The Stack

THE STACK - by G.B. Reid

In 1973 & 1974 Hudson Bay Mining & Smelting Co., Ltd., took on one of the largest renovations to our Smelter in its working life time. There was a new 825 ft. stack constucted by Custodis and there was also a total renovation to the flue system to accommodate all movement of dust, gas, smoke and other particles. On the production side there was a construction of a brand new anode plant to improve the quality of copper produced, and to provide a more efficient means of handling. This also took away many labor and intensive jobs that many of us had the opportunity to do when we hired on in the Smelter department. I don't think anyone was sorry to see the old methods of casting and handling of copper bars which weighed 420 lbs. done away with, but the new Copper Anode was refined to a much higher grade of copper and weighed in the neighbourhood of 720 lbs., and were handled with tow motors with the greatest of ease. As I look back on the spring of 1973, this was a huge undertaking. On my morning tours I carried a small pocket camera to and from the Smelter and I always took a few minutes to snap a few pictures. Believe it or not, daily you could see the landscape changing. In those days every department had individuals who had valuable skills that helped make Hudbay what it is today.

Looking back at early spring and the snow was barely gone, the surveyors and the surface blasting crew moved onto the location and commenced work on the area where the 825 ft. stack sits today. Two individuals known as surface blasters were Angus Fitzpatrick and Milton Crone. These men were always drilling holes, loading them with powder, and putting mats in place to prevent fly rock from punching holes in every roof in the proximity of their work location. Their first job was to blast out a trench, referred to as “the donut”, which was 5 ft. wide and 5 ft. deep, reinforced with much rebar, and 67 ft. in diameter. This donut nestled right into the bed rock becoming part of the precambrian shield. This is where the slip forms were set up and all preparation commenced for the erection of Manitoba's second highest structure.

In the above photo are Angus and Milton priming powder in preparation to blast the 5x5 trench which will contain the base for the stack. The next two photos will show how the trench was prepared.

This photograph shows you how these blasters prepared the trench for the donut. Hudbay was very fortunate in those days to have as many skilled people on their payroll. You can certainly see that this was a beehive of activity, with surveyors, drillers, blasters, heavy equipment operators and some sidewalk superintendents who probably should have been doing their job in some other part of the plant but couldn't help but come by to take a peek. After all, this was no small project and everyone had to see what was going on.

This photo here shows when Angus and his crew had completed the trench, and final preparation was being made for the carpenter crew to move in and construct the forms and rebar, and prepare for the pouring of the concrete.

This photo shows the forms being built, and the rebar being bent, shaped and wired into place; foundation work is something that is very important and has to be completely accurate for a structure of this size.

This photo was taken a few days later where the forms have been completed and the concrete was being poured. Up to this point all the preparation and construction had been handled by our local work force. We were very fortunate in those days to have these skilled people and also have the jobs to keep them part of the Flin Flon community.

This photo shows some of the first days when Custodis, the company that built the original stacks in 1929, are now preparing to erect the new one in 1973. This company has a worldwide reputation of erecting tall structures. In the above photograph you can see they were assembling what is referred to as the work platform and slip forms. This platform was anchored to steel, which was firmly embedded in the donut, and was continuously added onto as the stack progressed.

This photograph shows the platform, the revolving crane and slip forms, and at this point, they were preparing to commence. They commenced with the pour after the May long weekend in 1973. I believe it was some 93 days later that they held a topping off ceremony upon reaching 820 ft. The liner protruded 5 ft. above this, making it 825 ft. or 251 meters high. During the pouring of the stack, the higher they climbed, wind and weather some days became a problem which slowed their progress. There were only 3 days when they were unable to operate due to high winds. This came at the higher levels. Their best day I was told was 33 ft. and their shortest day was 17 ft. This was a continuous pour that went on 24 hrs. a day until the pour was completed.

Each load of concrete brought to the site was sampled for texture and density. Any concrete that didn't meet the required standard was rejected, so very tight control on the quality of the mixes was a high priority.

