20 
The N.Z. Journal of Science and Technology. [Jan. 
consists of two rotary converters—one of 1,000 and one of 500 kilowatts 
capacity. They also have five boilers of 2,000 kilowatts capacity, and 
four steam-turbines of 2,500 kilowatts total capacity, which are maintained 
for emergency supply in case of accidental stoppage of the supply from 
Lake Coleridge. This steam plant is capable at short notice of carrying 
the whole tramway load and also feeding back 500 to 1,000 kilowatts to 
Addington distributing - station for the use of other essential consumers. 
The effect of the introduction of Lake Coleridge power has already been to 
reduce the cost of power for operating the tramways by over £2,000 per 
year, although the steam plant previously used was of a highly efficient 
type. < 
Freezing-works .-—-The next largest consumers consist of three large 
freezing-works, at Islington, Belfast, and Kaiapoi, out of four in the district, 
and the fourth will be supplied as soon as power is available. These are 
supplied by means of indoor static transformer-stations, of 300 and 600 
kilowatts capacity, from the southern and northern primary feeders at 
distances of six to fifteen miles from the main distributing-station. Their 
load consists mainly of large freezing-motors of 100 to 500 horse-power, 
running on a seasonal load from December to about July in each year, 
but running twenty-four hours per day during most of the killing season. 
They also have a general day motor-load of 100 to 200 kilowatts during the 
killing season, falling off very much during the slack season. 
The freezing industry thus leaves a slack period of four or five months 
from July to November, in which about 600 kilowatts will be available 
for the development of suitable industries, the operations of which can be 
adjusted to suit the slack season at the freezing-works. Obviously such 
industries should, if possible, be associated with the freezing industries, 
and should consist in the working-up of their by-products by electro¬ 
chemical methods, or of other electro - chemical processes for the manu¬ 
facture of essential chemicals and manure-ingredients required in developing 
the existing business of the freezing companies on broader lines. Owing to 
the fact that the industries are already paying for the power they use in 
the killing season, it will be possible to continue this supply throughout the 
year for such purposes at a very small increased charge. 
Flour-mills. —In addition to two flour-mills situated within the city 
boundary, there are now three mills outside the city supplied from the 
primary feeders. These are all the flour-mills within reach of the present 
mains. 
The price at which energy is available from Lake Coleridge has enabled 
the cost of milling-power to be reduced from about 4s. 6d. per ton to about 
2s. per ton. Moreover, the absolute uniformity of speed and rotating effort 
of the electric motor as compared with the steam or gas engine has made 
a great improvement in the operation of the milling-machines, and there is 
a strong demand for extension of the mains to other milling centres, 
including Rangiora, Oust, and Southbridge. 
Tanneries and Fellmongeries.- —Five out of eight tanneries and fell- 
mongeries in the district (apart from the freezing-works) are now supplied, 
and the other three will be connected up as soon as power is available. 
In these cases the ease of distributing the power economically in small 
units wherever it is most conveniently required, and the possibility of 
working overtime in the rush season without having to run large driving- 
engines, have proved great advantages. 
Dairies and Butter-factories.— All the dairies and butter-factories within 
reach of the mains are now supplied, in spite of the necessity of raising steam 
