Embedded Components from Concept-To-Manufacturing
Copper Foil Elements Affecting Transmission Loss with High Speed Circuits
pH neutral Cleaning Agents - Market Expectation & Field Performance
Reducing Dust Deposition on Electronic Equipment
New Requirements for Sir Measurement
Effects of Mixing Solder Sphere Alloys with Bismuth-Based Pastes
The Development of a 0.3 mm Pitch CSP Assembly Process
Generalizations About Component Flatness at Elevated Temperature
Latest Industry News
iPhone 12 Production Could Be Delayed
Acer sees PC component shortages
Bio-Ink for 3-D Printing Inside the Body
Covid Seen Driving the Security Sector
U.S. Eases Restrictions on Private Remote-Sensing Satellites
EMS Manufacturing quote complexity drives OEMs to look behind EMS curtain
U.S. Manufacturing Rebounds to 14-Month High
IBM's New AI Tool Parses A Tidal Wave of Coronavirus Research

The Case of the Falling Floor

The Case of the Falling Floor
The line was running when suddenly there was a loud thud. The floor, supporting a vertical beam had given way. What happened?
Mysteries of Science


The Northern Engraving metal finishing plant had every kind of metal finishing and decorating process. There were 100 big presses for cutting, punching, and shaping metal. There were also many wet processes, including metal etching and cleaning.

One morning the etching line was running when suddenly, there was a loud thud and the entire building shook. One worker pointed to the ceiling, upon closer inspection it became clear that part of the ceiling had dropped by at least a foot. The ceiling was sagging, but still supported by its steel structure and I-beams.

The floor, supporting a main vertical I-beam, had given way. The plant was on very solid ground and the thick concrete floor rested on a well-settled gravel bed.

What caused the floor to give way in this particular area of the factory?

Here's the rest of the story

Could the footing possibly have been bad? Maybe the concrete was bad? There was no obvious answer.

The ceiling was supported so that the area around the column could be excavated. As the digging proceeded, they exposed a black plastic pipe that ran under the floor. The layout plan showed that it was the waste acid pipe that went to the waste water treatment plant.

A joint was leaking into the surrounding concrete. The leak contained hydrofluoric acid used to etch glass and stone. The acid partially dissolved the floor and footing. The process may have taken quite awhile.

But ultimately the floor degraded enough to cause the problem.


No comments have been submitted to date.

Submit A Comment

Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name

Your Company
Your E-mail

Your Country
Your Comments

Board Talk
Solder Paste Beyond The Shelf Life?
Issues With Fillets on Via Holes?
Can Tape Residue Contaminate a Clean Tank?
Suggested Stencil Wipe Frequency?
Reflow Oven Zone Separation Challenges
When To Use Adhesive To Bond SMT Components
How To Clean a Vintage Circuit Board Assembly?
PCBA Inspection Concerns
Ask the Experts
Lifted Lead on SOT Component
Allowable Bow and Twist on Round PC Fab
Mixed MSL Baking
Step Stencil Squeegee Angle
Solder Balling Splash After Reflow
Application Using No-Clean and Water Soluble Fluxes
IPC SOIC Defect Question
Mixed Process Solder Joint Appearance, Smooth or Grainy?