Mining history

Important years for the mining development

1652               The ore was discovered

1654               The ore was pointed out.  Exploring started

1655               Production mining started

1656               Svorkmo Smelting Works came into operation

1664               Grutseter Smelting Works came into operation

1743               Water power became the energy source for pumping and hoisting

1898               Salvesen & Thams was established

1902               Norway's first underground power station was built in the mine

1904               Orkla Grube-Aktiebolag (Orkla Mining Ltd Company) was established

1908               Norway's first electric railway, Thamshavn Railway, was opened on the section Thamshavn - Svorkmo

1910                Thamshavn Railway was extended up to Løkken Verk.  Fearnley Shaft and a new laundry were put into use

1911               The pyrite ore deposit proved to be the biggest in Europe.  Large-scale operations commenced    

1916               Wallenberg Shaft came into use

1931                The pyrite-ore smelting plant at Thamshavn started operating.  Continued until 1962 

1940-45         Sabotage actions against the railway

1963               The Thamshavn Railway passenger traffic discontinued

1972               Astrup Mine came into use

1974               The mine production altered from pyrite-ore production to selective flotation.  The Thamshavn Railway pyrite-ore transport ceased

1982               The Mining Museum was opened

1983               Thamshavn Railway became a museum railway

1985               The Old Mine was opened for guided tours

1987               The mining industry ceased after 333 years of operation

The circumference

On 13 May 1657 the participantship which operated the mine at Løkken Verk was granted royal privileges issued by King Fredrik III.  The king e.g. decided that:

  • the mine receive comprehensive advantages within a circumference of three old Norwegian miles (= 34 kilometres). "Gottes Glück", the first mine at Løkken Verk, should be the centre of the circumference.
  • the circumference not be too close to the circumference of Innset Smelting Works (Kvikne Kobberverk)
  • forest owners be responsible for cutting timber and wood and for carrying it up to the mine and to the smelting works.
  • noone, apart from the mine, be allowed to cut timber or run a sawmill for selling timber there.
  • the miners be exempted from tax and military service.

The priviledges were withdrawn in 1703, and after that time the mine had to compete with anyone else for timber and wood.


The miner's cultural landscape

The Løkken Verk production started in 1655 and was carried out just above the Old Mine.  Later ore was found in a number of places at and around Løkken Verk.  Industrial operations developed in Wallenberg and Astrup Mines, and there were also considerable operations at Dragset Verk and in Høidal Mine, compared to the standards of those days.

In old days the ore was partly smelted in the smelting works at Svorkmo, Nyplassen and Dragset Verk, and partly exported.  In modern times, from 1931 to 1962, ca. 60 % of the ore was smelted at Thamshavn.

In modern days the power station and railway were also constructed, in order to expand and to increase the production efficiency.

Items of historical interest showing miner activities have been indicated on this model. Use the push buttons to make a trip through the miner's cultural landscape.

The landscape model is a gift from Løkken Grubearbeiderforening (Løkken Miners' Association).

Past and present mine illumination

The first miners used pine torches when they should go inside the mine.

Later open fish-oil lamps and tallow lamps came into use.

Closed fish-oil lamps or tallow lamps were employed in the 18th century.

The carbide torch made quite a revolution when it appeared by the end of the 1860's.

When the electric lamps were invented, they meant an even greater revolution.  They produced better light and could be fastened on the helmet, so that the miner had both hands free.  The electric lamps were developed at the end of the 1930's, but did not become common until the 1950's.

Carbide torches were used parallel to battery lamps right to the end of the 1960's.

Pyrite ore from Løkken Verk

The cupreous pyrite at Løkken Verk consists of a number of minerals:

Suphur                    41.4%

Iron                            37.5%

Quarts                      13.7%

Copper                    2.1%

Zinc                           1.9%

Cobalt                      0.07%

Manganese             0.07%

Arsenic                     0.04%

Lead                         0.02%

Cadmium                0.01%

Selenium                  0.005%

Nickel                                   0.008%

Silver                           19 gram/ton

Gold                          0.2 gram/ton

Marius Rindal's wall painting.

This painting was made by Miner Marius Rindal (1912-1996) for the great 1954 mine anniversary.  The painting shows operation methods and techniques from the first years of mining at Løkken Verk.

