ust north of Perth, Western Australia, lies the city of
Geraldton, whose port is a bustling—and vigorously
growing—terminal for the export and import of iron ores,
grains, fuels, metals, mineral sands, talc, garnet and fertilizers.
Karara Mining Ltd, a subsidiary of Gindalbie Metals, is a heavy
user of Geraldton Port. As such, it owns and manages its own
infrastructure at the port, including a dedicated berth, a 5000
tonnes (5500 ton) per hour ship loader, and the enormous
290 x 55 m (950 x 180 ft) Karara holding shed.
Each day, four trainloads of iron ore are received at one end of
the facility and redistributed along its length via an overhead
conveyor system. Then, heavy machinery sorts the ore and
feeds it onto a conveyor belt for loading onto ships.
All this activity generates constant noise, vibration and dust
inside the shed. Large dust extractor fans contribute to the tu-
mult, but respirator masks are still always needed. During peak
summer months, temperatures inside the shed roof—35 m
(120 ft) above the ground—easily reach 55°C (130°F).
Every month, surveyors from Thompson & Delfos (HTD) surveying
company venture into this environment to measure iron-ore
stockpiles. With only a brief window between trainloads, they
must set up prior to where the next train will dump, survey,
and exit within 90 minutes.
From Total Stations to Spatial Imaging
Trimble S6 Robotic total stations with Trimble Survey Controller™
software initially provided a solid solution for the Karara job, but
HTD needed to remove their surveyors from the shed floor, both
for personal safety and to protect surveying gear. The job’s time
constraints also demanded the fastest possible solution.
In December 2012, in partnership with Haefeli-Lysnar (HL), HTD
acquired a Trimble TX5 3D scanner, a light and compact mid-
range system that was an achievable purchase for HTD, a small
to mid-size surveying company.
Surveying from a New Perspective—Upside Down
HTD accessed the shed’s ceiling space, which housed the over-
head conveyor and a walkway, to create a scanner setup high
above all activity. With scans required at 25 m (82 ft) intervals,
the walkway made a perfect platform from which to suspend
the scanner upside-down using a purpose-built bracket. (The
scanner does not need to be upright or level, but upside-down
scans must be inverted in Trimble Realworks® software at pro-
cessing.) This solution meant carrying the Trimble TX5 up ten
flights of stairs, so the instrument's small size and weight were
immediately an advantage.
Approximately 30 polystyrene balls of 300 mm (12 in) diameter
were suspended from the roof rafters. These would function
How to Tame a Wild Stockpile
Take One Everyday Stockpile Survey, Bring it Indoors and Intensify Conditions
with Dust, Extreme Heat, and Fast-moving Heavy Machinery—
Suddenly That Commonplace Job Makes for One Wild Ride.