TerraLiner:12 m Globally Mobile Beach House/Class-A Crossover w 6x6 Hybrid Drivetrain

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Of course, these Ketterer trailers are not off-road or even "bad-road" capable.

But Oshkosh does make a trailer -- the M1076 -- that is off-road capable. See http://oshkoshdefense.com/variants/m1076-trailer/ , http://oshkoshdefense.com/wp-content/uploads/2013/08/PLS_Trailer_6-13-11.pdf , http://olive-drab.com/idphoto/id_photos_pls_m1076.php , http://www.primeportal.net/hemtt.htm#M1076 , http://www.primeportal.net/m1076/m1076_empty_walk.htm , http://www.primeportal.net/m1076/m1076_irbi_walk.htm , http://www.primeportal.net/m1076/m1076_boat_walk.htm , http://www.primeportal.net/m1076/m1076_loads.htm , http://www.primeportal.net/humvee/m998a1hh_walk.htm , and http://www.primeportal.net/hemtt/brent_sauer/pls_dump_trailer/ :







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The Oshkosh M1076 is designed to be used with the Oshkosh HEMMT, but it demonstrates that an "off the shelf", rugged, bad-road capable trailer already exists. The dimensions of the M1076 -- roughly 8 m long, with hitch; 6 m long load-bearing platform -- would nicely complement a 9.5 or 10 m long TerraLiner. Of course, what I proposing here is the M1076 with a protective "box" on top, just like a Ketterer trailer.


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19. Re-Posting Some Videos


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thjakits and free radical, the videos you provided links for are so cool, they deserve to be reposted as embedded. First, the German truck-trial posted by thjakits:




Next, the Tatra video clips posted by free radical:




Yes, in the first video, MAN trucks rule. But that's probably only because it's a German video, and in Germany, MAN trucks dominate. If you were to post a truck-trial video from Russia, no doubt it would be packed with Kamaz trucks doing crazy things as well….

It's also worth noting that the MAN trucks in the first video often have wheels in the air too, and their frames are (almost) as rigid as a Tatra 815 frame. I suspect that most of them are adaptations of MAN-KAT military chassis.

The real contrast is not between a military MAN-KAT with straight axles, and a Tatra 815 with swing axles, but rather, between both of these rigid-framed vehicles versus trucks that have frames that deliberately flex, like the Unimog, the Zetros, or MAN commercial trucks.

free radical, many thanks for these videos of Tatra trucks with “CBE” (cab-behind-engine) designs. Tatra is indeed able to reconfigure its engine and cab locations to suit almost any customer requirement. I especially like some of the photos on the Facebook page you referenced, which also demonstrate that Tatra has long experience designing off-road vehicles that also have rear-wheel steering:





Again, see https://www.facebook.com/TATRATRUCKS/posts/733129246773483 .

free radical, are you Czechoslovakian? Because you seem to have the ability to search for Tatra videos documented in Czech, as opposed to Tatra videos documented in English. If you are Czech, welcome to this this thread!! This thread really needs a bona fide Czech contributor, given that its title is “MAN or Tatra…..”

Furthermore, as near as I can tell, the only 6x6 vehicle that has done a true “Round the World” trip, is the Tatra 815 GTC, which was documented at length in posts #284, and #288 to #304, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page29 , http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page30 , and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page31 .

There is virtually nothing available in English about the “Tatra Kolem Světa” 6x6 round-the-world expedition, and in those posts I tried my best to translate everything from Czech. So if I made any serious mistakes, please let me know!


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20. Why 6x6, and not 4x4


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I am still wedded to the 6x6 requirement, because I want the TerraLiner to be able to handle dirt roads like the G219 in Tibet, or similar roads in Russia or Latin America – see http://en.wikipedia.org/wiki/China_National_Highway_219 :




[video=vimeo;80452808]http://vimeo.com/80452808[/video]


The second and third videos posted above are especially informative: they were created by a really nice, warm-hearted Indian couple, who provide plenty of commentary. They enter Tibet with their SUV about 3:30 minutes into the third video, and at roughly 6:00 minutes into the video they reach an impasse, because the G219 road literally "disappears". They finally brave crossing through tracks of mud, and make it to the other side. The video also provides plenty of commentary about (a) the altitude (5100 m), (b) altitude sickness and their use of oxygen, and (c) the cold. Their complete trip was London to Delhi, documented in the following series of videos: https://www.youtube.com/watch?v=6WZ6sSAEAaQ , https://www.youtube.com/watch?v=TWEqrIobq0c , https://www.youtube.com/watch?v=A2Ds82xL2Ic , https://www.youtube.com/watch?v=1_OSqDxzV88 , https://www.youtube.com/watch?v=s2QVSmhQ-eU , and https://www.youtube.com/watch?v=7oBUi5g3cxw .

egn gave some more excellent arguments for 6x6 when he wrote:

Going up dunes you sometimes need a lot of speed and power per weight. Otherwise you will get stuck without power.

