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Brine pipeline display board, IGM 2021

The salt miner refers to all pipelines installed above and below ground for transporting the brine from the point of extraction in the pit to the saline (“sud hut”) as “brine streak”.

The brewing huts were built on the valley floor near navigable waters for cheaper transport of the necessary firewood and for transporting away the salt obtained. The tunnels, which were set on mountain slopes because of the easier access to the salt stores, have always been connected to the brewing hut via pipelines.

 

1. Tube materials of the brine lines:

The tubes of the brine lines were made of different materials. The first lines consisted of wooden tubes. From around 1840 cast iron pipes were used, from 1875 concrete pipes and from around 1930 pipes made of fiber concrete ("Eternit pipes"). Since 1970 only plastic tubes (“Polo – Kal tubes”) have been used.

 

1.1 Brine lines made of wooden tubes:

The brine lines were initially built from hand-drilled wooden tubes.

Spruce, fir or larch wood was usually used for the wooden brine pipes. The wood from which the tubes were drilled had to be drained beforehand. For this purpose, the wood is stored in tubes - ponds that were filled with water or, later, with brine.  

For drilling out, the suitable tree trunks were laid horizontally on transverse trees and fastened in the drilling workshop. The top part of the boring bar was placed on a wooden guide construction, the so-called "Hölb" (see Fig. 1). The hole, which started with a diameter of 1 inch (2.6 cm), was successively expanded to a diameter of up to 4 inches (10.5 cm) using larger and larger drill bits. The finished drilled wooden tubes could not be laid immediately. They had to be stored in tubes - ponds under water or brine for a certain time.

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Figure 1: Drilling of wooden pipes, manipulation description, 1807/1815, Archiv Salinen Austria

The length of the tubes depended on the length in which the logs were to be obtained; it usually differed between 12 and 20 feet (3.8 - 6.3 m). The width of the bore depended on the amount of brine to be let through, and since a width of 4 inches (10.5 cm) could only be exceeded in rare cases, since the tube should still have a sufficient wall thickness; usually a double tube run had to be laid.

Before laying, the tubes were lifted out of the tubes - ponds and transported to the place of laying. There, a worker fixed the tube with the "Schipepliers" so that a second worker could expand one end of the tube conically with the so-called "Flachneiger", a conical hand drill (see Fig. 2, representation b). This end of the tube was called the "flat place". The other end of the tube was also cut conically on the outside after fixing with the "slip pliers" with the "slip plane" (see Fig. 2, representation c). This end of the tube was called the "pointed place".

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Figure 2: Processing of the tube ends, description of manipulation, 1807/1815, Archiv Salinen Austria

An iron ring, ¾ inch wide and 1 inch thick, was then driven onto the flat of the tube. To do this, the flat area was trimmed with the "Strehnhoe".

During the laying, a worker grasped the point of the pipe with the pipe wrench and aligned the pipe exactly into the flat point of the pipe already lying in the pit. Another worker put a prepared piece of wood on the flat spot of the pipe to be laid to protect the connection piece and drove the pipes together watertight with a mallet. This process was called "shifting" (see Fig. 3). Before driving in, you could wrap the pointed end with thin strips of tow made of flax and animal fat (tallow) to get a better seal.

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Figure 3: Laying of wooden tubes, description of manipulation, 1807/1815, Archiv Salinen Austria

The service life of the wooden tubes manufactured in this way was 10 to 30 years, depending on the nature of the wood quality and the soil moisture as well as the pressure during operation of the line.

Wooden pipes often cracked and cracked during operation. In this case, it was resealed at the point of the crack with an iron ring that had a tension screw, the so-called "Haftelring".

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Figure 4: Neuberg tunnel, production of wooden pipes, Kefer, 1826, archive Salinen Austria

Elaborate repair work on the wooden brine lines was often necessary. To do this, the damaged spot, where the brine usually escaped, had to be uncovered with wedge hews and mining irons. After the damage to the tube was found, the strand concerned was shut down (“swept away”) in the nearest, upper brine room and the brine was diverted to another strand.

On the damaged tube tour, a spade was planed off with a planer so that the tube could be lifted out. A new tube was then trimmed and inserted. This work was referred to as "strand assignment". After the tube exchange was completed, the repaired strand was again applied with brine ("swept") and the tightness of the repaired area was checked. Once this was done, the exposed brine strand could be filled in again.

 

1.2 Brine lines made of cast iron pipes:

Cast iron tubes, despite their much higher price at the time, had a clear advantage over wooden tubes because of their greater durability and tightness.

The first use of cast-iron pipes was in the Salzkammergut in 1839 in the Altaussee salt mine. There, instead of the wooden drainpipes, one began to insert cast-iron drainpipes into the weir dams of the production plants.

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Figure 5: Wooden and cast-iron drainage pipes, around 1840, Archiv Salinen Austria

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Figure 6: Factory cement at the Ischler Salzberg with cast iron pipes, around 1932, Archiv Salinen Austria

Bergmeister Schwind pursued a different purpose at the Ischler Salzberg with the use of iron water pipes in the pit. In 1840 he wanted to significantly shorten the long distance that the water collected in the upper horizons had to cover to fill the production workers, whereby the line came under pressure in places. This made it possible to supply larger amounts of water to the production workers and the stretches that had been soaked by the weeping wooden pipes could be drained. The cast iron pipes required for the laying were procured and laid in accordance with a decision by the Court Chamber in 1842, 1843 and 1844. The stretches that had become superfluous due to the relocation of the drainage pipe could then be abandoned.