The painting was made on the wall of a lunch room at Fearnley Shaft.  When the building was demolished around 1990, the painting was cut out of the wall and preserved.

Ore skip

From old the ore was hoisted by handcraft.  There could be 400-500 kg ore in such a skip.

This ore skip is from Dragset Verk.

When the miner moved between different floors of the mine, carrying wood down into the mine and ore up and out of it, he would walk on socalled "kubbfaringer".  The "kubbfaring" was a log with steps cut into it.

The name "kubbfaring" is a mixture of Norwegian and German - "kubb" comes from the Norwegian word "kubbe" meaning "log", and "faring" from the German word "fahren" meaning "go".

The Norwegian miner's language was generally influenced by German words brought here by mining engineers from Germany.  Words like "gruve" (mine), "stoll" (gallery), "ort" (drift) and "sjakt" (shaft) are all derived from German words and expressions (Grube, Stoll, Ort, Schacht).  German mine people were those days' migrate workers, and they knew the art of extracting values out of the mountains.  Many Norwegian mine societies were founded on their knowledge.

The Løkken deposit

The Løkken Verk deposit of cupreous pyrite is one of the biggest in the world.  From the place of discovery it stretches four kilometres westwards and one kilometre downwards.  Close to the open-cut surface the shape was somewhat disorderly, and the first 250 years the operations were carried out in this area.  The main ore and two smaller deposits, Indien and Bak-Indien, were not found until the 20th century, with the highly advanced equipment and techniques which then developed.  The two smaller deposits, which were north of the main ore, dwindled away after ca.1500 metres, whereas the main ore continued.

Four shafts were needed to bring the ore up into daylight: Furthest to the east the Old Shaft 240 m deep, west of it Fearnley Shaft 300 m deep, then Wallenberg Shaft 480 m and Astrup Shaft a good 1000 m deep.

The main deposit was lens-shaped, and in the bigger areas the lens would be 250 m wide and 50-60 metres thick.

This model is made by Johannes Espvik for the 1930 Trøndelag Exhibition.  The model shows the deposit known at that time.  In 1957 the extention of the main deposit was detected through diamond drilling holes.  The part of the ore shown on the model is indicated on the map below.

On the model the Nidaros Cathedral is shown on the same scale as the pyrite ore deposit.  Totally ca. 25 million ton pyrite ore have been extracted.  Altogether the shafts, drifts, stopes and galleries are 200 km and have a total volum 42 times bigger than Oslo City Hall.

A sketch of the Løkken deposit with its shafts and main floors.

To remove the water accumulating in the mine, a pumping plant driven by water power was constructed.  Water was fetched from Frilsjøen and Bjørlivatnet.  A complicated system was developed, with water channels, water wheels and power transmissions through a pumping engine up to the mine.

The pumping plants were built and operated by specialists called "kunstknekter", a word derived from the German "Wasserkunst".

In the mine wooden pipelines were used for pumping.  These were made by hollowing out timber.  Inside these wooden pipelines were pistons pushing the water upwards through various steps.

Producing such wooden pipelines meant laborious work.  The drills were heated.  One would start using smaller drills and gradually increase the hole by using bigger ones.  Two men could drill 4 metre a day.

Fire-setting

The first 200 years the ore was extracted by fire-setting.  Big fires were lit against the wall of the rock, and the heat made the rock burst.  After the fire was extinguished, the miner used a gad to cut off stones where the rock had burst.  Through one fire-setting the miner would move four or five centimetres inside the rock.

For this method - and for the smelting of the ore - great quantities of wood were required.

As one came inside the rock, fires were made once a week.  This was often done on Friday evening, and therefore Saturday was day off in the mine.  Only a few people were present then to guard the fire.  They watched that the wood was placed where the fire would be as effective as possible, and also that the wood was completely burnt.

Strong heat and an acid smoke characterized the workday of the men guarding the fire.

From Høidal Mine around year 1900.

The Høidal deposit was discovered in 1659, and soon afterwards operations started.  Because of this new discovery the capacity of Svorkmo Smelting Works became too small, and new smelting works had to be built at Grutseter.

Operations have been carried out in two areas: the original one, Old Høidal; and New Høidal which came into use around year 1800.  Old Høidal has a big open-cast mine, where the ore has been ca.200 metre long and 15-20 metre wide.  Several shafts have been lowered, and a drift from east to west goes under the open-cast mine.  In New Høidal, which is

400-500 m east of Old Høidal, there is also a cavity going 50m down.  The mines contained high-grade sulphur ore, but have had comparatively little copper.

