Posted on

Events & Items of Interest, February 18, 2022

Could this be a bee bole?

We invite your response to this inquiry. Please email info@thestonetrust.org.

Dear Sir/Madam,

I recently came across your very interesting article on bee boles. I am currently leading an archaeological survey on the island of Luing near Oban on the west coast of Scotland. A resident there took me to a slate ‘box’, a feature that I have not come across before and situated in in her garden. I wondered if in fact the box is a bee bole but having no experience of these, I thought that I’d ask the Stone Trust for an opinion. The box is on the sheltered east coast and away from prevailing winds.

Would it be possible, therefore, to have someone in the Trust to cast an expert eye over the image and description below, please?

If it is indeed a bee bole, the Trust would be appropriately acknowledged.

Set into a slope in an east-facing garden on the island of Luing there is a ‘box’ measuring 520mm wide, 400mm high and 500mm deep. It is composed from this slate slabs and front of the feature there is another slab that would have enclosed the ‘box’.

Whitney Brown and Serena Cattaneo construct dry stone walls. They tell Kim Chakanetsa about the physical skill, problem solving and patience required to master this ancient craft.

Broadcast by BBC World Service

Keeping Connected to the Global Walling Community

Enjoy walling news from Down Under! Read the latest issue of The Flag Stone, published by the Dry Stone Walling Association of Australia.

Challenge! Cutting a Bike Trail Through Granite

On occasion people send queries to which we try to get answers. The correspondence below details a successful try at stone cutting to make a safe passage for mountain banks. Thanks to Eric for asking and to Sam Brakeley and Hilary Dees, Stone Trust instructors and professional members who each specialize in trail building.

Hi Stone Trust,
My name is Eric. I’m a volunteer with the Ottawa Mountain Bike Association and the lead trail builder for a scenic trail built on a rock barrens.
I have a particularly challenging rock face to split.
See attached photo.

I need to carve out an 8’ bench-cut into this off-camber granite rock formation in order to make the existing ledge wider by 12-18 inches. To do so, I need to split off 12-18” along the dotted line to a depth ranging from 12 to 22 inches.

I plan to use feathers and wedges.
Here’s my question: should I drill and wedge both vertical(s) and horizontal cuts? If so, could I get a clean cut by hammering the wedges in sequence along all 3 axis as pictured in the attached image?

Any insights would be greatly appreciated.
Best regards,
Eric

Good morning Eric,

My name is Sam Brakeley, and I’m one of the instructors for the Stone Trust, and a trailbuilder.  Amy-Louise passed along your contact information and question. Here are my two cents.

First off, I guess I’ll talk bigger picture first…trying to remove material like you’re suggesting can be a frustrating process. Bedrock doesn’t like to give up the ghost easily. So minimizing the amount of splitting that you have to do is always easiest…not sure if there is a way around this section at all, but before you get into something like this…avoidance is always easiest! Simply Re-route!

However…if you must shape this section of rock, because there are no alternatives, taking advantage of whatever inherent weaknesses there are in the rock will make it easiest. I’m a little confused by your pictures, but I’m understanding from the email that you want to take the entire chunk of rock out shown in the first picture, and not just the smaller chunk of rock out of the middle shown in the second picture. Is that correct? If so…I would certainly not start with removing a middle chunk of rock. It looks like you’ve got three weaknesses (running vertically in the first picture)…lines where the rock has naturally begun to split, or spread, or rot. Take advantage of those, and use them to break your larger project into smaller ones. Do NOT start with a middle chunk – you’re fighting against too much rock if you try to take out that middle chunk of stone shown in the second picture first. Instead, in the first picture, start on the far left of the picture and gradually remove one chunk or rock at a time, using the weaknesses to your advantage.

Remember that feathers and wedges are exerting a spreading force, putting the rock into tension. If you try to remove that middle section shown in the second picture, and you drive feathers and wedges along all your axises (you’d have four lines of them – one across the top, one across the bottom, and two along the sides), two of those lines of feathers and wedges will be working direct conflict with each other (the two vertical lines along the sides you’ve drawn in). Now, they would be working along a natural weakness in the rock, but they’re still working in direct conflict with each other.

If, however, you start at the far left of the first picture, you’ve got open space on more sides of the rock, and can drive only three lines of wedges, each line working towards open space…a top line working towards open space in the front, a bottom line working towards open space above, and a line along the right working towards open space to the left. You’ve then allowed the rock you’re trying to remove room to spread, to split, away.

