Waterjetting 19a - a little history

A small personal introduction – some fifty-odd years ago I was about to graduate with a BSc degree from the University of Leeds and was then offered the option of going on for a doctorate. Since this was a Mining Department they had a number of different options that I could have followed, but I discussed this with my father, who was responsible for mechanization of one of the National Coal Board areas, and chose to study the development of high-pressure waterjets as it applied to mining.

The technology was in an extremely early stage of its development at the time in the West, although as I rapidly learned, there were already major uses for the technology in what was then the USSR. And so, with a laboratory that contained a small Uraca 9,500 psi, 4 gpm pump, I began a study that led to a lifetime career.

Some of the early things that I learned came to be adopted throughout the industry, and some of the lessons quietly disappeared. But I thought it would be interesting to go back to some of that work, particularly tying in the work done around the world in the cutting of coal and rock, so that some of these lessons could become clearer, remembered and passed on.

I was fortunate that Leeds was close to the National Lending Library at Boston Spa, and thus we came to an agreement that should I need any of the foreign papers (particularly those in Russian) not otherwise available, that they would machine translate these for me, and then we would put them into technical English. (Not nearly as easy as it sounds since computational power was relatively at about the level of an abacus relative to the standards of today).

In the beginning we were much more focused on the work that the Russians had carried out in cutting rock, although once I came to Rolla that relatively rapidly switched over into studying the work done on the mining of coal. However it may make the story more easy to follow if I begin with a return to the beginning and then work through the use in coal mining and follow that through into rock cutting.

Just after I began this series I wrote about the early work in what is now the country of Georgia where the native inhabitants were collecting gold in flumes lined with sheepskins that they hung in trees to dry – only to have a bunch of Greek thieves led by some guy called Jason, come along and steal them. They had used the natural force of streams to erode away the valuable ore deposits and carry the debris down streams and into the flumes. This idea was then developed by the Romans. After weakening and breaking gold ore in Spain through fire and gravitational collapse, they used a diverted stream to carry the broken ore out into flumes, where again the gold could be captured.

It has been said that after the Fall of Rome and the following Dark Ages that it took the world over a thousand years to get back to the technological levels that the Romans had achieved (the example of concrete is often used). In a sense this is also true of what is now known as hydraulic mining, since the practice largely fell off the scene until the use of Hushing was resurrected in the UK. The technique involves storing water behind a dam and then rapidly releasing it in a torrent to wash out and carry ore and overlying cover away down into prepared flumes. The area around such mines (found in the Yorkshire dales) is characterized by the deep channels cut into the ground by the water flow.

Figure 1. The region above the mine at Bunton in Swaledale, where hushing was used to expose and erode the mineral veins. (My Learning )

These mines date back to the early 1800’s while earlier reported work in Cornwall (based on the use in the North) in about 1500 was not apparently as successful and led to some loss of life. But that reference does indicate that the practice was already in use in Yorkshire, although there are few records to describe it before the citation above.

And so the first lesson to learn is that, if you hit a body (in this case rock and the overlying soil) with enough total force and water volume, that the target will erode and be carried away by the water flow. This is something that is evident whenever there is a severe storm along a coast around the world. See, for example, the following sequence of photos of the coastal highway near Ocean Beach CA in 2010.

Figure 2. Wave erosion of the highway near San Francisco (USGS )

In this case the shoreline was eaten back a distance of some 184 feet. And each winter we are shown the evidence of waves eating away at the foundations of houses built too close to an eroding cliff wall.

Yet it was not until the gold-rush days in California following the discovery at Sutters Mill on the American River in 1848, that large-scale water volumes were first used for the removal of not only the soil overlying the gold, but also the removal and disintegration of the gold-bearing sandstone beneath. And that is the story that I will tell next time. Although I will close with a description form that time of Sutter's Fort.

Ten miles from the river we passed Sutters fort, an old looking heap of buildings surrounded by an high wall of unburnt brick, & situated in the midst of a pleasant fertile plain, covered with grass and a few scattering oaks, with numerous tame cattle & mules. We walked by the wagon & at night cooked our suppers, rolled our blankets around us & lay down to rest on the ground, with nothing but the broad canopy of the heavens over us & slept soundly without fear or molestation.

For those not in the know Sutters Fort is to be found in the heart of downtown Sacramento.

Waterjetting 2d - Adding cracks to Nature

In the last few weeks I have focused on demonstrating, with examples, that water effectively removes material by penetrating into natural cracks in the material and causing them to grow. But what happens when there are not enough cracks to remove material at an economic rate? The modern approach has been to raise the pressure of the water so that smaller cracks grow faster, thus providing the production rates needed, but that option wasn’t available in the past.

