Attachment 2 - MSC Computer Aided Designed.pdf

PREPARATION OF

COMPUTER AIDED DESIGNED (CAD) DRAWINGS

FOR USNS SHIPS

DRAWN BY:

CHECKED BY:

APPROVED BY:

PROJECT ENGINEER

DATE

DEPARTMENT OF THE NAVY

MILITARY SEALIFT COMMAND

WASHINGTON D.C. 20398-5540

HD LOGISTICS ENGN & ANALYSIS

DIR. ENGN MGT SYSTEMS DIV

COPMUTER AIDED DESIGNED (CAD)

DRAWING STANDARD

DIR. TECHNICAL DIVISION

SIZE

A

CAGE CODE

94421

SWBS

DRAWING NO.

7080803

REV

-9 APPROVED FOR COMSC

SCALE: NONE STD PLAN SHT 1 OF 28

REVISION SHEET

REV REVISION DESCRIPTION APPROVED

A 1. Revised in entirety.

2. Revised drawing format.

3. Added references (a) through (p).

4. Updated drawing format requirements, Section 2.1.

5. Changed drawing text size for A and B size drawing, Table 2-2.

6. Changed CAD layer colors, Tables 2-3 and 2-4.

7. Added symbol requirement, Section 2.7.

8. Revised revision procedure, Section 3.10.

9. Revised Appendix D.

10. Numerous minor changes throughout.

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References:

(a) MIL-PRF-28000, Digital Representations for Communication of Product Data: IGES Application Subsets and IGES application Protocols

(b) ANSI Y14.1, Drawing Sheet Size and Format

(c) ASME Y14.100-2004, Engineering Drawing Practices

(d) ASME Y14.100, Appendix B, Non-Commercial Drawing Practices

(e) ASME Y14.100, Appendix C, Drawing Titles

(f) ASME Y14.100, Appendix D, Numbering, Coding and Identification

(g) ASME Y14.100, Appendix E, Markings on Engineering Drawings

(h) ASME Y14.24, Types and Applications Of Engineering Drawings

(i) ASME Y14.34, Associated Lists

(j) ASME Y14.35, Revision of Engineering Drawings and Associated Lists

(k) ASME Y14.38, Abbreviations and Acronyms

(l) S9086-RK-010-STM/CH505; Naval Ship’s Technical Manual, Chapter 505;

Piping Systems

(m) MIL-STD-25, Ship Structural Symbols For Use On Ship Drawings

(n) MSC Standard Drawing STD 803-7079667, Preparation of Selected Record Drawings (SRDs) for USNS Ships

(o) Naval Sea Systems Command’s Expanded Ship Work Breakdown Structure For All Ships and Ship/Combat Systems (TMINS S9040-AA-IDX-020/SWBS 5D)

(p) MSC Standard Drawing 803-7081122; Military Sealift Command General Technical Requirements (GTRs)

1. INTRODUCTION

This standard plan is intended to be used by all shipyards, design contractors, and MSC functional codes tasked with preparing, updating or reviewing Computer Aided Designed (CAD) drawings for USNS ships of the Military Sealift Command (MSC).

This plan establishes a baseline for drawing format, content and development procedures for CAD generated drawings.

2. GENERAL

2.1. Drawing Format

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CAD drawings shall be prepared using a vector format conforming to reference

(a) initial graphics exchange standard (IGES) compatible with AutoCAD© 2004.

All CAD drawings submitted as a final submission shall be in AutoCAD© 2004 .dwg file format.

Selected MSC Standard Drawings, schedules, material/equipment listings, and calculations may be developed and submitted in either Microsoft Excel 2003 or Microsoft Word 2003. Drawings developed and submitted in either Microsoft Excel 2003 or Microsoft Word 2003 shall be restricted to size A or B. All files of the drawing shall be in the same format.

2.2. Drawing Standards

The following standards supplement this Guide and should be considered the default for CAD drawing preparation for MSC:

References (b) through (k)

2.3. Standard Drawing Sizes

Drawing sizes shall be per reference (b). Drawings delivered to MSC shall be of sizes A, B or F. Size H may be used only where the requirements for complete decks to be shown without breaks and at specific scales, which makes the use of this size unavoidable. See Table 2-1 for standard sizes.

