Posted 2008-09-12 7:54 PM (#91409) Subject: structural support under a trailer?
Member
Posts: 24
Location: Ohio
I am in the market for a two horse (similar to another post i've seen) and have visited a few dealers. I would have never thought of it before but a friend of mind was in a accident, her trailer landed on it's side. Her mare came out of it with only a few scrapes and bumps. She credits the structural support of the trailer. The aluminum shell took a hit but the steel frame was intact. I began looking under trailers at various dealers and was surprised at the variations. Some had numerous cross members. One trailer, the Shadow, had no supports just aluminum slats. Since I'm not a structural engineer I need to ask. What would be the best structure or combination of materials, to keep a trailer together (in case of an accident) and have a good long life span? -Thanks, Jan
Posted 2008-09-12 10:10 PM (#91416 - in reply to #91409) Subject: RE: structural support under a trailer?
Member
Posts: 5
Location: TX
Jan, I think very few buyers do what you have just done, questioned materials and engineering....they get wowed by just the look of a trailer and do not investigate the structural integrity of a trailer. What makes one run from a house purchase? If it is not a case of mold in the house then it is a bad foundation that will make you flee from a purchase of that house. Same thing with a trailer, if the basic foundation is not "right", then you WILL have problems in a short time.
Buyers do not research how a trailer is built. These things take alot of abuse and cost alot of money and they can last if they are built correctly. The "over the road industry" (18 wheelers) build to last 100's of thousands of miles with aluminum. Even items such as the fasteners used make a differance.
You are on the right track....there is a BIG distinction between manufacturers and what they are trying to market to......appearance or longevity.......if you dig into it you will discover which builder is doing which.....st
Posted 2008-09-12 10:28 PM (#91417 - in reply to #91409) Subject: RE: structural support under a trailer?
Extreme Veteran
Posts: 383 Location: Texas
When I was looking for a new trailer a couple years ago I got a lot of weird looks when I would go out on the lot and immediately crawl under to look at the trailer instead of looking inside. There are a lot of differences in how different brands and even different models of the same brand are made. I don't know that there is any combination that is the "best" but there are some that are obviously better than others when you look at them.
Posted 2008-09-13 9:10 AM (#91423 - in reply to #91409) Subject: RE: structural support under a trailer?
Veteran
Posts: 188 Location: Kinston, NC
we have had 2 trailers to come back recently because of an accident. In both cases, the insurance company totaled the car that hit the trailer. Amazingly, the trailers held up great with minimal damage. I couldn't believe it. Those trailers were steel frame, galvaneal skin.
Aluminum trailers can be built with good structural integrity as well but it takes alot of aluminum to get that strength. I put much thought into how to build the trailer to hold up to weather, use, and anything else that might happen.
Some aluminum companys built their trailers with the strength in the floor: large cross beams. Others built the strength in the walls: large beams running the length of the trailer.
In the story above, its amazing the trailer was on its side and the mare was ok. I bet that was a wild ride.
Posted 2008-09-13 3:53 PM (#91440 - in reply to #91409) Subject: RE: structural support under a trailer?
Elite Veteran
Posts: 824 Location: Kansas
Although my trailer buying is mostly a fantasy I still look every chance I get and I get underneath and look around also. Some of the trailer reps I have talked to can barely bring themselves to talk to me and others I feel are telling me what they think I want to hear. So...other than closely spaced bracing, welds looking good, etc., how would I know if a floor was braced enough for lq? Is there something specific to check out? Thanks, T
Posted 2008-09-13 4:17 PM (#91442 - in reply to #91409) Subject: RE: structural support under a trailer?
Member
Posts: 24
Location: Ohio
It was amazing that the mare came out of it with just bumps and scratches. My friend was on a narrow country road and, she thinks, but doesn't really know it happened so fast, that a tire got hung up in the soft berm of the road. There was on-coming traffic and a little car at that. In a split second she felt she'd kill anyone in the car so she tried holding on but the trailer yanked the truck off the road. The hitch was bent and stabilizer bar yanked off the frame when the trailer landed on it's side. An axle on the trailer was bent too.
Weight is something I'm concerned about too. I'm looking for light as possible (aluminum) but strong enough to handle being hit, tossed on it's side and last a good long time.
Then I'm also considering the discussions (arguments) slant load vs straight load. The trailer above was a straight load. Which makes me wonder what type of injuries the mare would have had in a slant load. The trailer landed on the drivers side which would have put the mare on her head. The other way would have put her on her hind quarters.
I'm looking for a GN with a decent 4-6 foot dressing/storage too. Any suggestions?
Posted 2008-09-13 4:19 PM (#91443 - in reply to #91409) Subject: RE: structural support under a trailer?
