Dry stone walling is such a scream?

Happy Halloween

Thanks to Ryan and Eric for this pic.

Before the advent of the arch . Part 5

Perce Rock before Roman times.

Perce Rock as it is now

When the right squared lintel opening failed they decided years later to reconstruct the undamaged left opening into a proper arch.

Before the advent of the arch. Part 4

http://www.pasthorizonspr.com/wp-content/uploads/2013/08/Entranceheader.jpg

Though there is evidence of a small number of true arches built in antiquity before Roman times, most acheologists back then considered the concept of the arch - illogical. 

Not only that, these naysayers made archilogical digs at anyone who claimed they'd uncovered one. 

Lintelectuals throughout that long dark archless period of history just kept telling the masons to keep repeating the same old design in more fanciful variations on the stone post-and-beam theme. 

http://en.wikipedia.org/wiki/File:Broch_Dun_Dornaigil%27s_door_lintel.JPG

Broch Dun Dornaigil 2000 BCE

http://jewelryandjunk.wordpress.com/2012/08/17/tl-17-the-lion-gate/

Lion Gate of Mycenae 1425 – 1190 BCE 

http://www.molon.de/galleries/Greece/Peloponnese/Mycenae/Atreus/img.php?pic=5

The Treasury of Atreus  - Mycenae -13th century BC

  

Archenge

I druid on photoshop.

Here is what Stonehenge could have looked like if they had just done a lintel bit more architectural thinking back then.

Before the advent of the arch. Part 3

Rainbows were corbelled

Before the advent of the arch. Part 2

The olden 'archless' MacDonald's 

Would they have had anything like MacDonald's back then, before the arch came along, and would it have taken off at all if they'd used two mortared lintel openings as their corporate logo instead ? I think not.

Before advent of the arch Part 1

Way back in history long long before the 'arch' came along as a concept (as a much better solution for spanning window and door openings in ancient buildings ) masons had to quarry and shape long heavy lintel stones and then hoist these huge rocks up into position very carefully. 

The span of the openings couldn't be very wide because of stone's inherent weak tensile strength as a building material. They might break with their own weight and come tumbling down.

Designs for stone structures back then must have been very limited. The ancient lintel-itects had no idea that a wonderful new age was to dawn with the Roman invention of the arch.

Things must have been very different before those arch-attachers came along.

Let's try to consider what that archless world might have looked like.

Arch # 17

A keystone-less arch.

People who explain arches to other people often like to point out how the keystone is the most important part of an arch. It's isn't . Actually it isn't any more important than any of the other voussoirs that make up an arch.  It's just that its often the last one to go in. 

Removing it is no more likely to have the arch fall down than removing any of the other stones.

There are many arches that don't even have keystones.

Arch #16

The Cemental Arch

The cemental arch was first built by the Italians who realized that a stone arch could be made without stones.

Arch # 15

 The Enemy's Arch?

Is there such a thing? 

Not really. There are only friendly arches. They all inspire and delight. They invite light in and allow interior space to expand, along with our imagination. It's hard to think of a negative thing ever brought about by an arch.

The enemy of the arch is someone who doesn't care as much about making them as smashing them or throwing stones at them, or pointing out their weaknesses and deriding the people who build them.

And the enemy's arch, if he tries to make one himself is more of an 'anti-arch'. It is a disconnect of unfinished ideas and projects, half truths and postured misinformation. Usually the span of development is stunted, compromised, narrow, and often halted altogether. 

Proper arches are structural and supportive and usually last a heck of a long time, unless they are purposely destroyed. There's a history of thousands of broken arch-laden castles out there in the world and most of them didn't fall down on their own. They succumbed mostly to aggressive, mean spirited, unreasonable, anti-social, 'anti-arch' activity. 

The people who built the lofty vaulted strongholds of history, the towering castles with arched openings (and even arched bridges) thought these structures would keep them safe from harm. 

But it didnt take long for the enemy to come along, determined to turn everything to ruins, the ghostly silhouettes of which are now a testament to the pointlessness of war. The lonely arches that are left standing are a poignant reminder that the enemy of the arch (and all that is beautiful and magical) has become nameless and insignificant, while the beauty of the true arch, however diminished, lives on.

Arch # 14

The Hot Wheels Arch

This was an original idea of mine back in 2004 that was considered for the focus of a professional walling demonstration at Canada's largest garden and flower festival show in 2005 - Two parallel walls joined by a spiral arch.

I photoshopped a plasticine model for the 'looping wall' idea (as it was first called) and planned how we were going make it. Cleverly, the cope stones going along the top of the wall became voussoirs as they went round the loop.

While we never got around to building it at Canada Blooms , a month before the show the 'hot-wheels' loop (as it came to be known) ended up being built by students of mine during a two-day workshop that was held at Landscape Ontario near Milton, Ontario, Canada, back in February 2005. We used a 16 inch diameter sono tube supported through its length by two 4x4s held at their ends with step ladders. 

Arch # 13

The Möbius arch

History was made on August 15th 2004 at the annual Scottish Festival in Fergus Ontario Canada. Members of the Dry Stone Walling Across Canada successfully attempted constructing the first Möbius arch sheepfold out of 20 tonnes of mica schist stone donated by Eisen Natural Stone..

