You Don't Still Use Candles Do You?

As visitors marvel at Jenolan’s underground wonders, they might notice a little box of candles, next to the path, and ask, “You don’t still use candles do you?”

The answer, strange as it as it may seem, is “yes”. The humble candle, whose fitful spluttering light first lit the gloom of the caves, still gets called into action, just in case the world’s most modern cave lighting system fails. (Of course today, candles are augmented by handy mobile phones.)

The candle, which the first intrepid cave explorers used, has distinct disadvantages. A breeze can blow out the flame. Wax can drip on clothes and crystal features. Worst of all, a candle and matches can be dropped into a pool of water. The result – disorientation and despair in the absolute darkness. To solve these problems, early cave explorer, innovative Jeremiah Wilson, made special candle holders that had saucer shaped receptacles, to catch the dripping wax. A spring loaded shaft pushed the melting candle up through the burn hole, ensuring that the flame continued to burn.

Bright magnesium wire lamps were the next improvement. A clockwork mechanism would unwind burning magnesium wire off a drum into a large reflector dish. Then, cave features could be individually illuminated to everyone’s satisfaction.

First Cave in the World to Have Electric Lighting

This is an amazing story. In November 1879, Thomas Edison patented his new invention, the vacuum light bulb with carbon filament. Less than a year later, in July 1880, in Australia, an Edison lightbulb was switched on in the Margareta Chamber of the Chifley Cave. To achieve this miracle, 18 zinc and cast iron batteries were dragged 18 metres up into the cave. Each set of six cells weighed 44kg. The whole, together with acid and generating apparatus, exceeded 762kg. The equipment was manhandled up to the cavern dry, then filled with acid. The resulting toxic cloud caused everyone to flee! But the batteries produced enough power to light the bulb and the chamber, and the results were photographed and shown at the Melbourne Exhibition later that year.  This story was described in the Sydney Morning Herald, 9 September 1880. (The article was entitled "The Fish River Caves", as that is what Jenolan Caves was originally called.)

Lightbulbs were a marvellous cave innovation! As it would be another 20 years before Sydney had street lights (and most homes remained lit by gas for many years) A wise person once said, “Technology is best when it brings people together.” That is so true for Jenolan, because Jenolan’s technological wonder, the lightbulb, became a tourist attraction in itself.

To power newly installed lights, a steam driven generator was set up in the Grand Arch, fed by a plentiful supply of cut timber. But because of its limited generating capacity, banks of only 10 lights could be turned on at any one time, and they would dim, due to power supply fluctuations.

Australia's First Hydro Power

In 1888, a water-driven turbine was imported from America. The Imperial River was dammed beyond the Grand Arch, and the Leffel Wheel (cutting edge technology at the time), was installed 200 metres downriver. This was the first use of hydroelectric power in Australia. 

Soon, to light all the caves, more power was needed. The 1908 solution was to build a considerably larger dam - the Blue Lake. The turbine and 2 generators were moved further down the valley. But after Caves House expanded in WW1, the Leffel Wheel was decommissioned. (This was delayed when a German submarine torpedoed the ship carrying the new equipment from Britain.)

In 1916, a new hydroelectric power station was switched on, 900 metres downstream from the Grand Arch. It operated until quite recently, and now awaits funds to infuse it with new life.

Most Advanced Cave Lighting System in the World

In recent years, the entire cave system has been relit, using a C–Bus system - the latest lighting technology. This microprocessor-based system features remote control. Diochroic lights and compact fluorecscents (later LEDs) have been installed in the caves. There are important advantages for conservation and sustainability. They operate at a much reduced voltage and draw much less power. They give off very little heat, to discourage the growth of mould and moss inside the caves. Jenolan’s carbon footprint, once elephant-sized, is now the size of a small bird. This technology is currently considered the most advanced Cave lighting system in the world.