I mentioned last time that miners in the Caucasus Mountains of what is now Georgia used the power of mountain streams to erode gold deposits over 3,000 years ago. Perhaps learning from that, when the Romans came to Las Médulas in Spain, some 2,000 years ago, they though of water again as a way of mining the gold-bearing sandstone of the local hills. And though they had to modify the initial idea, the result became the most important gold mine in the Roman Empire. It is now a World Heritage Site.

Figure 1. Location of Las Médulas in Spain. (Google Earth)

The sandstone was more resistant than soil, and so the Romans came up with two ideas to improve the rate at which the gold ore could be removed. The first idea was to run galleries into the sides of the hills, creating large chambers underground, with support for the roof from wooden supports that were left in place.

Figure 2. Tunnel driven into the bottom of the hill at Las Médulas.

Figure 3. Underground room at Las Médulas.

At the same time that the mining preparations were going on local streams were being diverted and dammed so that a large volume of water was held in reservoirs and then carried by manmade channels to a point over the mining chambers. With the water ready, the timbers were set on fire, which initially weakened the overlying rock so that it began to fail, falling into the opening, and as the support burned away more rock fell into the opening until the cavity worked its way up to the surface. At this point the reservoir gate was opened and water flooded down the channel to fall into the cavity. As the water fell it further broke the rock into grain-sized pieces, and carried these down and out through the original opening in the hillside.

Figure 4. A Collapsed cavity, not the two figures at the arrows to get a sense of scale.

The water and debris flow was directed into flumes, in much the same way as modern miners in Alaska practice today, except that where carpet is used to catch the gold particles in Alaska, in Spain the Romans used plant stems (silex) to catch the gold. After drying the plant could be burned, easing to recovery of the gold. (In more modern times Spanish miners have lined the flumes with oxen hides.)

Figure 5. Artist sketch of the troughs used to capture the gold particles at the Spanish mines.

The use of heat to weaken rock before using water pressure for cutting has been tried with a couple of interesting wrinkles both by researchers at Rolla, and at the then U.S. Bureau of Mines and in Colorado, among others. But those more modern trials will be described later in the series. Using water streams to erode surface outcrops of mineral survived as “hushing” in the North of England and elsewhere until fairly recently.

Move forward some 1800 years or so from Roman Spain, and at the turn of the 19th Century miners in both Russia and New Zealand had a problem in mining coal. In both countries there were good quality coal seams, but they sloped at a steep angle that made it difficult to move men around without their slipping and falling. It was also difficult to support the roof, which was achieved at the time by sawing wooden props to length and wedging them between the roof and floor. Both nations had the idea of modifying the Roman idea of using water to remove the mined coal, but coal was thought to be somewhat stronger and more resistant than the Spanish sandstone.

In the New Zealand case the mountainous countryside makes it expensive to drive roads and as early as 1891 wooden flumes were being used to carry coal to the consumer. However it was then realized that the water could be used to also remove the mined coal, particularly that which was left in regions of the mine where it was not safe for men to go. The coal was therefore initially blasted, and then the flow from the nearby streams was directed at the debris pile. The volume of water, and the slope of the mine combined to remove all the mined coal, often overnight, so that a new area could be worked the following day. It was not until 1947 that pumps began to be used to drive the water at greater pressures. At this point, with the higher pressures that pumping brought, it was no longer necessary to pre-crack and break the coal with explosives.

While the New Zealand coal seams outcropped at the surface in very hilly ground, the situation was somewhat different in the Donets coal seams in the Soviet Union, where the seams were thinner, and production was barely economic. The seams in these mines were much deeper than in New Zealand, and so jet pressure could be provided from the drop in height from the mine surface to the location of the large nozzle or monitor that was used to aim the water flow at the coal. As with the New Zealand experience the Soviet miners (at the Tyrganskie-Uklony mine) initially blasted the coal with explosives to weaken it with a high density of cracks, before applying the water. However the miners found that not only did the water double production (to 600 tons/shift) the streams were powerful enough that it wasn’t necessary to pre-blast the coal. The nozzle diameters of the time were up to 2-inches in diameter, and could throw a jet up to 60 ft.

Figure 6. Early Soviet underground coal miner

It was from these small beginnings that hydraulic mining began, it was, in its time the most productive method of mining gold in California, and was used for many years around the world for mining coal, and other minerals. But that again is a subject for more detailed discussion at a later time.

