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Coal Vs Oil

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Posted by Overmod on Saturday, August 15, 2020 2:42 PM

Erik_Mag
My somewhat tongue in cheek proposal was that the heat transfer between the steam generated by burning hydrogen and the boiler water would be done by condensation of combustion products directly into the "boiler" water.

It is less tongue-in-cheek than you think: submerged burners are a 'thing' and they could certainly be made to work with stoich air-hydrogen flame.  (Now for true fun you would of course use LH and LOX via turbopumps, with some kind of hypergolic igniter or flameholding -- at appropriate scale of course.  Ouch, I seem to have bitten the tongue that was in my cheek with excitement...

However why bother with all that combustion nonsense and firing up and wasted heat when the Oxford cycle generates 11 molecules of steam at 885 degrees from every molecule of methanol?

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Posted by Erik_Mag on Saturday, August 15, 2020 2:34 PM

My somewhat tongue in cheek proposal was that the heat transfer between the steam generated by burning hydrogen and the boiler water would be done by condensation of combustion products directly into the "boiler" water. Think charging up a fireless cooker. The "firebox" would resemble the combustion chamber of a small rocket engine as combustion would need to take place at somewhat above "boiler" pressure.

Makes a lot more sense to use hydrogen in fuel cells...

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Posted by Overmod on Saturday, August 15, 2020 7:19 AM

Erik_Mag
One could always set up the output of the hydrogen burner to be directly injected into the boiler with a little injected into the dry pipe for superheating...

I don't think I have explained things well enough.  What is desirable in a locomotive's radiant section is a long, luminous flame that does not touch the relatively cold walls enough to quench, and that *just* finishes the combustion causing the luminosity as the plume reaches the rear tubesheet, forward of the chamber.

Hydrogen is almost the antithesis of this: it burns very hot, very promptly, with a transparent flame with peaky spectrum, and while it is high-energy it is so light that a large volume is involved for high mass flow.

You may remember from anthracite discussions that there are problems vaporizing or levitating enough carbon to get the necessary rate of heat release for locomotive firing... at which point some parts of the firing system melt rather than act to transfer heat to steam.  A large hydrogen blowpipe can be expected to cause far more spot overgeating and differential expansion problems, even before we take up cumulative hydrogen embrittlement as a potential structural concern.

Use in separately-fired superheaters of proper design would make better sense, but again the required mass flow makes co-firing with something that optimizes proper heat transfer -- probably some high-carbon liquid -- desirable.  Besler tubes would be advisable, and while you might arrange hydrogen manifolding in them you'd need nanoinsulation inside, as Besler tubes are passive re-radiators.

After all, the ultimate proposed steam engine was the Aerojet M-1 engine that would have been good for 1.5m pounds of thrust.

If the reciprocating engine used hydrogen in internal combustion it would be one thing; if it could use reaction thrust like a glorified M-497 still better.  Unfortunately we're dealing with a practical extended Rankine cycle and heat balance, and rockets do very little good there...

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Posted by Erik_Mag on Friday, August 14, 2020 10:43 PM

One could always set up the output of the hydrogen burner to be directly injected into the boiler with a little injected into the dry pipe for superheating...

After all, the ultimate proposed steam engine was the Aerojet M-1 engine that would have been good for 1.5m pounds of thrust.

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Posted by Overmod on Friday, August 14, 2020 7:01 AM

Hydrogen in transportation is what's known as a 'carrier' fuel; its use is usually driven by concerns other than 'economic'.  In most cases, the cost to make and then supply hydrogen in suitable quantity to, say, fire a locomotive is far higher than even a fully renewable oil or 'coal' fuel would be, and there are further problems regarding its effective use for steam generation in a steel boiler structure.

Even the use of hydrogen in internal-combustion engines has been deprecated in favor of fuel cells producing electricity -- and there, to provide sustainer charging to what us otherwise a battery-electric or multipower vehicle like Coradia iLINT.

Hydrogen is particularly unsuited to modern steam locomotives in its combustion characteristics.  It has very high heat release, in transparent flame, and very low density, meaning that even liquefied or hydrided a large volume of storage, of materials not subject to hydrogen embrittlement or other issues, has to be provided. 

A better use for hydrogen is as a feedstock in something like the Fischer-Tropsch process for 'syngas' and then liquid-fuel synthesis from either renewable or fossil sources of carbon.  (This is generally cost-comparable technologically to 'solvent refined coal' processes to remove undesired impurities from various coal ranks -- neither has generally been successful from an economic standpoint, and of course both are politically reviled as research or development priorities today.

