Within the past few years quite a number of churches have been roofed with steel trusses, and a few have been built with steel supports extending to the foundation.

Figs. 187, 188 and 189* show, in part, the steel construction of St. Jerome's Roman Catholic Church, New York, Messrs. Dehli & Howard, architects, Mr. Bernt Berger, structural engineer. This church is a brick and stone building 98x150 ft. with steel columns, framework and roof. "The nave, which is 36 ft. wide and 120 ft. long, terminates in an apse and has a vaulted ceiling 60 ft. above the floor.

On each side of the nave there is a 20-ft. aisle with side walls about 32 ft. high and nearly flat roofs, with a gallery floor 22 feet above the main floor. About 76 feet from the front wall of the church is the axis of the transept, which is about 39 ft. wide and has a vaulted ceiling corresponding to that in the nave, and a low dome on pendentives, over the intersection.

The clerestory walls, about 25 feet above the aisle roof, are supported on double longitudinal I-beam girders attached to the main columns, and the walls of the tower above the first story are also supported by the steel framework. The main roof has six riveted trusses of the quadrangular type spanning the nave roof and four spanning the transept. The trusses are all similar to that shown by *From the "Engineering Record" of Dec. 14, 1901.

Fig. 187 - Steel Frame, Roman Catholic Church.

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Fig. 188 and are of ordinary riveted construction, with T-shaped members made of pairs of angles riveted together, back to back, on both sides of 3/8" gusset connection plates at panel points. The vertical member in the centre of the truss is made double to allow central connections for the ridge purlin and the middle longitudinal ceiling girder. The trusses are connected longitudinally by three lines of I-beam purlins and two lines of eaves girders, which latter are made of a channel and angle riveted together. The purlins support 5-inch channel jack rafters, about 4 ft. apart, which in some parts of the roof are arranged so that alternate ones are in the same vertical planes with the ceiling rafters which are spaced about 8 ft. apart. Where the ceiling rafter and jack rafter are in the same plane they are braced together by horizontal and vertical field riveted angles at the eaves (Fig. 189). The ceiling rafters have gusset plates and angle clips connecting them to the longitudinal beams which are riveted to the vertical members in the main roof trusses (see Fig. 189). There is no diagonal bracing and no X-bracing in the roof panels, but the columns are knee-braced with pairs of 4x3-inch angles to the gallery floor girders.

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Fig. 188.

The pitched roofs are covered with slate laid on 2x1 1/2x1/4-inch angles riveted to the top flanges of the rafters, roof trusses and jack rafters.

Wooden furring strips are bolted to the lower chord flanges of the roof trusses, to the ceiling rafters and to the column brackets, to carry the lathing for the vaulted ceilings. The total weight of structural steel in the building is about 370 tons." [For a more complete description of the steel framework of this building see the Engineering Record of Dec. 14, 1901.] crown, 7 1/2 ft. deep at the eaves and 2 1/2 ft. deep midway between these points. The lower chords support the furring and metal lath for the plaster ceiling which forms a Gothic vault and conceals the trusses. All the trusses are alike except one end truss which supports part of the transept roof, and is a little heavier than the others, the dimensions given in Fig. 190 being for this truss, the chord angles of the other trusses being 1/16-inch thinner. This truss carries on one side the ends of the longitudinal lattice girders, E, E, which are 31 1/2 ft. long, and have two 6x3 1/2x7/16-inch angles in each flange. These girders support the ends of a special arch truss corresponding with the top of the main trusses and located on the centre line of the transepts; they also support the ridge and valley rafters of the transept roof which intersects the main roof like a dormer. Between the other trusses a 12-inch channel purlin is used in place of the girder at E. The feet of the trusses are tied together across the building by the floor beams, shown in the figure. Beneath these beams is a finished basement.

80. Fig. 190* shows one of four arched trusses which support the roof, and ceiling of the Roman Catholic Church at Tremont, New York City. These trusses were also designed by Mr. Berger for the architect, Mr. John E. Kerby. The principal dimensions of the trusses, which are spaced 16 ft. 4 ins. from centre to centre, are given in the illustration. The trusses are about 7 ft. deep.

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Fig. 189.

*This cut and the accompanying description is taken by permission from the "Engi-neering Record" of Oct. 10, 1901.

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Fig. 190.

Below the eaves, the trusses depend upon the outside wall for longitudinal bracing. Chases 12 ins. wide and 10 ins. deep were left in the masonry to receive the trusses, and were filled solid with concrete after the trusses were set. Above the eaves, the trussss are united longitudinally by purlins 10 ft. apart. At the peak an 1 at the eaves these trusses are lattice girders with horizontal top chords and curved bottom chords. The intermediate purlins are 12-inch channels riveted to web angles of the trusses in planes normal to the top chords. The purlins support four 3x3x1/4-inch Z-bar jack rafters in each panel between roof trusses. The top flanges of the jack rafters are in the planes of the flanges of the top chords of the arch trusses and the bottom flanges rest on top of the purlins. The jack rafters are riveted to the purlins by means of connection angles.

This roof was proportioned for a dead load of 60 lbs. (the covering being slate) and a live load of 50 lbs. per square foot, and to resist a horizontal wind pressure of 30 lbs. per square foot. The main arch trusses were received from the bridge shop in four sections each, with field splices at the peak and eaves. The vertical end sections were set up in place in the wall chases by boom derricks and lashed to the heavy stone walls. The middle sections were simultaneously raised in pairs by two gin poles which supported them until the splice joints were made and the purlins and longitudinal girders were connected to them.