1840 rouble with awesome die polish

[bobh]

I get a little dizzy looking at the eagle:

 

1840 rouble

 

Now I know that pre-1844 roubles were technically not struck as well as later coins, and that they used a die until it fell apart. I have some Russian coins with similar die cracks. But what would cause the swirly shape of the letters? Is this also due to die polish and/or wear? Has anyone seen anything like this before?

[Scottishmoney]

That is more significant than die polishing, more like something like die rotation whilst the coin was struck. But I cannot imagine how that could happen.

 

There are 6 significant die cracks on the reverse of the piece, yeppers, I am guessing this was one of the last from this miserable die before it gave up the ghost.

[RW Julian]

I get a little dizzy looking at the eagle:

1840 rouble

Now I know that pre-1844 roubles were technically not struck as well as later coins, and that they used a die until it fell apart. I have some Russian coins with similar die cracks. But what would cause the swirly shape of the letters? Is this also due to die polish and/or wear? Has anyone seen anything like this before?

On first glance it does appear to be an over-zealous mint worker polishing the reverse

die. However Scottishmoney has a good point in that something else may have affected

the strike as well.

 

My inclination, however, is to think that most of the problem is due to the die polishing.

 

RWJ

[WCO]

Rotation of a die or coin during the very moment of strike. Note that letters are more "swirly" closer to periphery. Also during rotation metal in the surrounding fields was displaced and they look rough (it has nothing to do with die polishing).

 

WCO

[Scottishmoney]

I wonder how the die was rotated so violently, so much so that it blurred the lettering, this has to have happened as the die was being applied to the coin - like Ivan got pissed because he didn't get a potty break or something and decided to take it out on the coin.

[WCO]

Press has rotational momentum, it tends to rotate both upper die and therefore coin during strike.

 

WCO

[bobh]

Some interesting theories have been stated here. However, there are still some puzzles:

 

(1) Eagle and emblems show no signs of such motion. Otherwise, if the whole die (or planchet) were turning during the moment of strike, the eagle design should also show some signs of it, even if a bit less than on the lettering;

 

(2) The eagle and emblems show little sign of die polish, too;

 

(3) It appears to me that the distortion of the vertical elements of the letters is too great to have been caused by die polishing alone.

 

Now what about this theory:

 

(1) In order to strike the die from a hub (or from various hub pieces, as was common before ca. 1844), the die must first be heated (i.e. softened, then later annealed) to a point where it is possible to strike steel against steel without breaking the die or the hub ... the hub, after all, is also made of steel.

 

(2) Let's assume that the lettering was sunk into the die FIRST, before the eagle design! For obvious reasons, I believe that mostly it was done in the opposite order: First the intricate eagle design, then the lettering (the design having more detail should be done first; sinking the lettering, with the simpler design, could also occur at a later stage when the die was a bit colder). Of course, I'm no expert at die sinking ... maybe I have it backwards? But experience shows that many coins struck before this period also had convex planchets, which would mean that the eagle (i.e. whatever was in the middle of the coin area, as opposed to the parts near the edge) would have come in contact with the die first -- not the other way around (unless the die was constructed concavely, such that the force of the strike made the coin convex...in this case, the outer parts of the coin would indeed hit the die first... ).

 

Anyway, it LOOKS like the metal was still flowing when the letters were sunk, and not flowing when the rest of the coin was done. If the metal of the die was soft enough to distort the letters to such an extent, it could have cooled off enough to allow for a clean strike of the rest of the die -- assuming that the letters were struck first.

 

But there is something wrong with this theory as well: In 1840, the lettering was still applied piece-meal to the dies; even single letters were composed out of parts (thanks to RW Julian for this information!) If my theory were true, it would mean that all of the lettering would have had to be on a hub and sunk into the die as a unit! Perhaps they were experimenting with this technique as early as 1840?

 

What do you think??

[WCO]

May be my little theory is questionable, but here it is.

