Below are one or two more details of the electrical installation at
Trafalgar Colliery, Forest of Dean.
I will get photographs of the colliery and of the electric generating plant
up on my Forest of Dean Mining Web site at:
http://www.users.waitrose.com/~iapope/Coalopen.html
over the Christmas period.
Ian
A Dean Forest Guardian report of a visit by Captain and Mrs. Wemyss to
Trafalgar in October 1874 reads:
. . . that with Mr. T. B. Brain descended the shaft in the ordinary skip.
In this subterranean passage the visitors had not calculated upon finding
the roadways lighted with gas similar to that employed in the lighting of
streets and dwellings and were agreeably surprised to find instead of
impenetrable darkness, the workings clearly defined from the jet burners
which were dotted about the roadways . . . It may be of interest to add
that the gas is forced down the shaft by means of a one horse horizontal
engine
erected in the gas house at the pit bank.
The gas house is the building shown on the 1898 Severn & Wye plans
containing a circular structure.
Another account of the gas illumination at Trafalgar comes from a guide
book by John Bellows of Gloucester called A Week's Holiday in the Forest of
Dean and published around 1880. It also gives some details of the surface
workings and other facts about Trafalgar.
Before going down (underground) we may as well look at the large sandstone
quarry on the premises where stones are cut for supporting the galleries
below. Let us pass through the tramway tunnel, 150 yards long, cut through
the ridge of the hilltop, to a shaft on the other side. This narrow ridge
is the outcrop of the measures, and in the tunnel we can examine, rock,
clod and duns, and a little thin coal with rock again below it. Having seen
this we turn back again, enter the cage, and, closing our eyes to avoid the
giddiness, are lowered 600 feet so smoothly, that we are hardly conscious
of motion. At the bottom we go into the underground office, and are
supplied with a little brass lamp, and a bunch of cotton waste to wipe our
hands upon, and then attended by 'the bailey' enter one of the main
roadways...
... Where necessary, the underground workings are lighted with gas, and one
of the partners, Mr. William Brain, is now preparing to adopt the electric
light (which is already in use on the surface at night) and also to utilise
electricity as a motive power at many of the underground inclines, or
dipples, in the colliery, where steam is not available; and thus save many
horses. There are more than forty horses living in this pit. They never
return to daylight until worn out or disabled. Some of them have been down
here a dozen years, and are in excellent health.
Fire damp is wholly unknown in the Forest of Dean, and miners work with
naked lights. Choke damp breaks in rarely, and seldom gives any trouble.
The pit is remarkably free from water, and being furnished with every known
appliance, and most admirably kept, is probably one of the best in the
Forest, or out of it. Eleven hundred men and boys are employed here: 600
underground getting coal, and 500 as labourers &c., above ground, and in
subsidiary occupations. Good colliers earn, at present, 3s 8d per day;
masons 3s 4d; and labourers, 2s 4d. One can hardly imagine anything more
severe in the way of labour than that of a miner lying on his side in a
four foot passage, cutting away with his pick the hard rock encasing the
seam ...
... The output from Trafalgar, at the moment we are writing, which is a
dull season is seven hundred tons of coal per day.
The foregoing passage gives a reasonable account of Trafalgar Colliery and
is also notable in mentioning once again the use of electricity at the pit.
Francis William Thomas (Frank) Brain had been associated with the use of
electric floodlights on the Severn Bridge in 1879 where they had been used
to enable construction work to continue at night to make the best use of
the tides. After use on the bridge, the apparatus, consisting of a couple
of powerful lamps supplied by a Gramme machine, was re-erected at Trafalgar
on the surface to light the colliery yard, and a football match was even
played at night! Frank Brain was also connected with the Electric Blasting
Apparatus Company who made fuses for simultaneous shot firing underground,
and had buildings close to Trafalgar Colliery.
Electricity was also used at Trafalgar when the first underground pumping
plant was installed in December 1882. The installation at Trafalgar was
the first recorded use of electric power in mines. The equipment consisted
of a Gramme machine on the surface driven by a steam engine and a Siemens
dynamo used as a 11/2 horse power motor belted to a pump underground. The
Gramme machine still exists today, preserved in the National Museum of
Wales in Cardiff. It attained such success that three additional plants
were erected in May 1887 and these did the larger part of the pumping. The
last installation consisted of a double-throw nine inch plunger, by ten
inch stoke, situated 2,200 yards from the generator and 1,650 yards from
the bottom of the shaft. The pipe main was seven inches in diameter and at
its maximum speed of twenty-five strokes a minute the pump lifted 120
gallons to a height of 300 feet. The current was conveyed to the motor by
an 13/16 copper wire carried on earthenware cups. The E.M.F. was 320 volts
and the current required was 43 amperes. The installation cost of the
engine and the electrical plant was £644, whilst the weekly cost for
maintenance, including 15% for depreciation and interest on capital was £7
17s. or .002d. per horse power per hour. The efficiency attained
throughout was only 35% but the engine which was an old one lost 6.49 horse
power, or 22% alone. If this was removed from the equation then the
efficiency was 45%.
_______________________________________
Ian Pope
Cartographer
Oxford Centre for Cartography & Geographical Information Sciences
School of Planning
Oxford Brookes University
Gipsy Lane
Oxford
01865-483368
Chairman, Forest of Dean Local History Society
http://www.forestofdeanhistory.co.uk
_______________________________________
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