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The
location of the Snowy power stations, relative to engineering
services available in the capital cities, was remote
indeed. Thus the SMAwas obliged to be self sufficient
in almost all areas of engineering. With heavy plant
and equipment being manufactured overseas, items were
broken down into more manageable loads, both in weight
and rail track clearance dimensions (to allow for tunnels
and bridges through which items passed).
As
an example, even a transformer for Tumut 1 Power Station
weighing 81.2 tonnes, would be unloaded at the rail
head and transported by road to the site and unloaded.
Overhead travelling cranes were set up at the rail head
at Cooma, Cudgewa, and Tumut to unload onto the Authority's
ANTAR road transporter vehicles.
ANTAR
ANTAR refers to the name of a Persian
poet who was, apparently, renowned for
his Herculean feats of strength. The
vehicle was made in England. Its first
major deployment was in the Middle East
during the early 1950s, primarily to
transport oil pipes. It was named ANTAR
so that it would be recognised by the
Persian workers. In the SMA's version
it was redesigned to have the capability
of hauling 121.9tonne loads (162.6 tonne
tare weight of vehicle) from Cooma into
Tumut 1 PowerStation, and climb up the
steep mountain again fully loaded with
a 121.9 tonneload, which the road train
achieved (using two prime movers, pull-push)
while consuming fuel at the rate of
4.3 km per 10 litres of diesel fuel. |
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Cranes
A variety of large cranes, shovel loaders, and flying
foxes were used on dam and power station construction
sites. Two overhead cranes, which could be operated
independently or coupled in tandem, were installed in
the power station to move the transformers into place.
The cranes were designed to accommodate the maximum
weight of the equipment to be installed. In the case
of Tumut 1, each assembled generator rotor is in excess
of 203 tonnes. The rotor was delivered in component
pieces and assembled on site.
Lifting
beams
In order to handle such a weight, a lifting beam was
constructed. The beam is held between each of the two
crane hooks while the rotor is supported by a central
split ring, which fits in a recess in the shaft, and
secures the self-aligning attachment to the beam. This
allowed the heavy load to be lifted and very accurately
lowered into the generator stator.
Special
equipment
Throughout all power stations there are special facilities
for lifting power plant items such as turbine runners,
pumps, compressors, air receivers, and the like. Items
can be lifted, pulled or pushed and positioned accurately
without undue manual effort. In some cases, special
equipment is required such as when fitting a long 330kv
insulated porcelain bushing into a transformer located
outdoors. When such an item is inclined to the vertical,
the degree of handling difficulty is increased, but
innovative lifting gear has overcome such problems.
Erecting
towers
At the Upper Tumut Switching Station, the 330kv switchyard
consists of many lattice towers, beams and supporting
structures. When constructed, there were no mobile cranes
as we see available today. The whole of the switchyard
steelwork was erected using: pulleys, block and tackle,
steel wire ropes and winches on motor vehicles.
to
lift components high above the ground and to erect the
towers. Looking at the switchyard today, 40 years on,
one would find it difficult to imagine that expert rigging
practices and not cranes, were used to erect the steelwork.
Multiple
hydraulic jack system
Main transformers are large capacity items up to 101
tonnes each. These have to be unloaded on arrival using
the power station overhead crane to remove the load
from the road transporter, fitted out and then re-positioned
on wheels in the transformer bay. An innovative piece
of equipment used was a 508 tonnes German manufactured
MFD multiple hydraulic jack system. This enabled the
complete transformer to be jacked up and the direction
of the wheels changed to allow it to move into the transformer
bay. Such equipment is also used to right overturned
locomotives or train carriages, which have been derailed.
These
few examples indicate the degree of self reliance necessary
to construct major engineering work in remote mountain
areas where lifting devices are not readily available
from commercial sources. After the construction period
was finished (1974), further innovation has taken place,
including the use of air bags to lift and transport
loads.
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