Discussion on “alternating-current systems of underground distribution” (Lisberger and Wilson), and “an underground system and a few developments” (Clark), Portland, Ore., April 18, 1912 (see proceedings for April, 1912)

H. R. Wakeman: Messrs. Lisberger and Wilson have given us a very interesting and instructive paper on alternating current underground distribution. In connection with this paper I will ask Mr. Lisberger one or two questions. I understand that some of the alternating current feeders in the system described in the paper are not only underground feeders but also feed certain overhead districts adjacent to the underground district, and I would like to inquire whether or not this has presented any particular problems. Has it been found necessary to provide any protective apparatus either in the stations or at the junctions of the underground cables with the overhead system to take care of any heavy surges, such as are caused by severe short circuits?