Høidal Mine was from the beginning operated by the same participantship as Løkken Verk, at times with long intermissions.  In the 1880's the mine was taken over by Örkedals Mining Company, which operated the mine all the time until Orkla Grube-Aktiebolag took over in 1904.

Totally ca.100,000 ton ore have been extracted at Høidal.  As long as the smelting was done at Grutseter Smelting Works, the ore was transported there by horse.  From 1863 to 1876 it was taken by gravity haulage down to Løkken Verk and from there by horse to Orkanger for export.  In 1909 a telpher line was built from Høidal to Løkken Verk. Høidal Mine closed down in 1911.

The drawing on the wall is from Old Høidal Mine in 1867.  At that time both the water wheel, the pumping engine and the horse capstan were employed for draining the mine and for hoisting the ore.

Dragset Verk

The ore at Dragset Verk was found by Ole Dragset-brekken in the beginning of the 1860's.  The deposit was sold to Orkedals Mining Company, which started mining there in 1867.  From the beginning the company was owned by Marentius Thams at Orkanger and Chr.Salvesen in Leith in Scotland.  Salvesen later took over as the sole proprietor.  At its peak the mine employed 50-60 people.

The copper contents was high, and it was therefore natural to build smelting works next to the mine.  In 1875 a royal licence was granted for this purpose.  The smelting works were in operation only for a few years, however.  The ore was afterwards exported to England.  It was then stored at the mine until winter time made it possible to go by sledge, and people would take it by horse and sledge to Orkanger.

During the first years the Dragset Mine ore was drilled by hand and taken out by means of gunpowder.  It was not until 1900 that pneumatically operated drilling machines and dynamite came into use.

Production varied through the years.  The peak was probably during the years 1877 and 1878.

1877:              - 1650 ton copper ore 7%Cu

1878:              - 1362 ton sulphur ore 46.5%S

                        - 336.5 ton copper ore 9%Cu

                        - 761 ton copper ore 5%Cu

Later they produced ca.300 ton a year, but towards the end the production somewhat increased again.

The operations ceased in 1909.

Slag from the smelting works at Dragset Verk.

Manual drilling - gunpowder

Gunpowder came into use in a number of mines in the 17th century already.  When     gunpowder should be used, holes first had to be drilled into the rock.  Two men cooperated in this task - one turning the drill around, while the other one was hitting it.  When the hole was deep enough, it was filled with gunpowder.  The gunpowder was ignited by a fuse and made to explode, causing the rock to crack.

The Løkken ore is extremely hard, and manual drilling and gunpowder were therefore not much used in this mine apart from when they were mining granite boulder.  When mining the ore, fire-setting was used right to the end of the 19th century.

The mine water corrodes

Acid mine water heavily corroded iron-bearing equipment and installations in the mine. For this reason there was a need for acidproof material which could not be damaged by mine water.

Using acidproof steel in the railway rails in the mine became too expensive.  Instead rails with some copper alloy were employed.  These could stand the acid water better than ordinary rails.

After plastic became an ordinary product, this was used to protect iron constructions while they were not working.

In this showcase items have been collected which have been exposed to the mine water for a shorter or longer time.

The mining eras

PERIODOPERATION METHODPRODUCTIONPRODUCTS
1654-1845Fire-settingCopper miningCopper smelted in local smelting works
1855-1890Fire-setting, handdrill and gunpowderPyrite ore production for exportCopper and sulphur from smelting plants in England
1909-1931Pneumatically operated drilling machines, dynamitePyrite ore production for exportCopper and sulphur from smelting works in Sweden, Germany and England
1931-1962Pneumatically operated drilling machines, dynamiteSmelting pyrite ore (60%)Basic sulphur and black copper (35% copper) from the smelting works at Thamshavn.
Pyrite ore production for export (40%)Copper and sulphur from smelting plants in Germany
1962-1974Pneumatically operated drilling machines, dynamitePyrite ore production for exportCopper and sulphur from smelting plants in Germany
1974-1987Pneumatically operated and hydraulic drilling machines and drilling rigs, dynamite, anolyteSelective flotation: copper and zinc concentratesZinc smelted at Norsink at Odda, copper and silver smelted at Outokumpu OY in Finland.