Does that all make sense?

In the end, will it leave a nice rectangular bench when it splits? Maybe. If you’re lucky. Or you may just shear off a funky sliver. Rock doesn’t really like to split away like this, and honestly it may require a lot of jackhammering too, to get to the bench you want. Regardless, it’ll be slow.

But best of luck, and don’t fight more rock than you have to, or bite off more than you can chew!

Hilary, any other thoughts?

Cheers,
Sam

Hilary Dees Weighs In

Hi Eric,

What a fun project! I second everything Sam mentioned about using feathers and wedges and I agree that will be a hard split to execute. Anytime you are trying to split in more than 1 plane it becomes challenging enough in a studio – never mind out on a trail with a 10′ drop off into a beaver pond behind you.

I’ve also found it challenging to drill holes in the crevices of rocks like you are suggesting. The bit tends to jump around more than I’d like and I never end up having it in the exact plane I want when it’s all said and done. If you do want to go chunk by chunk I would recommend bringing the hole away from the crevice a few inches.

With all that in mind…the technique I have found most successful for removing bedrock in the quantities you are describing is using some kind of cutting implement (cut off saw or large angle grinder) with a diamond blade. By making a series of kerf cuts and then knocking out the material you are able to remove the bulk of the stone (if not slowly and painstakingly) layer by layer until you get to your finished tread height.  This process has the advantage of allowing you to control the depth of each cut, you can attack the stone from multiple angles, and once you figure out which way the grain is you can space your kerfs farther and farther apart. It will be slow and dusty but I’ve gotten too many feather and wedges stuck in bedrock trying to make decisions based on what I can see and not knowing the whole story of what’s underground/what other forces are acting on it. A gas powered cut-off saw/concrete saw is my preferred tool, they are easy and affordable to rent and have a pretty deep cutting bed. (Kerf cuts in blue…for granite and a ~4″ deep cut I like to space my kerfs out every 2-3″ until I get a sense of the rock).

If you do want to move forward with the feather and wedges, I would recommend looking at this guide if you haven’t yet (https://trowandholden.com/wedges-and-shims.html) and until I know what the stone is going to do I tend to be more conservative with spacing my holes apart, that is having them closer together to help ensure success. I would likely have my holes somewhere between 6-12″ apart for this project if the only tools I had available were feather and wedges. I would also measure the bit so I knew how far down each hole was (electrical tape or masking tape works well for this-wrapped around the bit at the depth you are going for). When trying to line up multiple planes I find it helpful to put a stick or extra drill bits or rebar in the holes as I drill them to give me a visual cue about the angle I am drilling at. As far as order of operations, you want the planes of the stone to split at approximately the same time, so I would drill all your holes, put in all your feathers/shims and give them all a good whack. You’ll hear them become higher pitch as they drive deeper into the stone and that can happen unevenly. Going by sound is the best way I have found; find all the lower pitch ones and hit them a little harder, then hit on the higher pitch ones, and then go back and forth checking for the sound until hopefully you have a nice chunk of bedrock that pops out.  Having a small rock bar or pry bar around can be handy to persuade those chunks out of the ground if you need it.

Good luck!

The Outcome

Good morning Hilary and Sam,

Thanks again for the tips regarding the challenging cut into bedrock.

It took about 20 hours of labour between 2 of us to make the cut. We widened the tread by almost 2 feet by 6’. Luckily, a fault line ran horizontally inward the length of the existing ledge.
The first few pieces came off like a charm using feathers and wedges. The remainder had to be cut, drilled, wedged, sledged, and even yelled at. Figured out the grain 3/4 of the way.

We armoured the approach and transition out. We considered cutting a transition from the ledge to the smaller off camber exit but a nearby flat angled rock suggested an easier solution, especially since we’re absolute novice rock cutters.

Thanks again for your insights.

May all your cuts be straight and true,
Eric

HELP WANTED

Sandri Stone, Harrisville, New Hampshire

Sandri Stone seeks an aspiring, or experienced waller for a full time walling position.  We are looking for an aspiring level 1, level 1, or level 2 waller to work as a team with one of our experienced level 2 wallers.  We are looking for a self motivated, hard working individual, who is interested in expanding their knowledge and honing their craft.  We offer competitive pay, flexible scheduling, and a great working environment.  Sandri Stone is a small, up and coming, dry stone design and construction firm, with 3 certified wallers.  We are professional members of the Stone Trust and we are based in beautiful historic Harrisville New Hampshire, surrounded by lakes and mountains.  Contact John Sandri at 603-289-5927 or sandristoneco@gmail.com, and check out our website: www.sandristone.com.

