ROSKILDE - Shots around town

This morning I took a stab at trying to get some images off my camera (now my equipment bag is here and I have the cables) and converted through the computer at my billet and up on the blog here. I will warn you that I am attempting to do this via Windows XP (which I know absolutely nothing about) and also via Windows Photo Editor (same deal) - but the Danish version so I can't even read any of the menues or instructions. I think I have got the images reduced to useful sizes. (I've also got so many windows open here I can hardly keep track of what I'm doing!)

I also have some artifact images posted this morning over on the DARC blog that readers may have some interest in. I am just posting a few sample images of the roughly 175 I have shot over the first three days of the trip!

The first image was shot over in the Medieval part of Roskilde. Thats over by the harbour, to the west side of the stream that runs down from the plateau mentioned in yesterday's post. I was surprised at the number of timber framed houses with thatch roofs. The crossed crooks of timber also caught my eye as distinctive. Many of these buildings are narrow and long, obviously subdivided into individual appartments. There was one being offered for sale - a bargin at something about 1.5 million CDN. The red ceramic tiles are the standard roof covering here on houses of all ages. I have even seen warehouses with sheet steel patterned to look like the tiles.

The second is an art shot of the cathedral. It stands to the north of the town square, and as such buildings do, dominates the sky line. As the ground here is 'relatively' flat, it serves as a navigation landmark visible for miles. (My billet was roughly 3 blocks to the west, so it was always easy to find my way back on my bicycle wanderings.

I hope to be able to keep up these travelogues, but I'm not sure what kind of computer - internet access I will have as I move around Denmark. In about two hours I will be leaving Roskilde and grabbing the train for Ribe. The trip takes about 5+ hours, Ribe is at the opposite diagonal corner of Denmark ( SW bottom of the Jutland, near the German boarder.)

ROSKILDE - About Town...

It turns out the early Viking Age history of Roskilde is a bit vague, and not well represented in the artifact record. Looking to the geography explains this a fair bit. Roskilde is at the base of a long twisted inlet. The last ice age basically straped the region to the granite, but as the glaciers retreated, a layer of sand and rock was left behind. Most of Denmark is basically a huge sand bar and bog network. Old Roskilde is centered on a hill with one side that slopes down to the salt water. As might be expected, this leads to a gentle sloping beach, which has moved outwards steadily over the centuries. The shore is a roughly V shaped pocket to the north of the hill area. The hill falls off in a quite gentle slope to the inland (south). This elevation, combined with the sand subsoil and the ever present bogs, means that a lot of natural springs seep out on the north sid. Some of these are quite large still, and in early times created a small river that roughly cut the V of the beach in two halves. So the town developed on three related locations. There was an original port - market area on either side of the river along the shore. The western side has a low hill, with its one side falling off into the shore. Ideal for early period defensive works, which is exactly where the oldest 'Medieval' part of town is. It may be that the original ancient port complex was to the lower eastern side. The hill further inshore commands the area, so was the obvious site for latter royal and church structures.

It turns out that the earliest references to Roskilde run from roughly 1030 - 1050. The earlier settlement remains have never been found. For this reason, there were few objects in the museum from the core part of the Viking Age. From this late Viking Age period, through the Middle Ages, Roskilde served as and important centre for trade, political and religious power. The Catholic Church established a number of buildings here, centered mainly on the tall hill.
In the period bracketed roughly 1500 through to the 1600's, Roskilde fell on hard times. The port, with its shallow sloping beaches and low tides, was ideal for Longships. As shipping changed to the larger and deeper draft Medieval types, the need was for a deep water port. So the bulk of the shipping moved to Copenhagen, which eventually also became the capital and centre of political power. Roskilde was heavily damaged in wars with Sweden in the 1600's, and also was sweapt several times with devistating fires which leveled huge sections of the remaining town.
The oldest surviving buildings are down towards the harbour on the west side. There are a lot of thatch roofed (still!) cottages on narrow winding lanes. Mostly these go back to about the 1600's. The modern town centre had many of its original buildings destroyed, and other than the major chuch buildings, most of what is seen today 'only' dates to the 1700's. These are mainly brick buildings, but there are a good number of timber framed ones still in use. The layout of the town centre shows its medieval origins. The streets are short, often narrow, and quite chaotic. Many of the houses are sort of 'plunked down' with twisting laneways obviously put in after the fact to join the houses up. (The place I am staying for example, is surrounded on all sides by other house yards. You can only access it down a path too narrow for a modern vehicle - there is no car parking here.)

The house I am staying at (highly recommended!) is 14 Lille Højbondstræde. Thats about 3 blocks due west of the town square. This means I'm maybe 5 -10 minutes walk from the Viking Ship Museum. I have been able to borrow a bicycle, and this has greatly extended my working range. As might be guessed, I'm still keeping my 'farmer's hours', so I'm awake pretty early. This gives me time to run e-mail and write pieces like this. Mostly the museums open in late morning, so by 10 - 11 I have been doing research. After four or five hours, I'm getting pretty worn out. I grab some kind of late lunch, then have been touring around the bike and doing a bit of shopping. Normally have diner about 6 - 7 pm. Then have chance for maybe another couple of hours on the computer or just reading while the sun goes down.

ROSKILDE - About Town...

