Strengthen Caravans and Trailers
Submitted: Sunday, Dec 05, 2010 at 02:28
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Member - Marc Luther B (WA)
Hi All
As someone who has a little knowledge with steel and the like, I thought I would submit this information.
On several occasions this year I had to repair the A Frames on trailers and caravans for people, yet this breakage and damage can be so easily avoided. If people are planning to travel rough and / or corrugated roads, it is simple to get a piece of angle line, preferable 75 mm (3"), and cut it with angles to slot in about half way between the trailer brake handle and the trailer cross member, (front frame).
Drill two holes in each end and fit it with bolts, nuts and washers into the A Frame, do NOT weld it in, and I strongly recommend double nut and lock tite to secure the angle line in. This way when the A Frame weld starts to fracture, which inevitably happens on really bad roads, the angle line WILL hold your trailer / caravan secure, and you will not be stuck somewhere waiting for help, or leaving your trailer behind.
The second method is to place some sheet steel adjacent to the brake handle, under the A Frame, and again, bolt it into position. This will prevent any separation of the A Frame join, and is a cheap and easy method of avoiding problems on bad roads.
Just a copuple of suggestions for people to think about.
Cheers
Reply By: Member - Marc Luther B (WA) - Sunday, Dec 05, 2010 at 02:34
Sunday, Dec 05, 2010 at 02:34
My apologies in advance to anyone who may ask any questions. In about 5 hours I am driving to
Kununurra yet again, and will be back Monday night, so will answer any questions Monday os Tuesday.
Cheers
AnswerID:
437851
Reply By: Sigmund - Sunday, Dec 05, 2010 at 08:41
Sunday, Dec 05, 2010 at 08:41
Good ideas.
With the 2nd method, are you advising drilling the RHS for bolting the sheet steel on or using something like shackles?
AnswerID:
437855
Follow Up By: Member - Marc Luther B (WA) - Tuesday, Dec 07, 2010 at 06:35
Tuesday, Dec 07, 2010 at 06:35
Hi Sigmund
Shackles of course would be preferable, but I find that drilling and bolting with washers upper and lower allow for more play and less stress.
Cheers
FollowupID:
709700
Reply By: Kelvo - Sunday, Dec 05, 2010 at 09:14
Sunday, Dec 05, 2010 at 09:14
I have very little knowledge with steel but why drill & bolt the extra steel and not weld?
Is this because the heat from welding would affect the original strength of the A frame?
Wouldn't drilling enough holes (10mm?) to hold the strengthening metal weaken the original A frame.
Just wanting to know.
AnswerID:
437863
Follow Up By: Member - Marc Luther B (WA) - Tuesday, Dec 07, 2010 at 06:37
Tuesday, Dec 07, 2010 at 06:37
Hi Kelvo
Yes, heat always affects steel. I recommended the drilling and bolting as it allows some play in the joint without the stress. Shackling would of course be just as effective.
Cheers
FollowupID:
709701
Reply By: snapper49 - Sunday, Dec 05, 2010 at 10:18
Sunday, Dec 05, 2010 at 10:18
I am a boilermaker/welder with many years experience working in and with structural steel work also a reired lecturer from Tafe
A lot of van manufacturers nowadays dont under truss the A frames
They should all be under trussed
Personally I wouldnt recomend drilling any holes in the existing A frame
I would recomend taking the van to structural steel fabricating place if you cant manage your self and getting some truss work done on the Aframe starting at the brake lever and continuing on under the front of the van to the end of the A frame
The truss can be made from pipe and flat bar or just flat
There are plenty of examples around just have a look
AnswerID:
437866
Follow Up By: Member - Marc Luther B (WA) - Tuesday, Dec 07, 2010 at 06:40
Tuesday, Dec 07, 2010 at 06:40
Hi Snapper49
Good to know a fellow boily. Unfortunately these days nearly 50% (or even more) of trailers and caravans are not under trussed. I did this thread so that perhaps people will look at what they have, and get them under trussed or do it themselves, as it is so simple, and avoids so many problems.
I see no problem with drilling the existing A Frame, obviously not too close to the edge, and only sufficient for the bolts being used. I have done it many times and have never had a problem.
Cheers
FollowupID:
709702
Reply By: Member - Ed C (QLD) - Sunday, Dec 05, 2010 at 12:54
Sunday, Dec 05, 2010 at 12:54
What is "angle line" ??
;-))
| Confucius say.....
