Bending Trailer

Hightower · 26 February 2008, 10:49

wonder if you RIBnet peeps could give me some advice please?

I bought an Admiral trailer last year for my Osprey, I've launched and recovered about 10 times with it and on the last 3 I've noticed this bending draw bar. There was always a little bend there as part of the design, but as a weak spot it has taken to bending when the weight of the boat is on the rear rollers whilst attached to the car. It's all a little tight around the area for reinforcing with a plate top and bottom, so any Ideas?

CJL · 26 February 2008, 11:11

Looks like its just not up to the job.

I'd take it back and either get it strengthen or insist on your money back as not fit for purpose.

Chris

Carl · 26 February 2008, 11:16

told you that console was to big,the trailer is bending right under it

Hightower · 26 February 2008, 11:28

Well I can't take it back as Admiral Trailers ceased trading last year.

Hugh Jardon · 26 February 2008, 11:29

as chris says I would agree that the trailer just does not look strong enough to take the load as the boat is quite heavy, on my trailer the arms meet a lot further forward which in my mind gives a much stronger trailer.

I would be seriously worried and be on the phone to admiral, if you need a pic of where my arms meet in relation to the boat etc then drop me a pm, but before friday as we are off to a warmer place

jwalker · 26 February 2008, 11:29

Another example of 'professional work'.

Take it back to them.

Edit:

Quote:

Well I can't take it back as Admiral Trailers ceased trading last year.

Oops, I was too slow.

You need more vertical height in the draw bar and possibly a thicker wall section. Getting the rails to join further forward will help as will ensuring the join is rigid to prevent it working as a pivot. Also, having the cross member further to the rear will reduce the bending moment.

Hightower · 26 February 2008, 11:29

Quote:

Originally Posted by Carl

told you that console was to big,the trailer is bending right under it

Hightower · 26 February 2008, 11:31

This thread is developing too quickly

Taking it back to Admiral is not possible as they are no longer in business

9D280 · 26 February 2008, 11:38

Quote:

Originally Posted by Hightower

Well I can't take it back as Admiral Trailers ceased trading last year.

Hows abouta parallel bar same width as the drawbar, then use half a dozen "long reach" U- bolts and backing plates to "laminate" a stronger bend?

Option 2 (messier) Cut the current drawbar with enough left sticking forward to bolt the new, straight one to that you can then install "on top" of the stub of the old one and sholudn't alter your angl of attaxck (so to speak) too much. You might (difficult to tel lform the photos) be able to use the Roller (replace it with a cast "bolt on" type) be able touse the roller base as a clamp to the crossbar too?

CJL · 26 February 2008, 11:46

Hmm. Bugger that they are out of business.

Try inserting a slighty smaller box section inside the draw bar (main beam from the hitch) which will straighten it out and then weld it in place. If you can get the inner box sectioned galvanised as well that will help.

However - make sure your repair the damage to the galvanising after you have welded it in place.

Plus I'm make an effort to float your boat on and off the trailer from now on rather than pushing of/driving on /winching on.

Chris

CJL · 26 February 2008, 11:47

You'll prob have to heat the draw bar before you put the smaller section in by the way.

Chris

Richard Selman · 26 February 2008, 12:21

The problem is that the poor two bolt arrangment means that none of the bending moment is resisted by the a-frame attachment plates and therefore the force is transferred to the prebent section of the drawbar inside the a-frame which is already weakened by the bending You will not be able to internally sleeve the pre-bent section properly - it will just bend again at the end of the sleeve or where the sleeve does not contact the old section well. As a minimum you would need to replace the drawbar with a much heavier section. Getting this type of thing made up is normally really cheap. Even getting the stuff properly galvanised is cheap.

Got a whole 20 foot catamaran trailer with funky sliding supports and racks etc made up for £200 plus £70 for galvanising. Its all the coupling, axles, wheels, rollers & winch stuff etc that makes it expensive (ended up about £2000). I would consider replacing the whole frame with one where the a-frame extends much farther forward and is welded to the drawbar.

Richard

Richard

Hightower · 26 February 2008, 13:55

Quote:

Originally Posted by Richard Selman

The problem is that the poor two bolt arrangment means that none of the bending moment is resisted by the a-frame attachment plates and therefore the force is transferred to the prebent section of the drawbar inside the a-frame which is already weakened by the bending You will not be able to internally sleeve the pre-bent section properly - it will just bend again at the end of the sleeve or where the sleeve does not contact the old section well. As a minimum you would need to replace the drawbar with a much heavier section. Getting this type of thing made up is normally really cheap. Even getting the stuff properly galvanised is cheap.

Got a whole 20 foot catamaran trailer with funky sliding supports and racks etc made up for £200 plus £70 for galvanising. Its all the coupling, axles, wheels, rollers & winch stuff etc that makes it expensive (ended up about £2000). I would consider replacing the whole frame with one where the a-frame extends much farther forward and is welded to the drawbar.

Richard

Richard

I would agree with everything you said, except replacing the frame (too many pennies) I was thinking along the lines of additional plates welded to the existing ones where I could get at least 6 bolts clamping the bar, I'll also be looking at a heavyer duty draw bar too.

Pete7 · 26 February 2008, 13:59

Boat in Haslar Marina for a fortnight (see Jimbo) trailer up to Degraff in Surrey for some mods before spring arrives and the world goes mad, there is also Hayling Trailers but there galvansing isn't as good.

Presumably it buckled in that direction as you winched the boat back on the trailer rather than when the boat is fully on the trailer.

Pete

jwalker · 26 February 2008, 14:16

Andy, my trailer is built in a similar way to yours but the drawbar attachment is as shown on the picture below. It is good to have the angle iron a little longer than shown because it flexes more easily to clamp against the drawbar. It would be easy enough to modify yours into a similat arrangement.

If welding your galvanised parts, it's good to use stainless welding wire because some of the chromium migrates into the mild steel tube and it gives that area around the weld a bit of rust resistance.

Hightower · 26 February 2008, 14:19

Quote:

Originally Posted by Pete7

Boat in Haslar Marina for a fortnight (see Jimbo) trailer up to Degraff in Surrey for some mods before spring arrives and the world goes mad, there is also Hayling Trailers but there galvansing isn't as good.

Presumably it buckled in that direction as you winched the boat back on the trailer rather than when the boat is fully on the trailer.

Pete

Yes Pete you are right, it was bending as the boat is being winched.

I'll send some emails and get some veiws of trailer companies.

jwalker · 26 February 2008, 14:21

Quote:

Originally Posted by Hightower

I'll send some emails and get some veiws of trailer companies.

And then you'll be relying on those professionals again!

Hightower · 26 February 2008, 14:26

Quote:

Originally Posted by jwalker

And then you'll be relying on those professionals again!

Yeh, I know

My only trouble about re-inforcing the area is that the hull is only about 1.5 - 2" above it all, I guess I can install spacers on the two front roller banks to move the hull in an upwards direction.

I like the idea of angle iron though, if it gets welded the frame will need to be galvanized again wouldn't it?

Pete7 · 26 February 2008, 14:32

Quote:

Originally Posted by jwalker

And then you'll be relying on those professionals again!

Ah, but were talking about Arthur DeGraff here, think he stayed on in this country after the romans left, so has made a few trailers in his time.

Pete

jwalker · 26 February 2008, 14:37

Quote:

Originally Posted by Hightower

I like the idea of angle iron though, if it gets welded the frame will need to be galvanized again wouldn't it?

If you can come by some galvanised angle, just weld it up with stainless wire and give it a lick of paint each year. I see me bolts are needing a wee touch in too...