In the beginning, iron pipes were only used in very long brine lines where the wooden pipes broke easily because of the excessive pressure. The wooden brine pipes were gradually replaced by cast-iron ones in the mid-19th century. Another important advantage of these tubes was that they could be made in any ratio of diameters, while wooden tubes were usually only 80 to 100 mm in diameter; in exceptional cases also 125 to 150 mm. In addition, the cast-iron tubes could be operated with a significantly higher operating pressure of up to 10 atm (wooden tubes up to a maximum of 2 atm).

Experience has shown that cast-iron pipes have lasted a good 50 years in the ground. After this time, the cast-iron lines had to be replaced because the cast-iron pipes were subject to severe corrosion, especially from the outside. The durability of wooden pipes that were laid without debarking and that could be used at up to 2 atm operating pressure was up to 100 years under ideal conditions.

The running meter weight of the cast iron pipes with a diameter of 125 mm was around 32 kg.

The connection of the cast-iron tubes could be accomplished in various ways. In the most commonly used type of connection, the socket-like extension of one tube was inserted into the second tube, the other end of which was also provided with a socket-like extension. Wooden wedges were driven in around the annular opening formed by the outer periphery and inner circumference. The cast-iron tubes could be joined in this way in a completely watertight manner, and this type of connection also had the advantage of allowing the cast-iron tubes to expand and contract as the temperature changed without the connection leaking. The usual lead seals did not work because they were less elastic than wooden seals and were also considered inadmissible because of the possible formation of toxic lead compounds.

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Figure 7: Cast-iron pipes, around 1850, Archiv Salinen Austria

Cast-iron pipes quickly became established in salt mining, because the more of these pipes a salt mine owned and laid every year, the fewer defects occurred in the strand pipes and the faster it was possible to fill the workers and thus shorten their rotation time.

Cast-iron pipes with a diameter of 100 mm were used to supply the return water to the workers and those with a diameter of 125 – 150 mm to drain the brine.

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Figure 8: Cast-iron pipes, Hallstatt brine line, Internet

1.3 Concrete brine lines:

From 1874 - 1875 a cement pipe factory was built on the Ischler Salzberg near the Leopold tunnel. The hydraulic cement burned by Ärar near the Josef tunnel is processed in this plant.

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Figure 9: Cement pipe factory at Ischler Salzberg, 1893, Archiv Salinen Austria

A mixture of equal parts of washed sand and hydraulic cement served as material for the production of the cement pipes, which was mixed in a stirrer with the addition of the required amount of water and poured into pipe moulds.

The dimensions of the cement pipe were 3.66 feet (1.16 m) long, 2½ inches (6.66 cm) wall thickness and 5 inches (13.15 cm) inside diameter. The weight of a cement pipe was around 83 kg.

After the tubes began to be used for brine and water lines in the pit, the heavy weight was a major handling problem. In addition, the small tunnel cross-sections were further narrowed by the massive tubes. For these reasons, the concrete pipes could not assert themselves against the much more manageable cast iron pipes, despite their lower price.

According to an entry in the Ischl stock book, a total of 1,780 m of concrete pipes were laid in the Ischler Salzberg from 1888 to drain water and brine from the Leopold tunnel. The concrete pipes were not used in above-ground brine lines.

In 1894 cement pipe production at the Ischler Salzberg had to be stopped. In the years that followed, the building was converted into a small power station to supply the mountain houses with electricity.

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Figure 10: Cement tube, Matthias Stollen, 2010, Kranabitl archive

1.4 Brine lines made of Eternit tubes:

From around 1930, the brine pipes, in particular the old wooden pipes that were still in use, were replaced with pipes made of Eternit.

Eternit, derived from the Latin "aeternitas" (eternity) is a brand name for fiber cement. Fiber cement is a durable composite material made from cement and added mineral fibers. It was originally made with asbestos fibers derived from silicate minerals.

In 1894 Ludwig Hatschek bought the Kochmühle rag factory in Vöcklabruck. He developed fiber cement products under the brand name "Eternit". The product combined lightness with waterproofness, it was inexpensive and non-flammable. The health hazards of asbestos were not recognized until much later. As early as 1900, Ludwig Hatschek received a patent for roof coverings made of asbestos cement. In 1903 he had the brand name "Eternit" protected. Pipes were also subsequently produced. Eternit pipes quickly established themselves on the market, so that pipe production at the Vöcklabruck site could be expanded between 1936 and 1939.

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Figure 11: Eternit works, Kochmühle Vöcklabruck, around 1905, Eternit Austria, Internet

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Figure 12: Eternit pipes, Eternit Austria, Internet

1.5 Brine lines made of plastic tubes:

Plastic pipes with the brand name "Polo - Kal" have been laid since 1970. These pipes, made from the plastic polypropene (PP), are used in water and sewage construction. They are resistant to salts, acids and alkalis. Later they switched to the even more wear-resistant "Polo-Dur" pipes made of PVC. Today, particularly low-friction GFR pipes made of glass fiber reinforced epoxy resins are installed.

Today's demands on the pipe material used are corrosion resistance, a simple and safe connection system, easy handling during laying, smooth inner walls, the best possible thermal insulation and resistance to pressure and bending.

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Figure 13: Polo - Kal - Rohre, Poloplast, Internet

2. Operation of a brine line:

The operation of a brine pipeline was a technically complex undertaking from the outset, since the originally wooden pipelines had to be operated almost without pressure, tended to break frequently and the secondary salts contained in the brine (above all Glauber's salt Na2Ca (SO4)2) caused incrustations on the pipelines led. In addition, for billing reasons, the amounts of brine released from the mountain had to be recorded as precisely as possible.

 

2.1 Brine release from the pit:

The brine that was used or drained during the continuous watering flowed through the open drain pipe of the production plant into a cement trough below (“factory cement”), where it was measured and passed on to one of the impact workers.

