The tunnel is sited adjacent to a footpath connecting
Llandeilo Road and Oakfield Road on the Twyn at Garnant. Until recently
its history has remained an intriguing mystery, but thanks to Gareth
Mathias of Swansea and his professionally equipped team of colliery
investigators, we now have a little more knowledge than has previously
been available.
The team visited this site in early November 2010, with
a view to survey and record details of any workings there. The conclusion
reached was that the tunnel was a test drift, probably dating back
to the 1870's. Drifts such as these were usually sunk where surface
coal was found and this particular drift was aptly placed for drainage,
with the mouth of the tunnel in close proximity to the River Pedol.
The high standard of stonework lining the first part
of the tunnel suggests that the owner expected his investment to be
lucrative, but alas after reaching a depth of approximately 500 metres,
the tunnel ends, the owner obviously having given up.
Inside Tunnel Opening
The drift passes through some large rock formations
and there is clear evidence of blasting. The badly de-laminating walls
and ceilings show that too much explosives were used at that particular
location. Disturbingly, at approximately half way along the tunnel,
the team found a stick of explosives protruding from the wall, dry
and in a volatile condition.
No toxic gases were detected in the tunnel at the time
of the survey, but the oxygen level had dropped to only 14% (normal
level is 20.9%) at the innermost end.
The exploration team discovered boot prints in the tunnel,
showing that others had been inside. Whether those others had been
furnished with the appropriate safety equipment necessary for a safe
visit is unknown and such an endeavour certainly poses potentially
disasterous consequences.
Gareth Mathias' overall risk assessment of the Twyn
test drift concludes that it is a potentially dangerous place to enter
and the following scale gives a general idea of the level of risk.
Danger Rating:
Lethal
1
2
3
Twyn Test Drift
4
5
6
7
8
9
10
Safe
A diagram of the Twyn Test Drift was created by a
member of the exploration team and is shown below. All rights belong
to the illustrator named in the image:
Following the survey, the results of which were passed
to the Coal Authority, the entrance to the tunnel has been closed
and warning notices erected.
Images from inside the Twyn Test Drift are shown below
and are displayed here courtesy of Gareth Mathias and his team.. Notice
the half buried tram embedded in the bank of the
River Pedol in the bottom photograph. Please click on the images to
enlarge.
The brief video footage below shows a 360 degree panorama
of the location. Please note that the "Further Suggestions"
listed at the end of the footage are due to You Tube's website programming
and have no relevance to Cwmamman History.
Thanks to Gareth R. Mathias of Swansea and R. Elvered
for the information and images on this page.
