The above rates will not include painting, or oiling, which should be charged at the rate of 0.10cts. per lb. for one coat, over and above the base price plus the extra specified above.

For plain punched beams where more than two sizes of holes are used, 0.15cts. per lb. should be added for each additional size of hole, for example, plain punched beams, where three sizes of holes occur would be indicated as: c +0.15cts., four sizes of holes; e +0.30cts. For example: 1 a beam within. and in. holes in the flanges and in. and in. holes in the web should be included in class e.

Cutting to length can be combined with any of the other rates, class d excepted, and would have to be indicated; for example: Plain punching one size of hole in either web and one flange, or web and both flanges, and cutting to length would be marked bf, which would establish a total charge of 0.40cts. per lb.

Note to class d.-No extra charge can be added to this class for punching various sizes of holes, or cutting to exact lengths; in other words; if a beam is coped or has connection angles riveted or bolted to it, it makes no difference how many sizes of holes are punched in this beam, the extra will always be the same, namely 0.35cts. When beams have angles or plates riveted to them, and same are not half length of the beam, figure the beams as class d, and the plates and angles as beam connections.

Note to class r.-This rate of 0.50cts. per lb. applies to all the material making up the riveted beam. In case of assembled girders in which one of the beams should be classed as a riveted beam, in making up the estimate, figure only the beam affected as included in class “r." When beams have angles or plates riveted to them and same are half length or more than half length of the beam, figure the beams as class "r," including the plates or angles and rivets. When 18 in., 20 in., or 24 in. beams are in "" class keep the I's separate from the material (plates, cast iron, separators, angles and rivets) which should go under heading, "15 in. I's and Under.'

Beams should be divided as 15 in. I's and under, and 18 in., 20 in. and 24 in. I's. If there are only one or two sizes of beams in any particular class, give exact sizes, instead of “15 in. I's and Under."

In estimating channel roof purlins classify 7 in. channels and smaller as one punched; 8 in. channels and larger as two punched, unless they are shown or noted otherwise, and keep separate from other beams.

No extra charge can be added to curved beams for riveting, cutting to length, etc. Subdividing work into a large number of classes should be avoided; it is better to have too few classes, rather than too many.

The only subdivision necessary for cast iron columns are: I in. and over, and under 1 in. Columns with ornamental work cast on must be kept separate.

In estimating the cost of plain material in a finished structure the shipping weight from the structural shop is wanted. The cost of material f. o. b. the shop must therefore include the cost of waste, paint material, and the freight from the mill to the shop. The waste is variable but as an average may be taken at 4 per cent. Paint material may be taken as two dollars per ton. The cost of plain material at the shop would be

To obtain the average cost of steel per pound multiply the pound price of each kind of material by the percentage that this kind of material is of the whole weight, the sum of the products will be the average pound price.

(c) COST OF SHOP LABOR.*-The cost of shop labor may be calculated for the different parts of the structure, or may be calculated for the structure as a whole. The following costs are based on an average charge of 40 cents per hour and include detailing and shop labor. The cost of fabricating beams, channels and angles which are simply punched or have connection angles loose or attached should be estimated on the basis of mill details, which see.

For cost of making shop details, see the author's "Structural Engineers' Handbook."

* With the present (1919) condition of the labor market the author thought it wise to reprint the costs of shop labor given in the author's "Structural Engineer's Handbook." These costs were based on conditions in 1913, and represented prewar conditions.

SHOP COSTS OF INDIVIDUAL PARTS OF BRIDGES.—The cost of fabricating joists and other similar members should be estimated on the basis of mill details, which see. (Based on prewar conditions in 1913 and a cost 40 cts. per hour which includes detailing and shop labor).

Eye-Bars.-The shop cost of eye-bars varies with the size and length of the bars and the number made alike. The following costs are a fair average: Average shop costs of bars 3 in. and less in width and in. and less in thickness is from 1.20 to 1.80 cts. per lb., depending upon the length and size. A good order of bars running 2 in. Xin. to 3 in. Xin., and from 16 to 20 ft. long, with few variations in size, will cost about 1.20 cts. per lb. Large bars in long lengths ordered in large quantities can be fabricated at from 0.55 to 0.75 cts. per lb. To get the total cost of eye-bars the cost of bar steel must be added to the shop cost. Half card extras given in Table IV should ordinarily be added to the base price of plain steel bars.

Chords, Posts and Towers.-In lots of at least four, the shop cost is about as follows: Members made of two channels and a top cover plate with lacing on the bottom side, or two channels laced on both sides cost about 1.00 to 0.85 cts. per lb. for pin-connected members weighing from 600 to 1,500 lb.; and about 0.80 to 0.70 cts. per lb. for members with riveted end connections. Members made of four angles laced cost from 0.80 to 1.10 cts. per lb. for members with riveted ends. Members made of two angles battened will cost about 0.50 cts. per lb. Angles used without end connections should have their cost estimated on the basis of mill details, which see.