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Figure 14: Factory cement at the Ischler Salzberg with wooden tubes, 1918, ÖNB archive

Aside from the fact that they were also reserve workers, impact workers had a number of purposes. First, they served as reservoirs so that the brine production did not have to follow every change in the needs of the hut; and to have some stock in the pit should the brine production falter by some accident. They were also used to be able to empty the plant immediately in the event of an operational disruption. as well as the reduction of the rotation times, since they made a quick emptying of the production workers possible in the first place. Finally, they acted as clarifiers for the mostly still "cloudy" brine from the production plants, since the sludge dissolved in the brine could sink into them. For reasons of operational safety, a brine production reserve of 3 to 4 months was kept in the mountain.

The now “pure” brine was delivered from the impact workers to the smelter as required after the measurement in the weir cen- tres. The "oldest" brine, which had been stored the longest, was tried to be delivered first, wherever possible, as it was the purest and most free of gypsum parts. The brine reached the brine stream from the weir ciment of the impact workers, which, lying on the stretch ulm, could absorb brine from a larger number of workers. The streak again ran as a single branch of the overall brine line to the main brine streak, which reached lower and lower levels through sloping connecting structures (“Schurfe”) and came to light through the deepest tunnel, uniting with the main brine lines.

2.2 Determining the amount of brine released on the mountain:

The brine brought to the surface from the pit was usually hammered into brine rooms on the mountain, i.e. introduced into reservoirs, partly to clarify the brine, partly to better regulate the amount of brine discharged to the brewing hut and to measure the amount of brine delivered to the brewing hut.

The device for the main brine measurement was located in a lockable hut near the mouth of the deepest tunnel impact. This was done either in a larger cementation trough (main brine) with a measuring machine or in the alternating filling of two or more brine rooms.

On the cementing trough of the main brine, instead of the usual circular openings, there was only a single small, adjustable brass gate, which was marked with markings to determine the amount of brine flowing out.

The brine rooms, mostly designed as double rooms, were watertight containers made of strong posts, which were alternately filled with brine and emptied again after the height of their brine level had been measured and noted with a divided slat. Although double rooms were more complex to maintain, they indicated the amount of brine flowing off more precisely than the other two measuring devices (main brine or measuring machine).

There were also one or two such measuring devices in the brewhouse so that the amount of brine released could also be checked from the hut side.

 

2.3 Cementing troughs:

Cementing troughs (from "cinnamon" = a metal, cylindrical, calibrated measuring vessel of the innkeepers = scoop) the salt miner understands a measuring vessel for brine and water.

The brine flowing in at the back of the measuring troughs flowed down the front wall through one or more circular openings of the same width and the same distance from the ground into the connected line. Since the hourly flow rate of a large and a small tube in buckets was known, it was sufficient to indicate the open large and small tubes in order to be able to calculate the discharge volume. The introduction of measuring troughs was a major step forward, because the measuring stations in the brine lines, which followed each other at short intervals, meant that losses due to broken lines could be quickly identified.

In order to be able to determine the brine billing and brine losses in the brine lines more precisely, in 1769 the Hallstatt master foreman Schmidt applied for the connection of 53 measuring troughs in the entire brine line from Hallstatt to Ebensee and in the supply line from the Ischler Salzberg.

A major deficiency of the cement troughs of the time was that the wooden measuring tubes expanded due to the moving brine and the frequent opening and closing with wooden pegs and lost the sharp edge of the influence, the flow rate increased with the same pressure level. From 1850, at the suggestion of the Ischler Bergmeister Franz v. Conceal swells in the troughs in front of the outflow to get a standing column of liquid in front of the outflow openings and used three different sized tubes with ½, 1 and 1 ½ inch outflow.

The perforated plate fitted in the measuring troughs was made of hard rubber from the 20th century to improve the durability of the perforated edges; usually the measuring troughs had perforated plates with 2 x 3 = 6 openings, each opening with a calibrated diameter of 20 mm, or 80 mm for measuring larger amounts of water. Depending on the amount of liquid, either all openings were free or some were sealed with rubber stoppers.

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Figure 15: Cementation trough, 1892, from August Aigner "Salt Mining in the Austrian Alps"

The measured amount of brine resulted from the number of open holes multiplied by the reading of the brine level on the scale of the measuring trough in hl / hour.

This scale was divided into hectoliters per hour and was determined empirically; the scale was inserted in the measuring trough in such a way that the zero point (0 hl) was at the level of the lower edge of the perforated plate openings.

 

2.4 Brine line from the mountain to the brewing hut:

From the main brine on the mountain, the brine ran in wooden tubes to the Sudütte, which, to the extent that they went above ground, were covered by it. The earth covering of the wooden tubes was not necessary because of the danger of freezing, because the highly saturated brine did not freeze even in winter. It protected the line from being damaged by humans and animals, the latter greedily licking and gnawing at the pipes. Another reason for the cover was protection from the sun, which easily cracked the wooden tubes.

Due to the large difference in gradient and the large distances between the mountain and the hut, brine rooms with measuring and distribution troughs, transfer valves and reservoirs had to be built on the brine line to relieve pressure or to control the amount of brine and to transfer the brine from one strand to another.

With the help of the cementing troughs, the amount of brine flowing out could be precisely controlled and any loss of brine could be quickly detected. Another function of the cementing troughs was to allow entrained air to escape and to catch objects such as wood chips and the like entrained in the brine so that they would not clog the tubes.

For the purpose of venting the pipelines, they were equipped with air valves, air taps or vent pipes. Venting was particularly necessary when the brine delivery volume suddenly increased significantly during operation, so that the air advancing through the brine could escape more quickly. This made it possible to avoid excessive impacts and air nests in the lines. Frequent changes in the brine delivery quantities had an unfavorable effect on the durability of the pipelines, because the shocks and blows that occurred often amounted to several atmospheres and could easily cause strand breaks.