Ore prospecting

During the whole industrial period there was continual ore prospecting.  Geophysical exploration started in 1926 already.  During the last decade of mining such measurings were also performed from helicopter in the search for evidence of ore.  And at the end seismic measuring was employed.  This is a technology also used in the oil industry.

The most common geophysical method of ore prospecting is putting a cable on the surface of the ground.  The cable is earthed to an open-air ore deposit, and electric current is led through it.  By measuring across the cable with a sensitive instrument, it is possible to establish if there are bigger electric conductors under the surface.

After measuring on the surface, diamond drilling is the main method of identifying a possible deposit.  Hollow drill heads with diamonds "eat" their way down inside the rock, enabling the miner to fetch samples of it.  The tests would give clear indications as to possible ore deposits, as well as to how big and how high-grade they were.

During the period 1980 - 1984 Orkla, in cooperation with the oil company Gulf, carried out an extensive ore prospecting project, without finding new commercially viable deposits in the geological Løkken field.

Diamond drilling

Pneumatically operated drilling machines

As soon as Orkla Grube-Aktiebolag got going, manual drilling was replaced by pneumatically operated drilling machines.  The first machines of this kind came in 1908 and were extremely heavy and slow-working.

During the first half of the 20th century, however, the drilling machines went through a rapid development.  The machines became smaller, lighter and more efficient.  At the Løkken Verk mines, close to 100 types of machines were tested to find which ones were most suitable.

The Løkken ore is extremely hard, and this put severe demands both on the machines and on the drills.  The first drills made out of carbon-fibre steel often had to be sharpened only after having drilled two to three centimetre.  Up to around 1960 there were extensive efforts to facilitate the work and make it more efficient.  The result became light machines and carbide drills.

In Astrup Mine electric drilling rigs with hydraulic drilling machines were employed.  These could drill up to 40 metre in the pyrite ore.

During the industrial period extracted ore was loaded into railway trams inside the mine.  In the beginning loading meant heavy manual work.  When hand mucking, the miner would use tray and pick hammer, scraping together stones.  Afterwards the tray would be lifted up and the ore tipped into small railway trams.  Hand mucking was done until the 1950's.

The work gradually became increasingly mechanized, however, e.g. by means of scrapers, pneumatically operated loading machines, and in the Astrup Mine even with big diesel-driven wheel loaders.

In the Astrup mine, in addition to railway transport, there were also diesel-driven dumpers.

From trains and dumpers the ore was emptied into chutes which led down to crushers at the bottom of the mine.  From there the ore was hoisted up into daylight.

Smelting in old times

In the copper mining period from 1654 to 1844 the ore was smelted at Svorkmo Smelting Works and Grutseter Smelting Works.  During a short period at the end of the 1870's smelting was also done at Dragset Verk.

The smelting was performed in five stages:

1.         Heap roasting

The ore was put into big heaps with coarse wood put in such a way that there were air lines in towards the middle.  In the heap roasting the ore was heated so as to expel the sulphur and iron.

2.         Coarse metal smelting

The ore and charcoal were put into big kilns made out of granite boulder.  Air was blown into them by means of big bellows or water-power-driven blasting machines.  Quarts was added in order to bind the iron.  In this process the species of stone were discarded, and the product was coarse metal consisting of copper, sulphur and iron, as well as big quantities of slag.

3          A form of dead roasting

The coarse metal was put with layers of wood into "boxes" made of granite boulder.  The process was repeated five to seven times to remove as much sulphur as possible.

           

4          Black copper smelting

After the dead roasting, what remained of the coarse metal was put into high granite boulder kilns lined with clay.  Charcoal was used for heating.  The result was black copper - a crude metal.

5          Gahring

This process removed the iron in the black copper.  Black copper was put into big hardening kilns together with charcoal.  Great quantities of air were supplied and finally water, which made the copper harden on top of the kiln.  The copper was cast into sheets of 15 kilogram 15 gram.  The grams were a kind of weight guarantee.

Separation

Outside the mine the ore had to be sorted. The Germans called it "scheiden" (separate), a word which was norwegianized into the term "skeiding".  The work meant sorting the real ore from granite boulder.  To reduce the costly transport by horse to the smelting works, much ore was discarded.  In this way you got the big old dungs on the hills around the Old Mine. 

