Some of you will remember that after Dave Nathanson's tongue collapse, I tried to come up with a tongue strength guide, though it never got very far.
So I am delighted that Adam ('eski') has pointed me to the Australian small trailer design rules - these contain a rule on 'drawbar' (tongue) strength that is dead simple to use and I have made up a web page with all you need to check your planned or existing tongue:
How strong does my tongue need to be?
If you want a sneak preview, here is a table that shows the maximum trailer weight (GVWR, not bare weight) for typical tongues sections and lengths. The web page shows you how to calculate the exact answer for your particular trailer.
If you are Mike, you'll notice that your favourite A-frame 2" x 2" x 3/16" is good for a 2,300lb GVWR trailer with a 36" tongue. Whereas some other people here may have a nervous look to them.....
Incidentally, I've done the calculations for Dave Nathanson's trailer details and his trailer tongue had only 71% of the strength required by these rules - so that more or less supports the rule.
All comments and suggestions gratefully received.
I think it's great to have something definitive on tongue strength, rather than just everyone's (including my) experience or opinion, so:
Thanks, Aussies!
Andrew