(As would be development of hydrogen-burning steam power, especially reciprocating 'conventional' steam locomotives, but that's beyond the issue of comparative fuels.)

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Posted by scilover on Friday, August 14, 2020 5:44 AM

Coal is the cheapest non-renewable energy that has been used widely in generating power if compared with oil. Just wondered, this will be an interesting debate if we include hydrogen fuel. German is the first country that has hydrogen fuel train back in 2016. 

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Posted by Overmod on Wednesday, August 5, 2020 10:31 AM

Hell, they brought her back with her own name train in 1949! (Her dress would stay white after dieselization anyway...)

Canpaign officially ended with restrictions on anthracite use for locomotive fuel in WWI.  

Did you know there were at least two real 'Phoebes'?  And, at one time, a board game?

Something else I did not know and still have to research is that there was an earlier Lackawanna campaign featuring unsmirched women in white called "All in Lawn".  Presumably this had replaceable women in it, not the strong figure we rapidly came to admire... ah! what wonderful promise the new century offered...

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Posted by daveklepper on Wednesday, August 5, 2020 10:15 AM

When did the DL&W stop using "Miss Snow" in advertisements?

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Posted by Overmod on Wednesday, August 5, 2020 9:34 AM

Warner (in 1940) pointed out that use of straight anthracite in DL&W passenger power ended around the time the use of relatively small engines for that service (4-4-0s and 4-6-0s) did.  By 1915, new Lackawanna power was set up to burn a mixture of bituminous and anthracite, and of course all the more modern engines burned only bituminous, even though in theory they could have been adapted to burn some admixture of waste grade hard coal.

It is interesting that Warner mentions the development of the PRR E1 as being driven by a competitive need to run 60-minute trains between Philadelphia and Atlantic City with 'no smoke, no cinders' -- and the Reading certainly had high-speed anthracite-burning locomotives!  One might surmise that the very early electrification on West Jersey and Seashore might have been driven by this... 

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Posted by daveklepper on Wednesday, August 5, 2020 2:10 AM

What about Anthrasite and the DL&W?  Phoebe Snow?  "She took the road of Anthsite?"

Locos equpped with Wootens?  Didn't look like it?

Incidentally. the B&O had a few Wooten Camelbacks for freight on the third rail Staten Island Rapid Transit.  Saw them regularly as a yougster.  Lasted through WWII/ 

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Posted by Erik_Mag on Monday, August 3, 2020 11:26 PM

Graphene is already used in heat spreaders for electronic applications. IIRC, the thermal conduction in graphene is related to the high electrical conductivity, whereas the thermal conduction in diamond is by phonons - diamonds made from carbon depleted in 13C has a higher thermal conductivity than natural carbon due to reduction in phonon scattering.

IIRC, conductivity of a bundle of carbon nanotubes can be much higher than copper.

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Posted by Overmod on Monday, August 3, 2020 8:29 PM

I was going to mention graphene (note sp.) as it has the interesting property that in electrical conduction the electrons are free to move at relativistic drift speed in-plane, and that promised to make thermal conduction very fast as well.

Fun stuff, and just like aerogel and buckminsterfullerene you can make it at home!

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Posted by Erik_Mag on Monday, August 3, 2020 2:45 PM

Overmod

 *The alert among you will already be gearing up to cry 'but diamonds are among the LEAST insulating materials, and they are carbon'.  Yes, there are differences between metastable octagonal lattice and more amorphous carbon, some of which are more notable than heat-transfer chracteristics...Wink

Graphene in the form of sheets or nanotubes is also an excellent heat conductor, and unlike diamond is also an excellent electrical conductor. The high thermal and electrical conductivity is due to the conduction electrons being above/below the plane of carbon atoms (outside/inside nanotubes). Conductivity is therefor much higher parallel to the plane (axis of the nanotube) than perpendicular.

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Posted by Overmod on Monday, August 3, 2020 5:12 AM

Flintlock76
Phoebe Snow notwithstanding, huh?

There are, of course, effective ways of burning anthracite or culm in locomotives; Angus Sinclair's History of the Locomotive Engine takes up many of the attempts in useful detail.  In particular anything with a Wootten boiler will manage, and locomotives with those could be quite large and powerful and also quite fast -- the fastest locomotives in the world in the early 1890s were so equipped.  But it becomes difficult to get the heat release to do both at the same time... which is the prerequisite for the rapid steam generation in good modern locomotive practice.