It turns out the early Viking Age history of Roskilde is a bit vague, and not well represented in the artifact record. Looking to the geography explains this a fair bit. Roskilde is at the base of a long twisted inlet. The last ice age basically straped the region to the granite, but as the glaciers retreated, a layer of sand and rock was left behind. Most of Denmark is basically a huge sand bar and bog network. Old Roskilde is centered on a hill with one side that slopes down to the salt water. As might be expected, this leads to a gentle sloping beach, which has moved outwards steadily over the centuries. The shore is a roughly V shaped pocket to the north of the hill area. The hill falls off in a quite gentle slope to the inland (south). This elevation, combined with the sand subsoil and the ever present bogs, means that a lot of natural springs seep out on the north sid. Some of these are quite large still, and in early times created a small river that roughly cut the V of the beach in two halves. So the town developed on three related locations. There was an original port - market area on either side of the river along the shore. The western side has a low hill, with its one side falling off into the shore. Ideal for early period defensive works, which is exactly where the oldest 'Medieval' part of town is. It may be that the original ancient port complex was to the lower eastern side. The hill further inshore commands the area, so was the obvious site for latter royal and church structures.

It turns out that the earliest references to Roskilde run from roughly 1030 - 1050. The earlier settlement remains have never been found. For this reason, there were few objects in the museum from the core part of the Viking Age. From this late Viking Age period, through the Middle Ages, Roskilde served as and important centre for trade, political and religious power. The Catholic Church established a number of buildings here, centered mainly on the tall hill.
In the period bracketed roughly 1500 through to the 1600's, Roskilde fell on hard times. The port, with its shallow sloping beaches and low tides, was ideal for Longships. As shipping changed to the larger and deeper draft Medieval types, the need was for a deep water port. So the bulk of the shipping moved to Copenhagen, which eventually also became the capital and centre of political power. Roskilde was heavily damaged in wars with Sweden in the 1600's, and also was sweapt several times with devistating fires which leveled huge sections of the remaining town.
The oldest surviving buildings are down towards the harbour on the west side. There are a lot of thatch roofed (still!) cottages on narrow winding lanes. Mostly these go back to about the 1600's. The modern town centre had many of its original buildings destroyed, and other than the major chuch buildings, most of what is seen today 'only' dates to the 1700's. These are mainly brick buildings, but there are a good number of timber framed ones still in use. The layout of the town centre shows its medieval origins. The streets are short, often narrow, and quite chaotic. Many of the houses are sort of 'plunked down' with twisting laneways obviously put in after the fact to join the houses up. (The place I am staying for example, is surrounded on all sides by other house yards. You can only access it down a path too narrow for a modern vehicle - there is no car parking here.)

The house I am staying at (highly recommended!) is 14 Lille Højbondstræde. Thats about 3 blocks due west of the town square. This means I'm maybe 5 -10 minutes walk from the Viking Ship Museum. I have been able to borrow a bicycle, and this has greatly extended my working range. As might be guessed, I'm still keeping my 'farmer's hours', so I'm awake pretty early. This gives me time to run e-mail and write pieces like this. Mostly the museums open in late morning, so by 10 - 11 I have been doing research. After four or five hours, I'm getting pretty worn out. I grab some kind of late lunch, then have been touring around the bike and doing a bit of shopping. Normally have diner about 6 - 7 pm. Then have chance for maybe another couple of hours on the computer or just reading while the sun goes down.

ROSKILDE - The Viking Ship Museum

(This post modified from one to the DARC group blog)This is the first in what is hopefully a series of field reports from Denmark. (Sorry if some of the charaters used seem odd - this is being typed from a Danish version keyboard.)

The first thing about the Viking Ship Museum - its ALL about Ships. Just ships. The complex is basically in four parts. Only the main 'Viking Ship Hall' appears to require admission. I had a comp anyway, so I'm not even sure if there was any cost. In the main building are four sections: the boat hall - an activity room - gift shop - temporary exhibits.

The boat hall has the ships. These are mounted on the steel frames that you have certainly seen photos of. I found the fames a bit of a pain. These do outline the hulls as they would have been when complete. They also cover over some of the detials on the joints, as the metal supports the timbers at both top and bottom. this is less a problem with Skuldeleve 1 (the ocean knorr). This is the hull that Paul Comptons 'Viking Saga' is based on.
The ships comprise the only artifacts on display in the museum.

In many ways the activity room was the most interesting. There are mock ups that you can climb into, the decks of Skuldeleve 1 and also number 2, the warship. The kids gravitate to the warship hull, which is larger inside and has shields and costumes to try on. The knorr deck is smaller (of course) but the cargo area is outfitted with a duplicate of the Mastermyr chest, the metalwork from Oseberg, a low tent cover over barrels and buckets. Some of these are open showing a cargo of glass work, pottery, grains. A very nice presentation over all.
Of most interest to our gang, there was a woman in this area working away on a WW loom. She is involved in a project to research production of a wool sail. I talked to her for about an hour, made a page of notes and shot a number of close in shots of her set up. Got some insight from her about weaving sails and some idea of the ongoing experiment. (Should I write this up here, or wait for a set piece lecture later...)

The outside areas make up the majority of the complex. There is a smallish building that houses the archaeological preservation lab, but it was closed (not staffed, or I would have tried to talk my way in).
There is a large dock area containing something like 20 or so various reconstructed boats. These range from a small one log duggout to the Ottar (based on number 1). Number 1 and number 3 (the coastal trader) are completely outfitted for sailing.
There are a number of various other Scandinavian VA boats reproduced as well. A very complete overview of lapstrake ships up to the early 1900's.

