ALTERNATING MOTORS FOR RAILWAY WORK. 185
All these facts point to the desirability of developing
polyphase work in the direction of fast interurban service
and heavy long distance work rather than toward ordinary
street railway equipment. In the former the polyphase
system is at its best, its many good features are thoroughly
available and its disadvantages are minimized.
Nevertheless the abolition of the commutator is so de-
sirable that therc is a strong tendency to work polyphase
apparatus for ordinary purposes, and it is noteworthy that
the first polyphase electric road to be put in operation be-
longs distinctively to the class of street railways. This
very important piece of pioneering work was carried out
a few months since by the famous firm of Brown, Boveri
& Company, at Lugano, Italy.
TLugano is a fine prosperous town situated on the lake
of the same name at the foot of the Italian Alps. A water-
fall a little more than seven miles away furnishes power
for lighting the town, and is now utilized for the railway
as well. 'The road runs for the most part along the lake
front on each side of the town. It has a totallength of al-
most exactly three miles, and its general situation is shown
on the sketch map (Fig. 100). There are only moderate
grades of about three per cent except for three short
pitches of six per cent. ;
At the power station is a 300 h. p., horizontal turbine
direct connected by a flexible coupling to a 150 k. w., three
phase generator. This machine is of the inductor station-
ary armature type generally advantageous for high volt-
ages and is wound to give directly 5000 volts between
lines at 40 ~. 'The exciter armature is carried directly on
the main shaft so that the generator is quite self contained.
Its speed is 600 r. p. m.
The line is of three wires each about No. 4 B. & S
gauge, and leads at present to a single transformer station
on the southern edge of the town not far from the middle
of the line. 'The three phase transformer here located re-
duces the voltage to 400 volts which is the working press-
ure between the conductors.