In modern time there was a big "skeidehall" in the Separation Plant.  Usually Women were performing this work.  They stood by a conveyor belt which took the ore to the crushers.  The women had a good eyesight and a well-developed sense of what was ore and what was granite.  Granite stones were removed from the belt, while the ore was crushed and exported.

Orkla Metal-Aktieselskap

During the period 1918 - 1929 experiments resulted in a pyrite ore smelting process which utilized the Løkken pyrite ore sulphur contents without losing the other components of the pyrite ore.  This process, which was developed in Portugal, in Sweden and at Løkken Verk, was named the Orkla method.

To employ the method, Orkla Grube-Aktiebolag built a smelting plant at Thamshavn, Orkla Metal-Aktieselskap (Orkla Metal Ltd Company).  Here 85% of the sulphur contents of the pyrite ore was extracted as elementary sulphur.  84% of the copper contents was extracted as black copper containing 35% copper.  The gold and the silver remained in the black copper, as it was not viable to extract it.

Orkla Metal-Aktieselskap removed 60% of the production from the Løkken Verk mine.  The smelting plant was in operation from 1931 to 1962.

The Thamshavn sulphur lost, however, in competition with cheaper sulphur extracted from natural gas and oil.

When the pyrite ore smelting came to an end, the plant was converted into a ferro-alloy plant, and the pyrite ore was exported to be smelted abroad.  In 1986 the smelting plant was sold to Elkem, and ferrosilicon is still produced at Thamshavn.

The cupreous pyrite at Løkken Verk contains small quantities of precious metals - 19 gram silver and 0.2 gram gold per ton.

With such small quantities neither gold nor silver could be extracted during the refining process at Løkken Verk.  The precious metals remained with the copper and were only taken care of during the smelting process abroad.  At the 300 years mining anniversary in 1954 there was an expressed wish for getting back from those smelting works gold and silver which had come from Løkken Verk.  Gold medals were then made for employees with a long service.  All the employees got an ashtray and a pin with the mine symbol made in silver.

During the period of selective flotation from 1974 to 1987, the silver and gold remained with the copper concentrate and were only smelted in Finland.  The silver gave 7% of the income, while the gold did not reach a payable amount.

With the great production of pyrite ore, there have during the years been extracted considerable quantities of gold and silver.  The diagrams show the annual production measured in kilograms during the period 1931 - 1987.

Selective flotation

From 1910 to 1972 the ore was sent from Løkken Verk without the various value components being separated from each other.  The ore was only purified and crushed.

In the beginning of the 1970's, changed world market conditions made the Løkken Verk sulphur unable to sell.

Therefore the production was converted, and a new production plant was built, the Flotation Plant, with selective flotation.  Copper and zinc concentrates were now extracted in a highly advanced and complicated process.

The annual production of the mine was ca. 400,000 ton crude ore, but there were only produced 25,000 ton copper concentrate and 7,000 ton zinc concentrate.  The waste constituted more than 90% and was pumped into an artificial lake at Bjønndalen in Bjørnli, where it was stored under water.

From the Flotation Plant

Løkken workers union

After Orkla Grube-Aktiebolag was established in 1904, the Løkken Verk staff rapidly increased.  In 1907 there were 342 employees in the mine.

The thought of organising came as a natural part of this process.

On 14 July 1907 the workers met in an establishment meeting at Skogheim, the temperance movement premises. Miner Olaf Asp, originally from Ålen, was the initiator of the association, while Ole Grefstad from Løkken Verk was elected chairman.

Løkken Grubearbeiderforening joined Norsk Arbeismandsforbund (the Norwegian Workers Federation) as unit no 111.  During all the years Grubearbeiderforeningen's foremost task has been to improve wages and working conditions.  During the first years this led to many strikes, among which was the longest one in the history of Norway, lasting for 13 months in 1909 and 1910.

After Second World War there was a good relationship between the company management and the workers, even though they still represented different interests.

Employee participation was introduced in 1973.  This gave the employees a voice in the management and a representation on the board.

The last years before the mining ended, the miners association played an active and important role in the work of establishing new industries.  The company and the workers cooperated, with good results.  The association manages a fund for promoting new activities and cultural arrangements at Løkken Verk.