For material-related reasons, the lines could only be operated without pressure, since the wooden tubes withstood an operating pressure of a maximum of 2 atm. The numerous cementing troughs also served as pressure break stations. This prevented the hydraulic pressure from building up too much, which would otherwise have resulted from the steep gradient in the brine lines.

Most of these cement troughs still had brine rooms. These served to clarify the brine better. In addition, in the event of a line breakage, they could absorb the brine coming from the mountain for the duration of the turnaround necessary for the repair work. Furthermore, they were able to keep a certain amount of brine in stock throughout the day so that the brewing process would not have to be completely interrupted if the brine strand needed to be repaired.

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Figure 16: Saline Ebensee, cementation trough, from Brandstätter "Salzkammergut", Vienna 2009

2.5 warming rooms:

Saturated saline solutions have a freezing point of -18.8°C; a temperature to which the brine in the pipes is normally never exposed.

However, Glauber's salt separates out at temperatures below 0°C. In the case of pure brine, which contained only 0.4 to 0.5% Glauber's salt, it was probably impossible for the pipes to become completely clogged with this salt, but it was still necessary to heat these brines to 1 to 2° C in the so-called warming rooms to prevent excessive elimination.

The alpine brines are saturated salt solutions that do not freeze, but can excrete secondary salts at low temperatures. If the brine in the pipes stood still, i.e. if there was no movement and the amount of brine was also small, then the rock salt (NaCl) separated out at -16°C and blocked the pipes.

In the case of very high levels of secondary salt in the brine, however, the danger of the salt separating out existed much earlier. In the case of salt-rich brine, the salt excretion was caused in particular by the Glauber's salt. With the Ausseer brine, which is very rich in secondary salts, this precipitation could already be observed at +4°C.

In order to avoid the precipitation of secondary salts, the brine was warmed up accordingly in the brine warming rooms distributed along the line. The brine warming rooms had simple heaters, where the brine lines were routed in pipe coils.

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Figure 17: Praunfalk brine heating room, Altausse brine line, 1868, archive Salinen Austria

Around 1900, 36 men were only needed to operate 9 brine rooms in the Hallstatt – Ebensee brine line. The fuel consumption was 1,500 tons of coal and 250 solid cubic meters of wood.

 

2.6 Highlight watering:

Gypsum built up in the brine lines after a correspondingly long period of use, and the reduction in the cross-section of the line greatly reduced the performance of the line. The strands therefore had to be watered from time to time. This manipulation was referred to as "hair wash". Impure brine, i.e. brine with a lot of secondary salts, such as the Aussee brine in particular, encrusted the pipes more than purer brine and pipes with impure brine therefore had to be watered at least once a year. With pure brine, strand watering every 2nd year was sufficient.

 

The watering usually lasted 4 to 6 weeks, ie 4 to 6 weeks as much water as was available was discharged through the pipeline. The fresh water gradually dissolved the gypsum crusts, i.e. the water softened them. After the specified time, the so-called "Schlädern" began. From the mountain down, certain stretches were filled with water and these stretches were suddenly allowed to drain at the cleaning box; as a result, the gypsum crusts, the so-called "Brinzen", were discharged. The Schlädern took about a week with lengths of about 10 km.

After the watering had ended, brine was added to the water and the low-grade brine that was forming was drained off at the brewhouse until it became normal. The time in which the brine became full depended on the size of the brine volume and the gradient, as well as the length of the pipeline.

For example, on the 4 km long Perneck – Ischl brine stream with a 151 m gradient and 60 hl of brine, it takes about 3 to 4 hours for the Schläder water to go sour before the brine is fully concentrated.

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Figure 18: Cast iron pipe with gypsum incrustations, from Hampl "Soleleitungsnetz", 1974, Archiv Salinen Austria

3. Pernecker brine pipelines:

Since two separate salt storage facilities were being mined at the Ischler Salzberg, separate brine pipeline branches had to be installed to transport the brine produced.

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Figure 19: Day district of the Ischl salt mine with Pernecker and Steinberg camps, 1932, Archiv Salinen Austria

3.1 Brine line from Steinberg - camp:

After the salt storage on the Steinberg was found through the Mitterberg tunnel, which had been struck in 1563, Emperor Maximilian II gave the supreme order on March 23, 1569 to build a brewhouse in Ischl. The first salt was boiled in Ischl as early as 1571.

A wooden brine line was built from the old Steinberg tunnel in 1571 to supply the Ischl brewhouse.

Until 1775, the brine line leading from the Salzberg to Ischl took its way from the tunnels in the Steinberg camp (Mitterberg, old and new Steinberg tunnels) and from the upper tunnels that were connected to the north and west of the Perneck camp (Lipplesgraben, Johannes, Matthias and Neuberg tunnels) along the Törlbach via the so-called "Sandpichl" into the Au near Perneck. It was doubled about 1715, requiring 997 tubes 10 feet long.

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Figure 20: Old Steinberg tunnel with 2 brine rooms and mountain buildings, situation around 1600, Archiv Salinen Austria

3.2 Brine line from Pernecker - warehouse:

After the lower-lying tunnels, which were connected to the north of the Pernecker camp (from the Frauenholz tunnel) were put into operation, a second line branch was laid along the Sulzbach stream, which probably met the existing Steinberg strand in the area of today's Maria Theresia tunnel.

