Mining, processing and transport
Ownership and licensing
Mines were variously owned by individuals, partnerships of individuals or limited companies.
In general a mine would be leased from the mineral rights holder (usually the land owner or The Crown) by the mine owner(s). Initially a takenote (which was a licence to explore and search for minerals with an undertaking to grant a lease if minerals were found) would be granted to the would-be mine owner. Subsequently a lease would be let for a certain period, usually for a fixed sum for each year of the lease (the consideration) plus a royalty of so much per ton of mineral extracted or some fraction of the value of mineral extracted. The lease might also contain conditions with regard to how the mine was to be developed, the minimum number of men to be employed (as, for example, in a draft lease for Llanenddwyn) and the removal of machinery and restoration of the land at the end of the lease.
The mine would be managed for the owner by an agent. In many cases in the Merioneth manganese mines the owner was local and acted as the agent. In some cases it would appear that there were unusually frequent changes of owner, operator or agent. However, it is probable that these are due to inaccuracies or inconsistencies in reporting of operations rather than any actual change of ownership. In some cases the same person served as agent for a number of mines - a practice commented on (and deplored) by The HM Inspector of Metalliferous Mines in 1874. [Evans 1874]
Mining
In Merioneth, the earliest workings were for the oxidised outcrop of the bed of ore which was typically .3–.45m thick. Because the oxidation did not penetrate far into the bed, workings were more or less exclusively opencast and extensive, in some cases approaching 1km along the outcrop worked as a single mine. When in the 1880s the unoxidised ore began to be worked, access was gained by adits driven in from the opencast cliff faces, along the bed, running more or less horizontally.
The general arrangement was as shown in the plan. Cwm Mynach appears to have been worked up-dip from levels driven on the strike, the roof being supported by pack walls and props. Elsewhere (e.g. Cilcychwyn) and the bed was stoped out both up- and down-dip from the adit (as shown). Good examples of parallel cuttings away from the opencast working face can be seen at Llyn Eiddew Mawr and, on a smaller scale, Llyn Dywarchen.
There is a lack of contemporary information on mining methods. Plans of Harlech mine in 1886–1887 appear to show the ore being worked up-dip in blocks, as well as in single stalls about 8 yards (7.3m) wide, with pillars of similar dimensions. Adits were driven in the bluestone overlying the ore, so that a 1.8m high adit would be 1.5m in waste and .3m in ore. Workings were kept as low as possible, and occasionally wooden props were set [Halse 1887: 108]. These were generally rare, however, and usually roof support was by carefully built packs, constructed of waste bluestone. Many of the mines still have these packs in good condition and there are few traces of roof collapse except at the entrances to adits. Cilcychwyn has good examples of these features. In some cases wooden props have been used to support stacked waste in inclined stopes.
In a number of cases the bed has been worked in from the surface over some distance and then the outer side of the working has been walled up with waste with an access passage left to create an underground working. Moelfre has a good example of this type of working.
The precise thickness of the workable ore varied greatly and whilst there are occasional reports of 1.2m, .3–.45m was more typical. Of itself this thinness was no great disadvantage (Russian ore beds were only .3m thick) but problems arose because of the low grade of the ore and the hardness of the bluestone overlying it.
In working, the ground was set by the yard, at around £1 15s (£1.91/m), although the actual amount varied greatly. The working method seems to have been that the waste was removed for, say, 1m ahead, after which the exposed ore is lifted up [Down 1980: 26]. The technology was simple; in the majority of mines the workings were driven, and ore broken, by hand. There are only rare traces of drills and explosives having been used (e.g. Cwm Mynach); in more recent workings such as the World War I reworking of Rhinog, compressed air drills were installed. There is an unsubstantiated report of a miner being killed by a blasting accident in 1917 [Smith 1997: 27].
Where the ore bed dipped steeply, as at Hafotty, or occurred in near-vertical veins as in the Arenig mines, conventional vein mining methods were used, with the ore being regularly stoped from levels - and shafts such as at Mynydd Nodol on the Arenigs.
Processing
On-site processing was minimal. In the 1890s the only preparation was hand picking of any obvious waste, and sifting out the fine (less than half-inch) fraction. In 1919, ore was broken into 2 inch (50mm) lumps for sale to the St. Helen’s glassworks.
There is no evidence at any of the mines for any form of mechanical processing such as stamps, jigs or buddles as used in some Devon manganese mines in the mid-19th century.
Surface facilities
At a number of mines are level stone floors, typically a couple of metres square, which may have been where ore was broken up and/or stacked awaiting transport.
Buildings, where present, were most commonly a smithy for sharpening tools, in some cases an office and perhaps a small shelter. There are occasionaly other buildings that may have been used as stables. In some cases farm cow sheds or cart houses were used for stabling. [Smith 1997: 26]. Rhinog was unusual in that it appears to have had barracks, probably provided for the World War I reworking. There were also barracks at Cwm yr Afon [Smith 1997: 25] and possibly at Diphwys.