The problem is that the heat-release characteristics for hard carbon are not favorable for the kind of luminous 'distributed' combustion that bituminous provides -- you need a broad, thin fire and the combustion products come off largely transparent.  Any attempts to build the kind of useful heel and thicker bed seen in advised bituminous firing practice lead to forge-like conditions when induced draft is applied, which is especially not happy for American grate designs in advanced practice like FireBar castings on a full rocking-grate linkage that must remain relatively undistorted to work.  I in fact worked many hours in my youth designing a firing system for anthracite on a ~6000hp modern 4-8-4, and it can be done but it requires more careful skill than any bituminous engine of comparable output.

Of course the more important consideration was that, just as with all the various experiments to use 'smokeless coke' or slack via briquetting or consolidation, firing with actual anthracite was literally like shoveling diamonds into a fire: the fuel had too high an 'opportunity cost'.   For most of the big-steam era, 'steam grade' anthracite was still a high-value commodity for building heating, and it certainly was less practical to transport it at 'railroad fuel margins' very far from the fields for locomotives requiring relatively expensive technical modification to suit them to use the higher "available" heat content.

There is then the latency issue: carbon is an excellent insulator*, which is one reason you find it in hypersonic airframes, and therefore it takes a while to draft up anthracite to the point it releases high heat flux.  Of course you also have 'thermal flywheel' effect when draft is quickly cut off... accompanied by heroic quantities of CO in the exhaust if you cannot somewhat hermetically cut off the primary air...

*The alert among you will already be gearing up to cry 'but diamonds are among the LEAST insulating materials, and they are carbon'.  Yes, there are differences between metastable octagonal lattice and more amorphous carbon, some of which are more notable than heat-transfer chracteristics...Wink

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Posted by Flintlock76 on Sunday, August 2, 2020 8:15 PM

Overmod
Anthracite has a higher heat value over oil than oil has over bituminous, but that doesn't make it a suitable locomotive fuel.

Phoebe Snow notwithstanding, huh?

Actually, anthracite coal WAS tried as a locomotive fuel in the 1830's, and it worked pretty well.  Unfortunately this was only in vertical boilered locomotives where the firebox was located directly under the boiler.  And of course vertical boilered locomotives were an evolutionary dead end.  So it was back to wood firing until bituminous coal came along.

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Posted by Overmod on Sunday, August 2, 2020 5:28 PM

Backshop
Silly me.  I read the question and thought it was a yes/no answer.

It is a yes/no answer, with the answer being 'yes' (for bituminous locomotive coals, anyway), but that doesn't imply you can substitute one for the other proportionally in firing a steam locomotive.

Anthracite has a higher heat value over oil than oil has over bituminous, but that doesn't make it a suitable locomotive fuel.

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Posted by Enzoamps on Sunday, August 2, 2020 5:02 PM

Yes, Kenny, just outside Lansing, Michigan.

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Posted by Backshop on Sunday, August 2, 2020 4:46 PM

Overmod

 

 
MJ4562
Wasn't oil typically higher in BTU value than coal, generally?

 

Yes, although there are a couple of factors to be considered.  Oil is denser than coal, and contains less 'ash' component; it is also much easier to divide finely and carburete (mix with combustion oxygen) to ignite and then burn even when containg a large proportion of carbon by mass.

 

Remember that carbon has more 'heat content' than the volatiles in steam coal, but is more difficult both to vaporize and to heat above its reaction temperature (reasons why firing anthracite as a locomotive fuel has been so difficult over the years-- it is literally easier to smelt the fire bars in the grate than to generate steam in a boiler with the evolved combustion gas...)  Oil has less problem in these regards... once you have volatilized it correctly.

Interestingly, the earliest complete volume on oil locomotive firing I have, from the 1880s, has an effective way of fire control: it uses a bed of hot lava rock, like a gas grill, and sprays the oil on this to volatilize and burn with much the same effect as a good gas-coal fire.  This is not as efficient as a von Boden-Ingles or Thomas burner, or a modern mechanical-atomization setup with lighter oil or 'distillate', but is has the practical effect of enormous stepless turndown which, with only a little concern for fuel distribution, reduces prompt thermal-distortion effects in the firebox and chamber structure, probably a greater concern on a practical North American road locomotive than sustained high heat release.

Net cheapness of fuel is a consideration.  Much of the perceived benefit (even of "#5" which is like Bunker C without the asphalt and other residual crap) was its cheapness; improvements in 'cracking' alone removed the cost advantage by the late '50s.  Today the only real reasons for oil firing with 'gas oil' involve convenience: nominal fuel compatibility with diesels and their fuel-distribution infrastructure, easier sutomatic firing, lower ash handling issues, etc.