Table 2-1. Standard Drawing Sizes

SIZE WIDTH (INCHES) LENGTH (INCHES)

A (HORIZONTAL) 8.5 11.0

A (VERTICAL) 11.0 8.5

B 11.0 17.0

F 28.0 40.0

H 28.0 44.0 (MIN)/143.0 (MAX)

2.4. Color

The majority of MSC drawings are printed in black and white, the main exception being Fire Control Plans and Damage Control Display Plans. However, the use of color in a CAD drawing enhances both the CAD operator’s and end user’s ability to follow and understand the information contained on the CAD file. All colors assigned to a CAD file shall be done by Layer only. Use should be made of varied line widths and line types to indicate new items, existing items, and

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different systems on drawings. Wherever possible, line widths should be varied using Plines rather than pen widths to avoid problems with differing pen settings from user to user. Refer to Section 2.6 for specifics concerning MSC’s Layering Convention for CAD drawings.

2.5. Text Selection

The AutoCAD text font for MSC drawings shall be ROMANS for general text.

Text for size A or B drawings produced in Microsoft Word shall be Times New Roman. Text for size A or B drawings produced in Microsoft Excel shall be Times New Roman. Note that examples herein are for illustration purposes and may not conform to these requirements due to reproduction limitations. The text size on full size drawings shall be as specified in Table 2-2, MSC Standard Letter Heights.

Table 2-2. MSC Standard Letter Heights

USE

LETTER HEIGHTS,

INCHES

DRAWING SIZES

Size A drawings; Drawing Title MS Word 16 point font or AutoCAD 0.16 Size A

Size A drawings; Size, Cage Code, SWBS, Drawing Number, Revision in title block, and general text

MS Word 12 point font or AutoCAD 0.12

Size A

Size A drawings; text inside tables

MS Word 10 point font or AutoCAD 0.10

Size A

Drawing Title, Size, Cage Code, SWBS, Drawing Number, and Revision in title block

0.188

Ship Name and Number, Scale, Drawing Type, Sheet Numbers, Approval Signatures and Dates in title block

0.125

Section and Tabulation Letters 0.240 Zone Letters and Numericals in border

0.175

All larger than Size A

0.125 Up to and including

Size B Dimensions, Tolerances, Limits, Notes, Subtitles for Special Views, Tables, Revisions and Zone Letters for the body of the drawings

0.150 All larger than Size B

All other Characters 0.125 All larger than Size A

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2.6. Layering Convention

Layers, colors and line widths shall be used to separate entities in drawings both to make them easier to identify, and to make the future modification of drawings simpler. Subject geometry should be produced in full size in model space. Text, dimensioning, annotations, piece bubbles, part callouts, etc. shall be produced in the paper space layout. Specific requirements for layers and line type for all MSC drawings are shown in Table 2-3. Table 2-4 provides additional examples of layers which can be used during drawing development.

Table 2-3. Required CAD Layers

REQUIRED LAYERS

LAYER COLOR LINE TYPE DESCRIPTION

0 BLACK CONTINUOUS AutoCAD Default

FORMAT (Title Block and Border)

BLACK CONTINUOUS

Title blocks, Borders, Tables, References and Notes

TEXT BLACK CONTINUOUS

Reference Text, Titles, Drawing Numbers, Revision Text, Title Block Text

CENTERLINE YELLOW CENTER

Centerline of Ship, Middle

Line of Equipment

Table 2-4. Example CAD Layers

EXAMPLE CAD LAYERS

LAYER COLOR LINE TYPE DESCRIPTION

STRUCTURE or SHIP BLACK CONTINUOUS Structural elements of ship or the ship’s hull form (Bulkheads, Decks, etc.)

FURNITURE CYAN CONTINUOUS Furnishings & Outfitting

EQUIPMENT GREEN PHANTOM Pumps, Engines, etc.

NEW MAGENTA CONTINUOUS

New additions or modifications to the drawing.

Can be sub-layer to an existing layer. (i.e. New

Equipment or System Mods)

FLUID SYSTEMS

Per reference (l) , Table 505-7-1 within the practical limits of the CAD system.