Grignaffini Earthscape, Shelburne Falls, Massachusetts

Grignaffini Earthscape is a small landscape design/construction company based out of Shelburne Falls MA. grignaffiniearthscape.com

We specialize in the creation of outdoor spaces with locally sourced, minimally manufactured material, for the type of client that is looking to homestead their property in varying levels.

The majority of our work is the construction of dry laid stone walls, rustic stone stairs, Goshen patios and walkways, however, a percentage of our work is also the planting of trees, shrubs, and perennials. Ranging from planting small orchards, to installation of vegetable gardens, and planting of perennial edibles. A smaller percentage of our work consists of building locust fences and pergolas, to setting up greenhouses and the construction of root cellars.

We are looking for a full or part time team member

Work will involve:

– Stone work
– Planting
– Pruning
– Carpentry
– Using a skid steer
– Work with a laser
– And more

The Preservation Trust of Vermont

Seeking Field Service Representative for The Preservation Trust of Vermont

The Preservation Trust of Vermont (PTV) builds community through the preservation of historic buildings and the revitalization of Vermont’s villages and downtowns.

PTV is seeking a Field Service Representative to help achieve this mission by working closely with Vermonters on a wide range of historic preservation and community development projects. The Field Service Representative provides field-based technical assistance on historic preservation best practices; supports community-led efforts by providing advice, education, encouragement, and connections to other resource providers; and promotes and administers PTV grant programs. The ideal candidate will have a strong technical background in historic preservation principles and construction, good understanding of community and economic development, the ability to work independently and as part of a team, and solid administrative skills. More information here: www.ptvermont.org/fieldservicerep

To Apply: Send resume and cover letter to Ben Doyle at ben@ptvermont.org.

Application Deadline: March 15, 2022. The Preservation Trust of Vermont is a 501(c)3 status non-profit and an Equal Opportunity Provider.

Latest Episodes from Nature Revisited: The Podcast

If you haven’t already listened, we also recommend Episode 47: The Stone Trust. Or listen again!

Episode 62: Alan Bergo – The Forager Chef

Alan Bergo is most widely known as a culinary personality and authority on wild Midwestern food, especially mushrooms. In 2012 he launched his website Forager | Chef which now reaches over 1000 people per day, and allows him to connect with mushroom hunters and foragers from around the world. His recent book The Forager Chef’s Book of Flora features 180 recipes and over 230 of his own beautiful photographs, inviting us to explore the edible plants we find all around us. In this episode, Alan talks about his experiences in restaurant cooking, discovering his passion for foraged foods, and why we should all venture outside the supermarket and discover what delicious surprises nature has to offer.

Episode 61: Richard J. King – Melville’s Oceans

Richard J. King is the author of Ahab’s Rolling Sea: A Natural History of Moby-Dick and other books of nonfiction, as well as articles, reviews, and interviews. His works often explore the history of our relationship with marine life and the sea, and Rich has been sailing on tall ships for over twenty years, traveling throughout the North Atlantic and Pacific Oceans as both a teacher and a sailor. In this episode, Richard discusses the historical context of Moby-Dick, its place in the fabric of American culture, and why it is still in many ways as relevant today as it was when it was published in 1851.

Why listen to Nature Revisited?

Our friend Stefan van Norden discovers compelling stories about people connecting themselves and others to the natural world in which we live. Over the course of the past two years, he has interviewed a remarkable collection of luminaries across a range of human endeavor. Stefan’s guests reflect deeply on topics ranging from the famous gardens of Monticello and Brandywine to portraying nature in paint from the confines of a prison cell. From fly fishing to homesteading to the Appalachian Trail to poetry and philosophy in nature, you can hear thought-provoking conversations from people viewing life on Earth through focused and sometimes unexpected lenses. Each reminds us that we are part of nature.

We hope you’ll listen, too.

Scott Farm and Landmark Trust USA

If you’ve been to the Stone Trust Center in Dummerston, Vermont, you’ve been to our host site, the Scott Farm, a historic property preserved by Landmark Trust USA. The Landmark Trust USA is a nonprofit organization that preserves historic properties and makes them available as short-term vacation rentals. Consider a stay!

Together we share the mission of preserving and revitalizing our historic landscapes and cultures.

The Scott Farm viewed from road