Dear Graham,
I can't tell you which it is but the time span for coal to deteriorate (to a
noticeable extent, whatever that might mean!) was almost infinitely
variable. I've read comments that refer to a few weeks - certainly within
your 'six months'. At the other end, coals must have substantially survived
for long periods - elsh steam coal was shipped all over the World, & it
wouldn't have gone in exactly the fastest ships. Some of it was then held at
overseas coaling stations, in some cases presumably for extensive periods.
Welsh steam coal dredged from Welsh harbours, where it must have lain for
possibly years, was found to be virtually as good as new. This led to a
suggestion to store it under water - I don't know if this was ever adopted
(but I doubt it). Not quite the same, but the worst I've come across is the
coke from a Welsh works (can't remember which, somewhere around Maesteg I
seem to remember) which became significantly less reactive if kept for as
little as six hours. (Yes, hours!) That said, many cokes had to be used pdq.
Hope it helps.
Kindest regards,
Ken (Smith).
On 4/27/08, GRAHAM BROOKS <[log in to unmask]> wrote:
>
> I am at present researching a set of early 18th century colliery accounts
> and on the sales side I keep coming across references to 'old coals' either
> been given away or used as payments for various services around the
> colliery.
>
> I have come up with two possibilities for this
>
> 1) coal deteriates after it has been mined and so is less valuable. If
> this is the case what sort of time span are we ta;lking about for this to
> happen. This is a new working of an old colliery and they are talking about
> old coals within 6 months of starting production.
>
> 2) As stated above this colliery is a re-opening of analready worked area
> with frequent refences to 'opening old workings' Is the 'old coal' coal
> that is being removed from these areas of old workings as they pass through
> into new areas of previously unworked seam
>
>
> Any comments gratefully accepted.
>
>
>
> Graham Brooks
>
|