 

Upper die was turning during striking. Since there is no weakness in strike at the central part of the coin possibly all the metal flaws there were "repaired" by the farther movement of the die. Not the same is at periphery. It seems there was not enough metal to fill all the small elements of the die, even denticles at the border are missing and letters are weakly struck, so the die was unable to "repair" metal flaws resulted from its early movement into the body of planshet. This may be also true if there was not enough pressure to make fully struck coin.

 

WCO

[rittenhouse]

I get a little dizzy looking at the eagle:

 

1840 rouble

 

Now I know that pre-1844 roubles were technically not struck as well as later coins, and that they used a die until it fell apart. I have some Russian coins with similar die cracks. But what would cause the swirly shape of the letters? Is this also due to die polish and/or wear? Has anyone seen anything like this before?

 

Hi Guys,

 

Been away while RW Julian and I worked on a couple projects for RNJ and Numismatic News. Bob told me about this piece. Since minting tech is my thing, he asked that I comment.

 

First off, the die(s) were not rotating. Here's a couple points:

 

1. Note that the flow pattern does not materially affect the bottoms of the letters nor the beading around the eagle. If the die really was rotating during impact, these would likewise be affected, as would the central eagle device albeit to a lesser extent.

 

2. At the moment of impact there is a very large force applied along the vertical axes of the dies. Even if the dies were loose this would effectively lock the dies in that position for the remainder of the strike. It would thus take a rotational force in excess of the vertical force to rotate the dies during strike. If one looks at the engineering drawings of the Boulton press (see Cooper) there is no potential causitive factor for such a large rotational force. In sum, proposing that the dies were rotating during the strike is analagous to proposing that one could rotate a CD with a 2 ton truck sitting on it. For those who doubt this, the solution is simple: draw a free-body diagram and then calc the forces. Sorry, ain't gonna happen, its physics 101.

 

Nor is this die polishing or die sinking related. OK, so what is it? It's very heavy metal flow arising from worn and misaligned dies. The planchet may aslo have been poorly annealed.

 

This type of metal flow is not uncommon in coinage, or any stamped or rolled metal for that matter. It is rather common on US, esp. Capped Bust Half Dollars, Large Cents, etc., in sum all of the screw press coinage were the strike is an impact strike. This type of strike has specific metal flow characteristics, one of which is very heavy peripheral metal flow once the dies wear and being to loose their "basin" or buckle. This wear reduces the amount of pressure at the periphery resulting in the metal only partially being constrained by the peripheral elements. As a result you see heavy flow lines off the tops of the peripheral elements. (BTW, the Boulton press was a screw press, it was merely powered by a steam engine rather than by hand. Thus the strike charateristics are screw press, just heavier than a manually driven one.)

 

The "twist" is certainly interesting although I've seen it before, just not to this extent. Very cool. This was probably caused by the misalignment of the dies (note the heavier strike at the dentils on left), the dies wear/damage, possibly combined with a poorly annealed planchet. Also note that the obv shows similar flow lining under the wreath to the right of the bow.

 

Be aware that the heavy flow lines are a solely an artifact of the planchet metal flow. These lines do not show on the die itself. Numismatists once thought that these lines were "gouged" into the die by the constant erosion of the planchet metal flow. However, the US 1806 Half Dollar obverse die in the ANS collection disproved this. Late state coins struck for this die show very heavy flow lining at the periphery, but the die itself shows no such lines. Rather it shows just fairly heavy overall wear.

 

Hope this helps with the discussion and that I've answered to eveyone's satisfaction. Very cool coin. I'd strongly suggest a bid for those who are advanced collectors. Unless there are a lot of late state pieces of this variety I doubt you'll find another like this anytime soon.

[LostDutchman]

ugh i feel dizzy...makes me feel like i just got off the tilt-a-whirl

[WCO]

Hi Guys,

 

Been away while RW Julian and I worked on a couple projects for RNJ and Numismatic News. Bob told me about this piece. Since minting tech is my thing, he asked that I comment.

