G.T.R betterments, construction, etc.

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Mimico roundhouse, etc.—The roundhouse and machine stop recently built at Mimico, near Toronto, contains 30 stalls, each 13 ft. wide at the inner circle, and 26 ft. at the outer circle. Each stall is 82 ft. long, divided into three sections, and carried on four columns. The entire structure is built of concrete, reinforced with Kahn trussed bars. The interior columns are 14 in. square, and contain each four 1/2×1 1/2 in. trussed bar. The diagonals of these steel members are bent horizontal in order to obtain the effect of hooping. Angle guards were placed in all corners in order to prevent chipping. The columns in the outer circle are T shape, forming a pilaster on the outside, and at the same time supplying recesses for keeping the curtain walls between columns. The joints at these points allow for expansion and contraction. In designing the columns in the interior circle, it was feared that locomotives striking the outside doors would break the concrete columns which carried the doors. For this reason these columns were made of three channels filled with concrete, and anchored to same. This construction was decided upon, as it is contended that such a column would not break, but would merely shift off its foundation if struck by a locomotive. Doors were fastened directly to these channels. On the side not containing a channel, were placed 1/2×1 1/2 in. trussed bars as reinforced concrete girders were placed between columns at a height of about 20 ft. 5 in. from top at the outer circle, and 24 ft. 2 in. at the inner circle. Seven longitudinal rows of reinforced concrete beams were spanned between girders and columns. Both beams and girders were reinforced with Kahn trussed bars in the bottom, and over the supports they were invariably made continuous will inverted bars. Each beam contains in the bottom at least two bars full length and one bar about two-thirds the length at the bottom in the centre and raised at the ends. Between the beams and girders is spanned a 4 in. concrete slab, which is reinforced in both directions, and made continuous over the entire area. Especial attention was paid towards obtaining an absolute monolithic character in the entire structure, so that if an excessive load were placed upon any one portion the same would be distributed over the adjoined panels. Anchors carrying steam pipes and controlling individual smoke stacks over locomotives were placed in the concrete while the same was green. The machine shop roof is constructed similarly to the roundhouse, using a series of beams about 12 ft. o.c., spanned with a 4 in. concrete slab. These are also reinforced with Kahn trussed bars. The illustrations on this page show the method of construction.

Railways: G.T.Ry.

Stations: Mimico Yard