The term "Drawing Revision" refers to modifications that are made to a drawing after it has been signed and issued. The first revision to a drawing takes place after the initial issue of the drawing is signed and released for bid or construction. "Drawing Revision" does not refer to changes made to a drawing prior to completion and signing.
File name extensions indicate the current drawing revision. The initial issue of a drawing has a file name extension of .r00. Subsequent drawing revisions have CAD file names of .r01, .r02, etc. The file name extension number shall match the actual drawing revision number.
Once a drawing has been signed, the corresponding CAD design file becomes a record document. As such, it should not be modified in any way. All reference files attached to that file are part of the document and they also can not be modified.
When a revision to a CAD drawing is required, the following procedures apply
Copy the CAD drawing file to the next Revision extension number. The actual file name remains the same, only the extension changes.
Determine which files are attached as reference files, and make sure that the most current revision of each reference file is attached. The revision number of each reference file will not necessarily match the revision number of the drawing.
The reference file attachments should be modified to reflect the new revision of all attached files.
If a master file is one of the drawing reference files, you will continue to work in the .MST file, but a record copy of that master file should be saved as part of the old drawing revision. The record copy of the master file will have the same name as the original, with the extension of .ms0, .ms1, .ms2, etc.
Type all previous signatures on the CAD file, as they appear on the original signed drawing. Use initials when the actual signature used initials. Use full names when the actual signature used full names.
Type the signature date of the previous revision on the CAD file. This may be the initial issue, or a revision.
Add the cell, MICFLM, from the Common cell library, to the drawing, as close to the signature and revision block as possible.
Bubble all drawing revisions to the drawing, using a WT=4, LC=0, LV=60 curve string, and the cell, REV., at each revision. The revision number is inserted in the data field of the cell.
Revisions to Manually Drafted Drawings
On occasion it is necessary to revise an existing manually drafted District drawing. When revisions are made to manually drafted drawings, the following guidelines shall apply.
On mylar or linen originals, black ink shall be used for all drafting.
On vellum originals, graphite pencil shall be used for all drafting.
Lettering shall be vertical block lettering, a minimum of 1/8” high.
Line weights and line styles shall match the line weights and styles on the existing drawing.
All drafting on drawings shall be dark and capable of reproduction by photo copy techniques.
Every revision to the drawing, whether it is an addition to the drawing or an erasure, shall be bubbled with a heavy line. The bubble should be placed on the back of the sheet for mylar drawings, and on the front of the sheet for vellum or linen drawings. The bubble should be broken when it crosses other line work or text.
Modifications to the drawings that were made to indicate as built conditions should not be bubbled as revisions.
A revision bullet symbol, with the revision number, shall be placed next to each bubble.
The revision block shall be filled in with the revision bullet and a description of the revision. The date shall be the date the revision is signed.
Generally, revision bubbles and bullets from previous revisions shall be removed. However, if the previous revision is still under construction, then the bubbles and bullets should remain on the drawing.