VARIOUS

Each system to have separate line type and layer.

2.7. Symbols

Standard symbols and line types shall be used in all MSC drawings. Symbols and line types to be used in MSC drawings shall be per section 4.19 of reference (c) unless otherwise stated herein. All symbols used in MSC AutoCAD drawings during drawing development shall be inserted into the drawing as a block with a unique block name. Additional unique symbols may be added to drawings as circumstances demand. All symbols used in a drawing must be defined in the drawing, including standard symbols. See Section 3.11 for more information on symbols.

Symbols and line types to be used in ship’s structural drawings shall be per reference (m). Symbols for Fire Control Plans shall be as directed in reference (n).

2.8. Reproduction Scale Bars

Reproduction scale bars, depicted in Figure 2-1, shall be shown on every sheet of all scaled drawings to assist users working with reduced size/odd size prints.

Such bars are not to be added to non-scale drawings such as distributive system diagrams. A 10 ft. scale bar shall be added to arrangement drawings showing only one or two compartments; a 50 ft. scale bar shall be added to arrangement drawings showing a large portion of a deck, such as General Arrangement drawings.

Figure 2-1. Reproduction Scale Bars

2.9. Delivery Requirements

2.9.1. Ship Work Breakdown Structure (SWBS) and Drawing Numbers

SWBS (or Group) and drawing numbers shall be assigned to all MSC drawings.

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Ship Work Breakdown Structure (SWBS) numbers are three digit numbers used to identify a ship’s system or drawing type. All Contract Guidance drawings shall have 800 SWBS numbers. Refer to reference (n) for Selected Record Drawings SWBS numbers. A complete listing of SWBS numbers can be found in reference (o).

Drawing numbers are a seven digit number assigned to each drawing for identification purposes. Drawing numbers are assigned by the MSC Technical Library.

2.9.2. Electronic Files

All files delivered with an MSC assigned drawing number shall be in a single software format. For example, if a drawing is in AutoCAD then all sheets will be in the AutoCAD format with a “.DWG” file suffix. If the file is in EXCEL then all sheets including the cover sheet and revision sheets will be in the Excel format with “.XLS” file suffix.

Drawings can be submitted on CD-ROM. Each drawing shall be stored in a directory named with the seven digit drawing number. The file shall include all sheets of the drawing and named with the seven digit MSC drawing number and Rev. For example, MSC Drawing No. 7654321 Rev B consisting of sheets 1, 2, 2A, 3,… and 115 would be stored and named as follows:

Directory: C:/7654321

With file: 7654321_B or if sheets are separate files: 7654321_B_001 ( Rev. B Sheet 1)

All AutoCAD drawings delivered to MSC shall use only AutoCAD standard menus, line types and fonts as supported by a standard AutoCAD installation.

Custom menus, unique line types, etc., must be replaced before delivery. All drawings made using AutoCAD’s XREF feature must have all the XREF’s bound into the drawing prior to delivery.

3. DRAWING ELEMENTS

3.1. Format

Locations are assigned for the following standard drawings elements:

Title Blocks Signature Blocks Drawing Border and Zone Markings

Regulatory Body Approval Block References Reservations Security Notes General Notes Applicable Ships Revisions List of Symbols List of Abbreviations Key Plan/Elevation

Each of the above listed elements is discussed in the following subsections of this Guide. The arrangement of the elements on the drawing shall be as shown in Appendixes A, B, C and D. All documents assigned a MSC drawing number shall utilize this standard format.

AutoCAD block files for the above listed drawing elements are available upon request.

3.2. Title and Signature Blocks

The format for the Title Block, MSC Signature Block, and Contractor Signature Block is shown in Figure 3-1. Areas shown as APPVD1, TITLE1, DRAWING, REV, etc., in Figure 3-1 are to be added using AutoCAD attributes to aid in modifying the drawing by MSC.

Figure 3-1. Title and Signature Blocks Template

3.2.3. Title Block

3.2.3.1. Drawing Title

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The drawing title is a short description of the drawing’s contents. For example, “General Arrangements and Profiles” would show the general arrangement and outboard/inboard profiles of a particular ship. If further explanation is required, a sub-title can be added to the drawing title; for example, “General Arrangements and Profiles – Arrangement of Main Deck”.