The last part of the complex is the working boat yard. This is a building roughly the size of the Wareham workshop, divided into two larger spaces plus offices and storage. A lot of work also goes on outside. Here was a large peg board arrangement with all the replica tools. They basically have copies of every known VA woodworking tool, thankfully for me each was labled with source, date and artifact number. (As these are replicas, I will be able to check back to the original artifacts for details.)
My pre-contact effort paid off best here. I was allowed to handle and record the tools. For the axes, I just made direct tracings of the profiles, as well as scaled photos. (Mind you, my normal inch-cm scale is also in the missing bag, so I had to use a cheap tape measure.) Again, I will leave the details to a later time or posting. The main thing of note was that their comparison of working these tools against the tool marks shows all the ships found at Roskilde were constructed using standard axes and then finished with planes. They also found that the small spoon bits for rivet holes need to be worked with a bow drill.

Today (Wednesday April 23) is my day at the Roskilde Museum. This will hold the majority of the artifacts from Roskilde. From what I have read otherwise, I'm expecting this collection to centre from the late Viking Age (post 1000) through to primarily the Medieval period.

There is also a tool museum in town. I think that collection is mainly after 1700 or so. I intend to take a look at that on Thursday.

The folks at my (quite excellent) lodgings had a spare bike in the shed. This has extended my range by a considerable amount. I have been up early in the morning (rual boy) and using that time for communications (like this). Most of the museums here open late in the morning, and this time of year also close late afternoon. I have been using the time in the early evenings to just blindly tour around town. As I am located just to the west a couple of blocks from the ancient town square, this puts me also about ten minutes walk from the harbour area. To the west especially, there is a series of good trails that run out along a fairly natural open area along the shore.

Travelogue 1A - Staying in Roskilde

14 Lille Hojbrondsstræde Roskilde

The house I'm staying at is about 10 minutes or less walk from the Viking Ship Museum, more or less between the harbour and the main shopping area. This is a long street with no cars allowed. This whole area is the Older 1700's section (as opposed to the Real Old - Medieveal section). The streets tend to be short and set at odd angles, most very narrow for modern traffic. A lot still the original cobbles and not allowed for cars. The house is set down what is really more of a lane than a street (or a street if you are on a horse). The house itself is down a walkway, set into the middle of a block of houses. It has a very large yard by local standards, and is framed in on all sides by the other yards. There is no access for a modern vehicle at all. The balance is that this (quite beautiful) yard is easily double the size of those around it.

This is written early in the morning of my second day in Denmark. Looks like another crystal blue sky day. I've been taking some art shots around town as well. (Which I will try to add once my lost bag with my input cables shows up!) The houses in Denmark almost all have red tile roofs. A lot of brick, but also stucco over something, which often are painted in earth tones. Any of the houses with the oak timber frames seem to paint around the natural ancient dark brown tone that oak takes (after a couple of hundred years). The result with the addition of the redish granite cobbles is quite striking. Have only seen one place with wood post carvings (like the Urnes church) but I think it was a late 1800's 'arts & crafts' era.

Today is my visit to the Viking Ship Museum, hopefully a report on that later...

DEMARK Research Trip

So how the trip has shaped up...

At time of writing this, I have about three hours till I leave for my Denmark trip. The centerpiece, and the reason for the whole expedition, is the Iron Smelting Seminar in Thy, which runs from April 29 to May 4. (details here)

I have arranged to meet up with experimenter Michael Nissen, from the Ribe Viking Centre. We will be driving up to the Seminar together the evening of Monday April 28 (its a roughly 3 hour trip). Michael has been working with the 'bellows plate' type of furnace, and I will be helping with at least one firing of that type at the Seminar.
Jake Keen (fellow Smeltfest 08 participant) is proposing to build and test a historic furnace from the Eastlands region of Norway and has asked me if I'd like to help out. I was unable to find any information on the smelter, but will certainly contribute if I can.

I published my intended schedule in an earlier posting (details here). Since then I have tracked down as many of the individual curators as possible (mostly due to connections given me by my mentor Dr Birgitta Wallace). This is what has come of those:

ROSKILDE
April 22 - the Viking Ship Museum
Its still early in the Museum's year, so not everything is in full operation yet. Although I did make contact with the sites Boatyard Manager Søren Nielsen, timing was not good for an in depth meeting. I have been assured that the working team in the boatyard will be expecting me, and that I will be allowed to closely examine their working tools. (This in aid of the current project for Parks Canada to produce a set of Viking Age shipbuilding tools for L'Anse aux Meadows HNSC.)
April 23 - the Roskilde Museum
From curator Jens Molter Ulriksen, I learned that recently this museum had lost its Collections Manager - due to cut backs. For this reason I will not be able to get into the 'back room' with the collection. I am expecting to see a wealth of material in the regular public galleries here.
April 24 - SPARE
I have switched my travel arrangements around to give me an extra free day in Roskilde. This will allow me to spend a second day as required at either of the main two museums. If not, there are plenty of other things in the area to take in.