The above photo is the bucket that was used to transport the concrete through the construction of the stack. In the beginning, for about the first 40 ft., this bucket was attached to Hudson Bay Mining's Lorain and operated by local employees. After they reached this height, the opening at the bottom of the stack, allowing access for the concrete trucks. The walls were set up adequately so that the bridging could be removed from the opening at the bottom of the stack, allowing the trucks to back in, and load the concrete into the same bucket which was winched to the operating platform and distributed to the slip forms on the outer perimeter. The next photo will show you how the truck accessed the bottom of the stack and then the following photograph will show you the work platform and the slip forms from the underside. This was quite amazing and a very effective method of transporting the concrete from the ground to the upper level in a smooth and efficient manner.

This shows how the trucks were able to come and go with ease. The next photo will give you a good view of how it appeared from the underside of the work platform.

As you look at all the above photographs, hopefully this is helping you understand the dynamics of this project. We know that the outer diameter of the donut or basic ring is 67 ft. We know that the base of the stack was 64 ft. 5 ½ inches, and when it reached the top, the opening was 25 ft. in diameter. The thickness of the walls started out at 26 ½ inches and ended up being 10 inches thick at the 820 ft. level. There were over 5000 cu. yards of concrete, and 250 tons of reinforced steel used in the stack construction. The total amount of concrete would be adequate for 125 average homes. The amount of steel used for reinforcement of the concrete would have built approximately 100 cars. So it is quite amazing when you look at a structure of this size and think that it was erected in approximately 93 days. The next photographs will show you how this structure progressed.

The above photograph shows the stack at about 60 ft. off the ground and well on its way. This photo was used in a press release in 1973 by Hudson Bay Mining & Smelting Co., Ltd.

This photograph is a good example of the old and the new. The old Zinc Plant stack was 175 ft. and the old Smelter stack was 250 ft. high. These stacks were erected in 1929 with special bricks and the hands of brick layers. Pretty labor intensive and probably took much longer than 90 days to complete.

This photograph was taken somewhere around the 350-400 ft. level. As this was a 24 hr. operation, at night, the work platform took on the appearance of a revolving restaurant. You can certainly see how in the summer of 1973, residents of our city had activity that they could look out their window at any given time and see this structure rising higher each and every day.

This photo is a good example of what the old Smelter stack at 250 ft. looked like. You can see the amount of brick that had to be laid by hand, and you can also see a small station which was somewhere around the 100 ft. level. This is where they tested the draft and the contents of the smoke that were being discharged from the Reverb furnace and the copper converters located in the Converter Pit. You can also see the support rings around the stack to help it maintain strength and stability.

This photograph was taken in 1974 after the flue system and liner had been installed, and the stack was commissioned and was operating. The actual smoke, after it has gone through the baghouse to remove particles that contain zinc and returned back to the zinc plant, travels up inside the steel liner. This liner is 17 ft. 6 inches in diameter and 825 ft. high, and is fully insulated. Expansion of the liner is about 15-20 inches from shut down temperature to operational temperature. Over 44,000 sq. ft. of steel weighing 290 tons were needed for this. This is enough for another 100 cars.

This is very close to completion. I took this photograph from an angle to give you an example of the Zinc Plant stack at 175 ft, the old Smelter stack at 250 ft. and the new Smelter stack approaching 825 ft. At one time we thought the first two stacks were tall but as you can see, they look very dwarfed by the new stack.

This photo was taken after the topping off ceremony, and the work platform and slip forms had been removed from the top of the structure. Now the big job of installing a liner and hooking up a very sophisticated flue system to take care of gases, smoke and dust, was no small job. This took place between November 10th and 20th of 1974. Over this 10 day period the Smelter went through a shutdown to allow all changes and modifications to be done. This was one huge job and the place was like an ant hill.

The above flow chart was designed by Rich Billy and he has granted me the right to use this in the above article. Rich designed a number of flow charts that were used in H.B.M.&S. publications during his working career. He had the skill and ability to illustrate how mining, milling or smelter processes worked so that the average lay person could look at it and see immediately how the process went from the beginning to the conclusion. This is a great skill which I feel privileged to be able to use.

Thanks Rich.

This photograph will give you a very good idea of what a large project of installing the new flue system was and making all the modifications to help reduce emissions and improve efficiency. Unfortunately, in spite of all the money spent and labor involved, it was not able to reach the environmental standards that are required today. In June 2010 the smoke from the 825 ft. stack was no more. There were approximately 225 jobs that were lost in the Smelter division, and this has had an effect on our community, as we were once a smelter town.