The drawing title shall be located in the spaces indicated by “Title1, Title2, and Title3” in Figure 3-1. Drawing title text height shall be in accordance with Table 2-2. Drawing titles must be approved by the MSC Technical Point of Contact (TPOC) or Project Engineer.

3.2.3.2. Ship

The ship name and number or ship class shall be provided just above the drawing title as shown in Figure 3-1. Examples are USNS COMFORT (T-AH 20)” or “T-AH 19 CLASS”. Text height shall be in accordance with Table 2-2.

3.2.3.3. Drawing Size

Indicate the drawing size of the drawing in the space marked “Size” in Figure 3-1. The drawing’s size shall be indicated by a capital letter specifying the standard drawing size. Text height shall be in accordance with Table 2-2. For example, a standard size F drawing would be indicated by a capital “F”. See section 2.3 on drawing sizes.

3.2.3.4. Cage Code

The five digit Commercial and Government Entity (CAGE) Code for MSC is “94421”. This shall be provided in the appropriate box of the title block. Text height shall be in accordance with Table 2-2.

3.2.3.5. SWBS Number

The three digit SWBS number shall be provided in this section of the title block. See section 2.9.1 for more information on SWBS numbers.

Text height shall be in accordance with Table 2-2.

3.2.3.6. Drawing Number

The seven digit MSC Drawing number shall be provided in this section of the title block. See Section 2.9.1 for more information on drawing numbers. Text height shall be in accordance with Table 2-2.

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3.2.3.7. Revision

The “REV” box shall show the identifying revision letter of the current page. The revision letter shall be shown by a capital letter and text height shall be in accordance with Table 2-2. See Section 3.10 for more information on Revisions.

3.2.3.8. Scale

The drawing’s scale shall be indentified in this location. If the drawing is not drawn to scale, the word “None” should be provided. Text height shall be in accordance with Table 2-2.

3.2.3.9. Drawing Type

The type of drawing shall be identified in this location. Text height shall be in accordance with table 2-2. For example a contract guidance drawing would have “Contract Guidance” listed under the SWBS number.

Standard drawing types are listed below. These drawing types are defined in MSC’s General Technical Requirements (GTR) No. 5 (reference (p)) and in reference (h).

Contract Guidance Drawings. Drawings which are for guidance only and are normally referenced in shipyard work packages. These drawings disclose basic technical information and performance requirements necessary for a contractor to complete the required detail design and produce required working drawings. These drawing can be created by MSC, Design firms, or the shipyard depending on the work item.

Working Drawings. Drawings prepared by MSC, shipyards, or design agents in order to accomplish the work tasked by the Work Package. The working drawings are the final design drawings and should receive, when necessary, the regulatory body approval. If contract guidance drawings were developed, the Working drawing should have the same MSC drawing number as the Contract Guidance drawing. The drawing should be a later revision if changes were made on the Contract Guidance Drawing.

As-Built Drawings. Drawings which are normally the final version of the working drawings reflecting the condition of all areas covered by the Work Package at the time of ship re-delivery. The As-Built Drawing will be issued a new, ship specific, MSC drawing number. Should changes be needed to

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the working drawings in order to improve future ship installations, the information should be captured by revising the working drawings.

Selected record Drawings. Selected record Drawings (SRD’s) show the general arrangement and important features and systems for individual ships. SRD’s provide Masters, Administrative Commanders, and Contract operators of MSC Force ships an accurate description of the ship as presently configured for operation. SRD’s are maintained and updated during the life of the ship. For further information on SRD’s, see reference (n).

3.2.3.10. Sheet Numbers

The sheet number is shown in the lower right corner of the title block.

The first sheet is numbered “Sheet 1” or Sheet 1 of X,” where X is the total number of sheets contained in a multiple sheet drawing. The following sheets shall show “Sheet Y of X,” where Y is the specific sheet number. Text height for sheet numbers shall be in accordance with Table 2-2.

