Chicago World's Fair Pluto insulator

[Trade Journal]

Publication: Western Electrician

Chicago, IL, United States
vol. 10, no. 14, p. 201-202, col. 1-3,1-3

Electricity at the World's Fair.

Interesting electrical features of the present stage of construction work at the World 's Fair grounds are shown in the illustrations presented on this and the succeeding page. Figs. 1 and 2 give an excellent idea of the work done on the electrical subways which are to contain the conductors for power and light. The former shows a view taken from a point just north of machinery hall looking north. It shows the big double conduit leading from the generating station in the machinery building as it appears in process of construction. Directly ahead is the electricity building, while a corner of the administration building is shown at the left. The latter will undoubtedly be the most handsome and imposing of all the buildings when completed. The picture shows the appearance of the staff covering. In Fig. 2 is given an interior view of the long stretch of single conduit extending north and south along the western side of the great manufactures building. The top had not been boarded over at the time the photograph was taken, and the lights and shadows on the side of the subway are plainly marked. About 3,000 feet of subway have so far been laid. An article on the "Electrical Subways for the World's Fair," with map and diagrams, was published in the WESTERN ELECTRICIAN of November 28, 1891. In view of the advanced stage of the work it is permissible to reproduce the following paragraph:

The greater portion of the conduit will be exactly eight feet and four inches square. The outer material will be two-inch tarred plank laid on stringers one foot apart, These stringers will be eight inches wide and they will support the inner skin of the conduit, which will be an inch thickness of cement plaster laid on metal lathing. The larger tunnels will be six feet six inches wide inside, and the smaller size four feet three inches. All will be six feet six inches high in the clear, so that a man may walk through without difficulty. In the larger conduits there will be a passageway in the center, with a row of cross-arms on either side, while in the smaller ones there will be but one row of cross-arms, with a side passageway. Man-holes will be provided at convenient distances. The cross-arms will be supported on iron castings especially designed for the purpose, which will be placed twenty feet apart, and bolted to the stringers. Glass insulators of a size sufficient to accommodate the largest cables will be used on the cross-arms. All wires must be covered with water-proof insulation. The conduits will be laid, on an average, eighteen inches below the surface of the ground, and will at all times be above the level of the lake. The interior will have the appearance of a concrete tunnel, and there will be ample room for all the wires necessary.


Fig. 1 Electricity at the World's Fair.


Fig. 3 is a reproduction of a photograph taken on the floor of the electricity building last week. It shows the springing point of the great iron arches that support the roof. The iron work of the building is now practically completed. The frame work for all the towers up to the main entrance line is now finished. About one-third of the gallery floor has been laid and the roof boarding completed over all the gallery trusses. Within a few days the staff men will be at work covering up the exterior frame work of the building with their white composition. For a month they have been at work in a temporary factory on the flooring of the great building, under the direction of Peter Taparelli, an intelligent Italian. A large stock of moulded material has already been accumulated, and the work will be finished in two or three months.

The trouble over the bids for the arc lights at the World's Fair has been settled by