Ultimate Cargo/Living Trailer

[bmzero]

I expect this post to survive for many years to come, as it will probably take me many years to build this trailer. I don't intend to start for another 5 years or so, but I thought it might be fun to throw some of my initial off-the-wall ideas out there to spark conversation.

 

So, as some of you may have noticed, the way I design things is sort of out of the norm. I start with extreme cases and work them back into reality as the design matures. That's what I have done here.

 

Major concept - the trailer actually splits into two distinct units. The rear unit (tag trailer) will be the storage unit, holding a four seat RZR and a small four door vehicle. This trailer will be a stacker with a rear lift gate. The front section (fifth wheel) is the living quarters area. It will have four large slides (2 in living room and 2 in master). The master bedroom will be above the hitch. The rear of the trailer will have a fold out deck, as our toy hauler does now with French doors as the entrance onto the rear deck. We love that aspect of our current trailer.

 

Two units connected:

 

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Two units separated:

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There are obviously tons of huge issues to work through with this design. I'm not overly concerned with those issues at this point. This is a highly malleable concept at this point.

 

Here are the reasons I want the trailers to separate:

• Ease of access - we want to be able to stay at state parks and other compact camp grounds. The front section of the trailer is only 33'. That means, we can separate the two sections (if necessary) and easily get into almost any camp spot. We can get two spots if needed; one for the living quarters and one for the toys.
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• Flexibility - there may be some trips where we do not need the toys and/or some events where we do not need the living quarters. Having two distinct units gives me the ability to split the units up if necessary. I could even pull the rear section with the F450 for short day trips.
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• Ease of parking - getting our current trailer (44' toy hauler) into our neighborhood is very tough. I have to unhook from the Volvo and park it with my F450. With shorter trailers, I could bring one unit in at a time and easily park them where they need to be.
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• Specific design needs - the trailers out there now are either a Nascar-style hauler with very sparse living quarters or a toy hauler with not enough room for the vehicles we want to take. This design concept, albeit raw at this point, solves this issue; nice LQ's and 20' of stackable storage capacity.
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Here's the current largest unknown - how to connect the two.

 

View High Resolution Photo

[brunsje]

I LUV your idea. Good luck. I recommend sharing with other engineers and see if anybody has ever rigidly connected two trailers together.

 

JohnnyB

[Star Dreamer]

Interesting concept.

 

For a connection, look at how extendable step deck trailers have their frame. Maybe you could have two frame rails on the rear trailer that extend out and slide into mating rails on the front trailer. Then for the rear trailer tounge, that could be hinged at the front of the rear trailer (located in a pocket at the front) and pivot down and connect to the extended frames rails.

 

You will have to watch the spread on the axles to avoid putting too much stress on the connection between the trailers when turning.

 

You will need some sort of wheels or jacks at front of rear trailer to hold up front at right level to connect and disconnect.

 

Dave

[bmzero]

Dave, you alluded to my greatest concern with this design; the spread of the axles. I'm trying to avoid any complicated auto-dropping axle assemblies or the like, but that may be where it ultimately ends up.

 

I'm not overly concerned with the connection between the two trailers at this point. There seems to be a multitude of ways to handle that. I will work on that at a later date.

[bmzero]

I LUV your idea. Good luck. I recommend sharing with other engineers and see if anybody has ever rigidly connected two trailers together.

 

Thanks, Johnny.

[Jmorris]

I seem to remember seeing a tag axle that worked like a floating steer axle on something, the memory is not sharp at this point. Perhaps it could be adapted to the LQ trailer and locked on center when pulled by itself. This would allow the wheels to turn and not scrub while cornering when hooked up double. I don't think it was actually controlled by steering, I think it would turn by forces applied by the turning motion. My thoughts anyway.

 

John

[wtgeodog]

Look at the Tag Axle setup on cement trucks. They tend to be some distance from the drive axles.

