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Post by John on Aug 8, 2007 6:37:19 GMT -5
Six miners are still trapped on what looks like their retreating longwall face. From all accounts, it looks like massive convergence has taken place at this mine with roof falls all over the place making a rescue extremely hazardous.
First time I've heard of an earthquake triggering problems in coalmining though, I worked down Wongawilli near Wollongong during the large aftershocks from an earthquake in the Picton area and never felt anything. We also had over a 1000 feet of Illawarra sandstone over our heads too, pretty similar to Crandall Creek.
Could retreating starting outbye and working inbye be the cause?? I also noted from their maps yesterday that they didn't leave anything between faces, ie single entry developments, something I'm not aquainted with. I was used to double entry panels which leaves a pillar of coal between faces and a little support in the goaf area edges.
Maybe Murray Energy should start to work double entry panels and start their production at the bounderies of their pits, working outbye. At least there will be a large block of coal from the faces to the mine portals.
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Post by John on Aug 8, 2007 10:13:19 GMT -5
Here's a bit of the mines history from the Utah government site.
CRANDALL CANYON MINE Permit Number C0150032 County EMERY Site Summary The Crandall Canyon Mine is located in Huntington Canyon on the eastern edge of the Wasatch Plateau Coal Field approximately 16 miles west of Huntington, Utah in Emery County. The permit area encompasses over 6,200 acres with a combination of fee land, and federal and state leases. The mine is entirely within the Manti-LaSal National Forest, and conducts its surface operations on 10 acres of disturbed land. Site Description Historically mining was conducted in the area from November of 1939 to September of 1955, using the room and pillar method. Mining was resumed in 1983 by Genwal Coal Company with production ranging from 100,000 to 230,000 tons per year. In 1989, the mine was purchased by NEICO, and in 1990, IPA purchased a 50% interest. A continuous haulage system was incorporated into the room and pillar mining method in 1991, allowing an increase in production ranging from 1,000,000 to 1,500,000 tons per year. In March 1995, the mine was transferred to Genwal Resources, Inc. 50/50 Andalex Resources, Inc., a subsidiary of UtahAmerican Energy, Inc. and IPA (Intermountain Power Agency). A longwall was installed midyear of 1995 and production was just over 2,000,000 tons. A longwall was purchased in 1997 to increase production from 2,500,000 tons to 3,500,000 tons per year.
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limey
Shotfirer.
Posts: 75
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Post by limey on Aug 8, 2007 13:08:30 GMT -5
Sounds to me like they were pulling pillars!
I did some work at the Sunnyside mines, not far from there. One night we were installing instrumentation on a JCM when there was a "bounce" or "bump" in a longwall section outbye of where we were. The ventilation stopped and the phones were out! What did we do? We ate our snap and discussed what our widows would do with the insurance money - then we walked out of the mine. They did loose the section, and the reason the ventilation stopped was because it blew out several air doors.
All we heard was a muffled "whump", and felt the ground shake. I was later able to contact the seismologists at the University of Utah who found the event in their logs - it was a 3.4 on the Richter scale! They told me they see a lot of that type of activity in the mining areas around Price and Huntington!
I hope they find them alive, but I have to say I don't think the chances are good.
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Post by John on Aug 8, 2007 13:38:05 GMT -5
The first longwall ever installed in Australia went into Bulli Colliery just north of Wollongong, it was a failure, and the last installation for many years. They installed modified Gullick Seamen five leg chocks designed for the UK coal industry. As it was a thick seam, the chocks had to be built up to accomadate the high roof. The roof was the Illawarra sandstone, very thick and doesn't like to break easily. Off they went and the goaf kept hanging up for yards behind them, then one shift when it came in, it wrecked all the chocks.
I worked in pillar extraction at Wongawilli, a few miles south of Bulli, quite an experience. We buried the miner twice! Once was the mining crews fault, second time on the shift I was on, was just nature acting unpredicatably. The Inspector and the Manager found no fault in the crews operating methods or deviation from the Managers support rules. That shift though I recall sitting at the belt road while the miner driver was "lifting off" 12 yards inbye of me. The roof behind me was working real loud, never heard it that bad before, so went inbye and pulled the driver up to have a listen. Our Deputy hadn't arrived as yet, he agreed it didn't sound too good and asked me to keep an eye on it for him and notify him if it got worse. It did!, we all pitched in and brought the miner back to safety, or ay least we thought it was!