 

First off, the die(s) were not rotating. Here's a couple points:

 

1. Note that the flow pattern does not materially affect the bottoms of the letters nor the beading around the eagle. If the die really was rotating during impact, these would likewise be affected, as would the central eagle device albeit to a lesser extent.

 

2. At the moment of impact there is a very large force applied along the vertical axes of the dies. Even if the dies were loose this would effectively lock the dies in that position for the remainder of the strike. It would thus take a rotational force in excess of the vertical force to rotate the dies during strike. If one looks at the engineering drawings of the Boulton press (see Cooper) there is no potential causitive factor for such a large rotational force. In sum, proposing that the dies were rotating during the strike is analagous to proposing that one could rotate a CD with a 2 ton truck sitting on it. For those who doubt this, the solution is simple: draw a free-body diagram and then calc the forces. Sorry, ain't gonna happen, its physics 101.

 

Nor is this die polishing or die sinking related. OK, so what is it? It's very heavy metal flow arising from worn and misaligned dies. The planchet may aslo have been poorly annealed.

 

This type of metal flow is not uncommon in coinage, or any stamped or rolled metal for that matter. It is rather common on US, esp. Capped Bust Half Dollars, Large Cents, etc., in sum all of the screw press coinage were the strike is an impact strike. This type of strike has specific metal flow characteristics, one of which is very heavy peripheral metal flow once the dies wear and being to loose their "basin" or buckle. This wear reduces the amount of pressure at the periphery resulting in the metal only partially being constrained by the peripheral elements. As a result you see heavy flow lines off the tops of the peripheral elements. (BTW, the Boulton press was a screw press, it was merely powered by a steam engine rather than by hand. Thus the strike charateristics are screw press, just heavier than a manually driven one.)

 

The "twist" is certainly interesting although I've seen it before, just not to this extent. Very cool. This was probably caused by the misalignment of the dies (note the heavier strike at the dentils on left), the dies wear/damage, possibly combined with a poorly annealed planchet. Also note that the obv shows similar flow lining under the wreath to the right of the bow.

 

Be aware that the heavy flow lines are a solely an artifact of the planchet metal flow. These lines do not show on the die itself. Numismatists once thought that these lines were "gouged" into the die by the constant erosion of the planchet metal flow. However, the US 1806 Half Dollar obverse die in the ANS collection disproved this. Late state coins struck for this die show very heavy flow lining at the periphery, but the die itself shows no such lines. Rather it shows just fairly heavy overall wear.

 

Hope this helps with the discussion and that I've answered to eveyone's satisfaction. Very cool coin. I'd strongly suggest a bid for those who are advanced collectors. Unless there are a lot of late state pieces of this variety I doubt you'll find another like this anytime soon.

 

Thank you for the comments, rittenhouse. Very interesting and informative as always.

 

...

First off, the die(s) were not rotating.

...

 

Please explain how screw press works so I can understand how it is possible to move die up and down without rotation involved.

 

If there would be ONLY one force involved there would not be swirly flaws of metal how we see them. They show exactly how the powers were applied. Flaws of metal in the case of strictly vertical power would go from centre to periphery as straight lines. So there definitely was "second power". Correct me if I am wrong.

 

What possibility I missed is that die could be misaligned (not parallel to a planshet) and may be that was the source of "the second force" present during strike. However, in this case "twists" or "swirls" would be much heavier on one side of the coin than on the other and their direction and form would be different and I do not see it. Weakness of strike should be very dramatic on one side of the coin too and it is not also the case. What do you think?

 

In any case there were two powers involved and what we see have nothing to do with die polishing.

 

I also want to add, this coin is not something never seen, many 1830-s early 1840-s Rubles have about the same look, may be not this dramatic but still.

 

WCO

[bobh]

[snip]

I also want to add, this coin is not something never seen, many 1830-s early 1840-s Rubles have about the same look, may be not this dramatic but still.

