How to Check Engineering Drawings? 8 Things to Know

How to check engineering drawings? Do detailed self-reviews, request third-party reviews, and build good review habits.

To better elaborate, I’m going to go over 8 techniques I use to check my engineering drawings. This will increase your design review efficiency, and help you sleep better at night. Especially, since your drawings may become a reference to your clients for decades to come.

#1 Self-review drawings

After you complete your design drawings, set them aside for a day or two before reviewing. This way, your original design decisions will not linger in your mind and affect you. I always find I can catch mistakes better this way.

Also, use the following tips in your review:

  • Check every drawing: don’t dismiss a drawing because it’s simple. Every drawing requires your attention.
  • Print drawings: use large-sized sheets. Somehow, mistakes better hide on computer screens.
  • Review environment: find a quiet area where you can focus without distractions.
  • Questions: write down any design elements you’re not 100% certain of.

With your name on the drawings, you need to put the greatest effort into the review. Don’t expect a stranger to do the heavy lifting for you. Especially, since you’re abiding by the engineering code of ethics.

I compare it to assembling a baby crib for your newborn. You’ll no doubt ensure you followed the crib assembly instructions perfectly. While triple checking all the screws are properly tightened.

#2 Yellow line drawings

In engineering, many design elements depend on one another. Elements in drawing #2 may somehow relate to elements in drawing #8. And through yellow lining, you cross-check these drawing elements together.

For example, in electrical drawings, you have a conduit schedule and site plan. These two drawings go hand in hand. The site plan shows tagged conduits routed from point A to point B. While the conduit schedule lists the same tagged conduits with added details.

So with a highlighter, you highlight conduit tags from the conduit schedule against the site plan. You’re cross-checking the conduit routing ‘from’ and ‘to’, and the conduit fill. To illustrate, below is a site plan and conduit schedule I’ve yellow-lined.

Site plan:

site plan yellow lining for review check

Conduit schedule:

conduit schedule yellow lining for review check

You can see if I mistakenly label a conduit on the site plan, the contractor will use the wrong conduit size and fill.

Important Note: place yourself in the shoes of the contractor or fabricator. Do your drawings include everything someone would need to implement your design? This exercise, allows you to properly check your drawings for what’s wrong and unclear. 

#3 Create a standard drawing review checklist

Every field of engineering will have the following review checklist markers in common:

  • Codes & standards
  • Calculations
  • Vendor cut-sheets
  • Formatting
  • Real-world application

Always be sure to check these elements in your drawings. We’ll go through each one by one, to highlight their importance.

Codes & standards

Find all codes and standards, which apply to your design. Then look for any violations.

Be sure to use the latest codes and standards in your review. You don’t want to review your drawings using a 1990s edition codebook.

To point out, only experience allows you to quickly check for compliance. Because it’s not practical to check designs against a 500-plus page codebook, by flipping pages.

Calculations

Double-check your calculations and units. Even the simple calculations. I can’t tell you how many times I’ve seen basic arithmetic and unit mistakes.

A simple mistake can propagate through an entire design. Then unbeknownst to all engineers, destroy the design down the line. This is why it’s important to properly review a design in progressive stages.

Product cut-sheets

Check all your specified products against the latest vendor cut sheets for compliance. You want to be 100% certain, you’re properly using a product.

For example, a cut sheet reads a product connects at 240 volts. But you show the product connected at 480 volts in your design. This is not only a code violation, but it’s a huge safety concern.

electric charger power specs in cut sheet

Equally important, you may have used the same product for several years. So you think you know the product’s specs like the back of your hand. But, the vendor updated the product a month previous and you weren’t aware. If you forgot to verify the cut sheet, you’ll have a huge error on your hands.

Formatting

Check the format of your drawings. No different than when you edit the format of a Microsoft Word document. The format checklist includes the following:

  • Line types: remain consistent with line types
  • View orientations: ensure section views are properly shown
  • Symbology: follow the industry standard
  • Appropriate border: use the correct drawing title block
  • Text: remain consistent with the project selected font size and type

Real-world check 

Do your designs cross over from paper to the real world?

Many times, a design looks great on paper, but it’s not buildable. So put on your construction or manufacturing hat, for this part of your review. This is where experience trumps classroom learning.

The following are checks to consider in your review:

  • Geometric accuracy
  • Buildability
  • Laws of physics

#4 Coordinate with other engineering trades

Most engineering projects have several trades working together. So you need to ensure your design conforms with others, through coordination.

If you’re the prime engineer, cross-check your design work with all your subs. I’ve seen one too many times, where one trade makes a change without informing others. In return, design busts ensue.

Important Note: for every project, request all the latest design information in an email. Then use this information for your design work. You’ll have record of the latest information to use.

#5 Request a review by another qualified engineer

engineering peer review

Have another qualified engineer in your team thoroughly review your drawings. I never recommend pushing out drawings without a second set of reviewing eyes.

And it doesn’t matter how long you’ve been an engineer, or how great you think you are. All humans make mistakes, including  10x engineers.

Just be sure, the other engineer is as or more qualified than you. Otherwise, you defeat the purpose of a peer review.

Helpful Tip: use colored pencils to mark up drawings in a review. Use yellow for correct items, blue for comments, and red for errors. Or, find a color scheme, which works for you and your team, and just follow it. 

#6 Create a global review process

Create an in-house process for reviewing drawings. Include a list of review checks every drawing set must go through, before going out the door.

This establishes structure for everyone to follow, for projects of all sizes. In return, you reduce design mistakes.

Management’s involvement in the review process

Make sure management is on board with the review process. This ensures everyone follows the review protocol for every project.

Even more, the review processes should only include qualified people. Because if everyone can make comments, then it’ll become a bloody chaotic mess. A design can be torn apart in countless ways, by too many unqualified commenters.

Important Note: if any design element remains in doubt, the designer must get the benefit of the doubt. Because in the end, the designer signs off on the drawings, receiving all the liability. 

#7 Learn what good drawings look like

I learned so much about what good drawings look like, by reviewing old designs. I’m talking about hand-drawn designs before the use of CAD. I find these older drawings are much more detailed than many drawings of today.

Not to say these older engineers didn’t make mistakes. Also, design standards have drastically changed since 40-plus years ago. But, the level of detail was greater compared to modern drawings.

As a result, the drawings are simple to review and easy to follow. You don’t want someone to look at your drawings, and curse you out because of their confusion.

#8 General tips on how to check engineering drawings

The following is a list of tips I’ve picked up over the years, which I find helpful:

  • Be consistent with the units you use – Metric versus English.
  • Before you review someone else’s design, form a preliminary design concept yourself. This way, you’re not unknowingly influenced, and in return overlook mistakes.
  • Check for number discrepancies throughout your documents. For example, listing Beam ‘A1′ as 10′ in one drawing and 20’ in another.
  • Fill out all the fields in your title block.
  • If your company uses an error-checking system, check what the most common errors are. Then learn from the errors.
  • Show all necessary equipment and product clearances.
  • List all important equipment and product dimensions.
  • Check all physical dimensions.
  • Cross reference other drawings as necessary, to create a cohesive drawing set.
  • On schematics, check for proper symbols, reference designators, and polarity markings.
  • Check spelling and grammar.
  • Review all drawing notes for accuracy. Many times, notes are incorrectly copied from one project to the next, due to laziness.

Conclusion

Learning how to check engineering drawings is a critical part of engineering. Every engineer needs to adopt best practice methods for reviewing drawings, in order to excel. Also, to ensure public safety!

What are your thoughts on how to check engineering drawings? What’s your favorite technique on how to best review drawings?

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