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Journal of the Nelson and Marlborough Historical Societies, Volume 1, Issue 3, November 1983

[Chromite and the Dun Mountain Copper Mining Company]

The mining of chromite began in Nelson in the late 1850s and continued intermittently until about the turn of the century. It was most successful in the early 1860s and the Dun Mountain Mining Co. Ltd., extracted several thousand tonnes of ore from the slopes of Wooded Peak. Production peaked in 1862 when 3,843 tons, valued at £24,719 (table 1.), was exported from Nelson. At this time total world consumption was, compared to the present day, very small and chrome was used largely to manufacture dye for the cotton garment industry in England. Dyes including yellow, rosaline and the newly discovered mauve colours as well as an alternative to those green dyes containing arsenic compounds whose use was regarded with some suspicion. It was also widely used in the arts for making pigments.

Chromite occurs throughout the 'Nelson mineral belt' extending from D'Urville Island to Tophouse. However, undoubtedly the most important locality was between the heads of the South Branch of the Maitai River and the Roding (or as previously known the Wairoa) River on the east and south faces of Wooded Peak some 2km WSW of the Dun Mountain. The location of the various deposits are shown on the 1911 geological map accompanying the Dun Mountain Subdivision and their origin has been recently discussed in the 1:50 000 Dun Mountain Geological map.

When chromite was first discovered in this locality is not known and certainly initial interest was in copper, specimens of which had been found in early 1852 in the Maitai River. Consequently a line of copper mineralization was defined extending along the eastern slopes of the 1110m high Wooded Peak. In 1854 particularly due to the efforts of William Long Wrey, a Cornish miner, some capital was raised in England and access up the Maitai to the mineralisation was improved allowing ore samples to be brought out. In 1856 this included 16 tons of excellent copper ores (Hochstetter) and according to Palmer, 15 tons of chrome ore. In 1857 the London registered and based Dun Mountain Copper Mining Company Ltd (6 Great Winchester Street) with a capital of £75,000 in one pound shares was formed. In the same year the company sent the engineer Thomas R. Hacket to Nelson to manage both the exploration and development of the mineralisation and to investigate an improved access to the area which was up to 1000m above sea level. On arrival in Nelson Hacket was not impressed with the copper mineralisation, recognising that although the quality was good the amount of ore available appeared small. However he noted that the chrome ore deposits were more extensive and recommended their exploitation. The principal deposits were high on the east face of Wooded Peak a little to the southwest of Coppermine Saddle and at the southern end of the line of copper mineralisation. The company lost no time in forwarding materials for a railway and these arrived in Nelson early in 1858, However, Bailey records that the material was "locked up in the company's store room on the beach" and construction did not commence because "the limited demand said to exist for this ore in the English market leaves it very doubtful whether the price realised will leave a sufficient margin for the shareholders". In April 1858 the company called for tenders to transport 50 tons of chrome ore to the Port. As this would have been by pack horse down the Maitai valley not surprisingly costs were high being not less than £6 per ton (Palmer).

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Aerial photograph of Wells Spur forming ihe southeast side of Wooded Peak (1110m). The contact between the "mineral belt" rocks (foreground) is marked by the abrupt change from low scrubby vegetation to forest. Above the railway are the tip heads of the chrome mines and the foundations of the ore chutes. – Photo: D. L. Homer. New Zealand Geological Survey.

Aerial photograph of Wells Spur forming ihe southeast side of Wooded Peak (1110m). The contact between the "mineral belt" rocks (foreground) is marked by the abrupt change from low scrubby vegetation to forest. Above the railway are the tip heads of the chrome mines and the foundations of the ore chutes. – Photo: D. L. Homer. New Zealand Geological Survey.