I went down and gave them a hand to set breaker props and some other props and bars. Then someone suggested we set a couple of rows of props at the intersection until it calmed down. "Who measured these props" came the reply, they are too long!!! Yeh, the roof was converging, so we knocked a tacked a couple of inches to the piece we cut and made each prop a couple of inches shorter, but the roof was beating us. Finally, the most experienced miner shouted "abandon ship"!! We all took off at breakneck speed down the belt road! BUMP, crash! The whole intersection from the lift outbye a few yards of the intersection and across it came in! Holy crap, the miner!! I ran through a cut through into the transport road and went inby to the cross cut the miner was in, the whole of the apron and cutting head were buried together with a loop of it's cable and water hose. I tried it for power and tried to lift the head and apron, but they were pinned under tons of rock. I went back and said, "well thats F%$^&*&^%$ that shift up" ;D ;D ;D We lost a couple of shifts while they dug the miner out.
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Post by John on Aug 8, 2007 13:43:05 GMT -5
Like you Eric, I don't think they will find the miners alive, I also think they were operating the longwall, six miners seems about a right number. Two shearer drivers, foreman, three men pushing over and chocking, who will also be the electrician and fitter, as seem to be the norm in US mines.
I was used to six miners, one electrican, one fitter and the Deputy in NSW mines. Even they have the two tradesmen incorporated in the team nowdays.
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Post by John on Aug 8, 2007 15:20:09 GMT -5
Latest MSHA press release.
Genwal Resources, Inc.’s Crandall Canyon Mine Wednesday, Aug. 8, 1:00 p.m. EDT. Miners continue to work round the clock to locate the missing miners. They are working 12-hour shifts. Approximately 39 miners are currently working underground and have repaired all ventilation controls, with all outby stoppings by the 119 cross-cut repaired. Drilling from the surface of the mine with a 2-1/2 inch drill has reached roughly 450 feet underground at an approximate rate of 70 feet per hour. A large rotary drill is still being positioned on the drill pad. The continuous mining machine’s electrical power cable was damaged from bump material and has been repaired. The trapped miners are believed to be 1,500 feet underground. Ground movement has required rescue efforts inside the mine to slow while additional safety measures are implemented to protect the rescuers. A total of 12 mine rescue teams are available to go underground, with four teams currently on site. Assistant Secretary of Labor Richard E. Stickler is on site to support the rescue and to ensure that all of MSHA's resources are brought to bear in reaching these miners.
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Post by linbylad on Aug 8, 2007 17:40:04 GMT -5
Hi, John and Limey, Linby Lad online. I've been following the rescue attempt on CNN. From what I have seen on the maps shown, the miners were extracting a thin panel of coal between two worked out sections at the inbye limit of the workings. The computer generated block images did not give enough detail to determine the type of mining being used but I saw from one of the actual mine maps that the owner was pointing to that the method was room and pillar and had not advanced very far. A lot of confusion has been caused by the use of the word retreat mining by the media who know less about mining than my mrs. No retreat mining was being done in this section and no pillars had been pulled. John, I only know of two longwall faces that were advanced in the USA, both at the Blue Creek mine in Carbondale, Colorado, in the 70s. Multiple entries are used by all longwalls, most of them using 5, typically 50-100ft on center with crosscuts at 100-200ft intervals. The two entries furthest from the face are sealed from the others and are used as twin tailgates for the next longwall face. The entry nearest the face is isolated from the centre two by temporary seals (breezeblock wall) and this is used for the conveyor belt. Fresh air travels down the two centre entries and the air is split at the cross cut nearest the face with the majority of the air going through the face and the rest going back to the surface down the first entry. This means the belt is in the return air. Too bad this system was not in use at Cresswell Colliery (in 1952?). I do not know if the mined out sections on either side of the caved in panel had been longwalls but if they were and the seam height is around 8 feet and inclined at about 15 degrees typical in that area then I would have expected this to put a lot of weight on the panel in between. But what do I know, I'm just a stupid electricain. Limey, I posted on the Price of Coal thread yesterday and gave a little bit of my work history. I visited the Sunnyside mine in 1978 so maybe we have common friends (my wife says all my friends are common) . Her inside is callng me to the trough, so i'll catch you later. Linby Lad.
