This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
Each piece must be detailed fully, with cuts, punchings, and framings clearly shown. In general, a standard size beam sheet, column sheet, and girder sheet are used; truss sheets are made to standard sizes as far as possible but on account of the different types and sizes of trusses, more variation is necessary.
Only one tier of beams is put on a single sheet even if of identical detail; also but one section of columns is covered by the same details. If the drawings are going into the mill, a further separation of the different sizes and shapes is necessary so that materials which have to be made in different mills shall not be detailed on the same sheet.
Standard Forms. The specific types of sheets and details will be taken up later.
There are standard forms of connections which cover all but special cases and which are used wherever practicable.
Figs. 146 to 148 show framed, coped, and bevelled beams.
There are certain conventional sizes and standards which should be known to those who have anything to do with working drawings.
A setting plan can be so jumbled and confused by careless arrangement of data, and by poor execution that it will take longer for the man on the job or in the shop to determine its intention than to work out independently what he wants to know. The draftsman should aim to put himself in the place of the shop foreman or erector, who, when he takes up the work, must rely entirely on this plan for all the information. He must aim to give all the necessary information and give it so plainly that it can be quickly seen and cannot be misinterpreted.
Wall lines are shown by red lines in order not to be confused with the beam lines. The walls shown are those upon which the beams rest. For instance, the setting plan of the first floor beams will have the basement walls shown and the second floor plan will have the first story walls shown. Columns are represented by a single line indicating the members composing the columns; this is illustrated by the columns shown in Plate I. It is important to indicate clearly the composing elements so as to show which way the web of the column sets.
Fig. 146. BEAM FRAMED BELOW TOP OF GIRDER.
Fig. 147. BEAM FRAMED FLUSH WITH TOP OF GIRDER AND COPED TO IT.
SPECIAL CONNECTION OF 2- I2 Is 40*.
TO PLATE AND ANGLE COLUMN Fig. 148.
Beams and girders are indicated by single lines corresponding to the center lines of webs of beams and backs of channels. All lines indicating the steel members should be heavy black lines. Beams framing into a girder or column are indicated by stopping the line of this beam a little short of the line of the girder or of the column. Where a beam runs over another, the lines indicating them cross or, if there is likely to be a question, a note is put on to this effect.
Measurement lines are put on in red, and should locate all bearing walls and all columns and each piece of steel. Beams are located by their center lines; measurements to a channel should go to the back. Channels placed against a masonry wall are generally put with their backs one-half inch away from the wall.
Tie rods are not located by dimensions on the plans except in special cases where a rod must come in a definite position to escape some other member.
The size of beams are marked along the line indicating the beam. In cases where there are a number of beams in the same bay of the same size, it is better to use the symbol " do " or write the size once and indicate on the drawing.
Each piece is given a number. The pieces maybe numbered consecutively or it is the practice in some cases to give the same number to all beams which are identical as regards size and detail. In all cases, the number or letter which serves to identify the piece should be put on conspicuously as this is what should be easily seen when using the plan.
The size of bearing plates should be specified either at the wall end of the beam or by a general note, giving the sizes of plates for different sizes of beams.
The general notes should also give the letter designating the floor as "A" for first floor, "B" for second floor, etc.
The grade of underside of all beams should be given in the body of the plan or by general notes and the relations of tops or bottoms of all beams to each other and to the finished floor line.
Sections should be made showing the framing over windows and of all special connections, and the relation of the different members to each other. In short, the setting plan must be a complete and final expression of all the data which has been gleaned from the general plans and specifications, and must be a guide to the shop man and the man at the job in fabricating, shipping, and putting the frames together.
Beams are generally marked thus: "A-No. 125," or " D-No. 56;" the lowest tier of beams being given the first letter in the alphabet, and so on in order, or First Floor No. 125, Fourth Floor No. 56, and so on.
Columns are generally marked "1st Section No. 10" or "3rd Section No. 5." Columns are sometimes made in only one story lengths but more often in two. They are sometimes marked thus: Col. No. 10 (0-2) or Col. No. 5 (4-6).
Hill or Shop Invoices. These are detailed schedules sent out by the mill when shipments are made. They give the designation of the piece with its weight and all connections and the mill marks, also the marks identifying it on the setting plan. These invoices are valuable as showing just what material has been shipped and in what car and on what date, and also serve to fix the weight when this is made the basis of payment. A form of invoice used by the mills of the Carnegie Steel Company is given by Fig. 149.
Estimating. In making an estimate of the cost of steel work, the basis is always the weight of steel of different kinds. This is determined by taking from the general or framing plans a detailed schedule of each piece of steel. As framing plans are always shown to a small scale and include only the general features of the framing, this work requires special training before it can be done accurately and in the most efficient manner.
In taking off quantities, the estimator generally scales the lengths as these are not usually given by figures. A test of measurements given by the general plans should be made when possible, to see how nearly to scale the drawings are made. A close estimate should not vary much more than 21/2 % or 3% from the actual weight, so it will be seen that considerable care is necessary.