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Although the Dun Mountain Company was London based its day-to-day operations in Nelson were controlled by a local committee comprising, for example, in 1858, Dr (later Sir David) Monro (Chairman), William Wells, and Hacket (Secretary). From the start things did not go smoothly for in 1859 the company was only receiving £3 per ton for the ore in London and until some reduction in the high transport costs from the mines to the Port was made it was obvious that the whole operation would be uneconomic. Consequently as Monro records: "Went to the Dun Mountain Company offices. Despatches have been received (from London), ordering the committee to pay off all the men and discontinue every item of expenditure. Mr Hacket's salary is not to be paid to him". In addition Bailey refers to public meetings held to investigate an alleged charge of fraud against one of the managing committee.

In August and September of 1859 the Australian geologist Dr Ferdinand von Hochstetter (1829–1884) visited New Zealand as a member of the "Novara" Expedition and was asked by the Nelson Provincial Government to report on the mineral potential of the province. In Nelson he visited Dun Mountain and found that it consisted of "a very peculiar kind of rock, of yellowish-green colour when recently broken, but turning rusty-brown on the surface when decomposing. The mass of the rock is olivine, containing fine black grains of chromate of iron… I called it Dunite". Monro's dairy for 29 August to 1 September 1859 records Hochstetter's visit to Dun Mountain and for 30 August he wrote "we went out to look at the chrome mine, but the rain came on again with sleet and we got ourselves wet through. Returned to the cottages…". In the afternoon it moderated again and we all went out and examined the original workings". At the time of Hochstetter's visit there was considerable controversy over the copper deposits on Wooded peak with the principal opponents being Wrey and Hacket. Hochstetter, who backed Hacket, had this to say: "The Cornish miner (Wrey) who instigated the mining believes with much too vivid an imagination that conditions in his native country, the rich copper lodes of Cornwall, must also be reproduced on this mountain. But the copper ores are here formed only in individual, generally
The 3ft gauge Dun Mountain railway crossing the "Mineral Belt" at 980m above sea level on the south side ot Wooded Peak. In the distance is Mt Claude (892m) southwest of the upper Roding River. – Alexander Tumbull Library.

The 3ft gauge Dun Mountain railway crossing the "Mineral Belt" at 980m above sea level on the south side ot Wooded Peak. In the distance is Mt Claude (892m) southwest of the upper Roding River. – Alexander Tumbull Library.

page 7not very rich (veins)… which … can be followed for a distance of about two miles. These conditions make it clear that the results of the mining enterprise must be an uncertain one. The chances of striking rich lenses of (copper) ore are too slender to continue the extremely costly mining venture". However, Hochstetter referred to the chrome deposits adjacent to the "Duppa Lode" at the south end of the line of copper mineralisation as "an extraordinary abundance of chrome iron ore was evident. Whole portions of rock consisted of it and many hundreds of tons of almost massive ore lay in blocks of various sizes scattered on the slope. The ore forms no lodes, but appears in bands in the serpentinite… it turns up more or less richly, either in massive great bodies, or individual grains". However at the time of Hochstetter's visit a tunnel ("Deep Adit Tunnel") driven west for 116 yards at right angles to the Duppa Lode had disturbingly failed to reveal anything of significance.

In 1860 when the price of chromite rose to £7 per ton on the London market (Monro) and later to £10.10.s per ton (1865 Juror's Report) there was considerable optimism which led to the construction of the Dun Mountain Railway. However, Monro (1860) had a word of caution in writing to Hochstetter "The Directors have written to me to get 2,000 tons ready, and they are sending out an engineer to lay down a line for a railway from the mines to the Albion Wharf. There can be little doubt that there is a large quantity of ore in the Serpentine of the Dun Mountain, but it does not appear to preserve its continuity in the same manner as metalliferous lodes in Europe". Hochstetter in a public lecture in Nelson in 1859 also expressed reservations about the in situ ore.