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Post by John on Aug 8, 2007 18:03:24 GMT -5
Hi, John and Limey, Linby Lad online. I've been following the rescue attempt on CNN. From what I have seen on the maps shown, the miners were extracting a thin panel of coal between two worked out sections at the inbye limit of the workings. The computer generated block images did not give enough detail to determine the type of mining being used but I saw from one of the actual mine maps that the owner was pointing to that the method was room and pillar and had not advanced very far. A lot of confusion has been caused by the use of the word retreat mining by the media who know less about mining than my mrs. No retreat mining was being done in this section and no pillars had been pulled. John, I only know of two longwall faces that were advanced in the USA, both at the Blue Creek mine in Carbondale, Colorado, in the 70s. Multiple entries are used by all longwalls, most of them using 5, typically 50-100ft on center with crosscuts at 100-200ft intervals. The two entries furthest from the face are sealed from the others and are used as twin tailgates for the next longwall face. The entry nearest the face is isolated from the centre two by temporary seals (breezeblock wall) and this is used for the conveyor belt. Fresh air travels down the two centre entries and the air is split at the cross cut nearest the face with the majority of the air going through the face and the rest going back to the surface down the first entry. This means the belt is in the return air. Too bad this system was not in use at Cresswell Colliery (in 1952?). I do not know if the mined out sections on either side of the caved in panel had been longwalls but if they were and the seam height is around 8 feet and inclined at about 15 degrees typical in that area then I would have expected this to put a lot of weight on the panel in between. But what do I know, I'm just a stupid electricain. Limey, I posted on the Price of Coal thread yesterday and gave a little bit of my work history. I visited the Sunnyside mine in 1978 so maybe we have common friends (my wife says all my friends are common) . Her inside is callng me to the trough, so i'll catch you later. Linby Lad. I'd like to see a mine plan proper instead of the crap they show the media. Multiple entries are the way to go as they leave what is known as "chain pillars" which give some support to the roof, very necessary when your under massive sandstone. Belts are forbidden in returns in NSW, too much of a hazard where gas is around. Cresswell was due to several factors, wrong material for conveyor belts being high on the list, inadequate training being second on the list, and extremely poor housekeeping last on the list. I remember having to study that accident in mining practice at tech. Poor old feller who was a stand in switchman never worked again after that fire. He's never been trained to use a fire extinguisher. I presume you were at Linby when Clifton had it's fire Linbylad??? That would have been around 1963ish, when 10's M/G conveyor caught fire under similar circumstances to Cresswell. Good job the belt was that PVC material and not rubber.
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Post by dazbt on Aug 9, 2007 3:49:39 GMT -5
Heyup everybody, good to see some action on here at last. A special heyup to Ron, welcome aboard mate. I can’t believe that you remember my ‘day trip’ to Braztah, the only thing that I recall about it was the 45 gallon oil drum stuck on top of the mountain and the pain of the cartilage in my knee coming out of place as I walked inbye. No more secrets now Ron, and I’ll buy you a beer later Re the Crandall tragedy, it is hard to make much sense of anything that is happening or has happened there from the media reports on the internet. The one thing that is obvious is that there is little respect between Murray and the rest of the world ! I don’t know how I’ve managed to form a picture in my head from everything that has been quoted, Murray insisting that the face being worked was an “advanced wall” (whatever that is) and not a retreat system in the accepted American sense of de-pillaring, whilst Amy Louviere insists that the section was definitely being retreated, I wonder if it is a Retreating Longwall taking a block between pillars. Time will tell. It isn’t easy to believe that there is a great deal of hope for these lads, but I’m confident that everybody involved will be giving their best whilst ever there is a glimmer, good luck to them all. “Nor seen the Dog on the Tuckerbox” Better than that J , I’ve seen one in a snap tin and on my plate, beat that pal !!.
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Post by John on Aug 9, 2007 6:20:03 GMT -5
Just seen the latest on CNN a few minutes back and Mr Murray had taken a CNN film crew to the "face head", it's a mess! Total convergence, no fall! Remember when you got to a fall, most of the time you could look to the top of a fall and somewhere up there was a cavity that you could climb up and get over the fall?? None there, it's just a solid heading, I doubt very much they will find anyone alive, if thats the state of all roads. This is the sort of scenerio you read in history books of collieries in the 18th century England, not 21st century modern mines where we know what happens if you take too much out.
IF, Mr Murray is lying through his teeth, God help him, they will crucify him when the reports are concluded by the authorities.
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limey
Shotfirer.
Posts: 75
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Post by limey on Aug 9, 2007 12:39:30 GMT -5
Ya know, when all is said and done, I am pretty glad I don't have to go underground to earn my living anymore. My heart goes out to those lads trapped, I personally cannot imagine a more terrible way to die. Then it makes me angry that mine owners, and the government, seem to take it for granted that the lads will do this work for them.
I, for one, would like to stick every member of the US government into a coal mine - just for one shift, and see what they think when they get out!
Sorry for the rant - just had to get it off my chest!
