To: "'seaint(--nospam--at)seaint.org'" <seaint(--nospam--at)seaint.org>
Subject: RE: Field Observations - Stupid things I've seen
From: "Smith, Steven A" <Steve.Smith(--nospam--at)PSS.Boeing.com>
Date: Tue, 29 Jun 1999 09:30:23 -0700
Commercial transport airplanes are designed with a 1.5 Factor of Safety (ratio of ultimate load to limit load).
Steve Smith, PE, SE
> From: JohnOttCE(--nospam--at)aol.com[SMTP:JohnOttCE(--nospam--at)aol.com]
> Reply To: seaint(--nospam--at)seaint.org
> Sent: Monday, June 28, 1999 10:46 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Re: Field Observations - Stupid things I've seen
> Talking about stupid plumbers...........
> About ten years ago, we had designed an apartment building with underground
> parking where the wood main beams spanned close to thirty feet. There was
> plenty of height so the joists were shown to rest on the main beams. It was
> anticipated that the plumbing waste lines would run between the floor joists
> over the main beams and there was a special note on the plans calling for the
> plumber to run the waste lines between the floor joists to a wall.
> Well, I got a frantic call from the builder one afternoon and was he beside
> himself. The builder was a particularly good builder and always knew what was
> good construction. He immediately realized a problem had developed. He had
> gone to the lumber yard to pick up some hardware. During the time he was gone
> the plumber, in his ultimate stupidity decided to not read the plans and to
> run the waste line through the middle of the main beams at the center of the
> span of the beams.
> Did this brain dead plumber drill a hole through the center. No! He took a
> chain saw and cut a notch slightly deeper than the wood beam. Naturally the
> builder was a little bit more than mildly concerned. He wanted to know what
> to do.
> I told him to order a new beam, shore the building up, remove the damaged
> beams and to install the new beams and backcharge the plumber. He did just
> that! However I have always wondered if the plumber learned anything at all.
> I have seen many plumbers on a job with a chain saw. I have always taken the
> time to inform them that if they cut any framing it will be at their risk. I
> sometimes think of the safety factors in the Code and wonder why they are so
> high. After all airplanes are designed with a 5-10% safety factor. But when I
> think of the plumbers (Electricians and H.V.A.C.) with chain saws I can see
> that quality control is lacking for our industry.
> John Ott