RIBE
April 26 - the Ribe Viking Centre
At this point the Centre is actually not open to the public yet. May 1 marks the grand opening, including a major 'Viking Market' special event. Curator Bjarne Clement has offered to meet with me for a short while on this Saturday despite how busy he must be.
I have of course been in contact with both Michael Nissen (iron smelting) and Trine Theut (glass making), two artisan / interpreters at the site. They have offered to show me around their own working areas as well. I have also offered to buy them dinner against pumping their brains, likely on Friday evening.
April 27 - The Ribe Museum
I have been unable to connect with the curator here. At the very least I expect a full day with the public galleries. (This is the artifact collection from the Ribe excavations.)
April 28 - SPARE
Michael and I drive up in the evening, so basically this day remains open. Apparently there is a just opened display of early industrial objects in town that Michael has recommended that I should see. My room in Ribe is right across from the cathedral, so maybe that should be checked out too (quite looking forward to this stay!)

COPENHAGEN
May 6 - the National Museum
Unfortunately the Early History (which includes the Viking Age) gallery is going to still be closed for its current renovation. Jette Arneborg, the curator of the Medieval collection, has offered to show me around her part of the collection.

April 20 / April 25 / May 5 are travel days within Denmark. I will basically be crossing the country in a large triangle that is anchored in its three corners. Each leg is roughly 5 - 7 hours. I think wisely, I have made no specific plans for the first day I arrive - after roughly 20 hours spend in transit!

Taken altogether, the extra research trips are not going to be as fruitful as they might. Almost all of the living history / open air museums in Denmark do not actually start their seasons until May 1. I had to put my museum visits on the front end of the Iron Seminar, as I have a full week of courses starting back in Wareham on May 9.

I would like to thank Dr Birgitta Wallace, who provided me with a lot of insider information and shared her contacts with the various museums.
My brother Randy made a substantial donation to the overall cost of the trip. What he called 'walking around money', but will make a big difference in the comfort level of the whole expedition.
I still have hopes that my application to the Canada Council for the Arts for a travel grant may prove successful. The earliest they would have replied would have been after April 15, so I was not really expecting to see the results before I departed.

I will be trying to make some short entries here over the weeks of the trip as I can make internet connections - stay tuned...

April 13 Smelt - Overview

Second Test - DARC Dirt 1

(this will only be a fast draft report, as my trip to Denmark is fast upon me)

In an earlier post, I detailed the setup of of the 'Econo Norse in a can' test smelter.
The weather the day before had turned cold again, with forecast of snow on smelt day. For that reason (expecting the worst and feeling weak) I set up the smelter inside on the main floor of the workshop. (For those who have never been to the Wareham Forge, the building is a converted circa 1930's drive shed. The main walls are poured concrete, with a pole construction roof above. The distance from the dirt floor to the peak is twenty feet. )
This smelt was to be a second test of the DARC Dirt 1 - bog iron ore analog developed by Gus GIssing. The first test (at Smeltfest 08) was not ideal, as the smelter layout was a new type we had little experience with. The dynamics of the 'bellows plate' type furnace, and its taller stack height combined to a low yield and very high carbon bloom.
In this case the mix of 80% 'Spanish Red' (Fe2O3) / 10% silica sand / 10% flour had been air drying for about a week. The cold and wet weather had slowed this process. At the time of the smelt the ore material was dry enough to easily handle, but still slightly damp to the touch. It was broken up from the large plate pieces (roughly 1 cm thick) by tapping through a 2.5 cm wire grid with a wooden mallet. A second screen, about 3 mm, was used to separate out the fine dust. (This step was not done for the Smeltfest test). The result was pulling off about 20 % of the prepared material as dust. As the analog was not baked this time, this dust can easily be incorporated into the next batch by just adding water.
It was generally thought that the pieces from the 2.5 cm grid may have been a bit too large. Use of a 1.5 cm grid is likely ideal.

The team consisted of:
Ken Cook - smelt master
Darrell Markewitz - assisting (and coaching)
Neil Peterson - measuring and recording
Lloyd Johnson came up to observe and assist with the final hammering of the bloom.
There was considerably less prep work required, other than the construction of the more durable metal can for the smelter. The charcoal used was the Black Diamondfrom Bruce Cowan, which was pre-crushed to the ideal size.

This experiment employed a number of new pieces of equipment:
1) The smelter itself, which was a smaller variation on our well proven fire brick construction Econo Norse furnace. This furnace was 20 cm in diameter, a change which is a considerable reduction to our normal size of closer to 30 cm. There was some concern that this roughly 40 % reduction in volume might prove a problem with the dynamics of the furnace. I was encouraged by Skip Williams' recent experiments with very small table top sized furnaces.
2) The use of the new, larger volume, electric blower I had just purchased. This is the same blower used by Sauder & Williams (to great success). It also would be the first time for the new sliding gate air control made up specifically for use with this unit. This would be coupled with the in-line set up for the air speed gauge and pressure gauge.

The extraction was from the bottom of the furnace, which had been constructed with a proportionally large tab arch. The image above shows Ken taking out the two bricks that blocked the arch during the smelt. (This was the first time Ken undertook an extraction.) As it turned out, there was a reasonably large slag block formed. The bloom proved properly positioned, and contained within the correct pool of liquid slag. With a bit of hammering, it was possible to break away the side of the slag and grab out the bloom.