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Post by John on Aug 9, 2007 13:17:32 GMT -5
I'd make it mandatory that ALL CEO's of mining companies hold a current Mine Managers ticket, and to retain that ticket and the license for their mining company to mine a lease, to spend a minimum of three working shifts per month at every mine within their leases! Make them sign the foremans report book with at least four miners from the team he was working with as signee witness's and the hours he was in that district, which must be a minimum of 8! Further, he must prove he has done every job within all his mines, except those that are technical by nature.
I also agree Limey, make them bastards in Washington go down pits and work side by side with miners on a face for a couple of weeks, and not just cushy longwalls either!! Let them do some bord and pillar work!
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Post by dazbt on Aug 9, 2007 13:18:18 GMT -5
Just found this video of Murray with a film crew, it shows as he explains that there is no broken roof but the blockage is loose rib coal resultant of the bumps, might be same thing that you watched this morning John but it certainly looks more promising than having to work out of the solid. The video is in three parts don't miss any, kutv.com/local/local_story_218103238.html
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Post by John on Aug 9, 2007 13:23:38 GMT -5
And the reporters still can't get it right Daz!! suttle cars!! They obviously don't listen to what they are told! and continuously mining vehicles!! God what do they have in their ears??? I'm sure Mr Murray told them its was a continuous mining machine.
Where that video was taken Daz was 300 feet from where they were the other day, they were recutting the converged roof to get to the other rescue machines they were driving when the roof lowered two day back and chased them out. The full video was on CNN half an hour back.
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Post by dazbt on Aug 9, 2007 13:52:45 GMT -5
I know what you mean about the misquotes and 'wobbly expressions', tell me this John, how long have you to live in the States before you can accept the fact that a coal mine shaft can mean anything that looks like a hole in the ground, it drives me to distraction, well it would do if I wasn't already there. Mr Murray does explain that the junction they were at was where they started previously, but the point that I thought was most relevant was the fact that the roof was undamaged with no major fractures and that the blockage as far as they had been previously was the result of extruded rib coal. Not long after that video was taken it was reported that the renewed advance was some 300ft forward, I know that most of that would be cleaning up of the second series of bumps. I just hope that things would move a bit quicker now that the weightings seem to have ceased, but the last estimate was yet another week, I hope that was just a pessimistically guarded statement.
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Post by John on Aug 9, 2007 14:40:57 GMT -5
A shaft is a shaft to me Daz, always will be, denotes a vertical hole. An adit is the entrance to a drift mine, and a portal an entrance to a roadway going horizontal in an outcrop. At least the Americans do call the roads to a longwall, Gates as we did.
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Post by John on Aug 10, 2007 6:23:45 GMT -5
Doesn't sound too good at the moment! Nothing heard from the listening devices.
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Post by John on Aug 11, 2007 8:42:20 GMT -5
No real news yet, the larger diam borehole is done and they are pulling the drill pipes out ready to lower the camera etc down in a couple more hours time.
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Post by dazbt on Aug 11, 2007 17:10:10 GMT -5
Hardly a snippet, but worth a read. Factual presentation and discussion relating to amongst other things, bumps and weighting problems and experiences relative to the Crandall area coal mining, dated May 2007. www.msha.gov/Beltair/hearingtranscript20070517.pdf
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Post by John on Aug 11, 2007 17:53:40 GMT -5
Thats an interesting paper Daz, shows the problems they have in Utah. Looks like the rock mechanics and geology depts of mining companies have their work cut out designing safe longwall faces! I wonder what the yield load was on the chocks at this mine? Sounds like the shearer would be under heavy load too.
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Post by John on Aug 12, 2007 6:09:16 GMT -5
Still no news yet other than a report from MHSA, there were no roof falls, all the debris was from the rib sides, ie the pillars crushing under the tremendous weight of convergence. Looks like when the reopen this mine for production, they will have to steel arch the whole of the main raodways.
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Post by dazbt on Aug 12, 2007 12:33:26 GMT -5
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Post by John on Aug 12, 2007 15:29:10 GMT -5
Never ending!
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Post by John on Aug 13, 2007 7:31:16 GMT -5
Still no real news, they are just inching their way forward.
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Post by John on Aug 14, 2007 14:11:36 GMT -5
They are making a little more progress now according to Bob Murray, he was underground with a cameraman making a video last night which was shown at this lunchtimes press conference. They are setting hydraulic props with mesh and wire ropes to prevent the ribs from spalling as they advance. According to Mr Murray there rate of advance now the ground has settled down is twice as fast as a couple of days back. They start drilling the second larger diameter borehole this afternoon.