3.2.4. MSC Signature Block

Once final MSC approval has been obtained, MSC approval signatures, titles and dates shall be entered into the drawing files as indicated below. Approval names, titles and dates shall be typed, with text height in accordance with Table 2-2, in the following manner:

Approval Name: First initial and full last name; for example: J.

Smith.

Title: Approving person’s title; for example: “Project

Engineer.”

Date: Entered as MM/DD/YY; for example: 02/24/09

3.3.1.1. Drawn By

Enter the initials of the person who developed the drawing. If the drawing is developed by a contractor, place “N/A” in this block and the contractor’s signature block discussed in section 3.2.5 will apply.

3.3.1.2. Checked By

Enter the initials of the person who checked the drawing. If the drawing is developed by a contractor, place “N/A” in this block and the contractor’s signature block discussed in section 3.2.5 will apply.

3.3.1.3. Approved By

Enter the Names and Title of the approving personnel. The actual date of signature shall be entered for the approved date.

3.3.1.4. Approved By COMSC

Enter the Name and Title of the person signing for COMSC Approval.

The actual date of signature shall be entered for the approved date.

3.2.5. Contractor Signature Block

Contractors developed drawings, with the exception of A size drawings, shall have a contractor signature block adjacent to the MSC signature block. The format of the contractor signature block is up to the contractor. However, the contractor’s name, address, the names of contractor personnel drawing and approving the drawing, and appropriate approval dates shall be provided.

3.2.6. Continuation Sheet Title Block

On multiple sheet drawings, the continuation sheet title block is used on all following sheets (see Figure 3-2).

Figure 3-2. Continuation Sheet Title Block Template

3.2.6.1. Drawing Title

The first line of the title on the continuation sheet title block shall match the main title of the drawing (first line of sheet one). The second line can be a sub-title explaining the contents of the sheet. For example:

“General Arrangements and Profiles – Arrangement of 01 & 02 Decks.”

3.2.6.2. Sheet Numbers

The sheet number is shown in the lower right corner of the title block.

Continuation sheets shall be numbered in the following format: “Sheet

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Y of X” where Y is the specific sheet number and X is the total number of sheets contained in a multiple sheet drawing.

3.2.7. Vertical Border Drawing Number Block

On all MSC drawings a vertical border drawing number block shall be provided in the right hand side border of the drawing. See Figure 3-3 for format.

Figure 3-3. Vertical Border Drawing Number Block

3.3. Drawing Border and Zone Markings

All drawings shall have horizontal zones numbered from right to left starting at 1 on the first sheet and running continuously throughout the drawing. Letters shall be used for the vertical zone designations starting with A at the bottom of each sheet. Zones on continuation sheets shall be sequentially numbered. For example, the second sheet of an F size drawing will start with zone 9-A in the bottom right corner, sheet 3 will start with zone 17-A.

3.4. Regulatory Body Approval Block

If the drawing is submitted to a regulatory body for review and approval, an approval block must be included on the first sheet. The regulatory body approval block template is shown in Figure 3-4. Text height shall be in accordance with table 2-2.

Submitted To – Name or abbreviation of the regulatory body the drawing was submitted to.

Submit Date – Date of submittal letter to the regulatory body soliciting their review and approval.

Re-submit Date – Date of the re-submittal letter to the regulatory body, if the first submittal of the drawing is not approved.

Approval Date – Date stamped on the approved drawing.

Approval Number – Approval number or reference number.

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Figure 3-4. Regulatory Body Approval Block Template

3.5. References

The reference block template is shown in Figure 3-4. Each drawing reference must be referred to in the field of the drawing, or in a drawing note or general note, for example, “For location, see Ref. 1.” Drawing references are often ship drawings depicting existing structure, systems, etc. which are being tied into by the subject installation or modification. When referencing a drawing, do not identify the drawing revision when writing out the reference, for example do not write “Rev. A”. This is to avoid having to check and update all the drawing references if drawing revisions are later made. Text height shall be 0.125 inch.

Figure 3-5. Reference Block Template

3.6. Reservations

The reservation block template is shown in Figure 3-6. A reservation is used to identify items on the drawing that need to be verified on a future shipcheck or are awaiting vendor information or approval by MSC. The reservation description must be terse. All reservations shall be cleared before final submittal of the drawing. Text height shall be 0.125 inch. Examples are “Verify Information” or “Waiting for Vendor Information.” A cloud containing the Reservation Number shall be used to identify where each reservation applies in the body of the drawing.