Member
Posts: 24
Location: Ohio
It was amazing that the mare came out of it with just bumps and scratches. My friend was on a narrow country road and, she thinks, but doesn't really know it happened so fast, that a tire got hung up in the soft berm of the road. There was on-coming traffic and a little car at that. In a split second she felt she'd kill anyone in the car so she tried holding on but the trailer yanked the truck off the road. The hitch was bent and stabilizer bar yanked off the frame when the trailer landed on it's side. An axle on the trailer was bent too.
Weight is something I'm concerned about too. I'm looking for light as possible (aluminum) but strong enough to handle being hit, tossed on it's side and last a good long time.
Then I'm also considering the discussions (arguments) slant load vs straight load. The trailer above was a straight load. Which makes me wonder what type of injuries the mare would have had in a slant load. The trailer landed on the drivers side which would have put the mare on her head. The other way would have put her on her hind quarters.
I'm looking for a GN with a decent 4-6 foot dressing/storage too. Any suggestions?
Posted 2008-09-14 10:04 AM (#91468 - in reply to #91409) Subject: RE: structural support under a trailer?
Expert
Posts: 1283 Location: Home of Wild Turkey Whiskey
Ok here I go, I have been in, under, on top of, most trailer brands out there and you can't get any idea of how well a trailer is built by looking under it. If you look under a Cimmaron you won't see any I-beams, if you look under a Kiefer they will be 4" and on 12" centers. If you look under a 4 Star they won't have any rhime or reason to the spacing??????? So what are you looking at? Most LQ conversions shops cut out two crossmembers to install the tanks????? I say to really see the quality in the trailer look at the materials themselves, 4 Star, Bloomer, Elite, C&C all use very heavy walled aluminum. I don't know the thickness but I know you have to pre-drill the holes for a self tapping screw. Not the case with Cimmaron, Kiefer, Exiss, Hart and the others. The bottom rail in the top brands is much taller than the intermediate brands, the wall studs are welded to the extruded sides, the top rail is much thicker in the top brands. So I repeat, don't get fooled by some slick willy, starched wranglers, polished boot salesman into thinking because his brand has more of this, or none of that, that he has a better trailer.
Posted 2008-09-14 12:39 PM (#91474 - in reply to #91468) Subject: RE: structural support under a trailer?
Veteran
Posts: 188 Location: Kinston, NC
I agree with HWBar(excellent analysis BTW),
Some good brands don't have large visible beams underneath. You are right about the conversion companys cutting out cross beams for tanks or even uprights in the walls (for refridge vents and such). I have to work with my LQ guy to get the positions correct so we don't have to cut out structural support. In my humble opinion, a beefed up bottom rail on the wall (running front to rear) is more important than huge I-beam crossmembers. Also, I would not recommend an all aluminum gooseneck either.
Posted 2008-09-15 11:47 AM (#91508 - in reply to #91409) Subject: RE: structural support under a trailer?
Member
Posts: 5
Location: TX
I'm going to take a different stance here. I am not going to name manufacturers, but, some may figure out my preferences as I "try" to pose some views. Yes, I do have likes and dislikes and I can change opinion when shown to be uninformed.I do believe if one looks under a trailer one will get a sense of what one is dealing with. Often, that is the only visible area that one can see any signs of structure. Thickness of materials is not the end all of the inquiry. With an aluminum trailer especially, it is how those materials are built together as a unit that gives strength. Wicker furniture is able to be sat in because of method of construction not individual strength of materials.Take for example floors. How can a smooth aluminum floor be stronger than an extruded floor? Often builders will take a smooth aluminum plank that runs side to side in a trailer. That plank before installation is "bent" or formed into what amounts to a "C" purlin. They then install that to make the floor in a side to side fashion through the length of the trailer. The bottom or underside edges of that "C" purlin is spot welded and can often "appear" to be I-beams.That floor as a unit is going to have tremendous flex to it. That is your foundation and it is flexing. How can that be good? Secondly, a smooth surface is going to concave with use. It can't help but end up with dips down the length of the trailer. An extruded aluminum floor.....the planks have form and strength manufactured into them from the very start, right out of the aluminum factory. Those are then interlocked and run the length of a trailer unit and welded to true I-Beams underneath. That floor as a unit is not going to have as much flex to it, I believe. Also it will tend to resist the tendency to concave with use. It is a grid built network of materials.This is just one area of a trailer and does not get into the Kingpin structure and mass or if that Kingpin runs back into the gussets and how all is put together. What type of rivets are used? Glues, tape.....they all use them but where and to what extent?Lots to consider, and I will take correction on my views if needed........st
structural support under a trailer?