Eventually in July 1860 the engineers G. C. Fitzgibbon and W. T. Doyne arrived in Nelson and construction of the railway began in March 1861. Thus Hochstetter wrote "Nelson can even boast of a rail-road, the first constructed upon New Zealand soil". The actual construction and operation of the 3 foot gauge 13½ mile long railway is described in New Zealand's First Railway" published to mark the centenary of its opening on 3 February 1862. Instead of following the Maitai valley as proposed by Wrey and others it ran from Port Nelson, through the Brook Valley to cross Third House Saddle into the Roding (Rhoding of some early accounts) valley. From there it continued to climb, around the flanks of Wooded Peak* to its terminus near Coppermine Saddle between the head of the Roding River and the South Branch of the Maitai River. Gradients on the line were as high as 1:20, with numerous cuttings, embankments (on which local rock was put to to good use), tight curves and bridges over gullies. In days of pick and shovel and wheelbarrow its building was a major engineering undertaking. However, despite being competently supervised it would appear that the foundations were not always adequate for a future manager Joseph Cook was to write on 10/9/1864: "I am not prepared to give you any estimate of the future cost of keeping the railroad in good working order as a large portion of it is built with very perishable materials laid upon insecure foundations, already it is showing signs of decay and giving way in many places" and on 11/11/1865 "The railroad is now in pretty good order but it requires great watchfulness and attention as there is constant sinking of parts of it".

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The company's yard was at the head of Brook Street and in places along the line a few bricks now mark the location of huts (or houses as they were then called). The most important of these was Third House on the divide between The Brook and Roding River (also known as Wairoa Saddle). At Third House and also at the end of the line there were stables for the horses (the Nelson Provincial Museum has plans for the former). Second House was about 100m west of where a tributary of the Brook is crossed and Fourth House is just before the Mineral Belt. There were also mine buildings on the lower flanks of Dun Mountain (Hochstetter – map) and the geologist S. H. Cox in 1882 refers to a managers house. About halfway between Third House and the mineral belt and where a band of limestone is encountered is the remains of a lime kiln. The kiln, like many of the embankments, is constructed of free standing slabs of rock and has an inner brick chimney. Operation of the railway was simple, with empty waggons pulled by horses to the mine. Full waggons, coupled in pairs and under the control of a brakeman, descended by means of gravity to the company's yard in the Brook Valley. During its first year the railway transported 3910 tons of chromite. However up to 900 tons a month could be carried giving an annual tonnage of 10,000 tons. This figure is of interest as at the time of construction ore reserves were calculated by Hacket as at least 10,000 tons. Thus at the first year's rate of extraction the reserves would last only 3 years and if the maximum capacity of the line was used, only one year. This is significant when it comes to accusations and counter accusations between the committee in Nelson and the Directors in London when the company's prospects later declined. Part of an unsigned and undated draft of a letter sent from the Nelson committee to the Directors exists in the provincial museum. This letter was written, probably in 1863, when the company had largely ceased operations and answers a number of the matters raised by the Directors. From this it is certain that the Directors criticism was not motivated by the price obtained in London for chromite for the committee wrote "…you remind the committee that you only authorised the construction of a railway upon their positive information that there were at least 10,000 tons of ore "in sight" – symptoms of extraction appearing after 2,500 tons have been got you hold the committee responsible for failure". However the committee declined to accept responsibility for "Beyond being the agents by which Mr Hacket's calculations and statements were forwarded to you we neither pretended to go nor do we see how we can have incurred any responsibility". Thus it appears that both the committee and directors were in agreement in criticizing Hacket for the same draft states "But we are glad to observe that…you place the report of the existance of the 10,000 tons of chrome on his shoulders stating at the same time that it was confirmed by Mr Fitzgibbon and Mr Doyne". At this time Hacket was "absent from Nelson". Whilst suspending operations the committee retained 4 men to maintain the railway in good repair and anticipated that "the receipts from the firewood, lime and the omnibus (the passenger service to the Port) enable us to pay your manager's salary, that of the secretary and the expenses of the men… The receipts and expenditure very nearly balance one another". Even in the 1860's labour costs were high and were blamed for the overrun of railway construction costs: "it is difficult perhaps for the Directors to realise the expense of everything where an ordinary labourer's wages are ten shillings a day".

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Terminus of the Dun Mountain Railway in 1863. The chrome ore was conveyed from the mines above the railway to the waggons by means of chutes, the rock foundations of which are still preserved. – Photo: Alexander Turnbull Library.