The first installation driven from the north side of the Pernecker Salzlager was the Frauenholz tunnel, which was struck in 1610. This reached the salt store in 1632 and by 1654 13 water dams were already in operation. The brine extracted from these dams had to be transported away via a brine line that was newly built along the Grabenbach at that time. Around 1707, the first dam weirs were built in the Frauenholz horizon from the intersected former pumping works, the brine from which was drained through the Amalia tunnel, which was struck in 1687. From about 1737, the brine was finally discharged via the Elisabeth tunnel, which was opened in 1712, as the mines moved deeper.

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Figure 21: Situation of the brine pipelines in the upper Pernecker tunnel, around 1730, Archiv Salinen Austria

In 1738 and 1753, two Sulzstuben were built above the Ludovika Berghaus on the left side after the bridge over the Radgrabenbach to bring in the brine coming from the mountain. In the two brine rooms there were 3 brine tanks ("Sulzkasten"), of which the smaller one held 1000 buckets (56.60 m³) and the two larger ones each held 1300 buckets (73.58 m³).

Presumably from the Maria Theresia tunnel, the common brine line ran with the Steinbergsträhn over the "Perneckfuss" into the Au, over the Pernecker fields to Jodlbühel and along the Luckenleiten above the Gasterbühel on the old Perneckerstraße to Reiterndorf. Finally, the stretch led along today's Grazerstraße to the Ischler brewhouse.

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Figure 22: Pernecker Solesträhn, before 1850, Archive Salinen Austria

3.3 Sole rooms along the Pernecker brine line:

For a long time, the Ischler Salzberg did not have any workers, so that the brine, which was still cloudy, had to flow directly from the outlets of the production workers out of the pit into the brine stream. Therefore, containers had to be created above day to clarify the cloudy brine before it could be fed to the brewing huts.

As early as 1780, the Ischl mountain championship called the construction of a third reservoir next to the two brine rooms at the Ludovika Berghaus urgently needed due to the sharp increase in brine production. The application was only approved by the mining administration in 1790 because of the expected high construction costs.

The mining administration chose a site below the Leopold tunnel in the Au for the new construction of the Solestube for the brine flowing out of the Maria Theresia tunnel, taking into account the future development of operations. The building known as the "double Au - Solestube" was erected between 1790 and 1795. In addition to a cementation room, this brine room also contained four brine tanks with a total capacity of 3440 hl, the drains of which could be regulated by 2 drainage troughs.

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Figure 23: Double Au - Solestube, 1894, archive Salinen Austria

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Figure 24: Double Au - Solestube, cross-section, 1865, Archiv Salinen Austria

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Figure 25: Double Au - Solestube, longitudinal section, 1865, Archiv Salinen Austria

With the approval of the kk: Hofkammer of May 29, 1834, another double brine room was built in the same year directly under the mouth of the Leopold tunnel. The brine room, known as the Au - Einschlagstube, was built to bring in the brine from the workers of the Josef and Maria Theresia tunnels. The costs incurred for the construction amounted to 1552 fl 39 kr. The capacity of the two timbered tanks was 2400 hl brine.

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Figure 26: Building site Au - Einschlagstube (16), double Au - Solestube (19), around 1834, Archiv Salinen Austria

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Figure 27: Au - Einschlagstube, 1834, Archiv Salinen Austria

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Illustration 28 : Au - impact room, cuts, 1865, archive Salinen Austria

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Figure 29: Double Au – Solestube and Au – Einschlagstube with lime mill, around 1860, Ischler Heimatverein archive

Finally, in 1894, the so-called “brine clarification reservoir in the Au” was opened as the last brine room at a cost of 3667 fl 93 kr. built. This brick and concrete building sunk into the ground had a total capacity of 4800 hl brine.

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Figure 30: Situation during the construction of the brine treatment reservoir in the Au, 1894, Archiv Salinen Austria

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Figure 31: Brine treatment reservoir in the Au, 1894, Archiv Salinen Austria

Along the Pernecker Solesträhn up to the Ischler Sudhütte there were two more Solestubes, namely the Linskogel Solestube (today Haus Eck 30, Gschwandtner family) and the Buchen Solestube (today Bestattung Anlanger, Wiesbühel). The Linskogl Solestube held 800 hl and the Buchen – Solestube 1500 hl brine.

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Figure 32: Linskogel - Solestube, sections, 1865, archive Salinen Austria

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Figure 33: Buchen - Solestube, longitudinal section, 1865, Archiv Salinen Austria

The location of the brine rooms along the Pernecker brine streak can be seen on a map from 1865.

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Figure 34: Pernecker Solesträhn, Au - Einschlagstube to Linskogel - Solestube, 1865, Archiv Salinen Austria

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Figure 35: Pernecker Solesträhn, Linskogel - Solestube to Ischler Pfannhaus, 1865, Archiv Salinen Austria

A total of 5,740 hl or 574 m³ of brine could be pumped into the 3 brine rooms along the Ischl brine pipeline. This roughly corresponded to the brine output of the Ischler Salzberg for almost 2 days.

The 4269 m long brine line from Perneck to Ischl was equipped with a DN 100 iron pipe for brine in 1934. The maximum delivery capacity was 13 m³ brine/h. The total gradient from the Au – Solestube at 622.35 m above sea level to the Ischler Sudhütte was 151 m.

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Figure 36: Pernecker brine stream, line diagram with brine rooms, 1934, Archiv Salinen Austria

The Klebersberg stretch laid next to the brine line was a DN 50 iron pipeline with a maximum delivery capacity of 0.5 m³/h. The self-brine collected in the Klebersbergkehr of the Maria Theresia tunnel was used during the summer months for drinking purposes in the spa and bathhouses of Ischl.

The brine line from Perneck to the brewhouse in Bad Ischl was in operation until 1957. From 1957, all the leach works in the Pernecker tunnels were used up and the brine produced in the lower horizons has since been released via the Franz Josef Erbstollen. The performance of the brine output could be increased to 30m³ /h.