I presented the idea of 'twisting' an arch as it connects two ends of a curved dry stone wall sheepfold in 2003 as a challenge to dry stone wallers in N.A. Scotland and England, to see if
it really could be done. The completed wall loop, with free-standing twisted arch, becomes a sort of mobius dry stone strip with essentially only one surface which continues around the wall, appearing to change sides every time it does a circuit of the loop. 

The main sheepfold, complete with stiles, was assembled on the Saturday Aug 14th and the Möbius arch part of the project was built the next day.

Twisting the shape of the wall as it went over the arch, took a lot of right brain activity and considerable dexterity. Our form was made of wet sand piled up on a raised platform and 'sculpted' into the twisted shape we wanted to achieve over the opening.

We had a pretty exciting time doing this project and lots of thinking hands and twisted minds worked together to make it happen. Sadly, the arch had to be taken down after the festival.
Dean McClellan Mike Patten, Bob Waller, Claus, and Joel Dick made an unimaginable shape take a tangible form. We are still looking forward to seeing a permanent  arch like this being done here in Canada or some other part of the world as methods of constructing it get more refined.

Arch # 12

The Butternut Squash Arch 2009

The butternut is a vegetable that lends itself well to creative arch building. It has length and hardness and it's tapered, which all helps towards making something structural with it. 

At all our DSWAC festival events in Canada we built things with kids, often with unusual building material. 

Maybe the butternut squash 'kid's project' at the festival in Grand Valley (where the grown ups built a dry stone black house) was the most unusual. To see this event go to...2009-canadian-dry-stone-wall-festival

I've always maintained that children should be encouraged to attend these events and should be part what we are doing to promote happy dry stone walling here in Canada. It's not all just about professional advancement and crawling through conventional hoops .

Abigail and her friend crawl through the 'Arch de Butternut', carefully avoiding being squashed.

Arch #11

The False Arch.

A 'false arch' is the name given to an opening formed by corbelling courses of stone from each side until they meet at a midpoint, where a capstone is then laid to complete the work. In this picture the big A 'arch' and a lot of the other openings are variations of false arches ( even the O opening in the R ). They are not true aches because they are not displacing the weight the same way a 'true' arch does.

The structural component of a false arch is dependent on the weaker tensile strength of stone. The courses of stones are merely inching over the opening, straddling it, rather than sending the force of the load in an arc around the opening, utilizing the material's stronger compressive strength .

Contra Vandalism

This is a 'guerrilla' cairn installation Sean Donnelly built the other day on the Grand river trail. He says " It's been a long time since I have built up a spontaneous cairn from a random stone pile but I have always sent you pictures when I have, so I'll keep that tradition.

"It feels good to just build for the love of it sometimes. It's tucked away up a creek bed in an opening that is pretty picturesque. I kind of wanted to draw attention to that space but not take away from it and also give people something to almost reward them for straying from the main trail and adventuring a little. It's 5' high and built from the stone in the creek, wild grape vine and urbanite (concrete) for the coping."

Sean used the existing materials around the area to build the cairn

John Scott wrote to say "The idea of hiding sculpture in the forest for others to discover is one of the most generous forms of art."

My thought is that this type of walling which I call "contra-vandalism", is a way of getting back at the chaos, destruction, meaningless (and yes often bureaucratic red tape) that surrounds us. It's doing something structural, beautiful and uplifting in our community without having to jump through a myriad of administrative hoops to get it approved.

Arch # 10

Heart Arch

Arch # 9

The Bridge Arch Retaining Wall

The basic 'arch shape' is very strong. A stone bridge can take a lot of weight because the arch is a fixed concave barrier to the downward pressure of gravity . Also, the stones in an arch are set on end, radiating slightly in such a way their strength and structure is maximized by their length relative to the direction of the forces coming down from above.

So then, why are there so few retaining wall applications utilizing this stronger 'concave' shape in the design. More importantly, why, in a wall that is supposed to hold back the horizontal force exerted by the ground behind it, are the stones laid flat? Shouldn't they be upright, standing on their ends the way they would if they were in an elongated bridge laid on its side?

Arch # 8

The Fall Arch

When we revisited Haliburton Ontario last week to see the permanent dry stone installation that was completed there this summer at the Haliburton School of Art, the colours were brilliant. I had only seen it in the summer and was pleased to see how beautiful it looked in the fall.

Not that it was a 'fallen' arch by any means.

The entire piece, entitled 'Unity Gate' incorporates a Gothic style arch surrounded by two swirling walls built with all the stones laid vertical. While students and staff are a bit sentimental about it, the arch is not actually a segmental arch but more importantly it is definitely not a cemented arch. It's permanent. It is a carefully laid edifice of stones all fitted together cleverly utilizing the principles of mass, gravity and friction. Oh and yes, there was one other important principal, that of having fun together which is something we need to hold on to here in Canada as wallers.

Last year at this time we held our 9th annual Rocktoberfest. I guess I am feeling a bit nostalgic. 