 

ShortyO

[Star Dreamer]

Or have the rear axle that slides like a semi trailer. Lock it in forward position when using with the fifth wheel. Move to rear position with bumper pull set up. This might also allow you to use double axles on rear and just use single tires on each axle. Using 17.5 tires might keep floor height low.

 

Dave

[Darryl&Rita]

Hate to say it, but this looks like an exercise in futility. Never mind tire scrub on turns, the unequal axle loading on something as simple as a speed bump will mean both axles need to be sized to carry the weight of both trailers. There almost has to be some give between the 2 units. I'm suspecting you're trying to avoid double tow restrictions, but think a better way would to run tandem axles on a trailer, with a stacker set-up in the garage area.

[Broncohauler]

Oh this could be fun?

I have a few ideas for when you get further along.

Being off-roaders sucks sometimes ( ok all the time) when you want to beach camp also.

[Star Dreamer]

Thinking about what Darryl posted, why not run tandem axles on the rear trailer and use a lift up axle on the front trailer. When connected together you only use the rear axles. When split, you drop the axle on the front trailer and now use it. This is assuming you can get the proper weight loading on the various combinations.

 

It will mean you may need a truck that can handle airbrakes on the rear trailer.

 

Dave

[JPL]

Britt I can see this is going to be interesting to watch it grow!! Pat

 

 

The Old Sailor

[Dollytrolley]

Zero,

 

As I predicted you are a hard-core case with the design-build sickness......

 

My experience with hard-core-gifted folks that the wife is very likely a very special lady.......Bill Lear was hard-core but his wife was the unsung hero.....I would bet your wife is a very special person as well.

 

We leased a couple of 550 ton Grove Cranes with cab forward design for the carrier low enough for plenty of space above the cab.

 

Go to a heavy haul terminal and you will have plenty of axle and infinite numbers of trailer coupling configurations to keep you awake for weeks on end.

 

Draw on......(sleep is for geezers)

[noteven]

Like this concept.

A belly winch on the lead would pull the toy trailer into sockets designed to rigidly join the two trailers. Great big pins to retain them. YouTube search electronic steering trailer Lamberet, and Simard Steering Trailer for some ideas on steering trailer axles, which you could use on your toy section. The two trailers turn radius would Center on the lead trailer axle. No scrubbing or huge lateral forces on the trailer connection.

 

This type of connection would not be considered a double tow if it was considered like a detachable neck lowbed and you could build it with one VIN.

 

Disadvantage would be having to tow one at a time when detached and move the license plate...

[Big5er]

This type of connection would not be considered a double tow if it was considered like a detachable neck lowbed and you could build it with one VIN.

 

Disadvantage would be having to tow one at a time when detached and move the license plate...

If they are towable separately, then they can not be "one" unit. They would be two units.

[Broncohauler]

If they are towable separately, then they can not be "one" unit. They would be two units.

Brings ups good point. You would need 2 plates and 2 vins

Witch means it's 2 trailers and double towing rather it pivots in the middle or not. IMO

[phoenix2013]

Making it a rigid pair would not work as the wheel scrub would be quite bad. But if you separated the two a bit further and connected them like the articulated European buses it could be interesting.

Now add the doors in the back of the front unit, the door in the front of the rear unit, put a walking sliding platform over connection stuff between the two, add an accordion cover between the two, now if officer 5r stops you you could argue, "But Sir, it is really one unit, only hinged and articulated in the middle !"

Incidentally, understanding wife is essential, I have one.

[noteven]

1 VIN no separated towing on public roads...

No axle scrubbing with the steering axles I mentioned. The trailer will turn at the lead axle.

[lappir]

Quite a lofty endeavor planned. I'm sure Marsha and Wyatt would make it happen for you if you provide the plans. Will be interesting to see how you will be able to stack the Quad and the Scion in under 13 feet and still keep an axle in that area too. I'm sure it can be done, but at what cost? Would love to have a lift gate on the back of my trailer. Drive on, lift it up, drive into spot and tie down. $10,000 if I remember correctly. Two custom built ramps $300 and the added benefit of getting my heavy lifting done before my trips to keep in shape.

