Dear all,

I am working with Scoggan's very welcome assistance on a project to explore the very last years of the Liskeard and Caradon Railway. We are making good progress!

As many of you will know, Phoenix United was recapitalised in 1907 and a major investment made in sinking a new shaft (Prince of Wales) with the optimistic view of intersecting the principal tin lode at 1200' below grass. The 80" engine to pump this depth was supplied by Holman Brothers new and powered by three Lancashire boilers. The engine was started formally on 9 July 1909 and ceased work in August 1914. I am trying to calculate the back tonnages of coal carried up the Caradon line by the GWR during this period- there are no useful GWR sources for a variety of reasons. What we do know is that around only 200 tons of ore were taken away down the line in six years.

I'd be really grateful if AN members with a greater knowledge of the coal consumption of an 80" Cornish engine working at pretty full stretch could help me here - just what sort of coal consumption are we looking at?

I hope you can help - kind regards!

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Hi Alec,

I've had a quick look through some of the performance records I have. For a range of 80" engines working on different mines, at differing depths it would appear that the range is about 15,000 to 25,000 bushels (1cwt) of coal per year. This would give a range of approximately 750t - 1250t per year. However Pellys 80" when working on Crenver and Abraham or Robinsons when at South Crofty consummed approximately 58,000 bushels or 2900t per year. The figures were taken during the mid-late 1860s to mid 1870s.

I do have many more records but this should give you a reasonable approximation at this stage.

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just for comparison when i was the boilerman at the elk mill in royton we had 2 boilers a hartley and sugden locamotive type and a vekos multifuel and had 17 tons delivered every fortnight amounting to 442 tons a year minimum and we rarely used both boilers at the same time.mind you when the manager started buying cheap foreign coal it went up to 20+ tons a fortnight and i struggled to get steam up in winter.

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Thank you, Agricola and Bograt!

I am very much obliged to both of you. My principal source on the machinery installed at PoW shaft at Phoenix is H R Shambrook's NMRS paper of 1982, 'The Caradon and Phoenix Mining Area'. The 80" engine was struggling from 1911 onwards as the shaft deepened and water was being drawn in from adjacent setts where pumping had stopped around two decades earlier. The 1910/11 winter was a wet one, and the Cornish engine needed supplementing by a 120hp horizontal compressor engine driving Cameron air pumps at the shaft bottom. The capital expenditure at this time was colossal- by 1913, at today's values, £6m had been raised through investors and spent- for less then 200 tons of ore sold.

At the tonnages of coal you both suggest - I'll go for the top estimate given the load on the engine - let's say well over 100 railway wagon loads of coal a year would have gone up the Caradon railway. This is unlikely to have been balanced by loaded returns of granite from Freeman's quarry at the Cheesewring, and certainly not by ore loads.

I'll now work on what this means in terms of trains per week from 1909-1914. Unless, of course, anyone out there has the GWR Working Timetable for that period!

Thank you very much indeed.

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Are you sure that coal wasn't also needed to fuel other machinery at the mine as well as the pumping engine? If so, how significant might that have been?

Thank you, Peter - indeed so.

Although beds were laid for 5 Lancashire boilers for the 80" engine, only 3 were installed.

As well as the Holman's 80" pumping engine with its steam capstan, there was the 120 hp compressor to which I have referred and a Holman horizontal duplex winding engine. Brown and Acton (1998) are of the view that the pumping engine boilers also supplied steam for the compressor and winding engines.

We know that a 550 hp Robey horizontal compound engine to drive a head of 12 Holman stamps was also installed, powered by a seperate installation of four Lancashire boilers (3 in steam and 1 spare). We know this as the Robey engine was removed 'for war work' by a contractor using steam road locomotives and trailers in 1917. What is less certain is that the stamps and associated mill were ever used - they weren't completed in 1914 and the Holman 80" ceased pumping for good in September of that year.

As you suggest, coal consumption could well have been higher than that calculated for the 80" engine alone -exaggerating the traffic flow issue up the Caradon line to Moorswater and beyond, as this would substantially been of 'empties'.

All the best -and thanks -

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