WCO

Thanks to both of you, WCO and rittenhouse.

 

I agree that elements of this kind of error are seen on lots of coins -- however, it is unusual that a coin with this kind of mint "errors" would exist in such a well-preserved state WRT circulation. It is indeed "AU", IMHO. As such, it is a highly desirable coin, but even more interesting for the fact that it was struck at such a late die stage (and that it is possible to tell the difference so clearly between circulation wear and striking features).

[gxseries]

Thanks guys, very interesting.

 

Here is one of the latter die state but not as dramatic as the one in the link:

 

 

sorry, the lighting is terrible. It's a 1842 ruble by the way.

[grivna1726]

Hope this helps with the discussion and that I've answered to eveyone's satisfaction.

 

Thank you for this explanation. It is indeed helpful.

 

I think this might make a worthwhile article for an upcoming JRNS (hint, hint).

[grivna1726]

Thanks guys, very interesting.

 

Here is one of the latter die state but not as dramatic as the one in the link:

 

 

sorry, the lighting is terrible. It's a 1842 ruble by the way.

 

Neat coin, gx!

[rittenhouse]

Thanks guys, very interesting.

 

Here is one of the latter die state but not as dramatic as the one in the link:

 

 

sorry, the lighting is terrible. It's a 1842 ruble by the way.

 

Neat coin gx, with a much more typical metal flow from the tops of the letters. The metal flow will vary in strength and direction due to a number of factors including die wear, die buckling, strike pressure, planchet hardness, position of devices, size of devices, etc.

 

Edited to add:

 

While flow lines are far more common on late state, I have also seen flow lines on earlier state coins. The cause is poor die pressure and/or poor basining of the dies.

[rittenhouse]

Thank you for the comments, rittenhouse. Very interesting and informative as always.

Please explain how screw press works so I can understand how it is possible to move die up and down without rotation involved.

 

If there would be ONLY one force involved there would not be swirly flaws of metal how we see them. They show exactly how the powers were applied. Flaws of metal in the case of strictly vertical power would go from centre to periphery as straight lines. So there definitely was "second power". Correct me if I am wrong.

 

What possibility I missed is that die could be misaligned (not parallel to a planshet) and may be that was the source of "the second force" present during strike. However, in this case "twists" or "swirls" would be much heavier on one side of the coin than on the other and their direction and form would be different and I do not see it. Weakness of strike should be very dramatic on one side of the coin too and it is not also the case. What do you think?

 

In any case there were two powers involved and what we see have nothing to do with die polishing.

 

I also want to add, this coin is not something never seen, many 1830-s early 1840-s Rubles have about the same look, may be not this dramatic but still.

 

WCO

 

WCO,

 

How a screw press operates without the uppper die turning is simple: the die is fixed to the upper die block, also called a slider. The block is held against the screw by various mechanical arragements including S-leaf springs, counter-weight and lever, or torsion isolation assembly. This isolates the upper die from the rotation of the screw. These are clearly shown in the photos and contemporary engineering drawings in Cooper.

 

For a further understanding I'd suggest you get a copy of Cooper. However, even this work is not complete enuf to answer the question as he does not go into metal flow mechanics. For this info you would need to consult several mechanical engineering texts. The Metals Handbook would be a start. A background in mechanical engineering helps (I was a Process and Quality Engineer in the metals forming industry).

[rittenhouse]

Thank you for this explanation. It is indeed helpful.

 

I think this might make a worthwhile article for an upcoming JRNS (hint, hint).

 

Oh great, now Julian will be on the phone bugging me for another article!....... Just kidding. I'll see what we can do. Either the journal or the newsletter.

[squirrel]

Thank you Rittenhouse. interesting and well said explanation. Does anyone have a source for this Cooper book? (Im assuming its The Art and Craft of Coinmaking; A History of Minting Technology .

 

Couldnt find it on the www. PM me, anyone, if youve got a copy for sale.