In the majority of cases where there was no living accommodation provided at the mines it seems that miners found lodgings at local farms. [Smith 1997: 26], [Thomas 2004]
Transport
Transport was a significant cost in view of the remote location of many of the mines and the low value of the product. Where long outcrops were worked it was first necessary to gather the ore at some central point, and in a number of cases this was done by tramway, often of 24 inch gauge ‘Jubilee’ type. Hafotty used at least one incline for this task. From here, it was necessary to build a road (no more than a cart track) or else, in the case of Diphwys, Foel Wen and Hafotty mines, lay a tramway to the nearest servicable cart track. These were lightly engineered railways with near-horizontal sections connected by inclines. The tramways terminated at stone loading docks where ore was transfered to road carts. There is no suggestion of locomotives being used in any of these undertakings. Short temporary tramways appear to have been used at a number of mines to take waste to tips.
At least one mine, Egryn, used an aerial ropeway rather than surface tramway. A ropeway could well have been cheaper to build than a railway, particularly across steep, very broken or boggy ground. In 1886 H S Lancaster, the manager of Hafotty mine, planned a ropeway to Barmouth at a cost of £130/mile [Halse 1887: 110]. Shorter ropeways were also used at Diphwys old and Rhinog mines.
The use of tramways and ropeways should not be over-emphasised. Probably most of the movement of ore within the mines was done by barrow or sledge (man- or horse-hauled) and transport from the mine by horse and wagon or sledge. Sledges and wagons were made, and repaired, locally. The daybooks of John Thomas and William Parry, joiners of Llanbedr, contain an entry for 27 May 1886 for “mak[ing] sledge for Thomas Lloyd to carry manganese” and there are many other entries concerning the manufacture or repair of wagons and sledges. Another maker of sledges (although not necessarily for manganese) was Robert Williams, farmer and joiner, of Caermeddyg [Bebb 2001: 373]. The advantages of sledges against wheeled forms of transport were that they were more controllable on steep ground and cheaper to make. At Cwm yr Afon the ore was brought down from the mine to the farm in samll carts and then transfered to larger carts for the road journey [Smith 1997: 25]. Similar arrangements may have applied at other mines where the ore had to be transported across rough terrain before reaching a cart road. In some (possibly most) cases the mines did not own carts but hired them from local farms (presumably at times of the year when they were not needed for agricultural purposes). The farm carts were robust and hiring them provided extra income for the farm. (Whitehead [2004] reporting a conversation with an elderly local inhabitant.)
Before the advent of the Cambrian Coast line serving the west side of the Harlech Dome area, manganese was probably transported to its users by sea. There was a harbour at Pensarn (between Llanfair and Llanbedr) capable of taking 300-ton vessels (used for bringing coal to the area) and Samuel Hennis claimed (in the context of his china-clay enterprise) that return cargos could be sent to Runcorn for “only a few shillings per ton” [MJ 1867 p. 254].
The ore itself ranged from 10 to 15 cubic feet/ton (3.6 to 2.4 tonne/m3), and the cost of transport to the nearest railway station was usually high. Some examples, not necessarily representative, are:
| Destination (station) | Distance (km) | Year | Cost/ton (£) | ||
|---|---|---|---|---|---|
| Artro | Llanbedr | 2.6 | 1886 | 0.14 | |
| Hafotty | Barmouth | 3.5 | 1886 | 0.15 | |
| Harlech | Harlech | 1.5 | 1886 | 0.04 | |
| Llanenddwyn | 1824–1826 | 1.14 | includes harbour dues, weighing etc. | ||
| Moelfre | Dyffryn | 4.3 | 1912 | 0.15 | |
| Ralltgoch | 1828–1829 | 0.90 |
In the twentieth century motor vehicles were used to carry ore to the railway stations from some mines.
With regard to transport on the standard-gauge railway network, manganese ore was classed as ‘B’ [Browne & Theobald 1911: 970], which, in 1911, was charged at 1.25d per ton per mile for the first 20 miles, 1d per ton per mile for the next 30 miles, .8d per mile for the next 50 miles and .5d per ton per mile thereafter, together with station costs of 6d per ton at each end of the journey [Browne & Theobald 1911: 962]. Thus rail transport from say Llanbedr to Mostyn (~ 90 miles) would have cost around 7s 3p (£0.36) per ton.
Productivity
The records of output are almost certainly inaccurate and incomplete. Consequently, productivity estimates based on them are somewhat speculative. However, the mean output calculated from the records is 54 tons per man per year, i.e. a little over 1 ton per man per week, which does not seem unreasonable. Individual mines varied from as much as 155 tons per man per year (Llyn Dywarchen) down to 2 tons per man per year (Crafnant) or even less, however, it is difficult to determine whether these figures are realistic or if they are artefacts of the available records. It should be kept in mind that these figures do not reflect the total amount of work performed by the miners as they do not include the work of developing the mines and removing waste rock to obtain access to the manganese ore.
Overall mine productivity could be affected by external factors. For instance, it was reported by the son of the mine foreman at Barmouth that there was a letter from the “owner in Birmingham” (presumably John Abraham) to the mine foreman complaining of falling output, to which the foreman replied that it was the result of an influenza epidemic in Barmouth [Giffin 2002]. Winter weather at the more exposed mines could also affect output [GAS CAO: XD/35/424 p. 160].
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