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Post by dazbt on Aug 14, 2007 14:38:43 GMT -5
Did today's report give any indication as to where the second large dia. hole was to be started and aimed to, in relation to the first drillings, will it be a great distance from them?
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Post by John on Aug 14, 2007 15:11:56 GMT -5
Did today's report give any indication as to where the second large dia. hole was to be started and aimed to, in relation to the first drillings, will it be a great distance from them? I don't recall the exact distance Daz, but he did show on the UG maps where they want to penetrate the workings. They had to clear a road and the new site as again it's on steep terrain.
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Post by dazbt on Aug 14, 2007 15:44:59 GMT -5
Thanks John, have just this minute seen a report that this third hole is now about 500ft deep in progress and is being drilled to reach the furthest reccess, a fourth hole has also been pre- planned for, intended to reach the central area of the workings should nothing be found on this attempt.
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Post by linbylad on Aug 14, 2007 22:50:21 GMT -5
Ayup, Linby Lad back on line, been away visiting friends. It doesn't look too good. I followed progress on the idiot box and spent sometime today searching on the computer. In a previous post I said on one of the maps that I saw being shown to reporters by Bob Murray that the section being mined had not advanced very far. Well one I saw today showed the section had mined out to the working limits. It could well have been retreating at the time of the accident. The mined out panels on each side had been longwalls and the set up entries could be clearly be seen as could the lines across the face which would be the monthly positions of the faceline. The CNN.com website contain 16 photographs and no. 2 shows the map. It is not unusual for a mine office to have several maps hung up and some of them could be out of date.
I spent a lot of time in a mine in Colorado in 1978/79 where the seam was very steep (28 degrees?) with 2000 ft of cover and "bumps" where common. I only experienced small ones but they scared the crap out of me and was glad to get away from the place. You will know which one I am referring to, Daz. When I first went on the face they told me that when they had a bad bump the face coal burst out and buried anyone near it. They had a compressed air hose running along the panside at the side of the cables with a box every 20 yards or so. Inside the box was number of small bore flexible pipes fitted with stopcocks. I was told if a bump was coming it would be indicated by puffs of orange dust coming out between the coal and the roof and if I saw this I should rush to one of the boxes, lie down as close to it as possible, open the cover put my hard hat over my face, insert pipe and turn on the air! If I was buried I was told to wait until some one dug me out. Yeah, right.
I don't know if anyone had to suffer this but I do know That 5 shearer operators had been killed on the 2 longwalls at this mine. I believe the walls had only been in production less than 2 years and had advanced very little due to being gassed out after 2 cuts every shift. The walls were being advanced taking the top 8 foot of a 26 foot seam and the plan was to cut to the limit drop the face to the bottom of the seam and retreat taking the bottom 8 ft of coal and letting the remaining coal drop through chutes on to the panline. I don't think they ever did this (thank God).
I don't think I'll be able to sleep tonight what with the memories typing this has brought back
Linby Lad..
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Post by dazbt on Aug 15, 2007 3:25:36 GMT -5
It is looking pretty desperate now for these lads, it will be nothing short of miraculous if they are rescued, just hope against hope that they are. I read yesterday a couple of press quotes that there had already been 'official' discussion as to sealing up the mine as being too dangerous to enter even if the men aren't recovered ........... what a statement, whether sealing the mine has been discussed or not how could anybody make a public statement that even suggests it at this time, sick, tosspotting newspaper reporters!! I think I do remember the mine in Colorado Lynbylad, JR and JJ's pit at about 11,000 ft elevation, worra place that was. The only face I've ever been on that continued to operate with most of the chock legs bent at 90 degrees, still in production whilst Gullick lads were sawing the old legs out and replacing them individually. The shearer was the only working one of its kind in the world I think, it was an AM 500 mechanical haulage, one of only two ever built if I remember correctly. I know that the mine suffered weight bumps and had at least a couple of outburst disasters where numbers of miners were killed, wasn't there an methane explosion there as well sometime in the early 1980s? I was told about one fairly bad 'verbal outburst' that occurred when a Brit working for Dowty (I think), told JJ the owner's son that the miner's bus had a misspelled logo on the back, when asked which part of "This bus carries the greatest miners in the world", "Was it the word greatest?" "No that part is true, it's the word miners that's wrong, it should be ass.oles" banned from the mine sine die. Bringing back memories now Lynbylad, my third son was born here in England whilst I was working nights at Mid-continent 1979, he was just about 2 months old before I got back to see him. Here's hoping things get better at Crandall.
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