The finished bloom is shown above. After a bit of compression hammering, it was decided to slice off a third as seen to give to Lloyd. The bloom was both smaller and less dense than I had hoped for:

Bloom Weight - 2 kg
Total Ore - 18 kg *
Total Charcoal - 150 L (about 30 kg)
Total Time - 4 1/2 hours (not including pre-heat)

The yield is a bit better than it looks at first glance. We baked dry a measured sample of the ore analog, and it was found to contain 12 % water. This puts the 'real' weight of ore used at closer to 15.8 kg. This gives us a yield of about 13%. Still lower than our usual, but enough that the DARC Dirt 1 analog is worthy of further testing. There is still a very large mass of hardened slag to break free of the interior of the furnace. This may prove to have other smaller masses of metal contained in it. Certainly it would appear that there is a larger proportion of slag formed than has been seen in past uses of the larger brick furnaces with other ore types.

Biting off more than you can chew?

(with a nod to Neil, who posted me privately in response to my notes on the upcoming test of the DARC Dirt 1 ore analog)

Neil Wrote:


So this upcoming smelt will have 2.5 variables?

(Are you sure you don't just want to knock off a standard econo-norse for this one and keep the focus on the ore?)

1. Smaller smelter (2/3 diameter) - this worries me the most

I'm not as concerned about that one. Especially after seeing the Aristotles Furnace in operation. We ran it maybe 20 times and got good results every time. Skip has also ran full smelts inside the same small size. We are talking 3 inch ID and about 12 inches total tall. We have run the Econo Norse successfully set with 9 bricks = 35 cm / 8 bricks = 30 cm / 7 bricks = 25 cm (the seven brick used most often). The main thing may be lowering the air flow to the required (that would be 300 - 400 LpM range) with the new blower.

So, one question will be the new or old air system! I will try to get numbers for the new blower and blast gate combination today.

2. Ore analog (the thing we are trying to test)

Still crossing fingers on getting it dry enough. Right now its sitting outside under the front awning to the shop. This gives it wind to air dry and whatever sun happens over the rest of the period. Was roughly 'leather hard' yesterday when I set it out. (I had started by putting it inside each night.) It would be usable at this point - but with extra water contained.

2.5 The thinner front plate

Not as worried about this - in terms of heat retention. The furnace always make way more than we need. This variable also follows on our smelts last fall using thin stone front plate construction. Biggest question is how well the low density brick stands up to the high temperatures. I use these in the gas forge, which does build up to just shy of welding (maybe 2200 F). Of course our internal temperatures have been pegged at as much as 2750. The experiments at Smeltfest were done using a mix of horse dung and dry clay to make similar plates. There was no problem with the plates themselves in those three smelts. Air problems - but that was the set up with the blast hole not being correct.
I ended up with a good quantity of the charcoal fines and clay mix, now in a plastic bucket ready to use. If worst comes to worse, I figure we can quickly re-enforce the area around the tuyere with this proven material.

'Econo Norse in a Can'

I had mentioned that I made a clandestine trip to my local dump specifically to get a half barrel sized metal drum. As luck would have it - I found exactly the size I was looking for. The idea was to build a more durable version of the dependable 'Econo Norse' firebrick smelter. The drum was just about exactly the same size as a hexagon arrangement of standard hard bricks - stacked the normal three sets tall. The result is a smelter containment that is roughly 20 cm internal diameter, but still at the normal plus 40 cm above the tuyere. I cut the required holes and ports into the barrel, and welded in some external and internal fittings and supports. On the lower view, you can see the removeable 'hatch' that covers over two of the lower ring of bricks which can be pried loose for either a large tap arch or for a possible bottom extraction. Although these bricks are also backed up with the clay and charcoal fines cobb, they were wrapped with paper first to make removal later easier.The section of barrel that was cut away to create the hatch is held back in place by a length of flat bar which also forms a simple handle.A rectangular hole was cut the same size as the brick that holds the tuyere and sits above it. This brick is made of low density fire brick which has been cut in half to about 2 cm thick. If past experience proves correct, this material should radiate excess heat on its outside surface - and reduce erosion.Looking down from the top, the cobb packing holding the bricks into place can be seen. The packing is a rough triangle in the gabs of hexagon pattern of the bricks. An air space has been deliberately left between the flat sides of the bricks and the curvature of the circular barrel. The hope is that this will allow some of the excess heat to bleed off into the gaps.
Hopefully the smelter will prove to be reusable. The reduced size and the hard support provided by the barrel should make the furnace body easy to move on a two wheeled cart. Although the fire bricks make it fairly heavy, two people should be able to pick it up to load it into a vehicle.

The proof of the design will come on Sunday, when this is the furnace that will be used for the second test of the bog ore analog.

FLASH - Smelt on Sunday April 13

SUNDAY - April 13

Wareham

Test 2 - DARC Dirt One

This is a fast extra test smelt being interjected into our normal series. I wanted to have a good controled test of the bog ore analog that Gus developed. His Harder-Gissing Machining had donated enough of the Spanish Red iron oxide for two full scale tests. The test on the first batch I ran at Smeltfest with Skip and Jake Keen was not conclusive. Mainly because we ran an experimental ore into an experimental smelter (two major variables on the furnace). The results pointed to problems with the furnace, and also suggested a possible important variable on the ore itself. (And no - I have not written up that experiment yet).

So yesterday I mixed up a second batch of the analog. Should give us about 50 lbs of finished material - certainly enough for a full smelt test. This is spread on the sheets for drying, I will be moving these into the sun as its available over the week hoping to just air dry this batch (as opposed to the problematic baking in Vandy's oven!). I did take a look at the dump for a gas fired oven, figuring it would be easy to convert into a propane fired drier for the ore - no dice. (I did grab up some oven racks against a possible future construction of this.)