Greetings and thanks to all those who made those festivals, and indeed, the last ten years of dry stone walling across Canada so amazingly successful. Happy Thanksgiving!

Let's do some exploring along The Catenary Trail

Stan Wagon, a mathematician at Macalester College in St. Paul, Minn., had a bicycle with square wheels. It was a weird contraption, but he rode it perfectly smoothly. His secret was the shape of the road over which the wheels rolled.

A square wheel can roll smoothly, keeping the axle moving in a straight line and at a constant velocity, if it travels over evenly spaced bumps of just the right shape. This special shape is called an inverted catenary.

A catenary is the curve describing a rope or chain hanging loosely between two supports. At first glance, it looks like a parabola. In fact, it corresponds to the graph of a function called the hyperbolic cosine. Turning the curve upside down gives you an inverted catenary—just like each bump of Wagon's road.

www.sciencenews.org/article/riding-square-wheels

Just as a square rides smoothly across a roadbed of linked inverted catenaries, other regular polygons, including pentagons and hexagons, also ride smoothly over curves made up of appropriately selected pieces of inverted catenaries. 

As the number of a polygon's sides increases, these catenary segments get shorter and flatter. Ultimately, for an infinite number of sides (in effect, a circle), the curve becomes a straight, horizontal line.

Maybe this is how they moved the huge stones way back in ancient times. Maybe the first invention wasn't the round wheel but the 'catenary trail' which the stones rode over.

Arch # 7

The Catenary Arch

A 'catenary arch' is the curve a hanging flexible wire or chain assumes when supported at its ends and acted upon by a uniform gravitational force. 

It is very close to a parabolic curve. Apparently it is the strongest of arch shapes.

Hanging a chain is a great way to figure out the shape of this kind of curve if your building a dry stone arch as long as you are planning to build it upside down.

The word catenary is derived from the Latin word for "chain." The curve is also called the alysoid, funicular and chainette. My problem is that making a catenary curve using a chain gives you many different shapes depending on how sort the length of chain is. It looks like a narrow rounded gothic when the chain is a long loop. As it gets shorter it takes the form of different segmented arches and if it gets really short it becomes almost a straight line! Can anyone explain this?

Does this mean that a jack arch can also be a catenary? It can't be.

Is there any arc besides a pointed one that can't be amongst the catenaries?

Arch # 6

The Cat n Canary arch

 ( Not to be confused with the 'catenary arch', which we will think about tomorrow )

Arch # 5

helen-johnson

The Draconian Arch

This is the administrative permit barrier, the bureaucratic pile of official red tape, the arch-shaped LOOP of paperwork, that people have to jump through, just to try to begin getting the go ahead from a municipality to have a dry stone arch or bridge built in their community.

I'm thankful for the people who have managed to get through it.

It's much harder than building an actual bridge. 

Arch # 4

The Arch de Treetrunk

There was some discussion from many readers about yesterday's blog about whether a jack arch is actually a true arch. The answer is yes it. This is because the line of compression between the stones travels in some sort of arc even though the voussoir stones look flat on the bottom.  

As with this arch that I constructed between two tree trunks last summer, even though the 'arch' seems to be more of a droopy flattened inverted V, the 'stress' is still displaced through the stones in an arched shape.

Arch # 3

The Jack Arch doesn't have a traditional 'arch' shape at all. It's flat. While the Jack Arch requires more mass surrounding the opening to stop any spreading, it is still amazing to see tons of stone suspended in air this way. I took this photo of this stone house with the Jack Arch windows still in tact after all the wooden frames were gone. Sometimes we imagine it's the wood or steel lintels that keeps the stonework up. Not so. 

I have never built a dry stone Jack Arch. I wonder if anyone has?

Arch #2

I always wondered what the centering would look like in order to do an arch with a number of voussoir stones protruding into the centre of the opening.  Eathan Stebbins cleverly figured out how to do it.

Is there any other way to do it I wonder?

Arch # 1

I had been building dry stone arches for years, before I went to Mallorca in 2005, but I'd always thought you could only build them with flat stones or at least parallel bedded stones - not with roundish irregular stones. When I saw this arch entrance to a well near Deià I realized that arches could be made with almost any kind of stone. And the more difficult the stone looked, the less worked it was, the more genuine it seemed and the more character it had.

Willowbank

Peter Isherwood, Andrew Mason, Andrew Loudon, Dean Mclellan,Jeremy Spanninga, Dale Thomas , Evan Oxland, Neil Beasley, Menno Braam, John Bland,  Jason Pinard,  Brian Fairfield, Matt Carter, Kenneth Davies,  Andre Lemieux, and Patrick Callon participated in the building of a partial dry stone forge studio at Willowbank School of Restoration Arts in Queenston, Ontario last month. The project is supposed to be completed next year.

The Rock Rook

In the theme of castles and castellations, former walling students at Sara's Garden Centre collaborated this year with me on raising the height the dry stone turret that we started last year. It is built with hefty rounded granite and local madina sandstone. Somebody referred to it as a large dry stone 'Rook', and the name took.

Garden centre owner Kathy Kepler and her daughter climbed up the nearly completed tower to enjoy the new fairy tale castle