COPPER BARS

This is a photo of the old copper bars and not a very good one. When I took this picture, I was very much a beginner. The speed of the film I would guess was 64 ASA Ektachrome, it was hand held and the light was poor. This photo illustrates how we stacked the copper when it came down the shoot from the old casting wheel in the late 50's. Any old smelter rat I am sure can relate to trimming, re-piling and loading these 420 lb. copper bars, and pushing the heavy steel carts which weighed approximately 150 plus pounds.

This photo illustrates those heavy carts and the shifting of the copper bar with the use of the cart to assist the two men hooking the bar up onto the cart. This was a job where you had to put steel toe caps on your boots and take a hook with a handle on it and lift the bar onto the above carts, then the operator of the cart would pile the bars in rows on a floor made up of old railroad steel (which was flipped over with the wide part turned up to make like planks on a metal floor). These bars were still pretty hot and if they touched you, they certainly would burn you. The metal floor provided an effective means to dissipate the heat, unlike concrete which would never stand up to the thermal expansion and contraction. They used a water hose to help cool the bars and the water was able to drain through the floor. This was an experience that I don't think many of us that performed this job would forget.

This photo is of the old casting wheel where these 420 lb. bars were formed in a 750 lb. copper mold and then knocked out by a swinging hoist operated by air. This casting wheel was installed here in 1929 and operated from that point until 1974 when the new anode plant was commissioned. The copper was originally poured from a large vessel which you can just see the edge of on the right hand side. In the late 50's and early 60's they installed a tipping device which was hydraulically controlled from a deep concrete Well, below the platform. At times, if the oil leaked from the hydraulics in this Well, it became a fire hazard. I recall this Well becoming a burning inferno on a couple of occasions when hot copper sparks ignited the oil.

This photo shows the tipping device in action with molten copper at about 2180-2250 F, being poured into the molds, and you can see them progressing into the cooling chamber on the right. If the copper was cooler than this, it was hard to keep it from freezing in the lip of the ladle and the spoon which delivered it into the moulds.

This photo shows the new anode casting plant shortly after it was commissioned in 1974. This was certainly high tech from what the smelter was used to. The copper was refined to a much higher grade, around 95-98%. The volume that was poured into each and every anode mold was weighed so a consistent size and weight became order of the day. The bars required little or no trimming because spillage and overflows had become a thing of the past. This was a great step forward. The anode weighed approximately 720 lbs.

This photo shows the “take off” rack for the anodes and you can see how the anode hangs by its lugs on the rack. Now the tow motor will come in and pick up the anodes and re-pile them in an area where they will be cooled before loading.

This photo illustrates how the tow motors handled the copper anodes, probably 8 or 10 at a time. I think you can see that this was certainly an improvement over the old hand carts and the 420 lb. copper bars.

In this photo you can see the tow motor loading the anodes into box cars to be shipped to the refinery. There appears to be 8 anodes which is approximately 5,760 lbs. of copper being loaded at one trip. I recall on day shift, with 6 men and 6 carts, it taking us 30-40 minutes to load a car with the old copper bars, but here, one man with one machine is doing it all.

This has been a good stroll down memory lane and a good opportunity to put my photos of the past into a story which I hope you will enjoy. Thanks to Rich Billy and Marvin Dowhan for their input on the facts that I was not sure of.

Steven W. Harapiak was Project Manager in 1973 & 1974 when the Flin Flon Stack and Smelter Renovation project took place. Mr. Harapiak joined the company in August 1972, as project manager at Flin Flon, became Manager of Plant Services in January 1974, and was appointed Production Manager in October 1974. He graduated from the University of Manitoba with a B.Sc. Degree in Mechanical Engineering in 1959 and later completed several extension courses in Business Administration at the University of Saskatchewan. Prior to joining the company, he held a number of senior positions in the mining industry and gained broad experience in production, engineering, design and construction, maintenance, recruitment and training of personnel. He was appointed General Manager of HBM&S mining and metallurgical operations at Flin Flon effective March 1, 1976, succeeding James E. Goodman who retired at the end of February.