Terminus of the Dun Mountain Railway in 1863. The chrome ore was conveyed from the mines above the railway to the waggons by means of chutes, the rock foundations of which are still preserved. – Photo: Alexander Turnbull Library.

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In 1864 the company sent a 'mining captain' Joseph Cock, of Cornwall, to report on the Dun Mountain property, Cock, his son John and two assistants, sailed for Nelson direct from Gravesend on the clipper ship 'Violet'. John Honeycomb Cock established John J. Cock & Company, which when taken over by his younger brother (Joseph Henry) became J. H. Cock & Co. Ltd., a firm closely associated with the Anchor Company.

Joseph Cock kept copies of the letters he sent monthly to the Directors in London and the provincial museum has some of these. He soon confirmed that the chrome deposits were aligned nearly north-south and although "it can be traced a considerable distance across the mountain (Wooded Peak)… the ore appears to be very irregular both in quantity and quality and is not of sufficient value to repay the expenses of working at the present high price of labour" (9/8/1864). Cock thought that the old workings (i.e. above the railway) were worthy of further investigations. However, he was hindered by the careless manner in which the workings have been left unsupported by timber and consequent falling in of the ground very little of the chrome bearing ground is at present visible" and underground investigations were required. His subsequent letters which became increasingly despondent about the chrome deposits, describe the progress of these investigations, including the driving of crosscuts and levels which extended (presumably westward) under the old workings. On 16/11/1864 he reported that they had located "300 to 400 tons of ore, that can be taken out and conveyed to the shipping port at a cost not exceeding thirty shillings a ton". As the ore was not first class chrome which the company had instructed its committee it was only interested in, he decided against making shipments at that time. He also prophesised that "if this sort of chrome will not pay. I can hold out no hope of making profitable returns from any part of the property". Thus the drives and levels found little chrome beneath the old workings and although elswhere on the property chrome is "scattered over a great extent…, it is however generally of inferior quality, I could not undertake to collect from the whole of the property one thousand tons of equal quality to the last shipment, nor even ten tons of the quality you ask for". By 10 March 1865 Cock had suspended many operations and the miners took "the places of some of our workmen who have left to go to the gold diggings". Explorations, however, continued with few encouraging signs. At one stage it appears that a branch line to chrome deposits below the railway was contemplated by the Director's in 1864 for Cock (10/9/1864) reports that a line "to the lower part of the property where it was proposed to make a branch railroad. I have carefully examined this and broken splendid specimens of chrome but 1 cannot see a sufficient quantity of it to warrant the expenditure that would be incurred in making four miles of railroad or even one mile". On 10/6/1865 Cock acknowledged the directors instructions that mining of the chrome (presumably the 300 to 400 tons located under the old workings) commence. This required the timbering of the mine and also the construction of about 50 fathoms (55m) of railroad, presumably an extension of the line further towards Coppermine Saddle. Costs were still established to be within the thirty shillings per ton upper cost limit of getting the chrome to Port Nelson. Mining continued through July (11/7/65) although much "dead rock was encountered with chrome" and "the layers or beds varying considerably in quality". However in the deepest part of the working a 2 feet wide layer yielded 3 tons of average quality ore to the 6 foot (of drive) and could be extracted within the thirty shillings per ton limit. Bypage 11August (11/8/65) ore was being extracted at the rate of "10 tons a week", ore grades were generally low, about 20% of chrome. In August 40 tons were extracted, increasing to 50 tons for September before declining to only 20 tons for October and 30 tons for November (letters 11/9/65, 11/11/65) Costs did not exceed twenty five shillings per ton and presumably ultimately returned a profit. In the meantime expenditure was met by sales of lime and firewood. From Cock's letters the return from these items was variable, there being for example a greater demand for wood in winter. Lime sales depended largely on building activity and it would appear that the lime kiln was not in the best place, for amongst the Cock papers is a letter (10.6.65) stating "that the lime kiln is built in the wrong place, and the necessity for building a new one… it would be desirable to do this as soon as possible, it would effect a saving of five shillings a ton on the cost of burning the lime which at present rate of sales would in 12 months repay the costs of building the kiln". Presumably the new kiln, if built would have been closer to more easily quarried limestone. At one stage the company instructed Cock to locate roofing slate but he replied negatively on the availability of this.