One error from the Smeltfest Test - the ore was somewhat over pounded, resulting in a fair amount of fine dust. I had originally intended to screen the crushed cake to pull this dust off (and just add it to the next mix) - but that step was not undertaken. I will be making up the required widow screen sieve today.

I also have 50 kg of charcoal remaining from Smeltfest (plus now can get at the trailer where the remains from last years operations are stored). So fuel is on hand and prepared as well.

I had gone to the dump specifically to try to find a half sized metal barrel. I did get exactly the right size. I want to prepare a more durable version of the Econo Norse smelter. I will line the inside of the barrel with the fire bricks, then pack the corners with a clay and charcoal fines mix. This should give us a heavy - but easily moveable - variation on our proven smelter design. By using the more refractory clay / charcoal mix, there should be far less clay slag formed than we get with the sand /ash black fill. I will be using our normal ceramic tube tuyere, standard set up (5 cm insert / 22 degree down).

One very important variable made obvious with the first test of the analog was the stack height. Skip had built a taller than usual furnace, almost the same size as Jormungand from Smeltfest 06. (It actually WAS Jormungand - repaired and extended from two years ago.) The fine particle size of the red iron oxide proved to suffer from the same working dynamic as we have seen from the hematite grit. So the tendancy (based on that single test!) is for the iron to pick up considerable carbon in the stack. This can be corrected (based on past experience?) on reducting the stack height to the optimal (40 cm) and slightly increasing ore amounts. Keeping track of burn times to the shorter end of the range will also help.

One last equipment note. I have set up the high volume blower that I ordered earlier in the year and had delivered to Lee's. I ran the anenometer on the air blast, the result was 166 KPH. If I have the math correct, the top end volume with this unit is 1350 litres per minute. (The best we could get out of the vacumn blower was about 950). Air will certainly not be a problem! I will make measurements of volumes delivered through the new sliding gate I made up earlier in the year so we have those numbers on hand.

Neil and I have a long teaching day on Friday, plus I have a late night theater opening that evening. For that reason I have decided to move this test smelt to SUNDAY. If any of you can make it up despite the short notice, all would be welcome. No problem if no one else shows. Normal hours: Preheat for 9 AM, expect extraction in the latter afternoon.

Iron Smelting Seminar in Thy 2008 - Schedule

The following was written by Jens Jørgen Olesen of the Heltborg Museum. He has given me kind permission to publish it here.
As you would have seen in earlier postings on the Seminar, this is an invitational event limited to just 30 participants.
Location: The Heltborg Museum / near Skjern, Denmark
Dates: Tuesday 29 April - Sunday 4 May

Jens also provided this information:
Saturday afternoon is a public day, where visitors and sponsors are invited to come and hear about what we are doing. We hope everyone will take part in this! ...
The Museum is open every day during the seminar. The visitors are allowed to watch the experiments...
The Heltborg Museum starts its regular seasonal opening on May 1.

The museum web site (hit the side bar for Heltborg Museum for a slide show) :
http://www.heltborgmuseum.dk/

**************

IRON SMELTING SEMINAR IN THY 2008

The experiments


The purpose of the Iron Smelting Seminar in Thy is to create a link between recent and older archaeological finds of iron smelting sites and the knowledge of people who work with the practical side of iron smelting. The seminar will provide opportunities for them to test their ideas in cooperation with archaeologists and metallurgists, and maybe in this way help to solve a few of the riddles that still exist within the field of prehistoric iron smelting.

The four main types of furnace known from Scandinavia are the earliest slagrum furnaces of the Espevej/Skovmarken type, followed by the slag-pit furnaces of Drengsted or Trøndelag type, to the slagtapping furnace of the Viking Age, best known from Norway and Sweden. Last comes the Evenstad type which appears in different versions, but which is known from written sources to have been run with wood as fuel.

The Tranamo group from Sweden will base their experiments on the Viking Age furnace where they have great experience. They bring their own ore which they have been working with and which was presumably used in the original furnaces.

Peter Hjort Jensen from our own iron smelting group will experiment with a medieval furnace, the Kjellerup furnace, a danish variant of the Evenstad furnace. We do have some experience with this furnace, but the results are not impressive so far.

Arne Jouttijärvi will construct an Espevej furnace on the basis of new finds from the Herning region. These form the subject for Martin W. Olesens coming Ph. d. dissertation.
Michael Nissen will work with a similar furnace. Within the latest year he has conducted several experiments with this type at the Ribe Viking Center.

Arne Espelund will conduct experiments with a Viking Age / Medieval furnace which in his opinion has been used in the first stage of a two-stage process. Here the ore was first converted into slag with a high content of iron, but no metallic iron. In the next stage this slag is processed in another or in the same furnace where the actual conversion into metallic iron takes place. Arne needs help for his experiments.

Jan Jennisen, Netherland will build a typical shaft furnace with slag tapping of the type found in the Netherlands (Veluwe). This is the same type that Thijs van de Manakker uses.

Apart from theses experiments there may be enough participants to make experiments with other types for furnaces. No one has made an experiment with the Eastland furnace from Norway. Is anyone willing to try?

People from our own iron smelting group will experiment with the Drengsted furnace using wood as fuel. We have been working with this type of furnace since 1994 and are getting good results, but we still have not quite reached the stage where we can say that we have found the perfectly convincing way of running the furnace. We hope to get there during the seminar.

