Al-Ko Trailer Tongue failure

Nigel Pocock wrote on 7/22/2016 8:32 AM:
As an ignorant non-engineer why not reduce the cause of the problem
rather than use a technical solution to it.
As I understand it the problem seams to be caused by excessive
pitching of the trailer exceeding the design loads on the tongue.
What caused this pitching? One thing mentioned it is large overhangs
between the rear axle and the hitch on the tow vehicle. If this is
sufficient to cause problems with the integrity of the tongue what is it
doing to the glider inside?
Another problem is loading the trailer so there is too much weight on
the tongue. The pitching causes a loading + or _ around that weight.
i.e if the tongue weight is 30lb and pitching causes a variation of +or -
100lb the load would vary between -70 and +130. If the tongue weight
was 100lb plus as I have seen recommended on this site it would vary
between 0 and 200lb. Insert your own figures but you get the gist of
my argument.
As a matter of interest I havnt heard of this problem on this side of the
pond where we usually tow with much more compact, lighter vehicles.

Changing to a more trailer-friendly towing vehicle than a motorhome is a
non-starter if I want my wife to travel with me; I also prefer
traveling (particularly to glider events) in a motorhome.


It does happen on your side of the pond when towing with motorhomes, but
likely isn't as common due to fewer towing miles and smaller motorhomes.
I've towed my ASH 26 E more than 170,000 miles in it's Cobra trailer,
and it's in fine shape, so the pitching doesn't seem to be a problem for
the glider. I did have to replace the original, smaller tongue about 15
years ago, which developed a crack at the weld for the tongue wheel mount.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-Launching Sailplane Operation"

https://sites.google.com/site/motorg...ad-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/...anes-2014A.pdf