 

Rod

[Refuzn-To-Grow-Up]

Here are features that I always wanted on my RV.

 

1. A deck that slides out (had powered is OK) from bottom of RV, complete with indoor/outdoor carpet preinstalled and railing that folds up. Sometimes, we boon dockers prefer to NOT be on the dirt.

 

2. A lounge/deck on the top of the RV, with fold up railing. Great for watching sporting events, sunsets, coyotes, bears and mountain lions that sneak into to camp at night. Or for sleeping under the stars. A spiral staircase to get to the roof would be sweet. Or, pull down stairs, similar to those used to access attics. Years ago, I met a custom RV manufacturer who had developed the idea. I think it was called a Sky Deck. the guy had fantastic ideas on how to build an RV. I suspect that his SoCal company is no longer in business.

 

3. A fuel pump that will remove fuel form "toys" before they are placed into the garage. I NEVER put my toys in the garage with fuel in the tanks. Fuel leak plus closed in garage plus spark = KABOOM.

 

4. A forced ventilation system for the garage. But, see number 3 above.

 

5. A winch in the floor of the garage that can be used to winch toys into the garage . . . . just in case the toys cannot make it on their own power.

 

OK, I "spent" enough of your money, for now, with my "Imagineering" (a Walt Disney term).

 

Jim

[Exile]

I can see this working, there a few restrictions to deal with and a few things i see as the way to go.

 

1. Length. 15 ft for cab and nose of tractor, 5 ft from cab to center of fifth wherl, 16 ft for stacker, leaves only 29 ft for living quarters.

 

2. Use a pintle hitch on the stacker, with a tongue of 8 or more feet for better towing

 

3. Commercial axles, with air suspension, and a lift axle or steerable axle on the front trailer. These are common up north, trailers up there can have 7 axles on them, and they have all these same issues.

 

4. To hitch them together, pull the pintle hitch into the forward trailer, this may require a higher than normal location of the hitch on your tractor to clear the top of the forward trailer axle when trailers are coupled. Use umhw on the mating surfaces, a tapered wedge design, and an adjustible linkage at the front of the receptacle to hold the pintle ring tight, with looser pins for safeties.

 

5. Axle placement of the stacker should be aft of the center of gravity for good towing single, this will put a lot of weight on the tractor if a lift axle on the living quarters is used.

 

6. Depending on final weight, could end up with three trailer axles if a lift axle is used. Three total axles with tractor should get you to the 27 ton range, so probably dont need tandems unless single tires are used.

 

7. Tongue receptacle might drive the design to have a lower deck in the middle of the living quarters like a lowboy trailer

 

8. Like someone said, stacking height might be a issue if vehicles are tall, unless axle less design is used on stacker trailer, which might make the frame design cumbersome in way of the connection area.

 

Or just buy a tractor with a 135" sleeper, and only pull the toys when you want them.

[bmzero]

Or have the rear axle that slides like a semi trailer. Lock it in forward position when using with the fifth wheel. Move to rear position with bumper pull set up. This might also allow you to use double axles on rear and just use single tires on each axle. Using 17.5 tires might keep floor height low.

 

Dave

That's what I was referring to earlier that I wanted to avoid if possible. At this point, I still want to evaluate all of the other options, but I agree that would be a workable solution.

 

Hate to say it, but this looks like an exercise in futility. Never mind tire scrub on turns, the unequal axle loading on something as simple as a speed bump will mean both axles need to be sized to carry the weight of both trailers. There almost has to be some give between the 2 units. I'm suspecting you're trying to avoid double tow restrictions, but think a better way would to run tandem axles on a trailer, with a stacker set-up in the garage area.