 

Silly me.  I read the question and thought it was a yes/no answer.

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Posted by SD70Dude on Sunday, August 2, 2020 2:52 PM

RE: fuel cost, the Big Boy was designed around burning massive amounts of the cheap low-grade coal from southern Wyoming mines that I believe were owned by Union Pacific.  I've heard a few times over the years that the Big Boy's performance and power output could have been improved with the use of better coal or a proper oil firing design, but I also recall reading that during the intial in-service testing period the boiler was shown to able to fully supply and keep up with the demands of the machinery while being fired with that low-grade coal.  

The early period of oilfield development in western Canada coincided with the final period of revenue steam locomotive operation, and both CN and CP converted large numbers of engines from coal to oil firing in the years after WWII, to take advantage of this newfound cheap fuel supply.  I've heard that in a few cases the refineries here had such a hard time dealing with the leftover residual grades that they actually paid the railroads to take the 'sludge' off their hands!

Greetings from Alberta

-an Articulate Malcontent

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Posted by Overmod on Sunday, August 2, 2020 10:15 AM

MJ4562
Wasn't oil typically higher in BTU value than coal, generally?

Yes, although there are a couple of factors to be considered.  Oil is denser than coal, and contains less 'ash' component; it is also much easier to divide finely and carburete (mix with combustion oxygen) to ignite and then burn even when containg a large proportion of carbon by mass.

Remember that carbon has more 'heat content' than the volatiles in steam coal, but is more difficult both to vaporize and to heat above its reaction temperature (reasons why firing anthracite as a locomotive fuel has been so difficult over the years-- it is literally easier to smelt the fire bars in the grate than to generate steam in a boiler with the evolved combustion gas...)  Oil has less problem in these regards... once you have volatilized it correctly.

Interestingly, the earliest complete volume on oil locomotive firing I have, from the 1880s, has an effective way of fire control: it uses a bed of hot lava rock, like a gas grill, and sprays the oil on this to volatilize and burn with much the same effect as a good gas-coal fire.  This is not as efficient as a von Boden-Ingles or Thomas burner, or a modern mechanical-atomization setup with lighter oil or 'distillate', but is has the practical effect of enormous stepless turndown which, with only a little concern for fuel distribution, reduces prompt thermal-distortion effects in the firebox and chamber structure, probably a greater concern on a practical North American road locomotive than sustained high heat release.

Net cheapness of fuel is a consideration.  Much of the perceived benefit (even of "#5" which is like Bunker C without the asphalt and other residual crap) was its cheapness; improvements in 'cracking' alone removed the cost advantage by the late '50s.  Today the only real reasons for oil firing with 'gas oil' involve convenience: nominal fuel compatibility with diesels and their fuel-distribution infrastructure, easier sutomatic firing, lower ash handling issues, etc.

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Posted by oltmannd on Saturday, August 1, 2020 5:52 PM

Erik_Mag

Best coal is around 14,000 BTU/lb, oil is 18,000 - 19,000 BTU/lb.

Read an interesting story about why the Russian aircraft carrier is a smoky mess, the ship has oil fired boilers running on what the Russians call Mazat, which is similar to Bunker 'C'. On a related note, the USN was rapidly converting from coal to heavy fuel oil before WW1.

 

...and to distillate in the 1970s - to avoid making smoke at all.

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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Posted by Paul Milenkovic on Saturday, August 1, 2020 5:31 PM

Shadow the Cats owner

Also according to several friends my hubby has in the navy the Russian carrier has never seen a full on Overhauling in its entire 30+ year service life.  Yeah it was launched in the 80's and never has been back to drydock for a full overhauling as it would cost the Russian navy more than it cost them new to repair the ship get it back up to snuff.  That ship literally had a fleet tug following it around during it's patrol in the Med when it was attacking Syria as it was that unreliable.  

 

 

Deferred maintenance!

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?

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Posted by Flintlock76 on Saturday, August 1, 2020 4:27 PM

Erik_Mag
On a related note, the USN was rapidly converting from coal to heavy fuel oil before WW1.

A bit of naval trivia.  The USS Arizona was built as an oil-burner from the outset.  However, it kept the ship stateside during the First World War, only the coal burning battleships were sent overseas to augment the Royal Navy, reason being the RN was hard-pressed to keep its own oil-burners fueled so it was less trouble logistically to have the American coal-burners on hand.  

As things worked out none of the American battlewagons fired a shot in anger anyway. 

