Previous in Forum: 2 SPDT Relays to Control Operating Pressure Range   Next in Forum: Grounding
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
7 comments
Rate Comments: Nested
elsytec
Member

Join Date: Jan 2010
Posts: 7

Friction Load

08/26/2011 1:12 PM

I am designing an Anchor block for pulling a power transformer of 40 Tons weight. I found some papers on Frictional force and arrived as below.

Can any one guide and suggest whether following method is ok?

Friction Load:

Assuming the thing to move slowly the F=ma becomes pretty negligible.

Say to move a Transformer - 5m in 100seconds


The speed equation is distance = 1/2 acceleration * time^2 and F = ma

Weight of Transformer= 40000 Kg

Movement: 5m in 100 seconds

So force = mass * 2 * distance/time^2

= 40000kg * 2 *5 /100^100 = 40N

Hence the friction Load is negligible
Register to Reply
Pathfinder Tags: Transformer on rials frictional load
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Good Answers:

These comments received enough positive votes to make them "good answers".

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
lyn
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#1

Re: Friction Load

08/26/2011 1:24 PM

"Hence the friction Load is negligible".

This is the stuff dreams are made of. How can you say the the friction load of an 80,000 pound mass will "be negligible"?

Just float it on an air cushion and move it.
Register to Reply
elsytec
Member

Join Date: Jan 2010
Posts: 7
#3
In reply to #1

Re: Friction Load

08/26/2011 10:03 PM

Dear Mr Lyn,

I agree with you we can no totally say as neglible. Wherever the % of friction load w.r.t the Mass is less tha 5% we can call it as negligible.

please see the link given below, where the friction load is stated a s negligible.

http://www.ehow.com/how_5931003_calculate-needed-move-railroad-car.html

Elsytec
Register to Reply
lyn
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#4
In reply to #3

Re: Friction Load

08/26/2011 10:24 PM

"What we have here, is a failure to communicate". Strother Martin, in Cool Hand Luke.
Register to Reply
Tornado
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#5
In reply to #3

Re: Friction Load

08/27/2011 12:11 AM

That's a railroad car on rails, not a transformer on earth. In your case, the acceleration load is negligible, but the friction load is much more. Passington Green's assumption of a 0.3 coefficient of friction is reasonable, unless more specific information is known.

__________________
 In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
2
passingtongreen
Guru

Join Date: Aug 2009
Location: Glen Mills, PA.
Posts: 2385
Good Answers: 114
#2

Re: Friction Load

08/26/2011 2:05 PM

You calculated the frictionless force.

If you intend to drag it over a concrete surface you would need a pull of say, 0.3x80,000lbs=24,000lb

More likely, it will be a skid and brought in on rollers of some kind. I have used Hillman Rollers and another time, used 5" nominal pipes. The pipes seem to have the right balance between flexibility and strength to roll over high spots.

__________________
 In a time of universal deceit, telling the truth is a revolutionary act. George Orwell
Register to Reply Good Answer (Score 2)
No more Good Answers. Go to first "Almost" Good Answer
TonyS
Guru
United Kingdom - Member - New Member

Join Date: Aug 2010
Location: Resting under the Major Oak
Posts: 4347
Good Answers: 181
#6
In reply to #2

Re: Friction Load

08/27/2011 5:34 AM

I'll go with passingtongreen use pipe rolers. Never failed me in the past

__________________
 The reports of my death are greatly exaggerated.
Register to Reply
nick name
Guru

Join Date: Mar 2007
Location: City of Light
Posts: 3943
Good Answers: 183
#7

Re: Friction Load

08/27/2011 7:46 AM

The way you treat the problem shows that you do not understand the physics of friction. Better hire a specialist since alone you will probably mess the thing.
Register to Reply Score 1 for Good Answer
No more "Almost" Good Answers.
Register to Reply
Have a Different Question?
7 comments

Good Answers:

These comments received enough positive votes to make them "good answers".

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Copy to Clipboard

Users who posted comments:

elsytec (1); lyn (2); nick name (1); passingtongreen (1); TonyS (1); Tornado (1)

Previous in Forum: 2 SPDT Relays to Control Operating Pressure Range   Next in Forum: Grounding

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Electrical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (71 right now)
Show Members
Advertisement