[WCO]

Thanks for suggesting literature, rittenhouse. I am not familiar with mechanics of a screw press of that time, once I find some time I will look into it. I appreciate the advise.

 

However, I am familiar with first law of Newton. Newton's First Law states that any object in a state of rest or moving in a straight line (uniform linear motion) tends to remain in such a state unless acted upon by an external force. So during strike there must be another force to produce non linear flows of metal. So what do you think what was the source of that second force if it was not an upper die?

 

 

WCO

[Hussulo]

If one looks at the engineering drawings of the Boulton press (see Cooper)

 

Hi rittenhouse. Can you tell me the title of Cooper's book as I would be interested in reading it.

 

Thank you,

Hus

[rittenhouse]

Hi rittenhouse. Can you tell me the title of Cooper's book as I would be interested in reading it.

 

Thank you,

Hus

 

 

Squirrel got it. It's "The Art and Craft of Coinmaking; A History of Minting Technology" by Denis Cooper. Denis is a former Chief Engineer of the Royal Mint. After retiring he formed a firm specializing in minting equipment. I had the good fortune of personal contact w/ Denis in the early 1990s. He's very sharp on minting tech and a wealth of info. His book is THE reference for thos interested in historical minting technology. It's out of print but you can occassionally find copes on eBay or ABE Books.

[rittenhouse]

Thanks for suggesting literature, rittenhouse. I am not familiar with mechanics of a screw press of that time, once I find some time I will look into it. I appreciate the advise.

 

However, I am familiar with first law of Newton. Newton's First Law states that any object in a state of rest or moving in a straight line (uniform linear motion) tends to remain in such a state unless acted upon by an external force. So during strike there must be another force to produce non linear flows of metal. So what do you think what was the source of that second force if it was not an upper die?

WCO

 

My, my. You think yourself terribly clever. However, you just outwitted yourself again (obviously not a difficult task).

 

Even if Newtonian mechanics applied here (which it doesn't) amateur-hour pseudo-scientists always forget to read the little cavet published in most texts: the laws and equations are presented as idealized for general principles and do not take into account the effect of friction. So, even if Newtonian mechanics applied, you forgot FRICTION - the friction of the planchet against the dies and the friction of the molecules of the planchet against each other as the planchet deforms .

 

BTW, Newtonian mechanics only deals with the motion of macroscopic objects. This is the wrong area of physics to describe the deformation of materials under pressure. Look it up in wiki.

 

So, to your lack of knowledge of the presses, you can add a lack of knowledge of mechanics. Suggest you do A LOT of reading and study before you post again.

[Maya]

My, my. You think yourself terribly clever. However, you just outwitted yourself again (obviously not a difficult task).

 

Even if Newtonian mechanics applied here (which it doesn't) amateur-hour pseudo-scientists always forget to read the little cavet published in most texts: the laws and equations are presented as idealized for general principles and do not take into account the effect of friction. So, even if Newtonian mechanics applied, you forgot FRICTION - the friction of the planchet against the dies and the friction of the molecules of the planchet against each other as the planchet deforms .

 

BTW, Newtonian mechanics only deals with the motion of macroscopic objects. This is the wrong area of physics to describe the deformation of materials under pressure. Look it up in wiki.

 

So, to your lack of knowledge of the presses, you can add a lack of knowledge of mechanics. Suggest you do A LOT of reading and study before you post again.

 

Is it really necessary to be rude?

 

Until this last reply I thought this was one of the best threads we have had in a long time. It was extremely interesting, with a lot of great information and a civilized exchange of ideas and opinions.

But we simply couldn't keep it up could we?

 

How very very sad.

[rittenhouse]

Is it really necessary to be rude?

 

Maya,

 

From WCO's wording and emoticon I took it that he was trying to be smart with me as he sometimes is. I do not appreciate that. Had he simply asked the question w/o trying to show his cleverness he would have received a polite response.

 

I any case I apologize to you since you took offense.