Tongue strength spreadsheet for British/European trailers

Ask questions about Harbor Freight trailers, or questions about building your own...

Tongue strength spreadsheet for British/European trailers

Postby angib » Tue Jul 17, 2012 3:31 pm

There might be one or two Americans who want to see this, but mostly I'm posting it so that any Europeans, particularly Brits, here can find it.

This October in Britain a trailer inspection is being introduced for the first time. As we don't register trailers (they just display a copy of the tow vehicle's license plate), up until now we had no controls over home-built trailers at all, but that is all set to change with the Individual Vehicle Approval (IVA) test. Much of the IVA test is concerned with detail that has always been required like lights and reflectors, but a big new requirement is proving the trailer has enough tongue (or 'drawbar') strength, which has to pass an international standard, ISO 7641.

To help with this, I've written a spreadsheet that takes in a few dimensions and weights, and then outputs the required tongue strength, plus some suggested steel sections that are strong enough. This uses metric units but if there's any interest it would be easy to make a version in American units. I do think it's about time I redid the tongue strength web page and made it more usable, so maybe this would be a good way to do it.

Here is the web page covering the drawbar strength spreadsheet or it can be accessed from a new IVA test section of the Design Library.
User avatar
angib
5000 Club
5000 Club
 
Posts: 5783
Images: 231
Joined: Fri Apr 30, 2004 2:04 pm
Location: (Olde) England

Re: Tongue strength spreadsheet for British/European trailer

Postby High Desert » Tue Jul 17, 2012 8:04 pm

Thank you Andrew. This American will be giving it study I assure you :thumbsup:
Shaun

"it's not the years honey, it's the mileage"
High Desert
Platinum Donating Member
 
Posts: 8780
Images: 27
Joined: Wed Apr 08, 2009 1:46 pm
Location: SW Washington state

Re: Tongue strength spreadsheet for British/European trailer

Postby Corwin C » Tue Jul 24, 2012 9:48 am

This is excellent information for all trailer builders on either side of the pond. The spreadsheet verifies calculations that I made myself and in my opinion is suitable for use by builders without an engineering background. Make sure that you read and understand the accompanying notes so the resulting information is correct. The spreadsheet is limited in both total tongue weight and percentage of total weight so it may not apply to some non-European designs.

I, for one, would be interested in an "Americanized" version.

Well done Andrew.
Corwin
Image Image Image
If I am unwilling to stand up straight before the world and admit what I have accomplished during the day, without excuses, in complete and honest detail, then I can do better ...
and no one should be expected to accept anything less.
-- myself
User avatar
Corwin C
500 Club
 
Posts: 916
Images: 78
Joined: Mon Oct 19, 2009 10:27 am
Location: Junction, Piute County, UT
Top

Re: Tongue strength spreadsheet for British/European trailer

Postby angib » Tue Jul 24, 2012 3:47 pm

Corwin C wrote:I, for one, would be interested in an "Americanized" version.

Yes, I've been thinking about that. It just happened that it was easy to make the spreadsheet suggest suitable tongue sections and I can imagine that many people might find that useful without having to do the maths (and reading) required by the American version at present. I'll keep thinking about it.
User avatar
angib
5000 Club
5000 Club
 
Posts: 5783
Images: 231
Joined: Fri Apr 30, 2004 2:04 pm
Location: (Olde) England
Top


Return to Trailer and Chassis Secrets

Who is online

Users browsing this forum: No registered users and 1 guest