Pins. The cost of chord pins will vary with the size, number and other requirements. The shop cost of chord pins and nuts may be estimated at from 2.00 to 3.00 cts. per lb. Rollers will cost practically the same as pins. Rolled rounds (pin rounds) are used for making pins and rollers.

Latticed Fence.-The shop cost of light simple latticed fence made of two 2 in. X 2 in. angles, with double lacing and about 18 in. deep, will be about 2.00 cts. per lb.; while the shop cost of latticed fence, with ornamental rosettes or ornamental plates, may be as much as 4.00 to 5.00 cts. per lb.

Floorbeams and Stringers.-Plate girders used for floorbeams and stringers will cost from 0.60 to 1.25 cts. per lb. depending upon the weight, details and number made at one time. Floorbeams made of rolled I-beams will cost from 0.50 to 0.75 cts. per lb.

SHOP COSTS OF BRIDGES AS A WHOLE.-The cost will be taken up under the head of pin-connected bridges, riveted bridges, plate girder bridges, combination bridge metal, and Howe truss metal. These shop costs represent prewar conditions in 1913, and were based on an average charge of 40 cents per hour and include detailing and shop labor.

Shop Costs of Pin-connected Bridges.-The shop costs of pin-connected highway or railway bridges, exclusive of fence and joists, are about as follows:

These costs include detailing and one coat of shop paint. For reaming add 0.15 cts. per lb. Shop Costs of Riveted Truss Bridges.-The shop costs of riveted truss highway or railway bridges, exclusive of fence and joists, are about as follows:

These costs include detailing and one coat of shop paint. For reaming add 0.15 cts. * Shop Costs of Plate Girder Bridges.-The shop costs of plate girder highway or bridges, exclusive of fence and joists, are about as follows:

These costs include detailing and one coat of shop paint. For reaming add 0.15 cts. * Shop Costs of Tubular Piers and Culverts.-The shop costs of steel tubular pier shel steel culvert pipe are about as follows:

The above shop costs include detailing and one coat of shop paint. The necessary to and rods for tubular piers are included.

Shop Cost of Combination Bridge Metal.-Where the bars and rods are standard a castings are made from standard patterns, the metal for combination bridges can be fabriz at about the same cost per pound as for pin-connected spans weighing the same as the we the metal in the combination bridges.

Shop Cost of Howe Truss Bridge Metal. The shop cost of highway bridge castings from standard patterns, is from 1.50 to 2.00 cts. per lb. The shop costs of the plates, rods other miscellaneous iron work will be from 2.00 to 2.50 cts. per lb.

COST OF ERECTION OF STEEL BRIDGES.*—The cost of erection ordinarily ind (1) the cost of hauling the bridge to the bridge site; (2) the building of the falsework a placing of the steel in position; (3) the riveting up of the bridge, and (4) painting the ste the woodwork.

Hauling. Transportation over country roads will ordinarily cost about 25 cts. per mile, in addition to the cost of loading and unloading. In estimating the cost of hauling œ particular job the length of haul, kind of roads, price of teams and labor, and the chara the teams should be considered. The cost of loading on the wagons and unloading will ** upon the local conditions, but will ordinarily be from 25 to 50 cts. per ton. For railroad br the steel work may ordinarily be brought directly to the site by rail.

*Based on prewar conditions in 1913.

Falsework. If piles are to be used the cost snould be carefully estimated. The cost of the piles in place will vary with the cost of piles and local conditions. Under ordinary conditions piles in falsework will cost from 25 to 50 cts. per lineal foot in place. The cost of the timber will depend upon local conditions and upon what use is made of it after erection. The flooring plank in highway bridges, and ties and guard timbers in railway bridges can often be used in the falsework without serious injury. The cost of erecting the timber in the falsework will ordinarily be from $6.00 to $8.00 per thousand ft. B. M.

Erection of Tubular Piers.-The cost of setting tubular piers for highway bridges will depend upon the conditions. Tubes 36 in. in diameter and 20 ft. long have been set in favorable locations for $25.00 per pair, not including the driving of the piles or the placing of the concrete. It is, however, not safe to estimate the cost of setting tubes from 36 to 48 in. in diameter under even favorable conditions at less than $2.00 per lineal foot of tube. When the cost of setting tubes is estimated by weight, it should be figured at from $15.00 to $20.00 per ton, for ordinary conditions. It will commonly cost from 25 to 50 cts. per lineal ft. to drive piles in tubes, in addition to the cost of the piles, which will vary from 10 to 20 cts. per lineal foot. The concrete will commonly cost from $6.00 to $8.00 per cu. yd. in place in the tube.

Placing and Bolting.-The cost of placing and bolting up riveted highway spans, and erecting pin-connected highway spans, no rivets being driven, is about as follows:

The cost of placing and bolting up railroad spans will depend so much upon the local conditions and equipment that it is difficult to give general costs.

