Page 121 - SAICE book proof 2 LATEST JULY 2014

s a i c e
WESTERN CAPE PROVINCE

studying a good road map. Suffice to say, the name line full of decomposed material forced a rethink and
Bain is associated with many of the old passes. The the engineering professionals eventually chose to
tales of hardship, perseverance and ingenuity abound. freeze the portion to stabilise it enough to drill the
tunnel through. At the northeast end, the water table
And what is worth mentioning is that after about two had to be drawn down by using a vacuum type method
centuries, most of the old passes are still in use without to enable construction. At peak about 400 000 litres a
major alterations except for upgrading and modernisa- day had to be drawn or drained out.
tion. These upgrades provided many challenges to add
new to old and to still preserve the historic heritages. At the end of the day this 12 m diameter tunnel
produced 750 000 m³ of granite rock. What is not
The younger among the venerable passes are the Du generally known is that this tunnel has saved millions
Toitskloof pass which was completed in 1949 and the of hours in travelling time and litres of vehicle fuel and
approaches to the Huguenot Tunnel on the same route the capital investment has most probably been paid for
but which bypasses most of the pass. many times over.

29. huguenot Tunnel is the longest road tunnel
in South Africa and was completed in 1988 and punches 33°44’18.01” S, 19°03’25.74” E
through the Klein Drakenstein Mountains. This state-
of-the-art, 4 km tunnel, passing below a high point of
700 m presented the designers and civil engineering 30. Sport and civil engineering in this province
contractors with many headaches due to very difficult include world famous events in which the percentage
geotechnical terrain. Initially, retaining walls had to of civil engineering professionals are substantial. The
be built to even get the western portal built. Due to Old Mutual Two Oceans Marathon road race each
the prohibitive cost to drill just one borehole along the year around Easter follows a route unsurpassed for its
centreline, a pilot bore was chosen. About 1.5 km in scenery, including Chapman’s Peak and attracts about
from the south western side, a mud rush from a fault 9 000 ultra-marathon runners and 16 000 for the half-

◊ Huguenot Tunnel

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