th and underwent repairs throughout the 20th century.

[Bettina]

I posted these photos before. But to make sure, that there is no mistake about their date; they were taken in June 2006.
Both depicting the dismantling of the gate section.

As far as the survival of Dr. Walter Bernard's work is concerned, I do fully support a complete publication of all files concerning Grianan Aileach and the work carried out by the Office of Public Works from 1904 on as this monument went into State care and therefore into the care of the OPW.

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[Bettina]

As June came to an end work at the wall continued.  What looks like a one row outer stone facade started to emerge, followed by a trench and a mixture of gravel, soil and stones forming the opposite side of the wall.

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[Bettina]

At the beginning of July concrete had been pored into the ditch and metal rods inserted.  On the side forming the inner wall with steps and platforms for visitors to walk on , work was also carried out. The material use as binding component between the stone appears to be soil.

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[Bettina]

It seems very doubtful, that a wall build in such manner is able to withstand the forces working against this way of construction as well as the weather and the stream of visitors for more then one year. Additionally problems are likely to occur between this section with a concrete fill and adjoining sections on the left and right of recent work carried out, since they have been filled in with a random gravel, soil and stone mix, as seen in the part of the wall under repair.

If someone would set out to build a wall destined to collapse, that would be the way to do it.

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[ocd]

Bettina

Are they pouring in concrete right up to the tops of the reinforcing rods?

Concrete sections and dry stone sections together?

Dry stone with gravel and soil infill is one method of construction for such structures, but the infill must be packed down hard as the structure is built.
The best stones are used for the outer face, while smaller stones/rubble ect are used as infill.


ocd

[shiny]

OCD....................................How Do...............................On a wall this thick, would the builders still have to incorporate cross stones, to bind the inner and outer faces together?

[ocd]

shiny, on 4 August 2007, 11:15, said:

OCD....................................How Do...............................On a wall this thick, would the builders still have to incorporate cross stones, to bind the inner and outer faces together?

hi shiny

Dry stone walling has regional variations and terminology - in a cornish hedge we use "throughs" which are long stones that go long ways through the hedge for stability. We use these intermittently where neaded.
If you are building on the top courses the "throughs" will go all the way through to the otherside and face of the hedge.
If you building on the lower courses the "throughs" won't go all the way through due to the width of the hedge. But "throughs" are still used lower down to add stability, because they rest and are held in place by the "infill".
Ideally "throughs" should be long and flat to carry and spread the load, easier to find this sort of stone when building in slate, harder to find in granite.
The packing down of the infill is important, if that isn't done adequately the structure will collapse from the inside out.

Some of the pictures show several courses of stone with no infill in place behind them. If you build like this then add infill in larger amounts it's likely it wont be packed down and behind the stones adequately.
Ideally the infill should be built up and packed down a course at a time with the facing stones.

regards

ocd

[Bettina]

OCD,

It looks like, that they are pouring the concrete over the iron rods. They height of these rods indicate this and it concurs with last years work at the gate section. They are not using dry stone methods on either side of the wall. Going by what I can see and what has been done so far, concrete is slapped  between the stones forming the o7uter face of the wall with the solid concrete fill and the iron rods in the middle. But I can’t be certain, that the inner facade of the wall does not include soil or gravel elements.
Around six weeks ago, the OPW put up a green screen at the fence, surrounding the area they are working on, which makes it rather difficult to take photos of the work in progress.
The adjoining sections to the left and the right of the current work remain a mixture of stones, gravel and soil. The result of previous repairs. The gate opposite the section of the work carried out now, has a similar concrete fill with iron rods in between.
In an effort to explain it to myself, I split the circle of Grianan Aileach in to quarters.  One of the opposing sides is the gate and the section under going work again.. The second constitutes the sides flanking those sections. Since the latter are still flexible because of their fill and way of construction, I would expect, that one section would tear the other one down rather within month then years. Maybe the intention of the OPW is to replace this set of walls as well during next year and the following, although only recently repaired.
But cracks already occurred in the gate section on top of the wall between the stones and the concrete employed and stones on the outside of the monument from this section are falling out, despite that the re-opening of Grianan was only in April of this year. Particularly on the right side when standing in front of the gate, as well as on the inside of the gate on the same side, where a nearly 10 inch piece of concrete can be pulled out with surrounding stones.

Photos July 26, 2007

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[ocd]

Bettina

I would guess you could be right about them concreteing sections at a time until the whole lot is done.

A shame if that is the case, dry stone structures work if they're maintained and built correctly in the first place.

Thousands of years of building using these methods is proof enough, if it didn't work we wouldn't have used it.

regards

ocd

[Bettina]

Thank you for your replies, OCD.
What puts this particular restoration beyond any contemporary arrogance is the sad reality, that sections of Grianan Aileach are rebuild again and again. Cracks above the gate are already showing, in work carried out not even a year old.
The most mind-blowing part of this display of utter and absolute confidence in their own power is, that they know, they will get away with it and milk the little left of Irish heritage for every last penny, they can possible get out of it.

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[Bettina]

Between July 11 and July 26, the pile of leftover stones from previous repair works was removed from Grianan Aileach.
It was a substantial pile and it is gone.
It included original stones from at least 1101, stones Dr. Walter Bernard used in his reconstruction between 1874 - 1878 from the hill and a mix of the two bonded by concrete and broken loose within a year or two from the last three attempts by the OPW.

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