Today only little reminds of the Pernecker strand. The Au impact room was demolished in 1954 and a garage for cars and bicycles was built in its place. After the Pernecker Strähn was shut down, the double Au – Solestube was used for a short time as a coal store and material magazine, but was removed in 1959 to create parking areas for visitors to the Ischler Salzberg. Only the Au – brine clarification reservoir has been preserved to this day. It is used as a guest room at the annual cellar festival in Perneck.

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Figure 37: Double Au - Solestube, shortly before its demolition in 1957, Feichtinger Archive

4. Brine line of the Sulzbach probe field:

The Ischler Salzberg is today replaced by the Sulzbach probe field. The production capacity of the probe field is currently around 90m³/h. The brine obtained here is connected to the brine measuring and distribution station ("cimentation") in the area of the former Ischler Sudhütte via a separate 3.4 km long strand and distributed there to the pipelines to the Steinkogel Saline.

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Figure 38: Brine line at the Sulzbach probe field

5. Cementation Bad Ischl:

In the Bad Ischl cementation system built in 1971, 2 pipelines each from the pipeline branches Altaussee, Hallstatt and Bad Ischl as well as a pipeline pipeline from the Sulzbach probe field flow into 2 outgoing pipelines to the Vordernberg distribution system in Ebensee.
 

The large distribution system for cementation in Bad Ischl is designed in DN 150 in GRP pipes and equipped with 84 shut-off valves. The purpose of the system is to distribute the brine and fresh water from 7 incoming lines simultaneously to 2 outgoing pipes to Ebensee, to interchange them as desired or to route the brine from the 7 feeder lines via 2 heat exchangers of the central brine heating system. It is also possible to discharge fresh water from the supply lines in a channel here. With the help of the brine heating system, which consists of two heating boilers, 100 m³ brine/h can be heated by 12°C via 2 heat exchangers.
 

The outflowing brine to Ebensee is quantitatively monitored by means of an inductive flow measurement. With this measurement method, the brine moves in a magnetic field and induces a current that depends on the flow rate and is therefore a measure of the flow rate. The display is in m³ brine/h on a digital basis.

Almost 4 million m³/a of brine are distributed in the Ischl cementation today. This means that around 1.16 million t/a of salt can be produced in the Ebensee saltworks.

The Bad Ischl state health resorts are also supplied with brine from the Bad Ischl cementation via their own pipeline.

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Figure 39: Bad Ischl cementation, from Hampl “Soleleitungsnetz”, 1974, Archiv Salinen Austria

6. Hallstatt – Ebensee brine line:

At the end of the 16th century, Hallstatt salt production could only be maintained with difficulty due to a massive lack of firewood. But the state coffers were empty due to warlike events and the emperor urgently needed the income from salt production. This predicament led to the idea of channeling the brine from the remote, wood-poor valleys to wood-rich areas. This was the only way to ensure salt production in the long term.

Emperor Rudolph sent a commission to Hallstatt in 1591 to examine the proposal made by the court clerk Zacharias Kuttner and Bergmeister Hans Kalß to build a brine pipeline from Hallstatt to Ischl and on to Ebensee to a brewhouse that was yet to be built. The elimination of the rather dangerous transport of salt on the upper Traun at the “Wilden Lauffen” near Ischl and the saving of the expensive transport of firewood by horse and ship across the lake to Hallstatt were seen as major advantages.    

After lengthy negotiations, Rudolf II ordered from Prague on December 16, 1595 the construction of a brine pipeline from Hallstatt to Ischl, finally one year later he ordered its continuation to Ebensee.

On September 17, 1593, the Ischl mountain master Hans Kalß agreed to take over the construction of the brine pipeline. After its rollover, 6,000 to 7,000 tubes, each 15 feet long (4.7 m) or 3,000 trunks were needed for the line

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Figure 40: Hallstatt – Bad Ischl brine line, 1596, Salzburg State Archive (Info DI Franz Federspiel)

On August 15, 1596, the general mandate was issued to build a new brewhouse in Ebensee. In 1599, the building site was purchased from the property of the town of Gmunden, construction began in 1604, and the first salt was boiled in 1607.

In 1613 the almost 30 km long brine pipeline from Hallstatt to Ebensee was finally completed.

Since the existing brine pipeline from Ischl to Ebensee was not sufficient to supply the second pan in Ebensee either, a second pipeline was laid at the same time as the new brewhouse was built in 1690, for which 13,000 wooden tubes were required.

In 1769, the foreman Schmidt requested that 53 measuring troughs be connected to the entire brine line from Hallstatt to Ebensee in order to take account of the brine billing and brine losses as it flowed through.

In the years 1751 and 1752, a second pipeline was laid along the entire brine pipeline from Hallstatt to Ischl, using stronger 15-foot pipes. The new pipe string delivered 16 rooms (3,912 m³) per week compared to 12 to 13 previously. At the same time, the diversion of the most difficult section of the entire line, the crossing of the Gosaubach, was tackled. Up to now, the brine has flowed down from the right side of the valley in three strong pipes reinforced with iron rings, crossed the stream on a wooden scaffold and then rose under pressure (“under constraint”) up the steep embankment on the other side. Block pillars were then erected and a massive bridge was laid over their heads at a dizzy height, over which the brine line led at a natural gradient.

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Figure 41: Hallstatt – Bad Ischl, Gosauzwang brine line, 1821, ÖNB archive

In 1800 the cold was so great and persistent that the secondary salts, Glauber's salt and gypsum contained in the brine began to separate out and blocked the pipe so badly that no brine ran out at all in the upstream brine room in Goisern. This incident probably prompted the installation of brine heating rooms along the entire line.