The combination of explosives and water power remains in use in harder rocks, particularly in South Africa in the gold mines. Here again the seams of gold are very narrow and can slope or dip at a steep grade, the working area is thus kept very cramped and difficult to work. By blasting the ore with explosive, it can again be moved with water pressure, although there is an additional advantage to water here that I will further explain when I write about cleaning rust from plates.

Gold, as is shown by the way it can be collected in flumes, is very heavy, and part of the problem in the South African mines is that small pieces can get trapped in small pockets on the floor of the seam. The higher pressure water flows can flush out these pockets driving the gold particles down to a common collection point. In that particular the practices haven’t changed that much in three thousand years.

From Cro-Magnon man to Celt

There are now a couple of different themes running through this short series of posts on DNA and what it means in the search for our ancestors. I had started out wondering when Europeans first arrived in America, and found that there appear to be more possible answers to that question than I had first thought. I must also confess that I had not realized until last week the scale of the warfare that was a common feature of life in the Paleo-Indian times. (Though I should not have been surprised, since it was still common at the time that the Pilgrims showed up, as the story of the Quawpaw peoples – who now live around Baxter Springs, Kansas – can attest). But while this is going to remain the main theme of the thread, the changes in the analysis of DNA over the last few years has brought some other surprises with it. This means that it is becoming possible to be more refined in tracking ancestral paths that was the case even five years ago.

To illustrate what I mean, let me expand a little using some of my own results to help explain the development, and then this might help in understanding some of the debate when I come back to the main theme later.

There are now three different places that scientists can look at a DNA sample. There is the basic Y-chromosome (Y-DNA), which provides the paternal line, but which is not passed down through women. Then there is the mitochondrial DNA (mtDNA), which comes down from the female line alone, and which goes to all children. With refinement it is now possible to look at the entirety of the DNA string and what is known as the autosomal DNA (auDNA), using new techniques to specifically focus on different regions, and, from historical records, to start to build a broader family history. Those investigations are beginning to show that there may be many medical benefits, coming from a better understanding of how the body works, and how DNA acts as the control.

I am going to cover those latter topics in posts that follow this, but for today I am going to return to the Y-DNA and the paternal, or patriarchal line. This is not meant as a personal history, but some background might help with context for the example. I am a Summers, of whom it estimated that there are some 15,564 individuals in the UK.

Figure 1. Distribution of the Summers families in the United Kingdom (Dynastree

Our group comes from the area around the village of Eglingham, in Northumberland where the First Duke of Northumberland (Hugh Smithson, who took the family name of Percy) founded a coal mine at Tarry, about 1750, with 9 workers, including a Grey, an Embleton and my relative George.

The region had, historically, been a mess, since it was the ground over which the Scots and English fought for hundreds of years until 1603 when James VI of Scotland became James I of England, following the death of Elizabeth. Bands of my Scottish ancestors (Littles, Maxwells, Moffats etc) came through the hills to steal the cattle and everything else from anyone they could find. Of course the Percys then led bands back, to burn, loot and destroy in return. Both sides of the current family lived through the time of the Border Reivers, and were likely participants albeit on opposite sides.

The current number of Summers is a little overwhelming, but looking at the lower density in the County, and that as one goes back in time, so the numbers of individuals drops considerably, and can focus back down to just one or two individuals. Bryan Sykes did a remarkable study which showed that the Celtic hero Somerled, who died in 1164, has had 500,000 descendants since (including the clans McDonald, McDougall, and McAlister). The lineage can be found here.

So how can this be proved, how can the different branches of the clan be distinguished, and how can I apply that to my own case?

Well the answer lies in the structure of the Y-DNA. Within the Y chromosome are a number of regions where a particular sequence repeats a number of times. For example (to quote Smolenyak) the four base pattern GATA might be repeated five times: GATA GATA GATA GATA GATA. But sometimes when this occurs the exact number of repetitions changes. This is particularly prone to happen when the number of repetitions gets to be more than ten where, as an example, one might find that the ten-sequence suddenly, in the next generation, becomes an eleven-count, or perhaps drops to a nine count. A generational marker thus exists, and it appears to be one where these changes can occur about every 10 to 20 generations. (Say 2-300 years). These “stutters” are known as Short Tandem Repeats (STRs) and they have become the definitive way of identifying much smaller groups of people, within the broader classification of a haplogroup.