We hope to create a possibility for analysing the results of the experiments. Therefore we will try to have the ore analysed, and we would like the slag from each experiment to be weighed and sample for analysis. Also the iron should be weighed and analysed in order to give the best opportunity for a comparison with the archaeological finds.
Thisted Museum alone cannot carry the burden of having all these analyses carried out, so we hope for help from those who have good contacts to metallurgists and others. By joint effort we hope to succeed.







IRON SMELTING SEMINAR IN THY
From Tuesday 29.04 - Sunday 4.05.
2008

Programme



Tuesday29. 04 : Arrival and accommodation during the day
Construction of furnaces begins
18.00 : Dinner
19.30 : Welcome and introduction of participants
21.00 : Coffee

Wednesday30.04 : 8.00-9.00: Breakfast
Allocation of space, formation of groups, building of furnaces
12.00 : Lunch
18.00 : Dinner
19.30 – 22.00 : Presentations

Thursday01.05 : 8.00-9.00: Breakfast
Building of furnaces, iron smelting
12.00 : Lunch
18.00 : Dinner
19.30 – 22.00 : Presentations

Friday02.05 : 8.00-9.00: Breakfast
Iron smelting, primary forging
12.00 : Lunch
18.00 : Dinner
19.00 : Excursion to the North Sea at Agger. “The Black Man”
21.00 : Presentations

Saturday03.05 : 8.00-9.00: Breakfast
Iron smelting, primary forging
11.30 : Lunch
12.00-16.00: Open to the public, iron smelting and primary forging
18.00 : Dinner

Sunday: 8.00-9.00: Breakfast
Iron smelting, primary forging
12.00 : Lunch
16.00 : Cleaning up the area.
18.00 : Evaluation
19.00 : Dinner and farewell party

Monday: 8.00-9.00: Breakfast
Departure after breakfast


During the whole seminar there will be free coffee and tea.
Around 15.00 there will be cake or the like for the coffee break.






Presentations


WEDNESDAY

19.00: Martin Winter Olesen, from Herning Museum: Presentation of finds of Early Iron Age furnaces from the Herning area.
The furnaces have slagrums underneath the furnace, and some of them are built into a house, together with anvil and forge.

19.30: Arne Jouttijärvi:
The metallurgy in Martin W. Olesen`s project.

20.00: Jake Keen, Great Britain;
Agaria smelting in India. From Jake’s journey to East Asia, visiting early iron smelting places.

20.30: Darrel Markewitz, Ontario, Canada:
The Viking Age site at L'Anse aux Meadows (Vinland) and what is known about it in terms of the iron smelting there.

22.00: Arne Espelund: Bloomery smelting as a two step process?
Based upon theory, finds of slag at bloomery sites and the quality of well preserved and representative blooms a discussion of bloomery smelting as a two-step process will be initiated.




THURSDAY

19.00. Arne Espelund: Calculations of output.
For an archaeologist, confronted with a slag heap, it is natural to ask: how much iron was produced here? The experimenter will rather ask: how much iron can be won from, say 10 kg of ore?

Iron in the ore will serve two purposes: provide a source for the metal and besides flux the gangue materials, above all Si02. Manganese, present as Mn0, will likewise flux the silica, while the remaining oxides simply will dilute the slag.

As the slag is composed of mainly Fe2Si04, only an excess of Fe0 can be reduced to metal.
Therefore only an ore with a ratio Fe0:Si02 > 2 (in molar proportions) can result in any iron. (As 1 mole of Fe0 weighs 72 g and 1 mole of Si02 60 g , divide the two values in weight % with 72 and 60, respectively).

Provided we have the analyses of the ore and the slag, we can follow the four elements Fe, Si, Mn and Al from the ore to metal and slag. A prerequisite is representative analyses. I prefer to use 10 kg of slag as a basis. By means of two equations you can determine the two unknowns ore consumed X and metal produced Y.

2. The quality of ancient blooms
In Norway some 20 blooms of medieval character can be found in our museums,
beside there are a handful of blooms from the Early Roman Age. The dating has been arrived at by means of careful studies of the remains of furnaces, lately confirmed also by 14C-dating.

The identity of a primary bloom has been determined by 1) density measurements – giving values from about 5.5 to 6.5, in contrast to the true density of iron 7.8.
2) shape: A medieval bloom are like a French cheese, from which a sector has been cut, with an external diameter representing the interior of the furnace, perhaps also a depression as a result of a primary smithing with a wooden pole inside the furnace.
3) metallography, including chemical analysis: the blooms are practically slag free.
Most of the iron produced was a mild steel, some times with less than 0.02% C.

From my point of view, it is not justified to name a mixture of slag and iron a bloom.


20.00: Leif Stark, Tranamo, Sweden:
Järnprocessen. The iron process.
Kolning.: Making the charcoal
Rödjord. The ore
Smide: Forging.
Historik: Historical background


20.30: Jan Jennisen, 412BC iron maker, Netherland:
who I am,
the place where I do my experiments (Archeon)
which types of furnaces I have experience with.
FRIDAY

21.00: Peter Hambro Mikkelsen, Moesgaard: Fuel for thought: Straw and wood in slag pit furnaces

21.30 Jens Jørgen Olesen: The use of wood in the Drengsted furnace, our experiences.

22.00 Arne Espelund:
Jens Jørgen Olesen arranged on Oct. 28th last year a full day of smelting, which I could attend. We used an ore, which was analyzed and measured the consumed amounts of ore and charcoal. Slag was tapped and analyzed, and a piece of the metal produced studied by metallography. The experiment will be discussed in detail, with emphasis on the results, expected and obtained.