Of course, the faster the brine flowed through, the lower the risk of freezing in the pipes; the largest therefore in the valley floor between Ischl and Ebensee, where there were also enough warming rooms for precaution. In these, the brine poured out into elongated pans, under which a fire burned constantly when there was a risk of frost. When the brine froze in spite of this in 1849, the Verwesamt Ebensee experimentally switched on cast-iron pipes in the wood pipe in the warming rooms, which led through a stove sunken into the floor and were thus directly coated by the fire.

In 1842, an experiment showed that a strand of wood with an internal width of 13 cm laid in a level road could achieve an output of 55 hl, and iron with an internal width of 12 cm could achieve an output of 120 hl.

To this day, brine lines have to be flushed with water (for 1 – 2 months) after one to two years of use (“watering of strands”). After rinsing, the softened gypsum crusts are washed out under water pressure ("Schlädern").

The brine lines, originally made of wooden pipes, were replaced by iron pipes from the second half of the 19th century. Cast-iron tubes withstood significantly higher operating pressures (up to 10 atm) than wooden tubes and lasted a good 50 years in the ground.

Between 1883 and 1885, the Solvay brothers in Ebensee set up an ammonia soda factory with the designation: "Österr. Association for Chemical and Metallurgical Production and Co., Ammonia Soda Fabrication System Solvay” was established.

The company was founded to provide work for the local population and to relieve the saline from the large influx of workers. The state supports the company insofar as the sales price for brine was granted below the production costs at a price of 4.30 kr. per hl. According to the contract, the Sodafabrik was entitled to purchase 1,000,000 hl/a, but this amount was by far not claimed at first.

This started the supply of industrial brine for the kk Salinen. The soda production started in 1885, the brine supply came from the Hallstatt and Ischl salt mines; from 1906 after completion of the brine line via the Blaa Alm, also from Aussee.

The construction of the ammonia - soda factory in Ebensee required a strengthening of the existing brine line between Ischl and Ebensee. The brine line from the Solestube Ischl to the Saline Ebensee (length 17,676 m) was carried out in 4'' wooden strands. In 1883/84, the supply line to the soda factory consisted of a wooden 5'' line to the delivery room at the inlet, to which a new cast-iron line NW 120 mm was laid next to the wooden one in 1887/88, mostly in the shoulder of the Reichsstraße.

The normal performance of the 6 strand was 290 hl/h. At that time, the consumption for all 7 Ebensee pans was 185 hl/h and the delivery to the soda factory was 105 hl/h.

The brine consumption for the Saline Ebensee was 1,375,611 hl in 1889, 10 years later, in 1899 1,752,502 hl. In addition, the soda factory could claim the annual contractual delivery of 1,000,000 hl. So something had to be done in the brine supply sector

.

This happened through the gradual replacement of the 4-inch strand of wood with a NW 130 cast iron pipe, which was completed in 1898. The cost of a 14,020 m line length was 60,783 fl.

In 1895, the wooden strands no. III and IV from the Ischler Solestube to the Johannisbrücke in Ebensee were replaced by NW 130 iron lines. In 1899 a fourth with the same diameter was added. In this year, strands I, II and V from the Ischler Solestube to the Johannisbrücke were also replaced by iron lines.

In 1982 the old strand on the historic route between Bad Ischl and Ebensee was abandoned due to insufficient transport capacity. Since it was not possible to re-lay it using machines because of the absolutely necessary maintenance of the brine flow on the old route, the cycle path of the B 145 was used as an alternative for the new pipelines. The starting point was the brine distribution station in the old saltworks building in Bad Ischl, the end point was the intersection of the cycle path with the 2 lines laid in 1978 from the Solestube Vordernberg to the raw brine tank at the so-called "Schulersteg" (length: 11.4 km).

The execution from 1981 - 1982 was carried out with 2 pipelines, each DN 350, PN 10 (maximum permissible internal pressure 10 bar), of which 1.15 km as pre-insulated steel pipes above ground from Bad Ischl Johannisbrücke along the Traunufer - retaining wall and the remaining length of 10.35 km buried as asbestos-cement pressure pipes.

Each line has a pumping capacity of 250 m³/h brine. The measuring device for the raw brine is located in the brine distribution station in Bad Ischl. Through the use of asbestos cement pipes and Reka couplings, the investment costs could be kept relatively low based on 40 years of experience. A total of around 4,000 of these pipes, each 5 m long, were used. The construction costs were around 52 million Swiss francs.

  On August 1, 1985, the areas of responsibility for the Solesträh were reassigned. The section up to the entrance to the Solestube Vordernberg belonged to the Bad Ischl area, this and the section on the old route to Ebensee up to the Wimmersberg reservoir and the Steinkogel salt works were managed by the Ebensee construction department. The area of supervision of the construction industry Bad Ischl covered a route length of approx. 33 km and a pipeline system of approx. 84 km length.

 

7. Brine line Altaussee – Bad Ischl:

To ensure the supply of brine to the Solvay plant in Ebensee (ammonia and soda production), a 16.5 km long brine pipeline was laid from the Kaiser Franzstollen in the Altaussee salt mine via the Rettenbach valley to the cementation in the Ischl brewhouse in 1905/06.

Since the production of this brine line, including all the necessary ancillary structures, such as brine reservoirs, warming rooms, etc., was not easily possible for the administration of the salt works, the Solvay works agreed to build the entire line initially from their own funds and, after completion, to own and manage it of the salt works, for which the Solvay works were given certain assurances regarding the brine price and the repayment of the pre-financed construction costs on the part of the finance ministry.