The cost of driving field rivets in pin-connected spans will vary from 7 to 12 cts. per rivet, while the cost of driving field rivets in riveted trusses will vary from 6 to 10 cts. per rivet. The number of rivets in riveted low truss highway bridges depends upon the number of panels and the style of details, and will be about 155 to 200 for a three-panel bridge, and 400 to 500 for a six-panel bridge. The number or rivets in through riveted highway bridges will be about 250 to 300 for a four-panel bridge, and 1,300 to 1,500 for a nine-panel bridge. Pin-connected bridges ordinarily have about to as many field rivets as a riveted bridge of similar dimensions.

Transportation. Fabricated structural steel commonly takes a "fifth-class rate" when shipped in car load lots, and a "fourth-class rate" when shipped “local” (in less than car load lots). The minimum car load depends upon the railroad and varies from 20,000 to 30,000 lb. Tariff sheets giving railroad rates may be obtained from any railroad company. The shipping clerk should be provided with the clearances of all tunnels and bridges on different lines so that the car may be properly loaded.

Freight Rates.-The freight rates (1919) on finished steel products in car load shipments from the Pittsburgh District, including plates, structural shapes, merchant steel and iron bars, pipe fittings, plain and galvanized wire, nails, rivets, spikes and bolts (in kegs), black sheets (except planished), chain, etc., are as follows, in cts. per 100 lb. in carload shipments; Albany, 30; Buffalo, 17; Chicago, 27; Cincinnati, 23; Cleveland, 17; Denver, 99; Kansas City, 59; New Orleans, 38; New York, 27; Pacific Coast (all rail), 125; Philadelphia, 24}; St. Louis, 24; St. Paul, 494; Detroit, 33; Baltimore, 33. (Add 3 per cent transportation tax).

COST OF PAINTING.-The amount of materials required to make a gallon of paint and the surface of steel work covered by one gallon are given in Table V. Structural steel should be painted with one coat of linseed oil, linseed oil with lamp-black filler, or red lead paint at the shop; and two coats of first-class paint after erection. The two field coats should be of

different colors; care being used to see that first coat is thoroughly dry before applying the second coat. Steel bridges and exposed steel frame buildings ordinarily require repainting every three or four years.

The steel work in the extension to the 16th St. Viaduct, Denver, Colo., was painted with red lead paint mixed in the following proportions,-100 lb. red lead, 2 lb. lamp-black and 4.125 gallons of linseed oil. This mixture made 6 gallons of mixed paint of a chocolate color, and gave 1.455 gallons of paint for each gallon of oil.

Light structural work will average about 250 sq. ft., and heavy structural work about 150 sq. ft. of surface per net ton of metal, while No. 20 corrugated steel has 2,400 sq. ft. of surface.

It is the common practice to estimate gallon of paint for the first coat and gallon for the second coat per ton of structural steel, for average conditions.

A good painter should paint 1,200 to 1,500 sq. ft. of plate surface or corrugated steel or 300 to 500 sq. ft. of structural steel work in a day of 8 hours; the amount covered depending upon the amount of staging and the paint. A thick red lead paint mixed with 30 lb. of lead to the gallon of oil will take fully twice as long to apply as a graphite paint or linseed oil. The cost of applying paint is roughly equal to the cost of a good quality of paint, the cost per ton depending on the spreading qualities of the paint. This rule makes the cost of applying a red lead paint with 30 lb. of pigment per gallon of oil from two to three times the cost of applying a good graphite paint, per ton of structural steel. For additional data on paints, see Chapter XV.

Cost of Painting Steel Highway Bridges.*-The cost of painting two steel highway bridges in Iowa in 1918 by day labor was as follows. Bridges were 110 ft. span with timber joists. Labor, one man at 40ct. and one man at 35ct. per hour, $157.50. Twenty-five gallons blue paint, $53.75. Ten gallons white paint, $22.50. One and one-fourth gallons linseed oil, $2.25. Brushes, $8.18. Total cost $244.18. Cost per lineal foot of bridge, $1.11 for one coat.

Eight old highway bridges were painted by contract. The bridges were painted two coats. The county furnished the paint, paint brushes, and the contractor furnished all the work including the cleaning of the metal with wire brushes. The cost of painting four bridges having spans of 190 ft., 170 ft., 160 ft. and 140 ft., all on steel tubular piers was 85 ct. per lineal foot of bridge for labor. Wood guard rails and steel tubular piers were included in cost per lineal foot of span. Bridges on abutments cost for labor to paint two coats from 55 to 70 ct. per lineal foot.

Cost of Repainting Old Steel Highway Bridges.-The Iowa Highway Commission published the following data in its Service Bulletin in 1918.

One gallon good quality paint will cover 1,100 sq. ft. of steel surface or about 5 tons fabricated metal; I gal. of sublimed white or blue lead paint will cover 700 sq. ft. of steel surface, or 3.5 tons of fabricated metal. The cost of sand blasting to remove old paint is about $1.50 per ton of metal which includes a rental charge on equipment. Sand blasting equipment costs from $500 to $700.

Engineering and Contractor, Nov. 13, 1918.