Because the numbers can change at different marker sites at random intervals, it is only when comparing across a number of different sites that one can establish who might be related to who. Consider the results from a group of individuals, looking at the number of repeats which are counted at different markers along the chromosome. (The marker site locations are standardized and given at the top of the table).

Figure 2. Short Tandem Repeat counts for 12 individuals that all share the same basic haplogroup designation (R1b1a2) but with varying count numbers at different marker sites. The different shades show variations from the numbers of the defined count for this particular lineage, given as the bolder numbers on the top line.

To return to the McDonald lineage, as time passed the number of repetitions at different locations changed in an individual, and his children, so that different patterns (as in the above) developed. However they did not necessarily follow the divisions of the clan, though once separate any changes in the counts would be restricted to the line in which they occurred.

Figure 3. Variations in the Y-DNA counts as the branches of the Somerled lineage have developed over the centuries. (The values are the sites and the count changes at different marker locations). (Clan Donald)

For the nerds among us it is interesting that the Clan study shows

The calculated haplotype of Good John is the same as participant &PGTBN to 37 markers. We have descendants of three of John's sons. Nine of these have excellent paper trail pedigrees. As shown above on the two charts, there are 22 single-step mutations in 37 markers in 139 transmission events. This is a mutation rate of 0.0043±.0009 (one standard deviation) per marker per birth. The value calculated by the Webmaster from all available data, both academic papers and surname studies, is 0.0031, only slightly more than one standard deviation off from our Clan Donald value.

Note that the rate is calculated by dividing the number of mutations by the number of births and by the number of sites monitored. If one were looking only at the rate at which a single mutation would occur, then this would be 22/139 = 0.16 mutations per birth, or one mutation every roughly 7 generations. With an average generation being around 30 years, this gives a dividing mutation every roughly 200 years per line.

Figure 4. Division of the Clan Donald into various Septs into the 16th Century (Clan Donald). The divisions have multiplied since.

So, by establishing the basic marker counts for a group (i.e. the Haplogroup) one can then, as with the clan lineage above, establish, over time, the branching of that tree, and, for those on one of the branches, this also provide a path back to the original ancestors. There are several ways in which the different groups can be designated.

Oxford Ancestors (OA) has built on the classification system initially created by Bryan Sykes in Saxons, Vikings and Celts, which divides the results from Y-DNA STR counts at 12 sites (those in the table above) into five different major groups. This seems to now be quite widely accepted as a primary classification system, although the names of the five groups can vary from site to site. I found the Border Reiver Ancestry site useful, since it looks at several ways of assessing my particular ancestors.

The most common is the R1b group (that with the baseline values of table 2) and this Sykes called Oisin. It is now being called Celtic and can make up some 67.5% of the DNA profiles from the Border Reiver region, although Sykes found that it designated 62.8% of the samples he took in Northumberland. (The group includes me). Using the ordering of the STR count marker sites as shown in Figure 2 the values would be:

13;24;14;11;11;14;12;12;12;13;13;29

The second is Group I, called Wodan by Sykes, and now being also referred to as Anglo Saxon/Danish. The STR counts for this Haplogroup, some 20.7% in the Border Reiver sample, 15.9% in Sykes’ Northumberland, would be:

13;23;14;10;14;14;11;14;12;12;11;28

The Haplogroup R1a is the Norse Viking, which Sykes called Sigurd. Interestingly this is also the group into which Somerled falls. The STR counts for the basic member of this Haplogroup, which makes up 3.7% of Border stock but 7.3% of Sykes Northumberland, possibly because of a close Scandinavian tie to that county even today, would be:

13:24;16;10;11;14;12;12;10;14;12;32

The fourth grouping is the E1b1b group, which Sykes called Eshu. This is some 1.6% of the Sykes sample but was not recorded in the Border Reiver analysis. The counts are:

13;22;14;10;16;17;11;12;12;13;11;30

And the fifth group, defined by the letter J, which Sykes referred to as Re, and which is also referred to as Ancient Roman. It makes up 3.1% of the Border Reiver sample, and 2.4% of those sampled by Dr Sykes in Northumberland. The counts are:

12:22;14;10;12;14;11;15;12;12;11;29

Even within a single surname, and haplogroup there are individual marker count changes that have built up over the centuries that surnames have been around (roughly a thousand years). It turns out that there are Summers whose DNA falls into all five of the groups. But knowing that I am a Celt, although the Summers are reputed to be either Anglo Saxon or perhaps Norman French does perhaps explain my predilection for bagpipe music, including Spanish and Portuguese.

The story will continue . . . .