The most difficult part of the line was in the area between Salzberg Aussee and Karbach at the south-east end of the Ischler Rettenbachalm. In this section of the valley, narrowed by steep cliffs, there was no path at all for long stretches. The route of the pipeline had to be built using costly blasting work. It was also necessary to construct an approx. 60 m long road tunnel ("Ahornberg Tunnel") between pressure relief station IV and the Karbach transfer station, because the rock showed fissures at this point and therefore offered no security against major slides.

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Figure 42: Altaussee – Bad Ischl brine line, construction work on the Ahornberg tunnel, around 1906, archive Salinen Austria

A narrow path of approx. 1 m width would have been sufficient for laying and maintaining the brine line, but the forestry era demanded that a 2.5 m wide road had to be built in return for permission to build the brine line, which of course was for the bringing of wood was of the greatest benefit. The Solvay works found themselves in a predicament, as they were dependent on the supply of Ausseer brine for the planned expansion of operations in Ebensee. They therefore agreed to the specifications of the forestry era, who only made a small contribution to the construction costs.

The brine line, which was laid at a depth of 1.2 m in the street, consisted mostly of cast-iron sleeve pipes with an internal width of 80 to 150 mm, depending on the slope conditions.

A capacity of 208 hl per hour had to be guaranteed for the line, which was far exceeded during the takeover test. The amount of brine flowing off the Altausseer Salzberg could probably have been increased to 260 hl or even more. With 248 hl per hour, however, the performance limit of the high-performance route Karbach - Ischl was reached.

In order to ensure that the brine was released as evenly as possible, it was also necessary to create a large underground brine reservoir, which was built from quarry stone and provided with closed cement plaster. The reservoir was divided into 3 compartments, each with a capacity of 1200 hl, and equipped with measuring devices for both the inflowing and the outflowing brine. Since the apex of the line on the Blaawiesen was 13.965 m higher than the bottom at the Kaiser Franzberg - Mundloch, the reservoir built in the mountain had to be placed correspondingly higher.

The first brine delivery, on the occasion of the performance test of the new line, took place on August 31, 1906. For reasons that are no longer known, probably because of the execution of necessary additions, the brine delivery was stopped again after some time. In December 1906, the brine delivery was resumed, but after only two days the line was encrusted because of Glauber's salt excretions, which is why a second brine heating room had to be built in the Brunnkogelwald. In order to be able to drain the pipe from time to time to free it from incrustations that settled on the pipe walls, 4 water pipes were connected to the brine pipe. Stream water could be fed into the brine line via these water lines to clean it.

In order to be able to check the amount of brine released from the reservoir at certain intervals, pressure interrupting stations were installed at suitable points, into which the brine ran into measuring troughs. Four pressure interruption and measuring stations were set up on the route from the Kaiser Franz tunnel to the Karbach Stube. In addition to the measuring device, a coal stove for heating the brine was installed in the Solestube Karbach.

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Figure 43: Solestube Karbach, brine heating device, 1940, Archiv Salinen Austria

After completion of the entire brine line and approval, it became the property of the saltworks era according to a decree of the Linz State Finance Directorate of May 22, 1908, Zl.38/9 C-VII.

In the following years, the commissioning of this line also led to a significant increase in the brine delivery from the Altaussee salt mine to the Bad Ischl and Ebensee salt works.

In 1932 a second and in 1950 a third line of iron was laid in the Altaussee – Bad Ischl brine line.

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Figure 44: Altaussee - Bad Ischl brine line, Eisensträhn laying, 1950, ÖNB archive

Finally, in the years 1972 – 1973, a double strand of Polo-Dur tubes with a diameter of 200 mm was laid at a greater depth. This required extensive blasting work.

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Figure 45: Altaussee – Bad Ischl brine line, production of blast holes, 1972, Feichtinger archive

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Figure 46: Altaussee - Bad Ischl brine line, laying work in the Ahornberg tunnel, 1972, Feichtinger archive

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Figure 47: Altaussee - Bad Ischl brine pipeline, pipe transport by moped, 1972, Feichtinger archive

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Figure 48: Altaussee - Bad Ischl brine pipeline, cutting the Polo-Dur tubes to size, 1972, Feichtinger archive

8. Today's brine pipeline network in the Salzkammergut:

Today, more than     4 million m³ raw brine promoted.

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Figure 49: Brine pipeline network in the Salzkammergut, 1981, Archiv Salinen Austria

Sources used:

Carl Schraml "The Upper Austrian salt works from the beginning of the 16th to the middle of the 18th century", Vienna 1932

Carl Schraml "The Upper Austrian Salt Works from 1750 to the time after the French Wars", Vienna 1934

Carl Schraml "The Upper Austrian Salt Works from 1818 to the end of the Salt Office in 1850", Vienna 1936

L. Janiss "Technical help book for the Austrian salt mining company", Vienna 1934

Ischl home club "Bad Ischl home book 2004", Bad Ischl 2004                                                                  

Kurt Thomanek "Grains of Salt", Leoben 2007

Gottfried Matl "Chronicle of the Saline Ebensee 1595 - 1985", Ebensee 1986

NN "Saline manipulation description", 1807 -1815, Volume I, Archiv Salinen Austria

Carl Karsten "Textbook of Saline Science", Berlin 1847

Fritz Hampel "Report on the brine pipeline network of the Salzkammergut", Bad Ischl salin administration, 1974

Leopold Schiendorfer "Salzkammergut brine pipeline network - inventory 1990", Bad Ischl 1991, archive Salinen Austria,

Vogl "History of the development of the Ausseer Salzberg 1890-1929", Part II, Archiv Salinen Austria

Ischler stock book no. 04 "Solenstube in der Au", no. 05 "brine clarification reservoir", no. 06 "brine room first to the Emperor Leopold tunnel", archive Salinen Austria

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