×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# Required Tractive Force

## Required Tractive Force

(OP)
This may be too vague a question, but here goes:

I have to get a 420 tonne (GVW Load & trailer) load up a 13% grade. How much tractive force would the tractor unit need to have?

Not much I know, but that's all the information I have for now.

### RE: Required Tractive Force

Draw yourself a simple right triangle with the slope that you have to pull as the angle opposite the short side.  The truck is shown as a weight and the rest is simple trigonometry.  Once you determine the force at that angle, then you need to determine the coefficient of friction of the drivers and figure the weight you will have to have on those axles (and maybe how many axles will be required as drivers.)

rmw

### RE: Required Tractive Force

(OP)
While I appreciate your taking the time to answer, you say "Once you determine the force at that angle" and "then you need to determine the coefficient of friction"
If I know how to do that, I wouldn't have asked the question.

### RE: Required Tractive Force

Use better brush up on Trig 101

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!