Late in 1865 the grade of chrome was declining and by the end of the year chrome of economic ore grade was exhausted with Cock reporting in despair (10/1/1866): …and I know not where to get another ton of ore of the quality required to be remunerative" … "Having fully satisfied myself by careful and minute examination of the whole of the property as well as by various trials underground that the prospects of the mine do not warrant further outlay, I have suspended all mining operations". Of the 400 tons extracted from beneath the old workings 100 tons was rejected as inferior quality containing less than 30% Cr20 3. Of the remainder "carefully picked ore" 200 tons was shipped to England in November 1865 in "British Merchant" and the rest in January 1866 in the "Water Nymph; Morrison, Sclanders & Co. handled the shipping arrangements.

Whether any further ore was extracted from the Dun Mountain property is not known but it appears unlikely although Cock continued as manager. The geologist E. H. Davis wrote after a visit to Nelson in 1870 that "There is a little (chrome) left about the old workings but I was assured by the present manager to the company that there was none left underground". In 1872 the company's affairs were wound up and on 15 May 1872 the "Nelson Examiner" announced the sale by auction of "the whole of the property of the Dun Mountain Copper Mining Company" with Morrison, Sclanders & Co. the company's agents. Except for the port section, the line must have been under discussion for some time for in a letter (12/1/72) to the company, Cock asked for a decision concerning the transport of building stones before the rails were taken up.

Various reasons have been given for the demise of the Dun Mountain Company. For example, it has been argued by A. N. Palmer that the American Civil War (1861–65) with its consequent blockade of the southern confederate ports and considerable disruption of the cotton industry reduced the demand for dyes and hence Nelson chrome. Another possible reason, given by Davis, is that as the total consumption of chrome in England did not exceed 2,000 tons per year Nelson chrome because of high labour costs and distance from the English market could not compare against mines in Orkney, Norway and Baltimore. Also only a slight increase in price would make other page 12European deposits economic. These reasons, whilst perhaps contributing to a decline in price do not appear to be the main reason for the company's difficulties.

All through the company's existence the price of chromite was high reaching a peak of £10.10s per ton and even in 1865 when the company ceased mining the 1865 Jurors report gives the price as £5 per ton. Also Sir James Hector gives one possible reason for the price dropping from its peak and that was the discovery and ready availability of aniline dyes which were extracted from coal tar. It appears that labour or shipping costs did not seriously disadvantage Nelson for the Cock papers show that ore was extracted and transported to Port Nelson at less than 30/- per ton stipulated by the company directors. The cost of freight to London is not known but Hector gives a figure of £3/13s per ton for ore delivered to London and in 1882 when there was a resurgence of interest in chrome, 15/- per ton were quoted by Cox. There is also an intriguing reference by Hector to chrome ore being shipped as ballast thus implying cheaper rates on ships bound for England that would in all probability be returning largly empty. The company's report to 30 June 1864, a copy of which is held in the museum, states that the company was involved in the establishment of Connah's Quay Chemical Co. Ltd. to use the company's chromite. This and the Directors instructions of 1865 to Cock to mine the ore remaining under the old (Hacket's) workings implies that the company could still dispose of chrome if of suitable quality. It is therefore difficult to avoid the conclusion that the unavailability of chrome of reasonable grade (30% or better Cr2O3) after the relatively easily accessible deposits on the surface of Wooded Peak were worked out was the major cause for the company winding up its New Zealand affairs.It is also probable that the high quality chrome formed relatively thin, steeply dipping layers within the serpentinite of Wooded Peak. However over a long period of time the erosion of the softer serpentinite enclosing the deposits resulted in a large accumulation or lag deposit of high quality chromite blocks on the surface. This in turn gave a false impression of the quantity and quality of the chrome underneath.