"He who lie underneath automobile with tool in hand,
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437884
Follow Up By: Wayne (NSW) - Sunday, Dec 05, 2010 at 13:03
Sunday, Dec 05, 2010 at 13:03
Ed
Angle iron is what Marc is talking about. It is in the shape of the letter " L "
Wayne
FollowupID:
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Reply By: Member - Stuart P (WA) - Sunday, Dec 05, 2010 at 13:30
Sunday, Dec 05, 2010 at 13:30
this was discussed by me when i first joined , there are a lot of trailer builders out ther that insist on welding the a frame to the leading edge of the trailer box , this always causes fracturing. we build trailers at work and have never had a failure
AnswerID:
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Follow Up By: Member - Marc Luther B (WA) - Tuesday, Dec 07, 2010 at 06:43
Tuesday, Dec 07, 2010 at 06:43
Hi Stuart
How's Paruku ?
I 100% agree with you about the fracturing, and it is the predominant reason that I had to do a few trailers this past year.
Catch you on Skype soon my friend.
Cheers
FollowupID:
709703
Reply By: Member - Joe n Mel n kids (FNQ - Sunday, Dec 05, 2010 at 14:37
Sunday, Dec 05, 2010 at 14:37
if you have concerns about welding to the existing chassis you could use "U" bolts, the same as is used to fix the axel to
the springs .....
Marcs point is that something is better than nothing as i also have seen a lot of cracked chassis on trailers, remember more often than not the contents on and in the trailer are worth far more than the bare trailer so it is
well worth a thought ......
It is simple to do, say the existing "A" frame is 50mm wide, all you need is maybe 2 x 1.5M long bits of 50mm x 50mm box "section", (i think you could even get it from Bunnings) and go to a trailer place and get "U" bolts and base plates long enough to bolt up the 2 peices ...... example is "A" frame is 50mm x 50mm box and the bit you buy is 50 x 50 so you need it to bolt togeather 100mm of steel and have some more for the thread and nuts to tighten up on, around 125mm, also go "Nylock" nuts if possible and dont do them very tight, no need to be.....
I would use 4 bolts on each peice ......
Good luck
AnswerID:
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Follow Up By: Member - Joe n Mel n kids (FNQ - Sunday, Dec 05, 2010 at 14:41
Sunday, Dec 05, 2010 at 14:41
should point out that i means you dont have to weld or drill the chassis, if the "A" frame up under the trailer is hard up against the floor, drill holes for the "U" bolts in the PLATE floor and insert bolts "down", threads underside, still no need to drill the chassis .... seal any gaps with silicone
FollowupID:
709482
Follow Up By: Member - Marc Luther B (WA) - Tuesday, Dec 07, 2010 at 06:45
Tuesday, Dec 07, 2010 at 06:45
Hi Joe n Mel n Kids
I do like what you are suggesting, and that would work beautifully.
Cheers
FollowupID:
709705
Reply By: snapper49 - Sunday, Dec 05, 2010 at 17:25
Sunday, Dec 05, 2010 at 17:25
Bottom line is that if the A frame is built correctly in the first place that is with under trussing and yes not welding the leading edge the precaution mentioned in no way should be warranted
Also many Aframes do not break on the leading edge but around the point where the stabiliser bars are connected
AnswerID:
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Follow Up By: Member - Marc Luther B (WA) - Tuesday, Dec 07, 2010 at 06:46
Tuesday, Dec 07, 2010 at 06:46
Hi again Snapper49
One question. How frequently are the same stabiliser bars welded into position, which has fractured the steel ?
Cheers
FollowupID:
709706
Follow Up By: Member - Boeing (PER) - Wednesday, Dec 08, 2010 at 20:01
Wednesday, Dec 08, 2010 at 20:01
Hi Snapper49 and Marc. By under trussing do you mean whereby pieces of steel are welded under the A frame and then a piece of steel "rod" is run from the front to the back of the A frame and welded at the points where the additional pieces of steel have been previously welded. They use a similar method on the tilt a door garage doors. Sorry the description is not that good.
Regards
Mark (with a "k")
FollowupID:
709979
Follow Up By: snapper49 - Wednesday, Dec 08, 2010 at 22:38
Wednesday, Dec 08, 2010 at 22:38
@ Marc
Nevre have I seen stabiliser bars or brakets welde in position only clamped
@ Boeing
under trussing is exactly as you have described
The flats only need to be 40mm deep so not much depth is added to the Aframe
The bars need to run from as close as possibel to the tow hitch and all the way to the back end of the A frame
The flats usually 2 is enough on each side one positioned at the stabiliser bracket and the second at the point where the A frame passes under the front of the van
FollowupID:
710018
Reply By: Gramps - Wednesday, Dec 08, 2010 at 20:14
Wednesday, Dec 08, 2010 at 20:14
Blokes,
Some (at least one anyway) of us have difficulty envisaging what you mean. Is there any chance you could post a photo for the mechanically challenged :)))
Regards
AnswerID:
438290