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Posted by Shadow the Cats owner on Saturday, August 1, 2020 4:08 PM

Also according to several friends my hubby has in the navy the Russian carrier has never seen a full on Overhauling in its entire 30+ year service life.  Yeah it was launched in the 80's and never has been back to drydock for a full overhauling as it would cost the Russian navy more than it cost them new to repair the ship get it back up to snuff.  That ship literally had a fleet tug following it around during it's patrol in the Med when it was attacking Syria as it was that unreliable.  

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Posted by Erik_Mag on Friday, July 31, 2020 11:40 PM

Best coal is around 14,000 BTU/lb, oil is 18,000 - 19,000 BTU/lb.

Read an interesting story about why the Russian aircraft carrier is a smoky mess, the ship has oil fired boilers running on what the Russians call Mazat, which is similar to Bunker 'C'. On a related note, the USN was rapidly converting from coal to heavy fuel oil before WW1.

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Posted by MJ4562 on Friday, July 31, 2020 9:08 AM

Wasn't oil typically higher in Btu value than coal, generally? 

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Posted by Overmod on Thursday, July 30, 2020 2:25 AM

kenny dorham
Sorry.... when i said  "oil"  i was not talking about diesel electric......... i meant steam trains that burned oil instead of coal.

Bunch of stuff there, too.

History of burning oil in steam locomotives was understood as valuable surprisingly early, decades before oil became an optimal fuel for gas engines.  There are various reasons why railroads adopted it over time, the most interesting being in locomotives like the Milwaukee A 4-4-2s where the hotter flame and lack of ash problems allowed optimization of high-speed design, and in railroads that could run oil-burning power over significant distance like Milwaukee and Santa Fe.

Most of the historic roads used cheap residual or heavy oil -- #5 if not 'Bunker C' -- and much of the burner design and placement was done to facilitate this stuff, which had to be heated but not too much.  I think use of high elemental carbon content was instrumental in assuring good luminous flame in the radiant section, something that may get overlooked if the attempt is made to convert to light-oil firing with more 'efficient' more-modern burner technology.

Obviously the use of oil fuel involved  a cost-effective source of reliable supply and the infrastructure to deliver it as a product that usually needed substantial process heat to flow.  The oil 'boom' around the turn of the century combined with the relative scarcity of good locomotive coal in the West led to its preferential use there... but some sources were relatively rich in vanadium, for a reason I've always wanted explained, and this caused accelerated damage to internal boiler components, increasing overall operating expense.

Several improvements in refinery tech and alternative uses for heavy oil as a 'feedstock' changed the relative economy of this kind of firing -- along with the interesting effort to burn heavy oil in diesels and gas turbines for the perceived cost savings from vastly cheaper fuel.  Very quickly when the cost went up, the special attempts disappeared...

Training and then a professional approach were important in oil firing, and the 'knowledge' is different from various kinds of coal.  This implied that railroads would carefully track the bottom-line cost of different firing, probably with relatively complex models that were not well documented,so we may not be able to distinguish whether on a given railroad at a given time it was 'cheaper' to burn one or the other independent of all the other distinct factors.

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Posted by Paul Milenkovic on Wednesday, July 29, 2020 9:13 PM

I think that the heavy oil used in steam locomotive fires was half the cost of the lighter oil used in diesel locomotives, but a steam locomotive generally used 6 times the BTUs as a diesel locomotive.

Ralph Johnson's The Steam Locomotive claims that for an oil-fired switch engine, it only uses 4 times the BTUs as a diesel and hence its fuel cost is only twice that of a diesel.

The other consideration is that during the Diesel Transition Era, oil got to be quite inexpensive because of its abundance from easy-to-exploit oil fields whereas coal was getting expensive owing to increased labor cost related to John Lewis' actions with the United Mine Workers union -- I guess labor action was held of during WW-II but after the war the union was more energetic in its demands for workers.  There was at least one nationwide strike that impacted coal availability just as railroad were thinking about whether they wanted to keep using coal in steam locomotives.

The final consideration is that Eastern railroads were close to high BTU/low ash coal supplies, Western railroads not so much but they were closer to the Texas and California oil fields.

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?

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Posted by kenny dorham on Wednesday, July 29, 2020 9:07 PM

Enzoamps

Hey Kenny.  If it helps, that is what I thought you meant when I read it.

 

 

Yeah..... 10-4.
Partly my fault. It is not easy to communicate via text. I admire the people that can always get their Point/Idea across the first time.Emoji
 
On a side note.... are you in Michigan by any chance.?

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