An example is shown in Figure 3-7. Final drawing should not be submitted with any reservations.

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Figure 3-6. Reservation Block Template

Figure 3-7. Example of Drawing Reservation

3.7. Security Notes

Space shall be provided in each drawing for any required security notes. Drawing classification, security notations, distribution statements, federal statute and group marking, and safety notes shall be addressed as applicable. The MSC TPOC shall determine if security notes are required and shall provide same. Text height shall be 0.125 inch.

3.8. General Notes

Each drawing shall include general notes which provide pertinent information.

The template for the general notes block is shown in Figure 3-8. Specific notes may be required for certain types of drawings. For example, all contract guidance drawings include the notes stating the drawing is for guidance only and are part of a work specification; all fluid system drawings include the note, “All dimensions are in inches. All sizes are nominal pipe size (NPS).” Drawing notes which are tasking statements are not permitted. General notes which are broadly applicable to the drawing need not be referenced in the body of the drawing; these notes

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apply to the entire drawing. However, specific notes applicable to drawing details must be referred to in the body of the drawing at the locations to which they apply.

Text height shall be 0.125 inch.

Figure 3-8. General Notes Block Template

3.9. Applicable Ships

Each drawing shall include an Applicable Ships table listing the ships covered by the drawing. The template for the Applicable Ships block is shown in Figure 3-9.

The Ship’s Name, Hull Number and Design Class shall be provided in the table.

Text height shall be 0.125 inch. For examples, USNS SATURN, T-AFS 10, T- AFS Class.

Figure 3-9. Applicable Ships Block Template

3.10. Revisions

Initial drawings are issued as “Rev. –“, this is the version which is signed and approved by MSC. Subsequent drawing revisions follow the A, B, C, etc.

lettering system. The drawing developer is permitted to make changes on his own during development of the preliminary drawing (see below). After the drawing is signed and approved, configuration control is strict and changes may only be made with MSC TPOC authorization.

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Working preliminary drawing revisions that are not yet approved shall use sequential numbers to denote working revisions. Working revisions shall follow the 1, 2, 3, etc. numbering system. After initial issuance of a drawing, working revisions shall follow the 1, 2, 3, etc. numbering system in conjunction with the current revision letter, e.g. -1, -2, -3, if the working modifications are to revision “-” of a given drawing or B1, B2, B3 if the working modifications are to revision “B” of a given drawing, etc. Once the drawing or revision development and review is complete, and the final product is approved by the MSC TPOC the drawing revision shall be issued by the MSC TPOC with the next subsequent letter revision notation.

The drawing revisions block template is shown in Figure 3-10. The following is a brief outline of procedures for incorporating drawing revisions.

Revisions shall be made, within AutoCAD, by deletion, crossing-out, addition of information, or by redrawing. When the crossing-out method is used, a series of 45 degree parallel lines shall be drawn through the item being deleted. The superseding data, if any, or reference to its location, shall be placed near the area crossed-out and shall be indicated by a revision letter contained within a triangle.

A drawing revision may include multiple changes. If this is the case, each change shall be numbered to permit ready identification. These numbers shall be entered in the “description” column along with a brief description of each change per reference (c). All zones affected by each numbered change shall be noted in the “zone” column. Also, the revision letter and change number shall be indicated in the body of the drawing adjacent to each change location using a triangle with the revision letter inside and the change number noted as a superscript outside the triangle. An example of a revision triangle is shown in Figure 3-11.

The change shall be briefly described in the form of “added…”, “deleted…”, “modified…”, “changed…”, “increased…” etc. Each entry shall provide sufficient information for a drawing reviewer or user to understand what was changed.

When a drawing revision has been completed and approved by the MSC

TPOC, the approval date is entered into the “date” column and the TPOC’s initials are added to the “appvd” column.