I suspect most exceptional designs were at some point deemed futile. I'm not going to build it if I don't find a way to make them solid connected. Otherwise, it's nothing special. I'm more so trying to avoid maneuveratility issues. Backing up a single trailer is not an issue, especially if I can get the pivot worked out. Backing a double tow trailer is not something I want to deal with.

 

 

Thinking about what Darryl posted, why not run tandem axles on the rear trailer and use a lift up axle on the front trailer. When connected together you only use the rear axles. When split, you drop the axle on the front trailer and now use it. This is assuming you can get the proper weight loading on the various combinations.

 

It will mean you may need a truck that can handle airbrakes on the rear trailer.

 

Dave

As mentioned above, I feel like this is where I will probably end up, but I'm not in a hurry to get there.

 

 

I would bet your wife is a very special person as well.

You have no idea. I couldn't ask for better support from her.

 

Like this concept.

A belly winch on the lead would pull the toy trailer into sockets designed to rigidly join the two trailers. Great big pins to retain them. YouTube search electronic steering trailer Lamberet, and Simard Steering Trailer for some ideas on steering trailer axles, which you could use on your toy section. The two trailers turn radius would Center on the lead trailer axle. No scrubbing or huge lateral forces on the trailer connection.

 

This type of connection would not be considered a double tow if it was considered like a detachable neck lowbed and you could build it with one VIN.

 

Disadvantage would be having to tow one at a time when detached and move the license plate...

That's almost exactly my first plan of attack. I'm also cosidering a hydraulic hitch that extends out to grab the hitch on the rear trailer and suck it up into the front trailer. Then, secure the pinning mechanism(s).

 

If they are towable separately, then they can not be "one" unit. They would be two units.

Seems reasonable.

 

Making it a rigid pair would not work as the wheel scrub would be quite bad. But if you separated the two a bit further and connected them like the articulated European buses it could be interesting.

Now add the doors in the back of the front unit, the door in the front of the rear unit, put a walking sliding platform over connection stuff between the two, add an accordion cover between the two, now if officer 5r stops you you could argue, "But Sir, it is really one unit, only hinged and articulated in the middle !"

Incidentally, understanding wife is essential, I have one.

I like your suggestion of a walk through door between the two units, however, my requirement for a rear deck makes that a little harder. As mentioned above, if I can't figure out a way to make them rigid, I just won't build it.

 

Will be interesting to see how you will be able to stack the Quad and the Scion in under 13 feet and still keep an axle in that area too.

I'll have 20' on the floor in the rear, or at least that's what I used in the inital drawings. I can make that work with a four seat XP Turbo (~13') and a small four door car. I plan on building the RZR to drop to the ground with relocatable upper shock mounts. The RZR would ride on the top.

 

The lift gate is essential. I won't build it without it.

 

Here are features that I always wanted on my RV.

 

1. A deck that slides out (had powered is OK) from bottom of RV, complete with indoor/outdoor carpet preinstalled and railing that folds up. Sometimes, we boon dockers prefer to NOT be on the dirt.

 

2. A lounge/deck on the top of the RV, with fold up railing. Great for watching sporting events, sunsets, coyotes, bears and mountain lions that sneak into to camp at night. Or for sleeping under the stars. A spiral staircase to get to the roof would be sweet. Or, pull down stairs, similar to those used to access attics. Years ago, I met a custom RV manufacturer who had developed the idea. I think it was called a Sky Deck. the guy had fantastic ideas on how to build an RV. I suspect that his SoCal company is no longer in business.

 

3. A fuel pump that will remove fuel form "toys" before they are placed into the garage. I NEVER put my toys in the garage with fuel in the tanks. Fuel leak plus closed in garage plus spark = KABOOM.

 

4. A forced ventilation system for the garage. But, see number 3 above.

 

5. A winch in the floor of the garage that can be used to winch toys into the garage . . . . just in case the toys cannot make it on their own power.

