The construction is awesome, ropes and chains crisscross
on and between corrugated iron frames. The dredging machines whine
under the strain but continue obediently and each railing, corner
and cog wears every second of its 60 years in service. The character
of this tin dredge, operated by the Sino-Thai Resources Development
Public Company Ltd., is evident to all the senses.
Sino-Thai is run by Khun Varin Cherdboonmuang, a very personable
mining engineer with some 40 years experience. There is currently
only one dredge in operation in the sheltered waters of the Tukkae
Bay area which employs approximately 60 people.
The mining of tin in Thailand dates back to the reign of King Narai
during the Ayutthaya period. Tin was used for making spear tips,
swords and body armour and so was considered a valuable commodity
not only by the Thai Kingdom, but by all Oriental and European powers.
During the mid 1800's the demand for tin and related alloys
surged. It was used in Bangkok for coins and roof tiles and was
sought by industrializing Europe for anti-rust coatings, tin cans,
foils and electronics. Thousands of Chinese migrated to Phuket to
work in the tin mines where conditions were adverse and labour intensive.
History was made at Wat Chalong in 1876, when a riot involving 25
000 migrant workers was quelled by two temple abbots who rallied
with the local people.
Over the years the excavation process has evolved and now uses
a sophisticated method to mine and extract tin ore. The seabed is
scooped up by a bucket ladder, a system of large bucket shaped cups
that revolve around a pulley stretching from the top of the dredge
down to some 117 meters below sea. The pay-dirt is sent through
a large revolving screen, where the oversized particles are discarded
and the more precious mixture of sand, gravel and tin is collected.
Next it is sieved by one of seven primary jigs before being pumped
back up into a hydro-cyclone. Here the heavy, metallic particles
are retained and sent through a secondary jig. This gravity theory
is also applied to the next two refining stages, the Willoughby
jig and the land-chute. Finally the precious remains are dried,
bagged and shipped to the Sino-Thai refinery in Phuket. At this
stage, the tin material is approximately 30% pure. It is then thoroughly
cleaned using plain water to become about 74% pure tin.
Sino-Thai sell all of their tin to the Thailand Smelting Co. Ltd.,
where it's once again processed and smelted into tin blocks.
Tin is used to make common alloys such as bronze, as we see in many
Buddha images, solder, used widely in industry, and pewter which
is readily available in almost any souvenir shop. Even the aerospace
industry depends on an alloy made from titanium and tin for space
No one could deny the usefulness of tin products in our society,
yet the relative value of tin has decreased by about 50% since the
hey-days of the industry back in the 1900's. The tin mining
business has repeatedly come under fire throughout its long history
in Thailand. The environmental impact of early mining was considerable.
Open cut tin mines devastated the pristine landscape of Phuket and
eventually angered residents. In 1985 construction began of a tantalum
refinery, a valuable metal by-product of tin processing. The procedure
would have significantly damaged air and water quality, but a citizen
protest, 50,000 people strong, broke into chaos resulting in the
destruction of the plant.
Khun Varin assures me that nowadays excavation of tin ore is conducted
to reduce the environmental impact as much as possible. The discharge
chute is now aimed straight down to the ocean floor which lessens
the deluge by up to 90%. Khun Varin wants people to understand that,
"we do care about environmental issues and we want to work
together with other industries in Phuket.' He pays homage to
the foresight of Phuket Governor, Phompaiyom Wasaputi, who allows
dredging to continue seeing it as an on-going source of revenue
for the island's economy.
Khun Varin's vision of working together with other industries
includes Phuket's latest economic boom area, tourism. The tin
dredge and refinery stand as the last evidence of a once flourishing
industry which helped shape the history and landscape of Phuket.
Sino-Thai has a license to dredge for the next two years with no
guarantee of renewal. They hope to keep their employees in work
after this time rather than move to neighbouring countries to operate.
The future is cloudy for this understated natural resource as the
high costs of exploration, excavation and refining can't compete
with low market values forever. So, it remains to be seen if the
refined life of tin can endure the 21st century.