SA’s little-known defunct manganese mine

28th March 2014 By: Jade Davenport - Creamer Media Correspondent

Manganese is a commodity that barely features in the popular historical narrative of South Africa’s mining industry. This is slightly odd, considering that the country, specifically the Kalahari manganese field, in the Northern Cape, is host to more than 80% of the world’s known manganese resources.

However, given that the history of manganese exploration and mining is somewhat checkered and that the commodity is not nearly as exciting as gold, diamonds and platinum, perhaps the lack of historical narrative is not surprising.

Nevertheless, the early history of manganese is quite remarkable in that mining did not start in the Northern Cape, as one might expect, but in the vicinity of Cape Town, in the nineteenth century. In fact, one of the country’s earliest recorded manganese discoveries and operations was the Hout Bay manganese mine, located just above the start of the world-famous Chapman’s Peak marine drive, on the south-western side of the Cape Peninsula.

Written historical records suggest that manganese was first discovered in the vicinity of Hout Bay in November 1873. However, because the deposit was deemed to be of inferior quality, being low grade and largely associated with sandstone, and because there was no great demand for the commodity at that time, no effort was made to exploit the discovery. It was only a decade later, following Sir Robert Hadfield’s revolutionary metallurgical invention of manganese steel, an alloy of exceptional durability, that the deposit became a more attractive proposition.

It was on the back of substantial rising demand for the chemical element that an assay of the deposit was undertaken by a metallurgist in the employ of the South African College in the mid-1880s. The results of the assay were positive, indicating the ore contained between 76% and 83% manganese dioxide.

Despite the positive results, no more information relating to the Hout Bay manganese deposit was recorded for almost two decades. It was only in March 1909 that an article published in the London-based publication, South Africa, revealed that a tentative start had been made to mine the manganese deposit. The article stated: “Manganese, which is common in the mountains of the Cape Peninsula, had until recently failed to prove a payable proposition, the cost of labour and difficulty of haulage being obstacles to enterprise in this respect. At Hout Bay, however, the difficulty has been solved, and a manganese mine is actually at work. “Manganese ore is being shipped from the Cape to Belgium, where it has been favourably reported on. “As regards the manganese mine at Hout Bay, a shute, erected on poles, extends from the top to the bottom of the mountain, a distance of some 2 000 ft to 2 500 ft. “Down the shute, at an angle of something like 45˚, the manganese ore comes tumbling to the seashore. At the mountain base, a jetty is being built so that lighters may come alongside, fill up, and discharge their cargo into the ships waiting in the bay.”

As the manganese ore occurred in a relatively narrow vein running vertically up the side of the mountain, a set of eight adits was driven into the mountainside. These varied from 20 m to 85 m in length and up to a few metres in width. After sorting the ore according to grade, it was stacked in 1-m-high piles adjacent to the vein running up the mountain to await transportation down the shute to the jetty.

There is evidence that, by 1910, the mine was fully operational and had begun to export small quantities of manganese ore. By 1912, despite the fact that a substantial quantity of ore was still lying in heaps up on the hillside, the mine had closed. The reasons for this are not completely clear, but it could be due to the fact that the ore had been found to contain an undesirably high percentage of phosphorus and the company experienced many problems with its shute that conveyed the ore down the mountainside to waiting cargo ships.

The mine lay abandoned until the fateful year of 1929, when an attempt was made to restart the operation. However, given the Wall Street Crash and the subsequent collapse in demand for commodities such as manganese, and given that the world-class manganese deposits near Postmasberg, in the Northern Cape, had been discovered some three years earlier, the attempt to mine such a small and low-grade deposit was quickly abandoned.

Today, little evidence remains of that century-old manganese operation and consquently many local residents are unaware that a mine once operated on the fringes of the village. The only real indication of those activities is the dilapidated remains of the jetty, just below the start of Chapman’s Peak Drive, from which the manganese ore was loaded onto cargo lighters.

However, it is possible to hike up the mountain and explore some of the old adits and see for oneself the numerous heaps of manganese ore, which have sat intact for more than a century. However, a word of warning, based on personal experience: although there is no actual climbing involved, the mountain is quite steep and the walk to the first of the adits and then up the mountainside following the piles of manganese ore is extremely strenuous and not for the faint hearted. But it is certainly worth the effort – if only for the beautiful vistas of Hout Bay and the Atlantic coastline.