 

OK, I "spent" enough of your money, for now, with my "Imagineering" (a Walt Disney term).

 

Jim

Deck - Due to my hitching needs, I think the deck will fold down as it does on our toy hauler. I'm good with that design. Quick and easy and secure.

 

Deck on roof - absolutely, probably on both trailers. The trailer will be built with that in mind from the start. My biggest issue with the deck is still having a way to keep ample solar coverage. That may require some hinging mechanisms up there. Airstream built several units a few years ago for events. They were called Sky Decks. I had a web client that owned one for rentals. We took it out a few times to races. Super cool deck on the top, but other than that, they were very utilitarian in their buildout.

 

Ventilation - the garage will have its own AC system (not roof mounted - I hate RV air conditioners with a passion).

 

Winch - the RZR will have a winch on it. I don't think that would be necessary in my case, but building the provisions to attach one to the floor would probably be good foresight.

 

I really appreciate all of the suggestions and feedback. This will be a lengthy process and I'm in no hurry to strike a welding arc...

[peety3]

I truly doubt it's possible, as you'd either have to overbuild it for rigidity (so everything would mate up just fine) or overbuild the junction area so it could all mate with strength, or build it with so much flex to accommodate the individual units' flexing down the road that it'd be a box of jello. I also see huge weight&balance challenges with respect to axle placement, and a likely need for a third (or first) air line that's not red (emergency brakes) or blue (service brakes) so you can tie together the air suspensions (which would equalize the loading).

 

A couple of real-world things to note: FDNY used to love the Aerialscope 75' and 95' aerials, but their design traditionally required 2 front stabilizers (plus two mid-mount "tormentors" and two rear stabilizers). For a while, they used Seagrave split cabs: the driver/officer area and half of the wheel well (and up) would tilt forward for drivetrain maintenance, while the rear half of the cab (4 firefighters who would kick butt and take names in no time flat) remained on the frame. They discovered that the 2 front jacks would impart too much stress on the cab junctions, so they switched to an oversized single jack in the center. That complicated the radiator/grille placement so the cab could still tilt, etc.

 

A station I previously volunteered with had an E-One "Hush" pumper with a rear engine. See http://www.windcrestfire.org/appartus/fullstory/item_id/3313 for a page and photo. The engine is in the back, and if you look closely at the enlarged pic, you'll see the rearmost compartment is framed out separate from the rest of the body. One bolt on each compartment can be removed (it's under the truck), and the whole compartment can slide aft about 8' to reveal the engine. That was a $10,000 option, apparently, but it's about the only way to reach the power steering fluid check/fill since it's on the frame rail. With only a slider track at the top and a bolt at the bottom, I'd be surprised if that unit wasn't sitting on the side of the road separate from everything else after a wreck.

[Steve from SoCal]

You design is 53' long? That alone would limit access and put you well over 65' OAL, unless you had a COE. I am not a "Swiss Army Knife" type myself, the logistics look clumsy. There is a fair bit of wasted space with two complete front and back end walls, the CG on the back section alone may need moveable ballast, steer axle on the back will lots of complexity and weight.

 

Somebody here has a tag trailer with a pick up inside, I would rather risk double towing that set up and use the pick up to haul the tag trailer if needed.

 

I actually have a trailer in design now with a 20' garage under the bed/bath 80" wide, 56" high for 12 feet tapering to 44" high for the remainder. The garage is designed to carry a 3600-4000 car. The trailer is 48' long 13.6" high, it is more of a reverse fifth wheel. Flat floor from the gooseneck to the bath with a couple steps up, ceiling height up is 82". It may not be ideal for off highway though, the belly is 14" off the ground.

 

Steve

[noteven]

https://www.youtube.com/watch?v=KNeBGYDRCzk

 

Volvo FH living quarters / horse van ... with rear steering tag axle ... and some nice interior appointments