SMELTFEST 08 - Overview with images

Smeltfest 08
Rockbridge Bloomery - Lexington Virgina

Lee Sauder again hosted an intensive 10 day long session of iron smelting and related activities for a small invited group : Skip Williams, Mike McCarthy, Darrell Markewitz, Jake Keen (who flew in from England). Jesus Hernandez dropped in for two days. Shel Browder and Steve Mankowski (and their team) hosted a couple of days at Colonial Williamsburg latter in the week.

Lee and Mike were working on a special smelt to sculpture project. (I will not attempt to describe the details, and hope they will report.)
Over a series of smelts (I think it was four) they smelted new bloom on top of the existing mass. The end result was a bloom totaling some 175 lbs. One of the single additions resulted in 75 lbs of new material created in a single smelt - a new record for the team.
(Working over the boom after the 75 lb single smelt addition)

Skip, Jake and Darrell undertook a total of three smelts, working on the 'bellows plate' furnace Skip and Jake had seen at Enderhoven last summer. Much was learned about this set up (mainly from trying to snatch victory back from the jaws of the fire monsters!)
The series included a test of the DARC Dirt 1 bog ore analog, which proved 'proof of concept' at least.
(Set up of the smelter with bellows plate and gap in air blast)

Skip, Jake and Darrell spent three days with the team at Colonial Williamsburg (while Lee and Mike finished the sculpture project). Browder and Mankowski lead a very sucessful smelt using all Colonial Era methods.
(The smelter set up at Williamsburg.)
We also built and demonstrated the small 'Aristotle Furnace' developed by Williams.
(Jake mans the bellows, Skip inserts a piece of scrap wrought iron, while a Williamsburg smith looks on.)
Other activities included a day trip to the Jamestown Archaeological site to view artifacts related to the first American iron smelting.

We also were taken to visit gunsmith Jon Laubach and allowed to gather several hundred pounds of the Jamestown/Williamsburg iron ore.
(Land of Riches! Good quality ore just inches below the sand surface.)

This years session was especially packed with smelting, and everyone felt they had not only a wonderful time, but learned and achieved a great deal. Thanks again to Elizabeth and Lee Sauder for hosting the workshop.

There should be upcoming reports on all the various smelts and related experiments from the session.

April Fool's - Again

..or why there will not be any smelting in Wareham for a good long while.

We FINALLY got some warm(er) weather here. The snow has melted back considerably, but still is well over boot tops in most of the yard. I thought I would trek back to the back and check things out:

This was the first surprize. Taken at the small overhead cover for the fire pit. The snow here is about 12 inches deep still. The shock was the water. The ground here (and over most of the rear yard as it turns out) has roughly 4 inches of water standing on it (under the snow).

This all goes into the pond of course. This is the highest the water has ever been in the pond in the 20 years we have lived here. At the time this photo was taken, the water level was about 4 inches below the maximum possible. So thats 4 inches less than the rear retaining earth bank that sepparates the yard from the creek behind us.

This is our smelting area. Looking closely around the block retaining wall, you can see the level of the normal work platform. In this image its at least 4 inches BELOW water level - even deeper at the side that normally stands up above the pond.Last year at this time the water level was at least 10 inches lower than this.

Now just after I took the images above, I shoveled off the roughly three feet of melting snow that was piled on our upper decks. Of course the gods take this as a sign that I'm weak and presumptuous, and almost always wham me with more snow. (The reason the image is blurred is snow in the air!). More importantly, all that water in the yard has continued to drain towards the pond. The last image was taken roughly 5 hours after the first. Latter in the afternoon the pond was closer to 2 inches below possible running over. Add another two inches to the level over the smelting area as well.

I fully expect when I go outside to check (after finishing this) that the pond will have started to wash over the rear bank. Night temperatures dropped here (its -6 C as I write at 8:20 AM) which may have slowed things. In past years, we have had the water table come to within 4 inches of the SURFACE. Already the water level below my raised wooden forge floor is at that height (and the ground is still pretty much frozen still) My main concern is that if the pond actually runs over the rear earth berm, the run off will cut into and erode that bank. The fast solution would be to install a length of drain pipe to channel the water off (I have some 4 inch plastic pipe). But of course the ground is frozen solid still...

Happy Spring

Hanging at the Sauders

This is a wee bit of a travelog from my trip to Lexington Virgina for SMELTFEST 08. We were (grandly) hosted by Lee and Elizabeth Sauder. I will show the place we actually stayed at in a future post (just down the hill from Lee & Elizabeth's).

This is what their home looks like:

Lee built this passive solar house into a 'tolerably level spot on their mountainside acres. They are at something like 2800 feet - a very good amount above the town of Lexington (where the workshop is located). The view here is roughly towards the north. Elizabeth has a studio up even further behind the house. The slope is a good 20 degrees.
The following panoramic view is taken from roughly the foot of their drive. The images were taken by sweeping roughly west to east.

These images were taken on March 22. Those in Ontario know can see why we took a dream look at housing prices. Did see a 1500 square foot circa 1960's ranch style on 3 acres listed at a mere $200 K (certainly no more that around here!)...