Figure 3-10. Revisions Block Template

Figure 3-11. Revision Triangle Template

The revision status block template is shown in Figure 3-12. This block is used to note the current revision statues of each drawing sheet. Only modified sheets of the drawing have their revision status changed, not all sheets. Thus if Sheets 4 and 5 of a 10-Sheet “Rev. –“ drawing are modified, only these sheets and Sheet 1 become “Rev. A” while the other sheets remain “Rev. –“. Note the revision status of Sheet 1 changes, even if the only changes were made to other sheets. The Sheet 1 statues automatically changes because is contains the revision block and the revision status clock, both of which are modified to reflect the changes to the other sheets. In certain instances, the MSC TPOC may authorize the changing of all sheets to the latest revision vice just the revised sheets. In this instance, the revision note shall be annotated to state that “All sheets have been changed to the latest revision letter”.

Refer to reference (c) when adding, replacing or deleting a sheet of an existing drawing. (NOTE: An existing sheet is never deleted, only superseded or replaced.)

Figure 3-12. Revision Status Block Template

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3.11. Symbols and Abbreviations

The standard symbols to be used in MSC drawings are addressed in Section 2.7.

Additional unique symbols may be added to drawings as circumstances demand.

Each drawing shall list all symbols and abbreviations used in the drawing, even MSC standard symbols and those abbreviations which appear in reference (k).

Do not include any symbols or abbreviations in the lists which do not appear in the drawing. The List of Symbols template is shown in Figure 3-13. An example of a List of Abbreviations is shown in Figure 3-14.

Figure 3-13. List of Symbols Template

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Figure 3-14. Example of List of Abbreviation

3.12. Key Plan/Elevation

Where necessary for clarity, a key plan or key elevation shall be provided on a complex drawing to illustrate the area on the ship affected by the drawing. One or more adjacent spaces in all directions surrounding the affected area may also be shown. The key plan scale shall normally be 1/8 inch or 1/16 inch equals one (1) foot. The area on the ship affected by the drawing shall be shown in a phantom line. Section lines in key plans shall be shown with bold poly lines and labeled following standard drawing practiced. The ship’s centerline, baseline and other reference lines shall be shown in addition to all accesses to compartments and compartment names and numbers. The key plan or key elevation shall be oriented in the same direction as other views shown on the drawing to the extent practicable. Since the purpose of a key plan or elevation is to orient the drawing user, it is not intended to be scaled. Thus, the scale of the key plan/elevation shall not be noted nor shall a reproduction scale bar be added to the key plan/elevation.

Examples of a key plan and a key elevation are shown in Figures 3-15 and 3-16, respectively.

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Figure 3-15. Example of Key Plan

Figure 3-16. Example of Key Elevation

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Appendix A – Drawing Layout for F and H Size Drawings

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Appendix B – Drawing Layout for B Size Drawings

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Appendix C – Drawing Layout for A Size Drawings (Horizontal Orientation)

Appendix D – Drawing Layout for A Size Drawings (Vertical Orientation)

PREPARATION OF

COMPUTER AIDED DESIGNED (CAD) DRAWINGS

FOR USNS SHIPS

DRAWN BY:

CHECKED BY:

PROJECT ENGINEER

DEPARTMENT OF THE NAVY

WASHINGTON D.C. 20398-5540

HD LOGISTICS ENGN & ANALYSIS

DIR. ENGN MGT SYSTEMS DIV

COPMUTER AIDED DESIGNED (CAD)

DRAWING STANDARD

DIR. TECHNICAL DIVISION

SIZE

A

CAGE CODE

94421

SWBS

DRAWING NO.

XXXXXXX

REV

A APPROVED FOR COMSC

SCALE: NONE STD PLAN SHT 1 OF 25

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REVISION SHEET

REV REVISION DESCRIPTION APPROVED

A 1. Revised drawing format.

2. Added references (a) through (u).

3. Updated drawing format requirements.

4. Changed drawing text size for A and B size drawing, Table 2-2.

5. Changed CAD layer colors, Tables 2-3 and 2-4.

6. Added Trim and Stability Booklet to SRD list, Table 1 and page 9.

7. Added Fire Symbol requirement, page 13.

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Appendix D – Drawing Layout for A Size Drawings (Vertical Orientation) (Alternate)

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