TECH: Sweden

Avid cave and mine diver Phil Short goes back to his ‘happy place’ - Langbans Mine in Sweden –a location he describes as being the best mine dive in the world

Photographs by Erik Matteusson and Anders Torstensson

From a divers’ perspective, the mine is managed with permission and support of the mine museum by a group of Swedish technical divers along with several other mines in Sweden. So access to dive is easily arranged, starting with an orientation that includes a guided tour of the surface features including the six-plus shafts leading down to the flooded levels

As you descend a wooden stairwell

This bridge lies at 70m of depth some way into the Langbans Mine in Sweden, an amazing time capsule of industrial archaeology.

Langbans Mine is situated in farmland Sweden, the nearest city being Filipstad. The mine at Langbans was mined from 1711 to 1972, but has traces from as early as the 15th century. The area and specifically the mine has been described as one of the most mineral rich places in the world having produced over 270 different minerals. The prime purpose of the mine, however, was the extraction of iron ore later processed on site in the Langbanshyttan blast furnace from the 16th century until 1933. Also the mine is famous as one of the factory manager’s sons, John Ericsson, the Swedish inventor known for the screw propellor and the Monitor battleship, was born and raised here.

From a divers’ perspective, the mine is managed with permission and support of the mine museum by a group of Swedish technical divers along with several other mines in Sweden. So access to dive is easily arranged, starting with an orientation that includes a guided tour of the surface features including the six-plus shafts leading down to the flooded levels. Although most of these can be visited and passed under during dives in the mine, all diving activities take place from one entrance point where kitting up benches, platforms and stairways into the water have been constructed, making access easy.

The water temperature is a constant 6 degrees C at all depths, so for Scandinavian mines in general ‘warm’, and crystal clear with ten metres plus of visibility usual.

As with most mines, the galleries were dug to follow ‘seams’ of ore and are formed in levels. The most common accessible, lined levels in Langban are 21m, 40m, 55m and 75m and the original miners’ maps have been reproduced and the guide lines added, making a dive simple. The levels are connected in several places, including the ‘Loka’ shaft that goes from its surface winch building (still intact and

preserved as part of the museum) to the water surface and then the elevator cables descend to the bottom at 130m. Other shafts including the last working shaft used up to the mine’s closure in 1972 descend beyond 300m.

Personally I have been diving Langbans yearly for the last six or more years teaching CCR Mine, CCR Normoxic and Hypoxic Trimix classes and CCR Advanced Mine classes in DPV, Multi Stage and Cartography, as well as many fun dives. To me, I often say each year when I arrive back that I’m in my ‘happy place’ and it’s true - for me, it’s the best, most-preserved and varied artefact-rich mine I have been privileged to dive in.

This year I had the opportunity to make seven days of personal dives at the mine between work commitments and classes, so my ‘buddy’ Oscar Svensson and I decided to plan, build up to and set up a dive we had both wanted to achieve for many years - the room at the base of the ‘Loka’ shaft at 130m.

Now to dive that room did not involve a straightforward vertical descent from water surface to base, rather a complex route initially descending from the divers’ entrance to the 55m level, then a DPV journey through the tunnels to a descent following a flight of wooden stairs to the 70m level before crossing a huge hall and entering the ‘Loka’ shaft at 80m and continuing to its base and the room beyond from there… and, of course, reversing the whole route and decompressing to return. The first phase of our set-up/build-up dives was to put all the gear the two of us would need into the mine and then make a series of dives to ‘stage’ the bailout and deco gases and lay the directional markers and jump lines at all junctions on the route. Next, we had to take air cylinders to fill the two decompression habitats ready for use. They hold their air for many days or weeks, but not forever, so occasionally need topping up. We do not breathe the habitat environment, rather we keep the CCR loop in the mouth throughout the deco, but being dry significantly increases the warmth, for example the 6m habitat with two divers in after about half an hour of deco has risen to 12 degrees C or more rather than the frigid 6 degrees C of the water. A huge difference on a four-plus hour run time!

The bailout requirement necessitated five different Trimix blends plus pure Oxygen and several of the Trimix blends required two cylinders of each to allow safe bailout from a worse-case scenario of CCR failure at the furthest/ deepest point of penetration. This meant that Oscar and I had 14 x S-80 cylinders staged in the cave for the dive. We were carrying two to three at all times and at regular points swapped them out for the next most-suitable mixes. We also staged various other equipment including metal thermos flasks of hot drinks Mines are man made and

inherently present a higher risk environment than the vast majority of natural cave systems, which were formed over a long period of time and are thus far more stable.

for the 6m habitat (and a waterproof speaker and media player for music) and additional heating batteries for the heated undersuits.

No plan is complete without a team and in the case of deeper Langbans dives, the rules require an in-water team to meet the ascending deep divers on ascent, a shallow water team to check on the divers in the 6m habitat and surface support throughout. The team we had on the weekend for the final set-up dive to 115m and the actual dive were simply marvellous and went above and beyond to support us in every way. This meant that as we ascended from the final dive, they could take no longer needed gear from us and remove it from the mine so at the end, the mine was clear and no further dives were required to ‘clear’ the mine. This did however mean the entrance platforms at the end of the dive were covered in more cylinders and regulators than a busy resort dive centre may need!

So ready at last we descended, checked our staged Oxygen at the 6m habitat and continued down to the 50m level before starting the DPV run of 150 metres to the prelaid jump to descend a stairwell to the 70m level. Here is one of the most-spectacular sights I have ever seen in a mine, you enter a huge hall with the roof at around 65m and no floor in sight, just a black void below. To the right is a small tunnel, but to the left the tunnel exits onto a ‘hanging bridge’ supported over the void on chains from the wall and ceiling, which you DPV across to the far side of the hall. A further descent into the void beneath the bridge on a pre-laid line passed under an arch and enters the circular ‘Loka’ shaft, with the multiple elevator cables rising above and descending below you. Here we began the descent, passing the 115m area reached on the previous days set up and gradually approached the shaft base, where a huge elevator counter weight was reached at the end of the cables. A perfectly preserved wooden stairwell was found to lead off from the safe base with bannisters and rails leading down to a small room, the floor festooned with the detritus of a working mine and the tunnel leading from this room was sealed with a huge wooden wall with a small door on large orange (oxidised) iron hinges. This shaft was used to transport workers only to this level, when the archive maps are consulted, beyond this wall and door is a long access tunnel leading to the ‘Nya’ shaft that reaches the very base of the mine and all levels in between. A brief look, a little GoPro video captured and time to turn the dive with the TTS climbing rapidly. We reversed the route and picking up staged gases on route, headed up to our first deco stop at 57m and then every 3m from there up to our final 6m stop.

At 18m we were able to enter our deep habitat, actually an airfield dome in the roof of the mine with a floating pontoon. Within the pontoon was an open centre (Moon Pool) with a submerged floor, and completed our 18m, 15m and half of our 12m stops. It’s a bit chilly when you leave the air habitat and re-enter the water but not for too long, as after the remainder of the 12m and the 9m stops we could enter the luxury of the seated 6m habitat where the long stop could be competed in relative comfort.

These dives would simply not be safely possible without these habitat as in the event of a serious drysuit leak, in-water deco at this temperature to complete safe and efficient decompression would be unlikely.

So once again, thank you to all the divers who helped on all the build-up dives and offered their support, it simply wouldn’t have happened without them. An incredible opportunity to learn more and see an additional part of this fascinating time capsule on industrial srchaeology hidden in the Swedish forest. n