At our KAT meeting a fairly light 4x4 with a tuned 6x6 engine ran circles around high powered 8x8s with up to 1.100 hp. It ran up a steep sandhill at first attempt, where others needed several attempts, because they couldn't accelerate high enough on the available distance.

Sand dunes are very different to mud terrain, in which trucks with more axles have advantages. And on washboard and other roads longer vehicles with more axles and spring suspension are hard to beat regarding riding comfort. You can go much higher speed.

I tend to think of driving on dunes as “off-road” and not “bad-road” driving. Whereas driving the corrugation of the Tanami trail in Australia is most definitely “bad-road” driving, the kind of driving in which a 6x6 would have an advantage.

The excellent video that egn posted earlier in the thread makes this abundantly clear: the big 6x6 truck would probably prove vastly superior and much faster than a Range-Rover 4x4 on the really rough stretches of the G219:


[video=vimeo;47170669]http://vimeo.com/47170669[/video]


As egn suggests, size really does matter. But granted, Range Rover Hybrids have recently traversed the G219 – see posts #365 to #380 in this thread, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page37 and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page38 .

The 6x6 in the video is an Oshkosh MTVR, and MTVR that has been specially equipped with electronics so as to function much of the time as an autonomous vehicle, but also as a remotely driveable “drone” – see http://en.wikipedia.org/wiki/TerraMax_(vehicle) , http://oshkoshdefense.com/technology-1/unmanned-ground-vehicle/ , http://archive.darpa.mil/grandchallenge05/TechPapers/TeamTerraMax.pdf , http://vislab.it/defense/ , http://vislab.it/highlights-defense/terramax-at-the-darpa-grand-challenge/ , and http://vislab.it/highlights-defense/terramax-at-the-darpa-urban-challenge/ . The autonomous vehicle technology used in the Terramax was developed by “VisLab” at the University of Parma, and is no doubt the same technology as that used by Beppo Tenti's Overland 13 Expedition in 2010, Milan to Shanghai, with driver-less, all-electric minivans – see posts #222 to #224, much earlier in the thread at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page23 .

The MTVR is basically Oshkosh's rough equivalent to a MAN-KAT 6x6, except that the MTVR is a CBE design, and its frame is not rigid, and it does flex. So although I've discussed the MTVR a few times in the thread, it has not received the same attention as Tatra or MAN 6x6 vehicles.

But do note this: the MTVR in this video is running across incredibly rough terrain, filled with rocks, using Oshkosh's TAK-4 independent suspension technology…..:smiley_drive: ,,,So if TAK-4 can handle such terrain, again, playing devil's advocate, I wonder whether fully independent suspension (campo's preference) would really be that much worse than straight axle.


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21. Overall Weight


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Another technical detail: plumping for 6x6 does not mean that one can “think heavy” and go up to 30 tons. As eloquently described by Julius0377 in another thread:

On the topic of dimensional information, weights is often overlooked when traveling in Europe, and can lead to large-ish fines if not considered. Each country is different, and has to be researched individually. It does not matter if your vehicle is registered in another country, the weight classes are absolute and final, for all traveling on the road.

Here is a table of maximum weights (don't know if its accurate), the maximum weights are usually highways and other large roads, with backroads and scenic routes having lower specs (closer to 6 tonnes pr. axle): http://www.internationaltransportforum.org/IntOrg/road/pdf/weights.pdf

To give you an idea of how complex this is for the nordic countries, the maximum permissible weight in each road class for your vehicle will be calculated differently based on factors like:
*Distance between axles
*Winter or summer
*Tractor vehicle with trailer, or rigid, (and number of axles)
*How many axles the trailer has
*How many of the axles are driven (4x4, 6x4, 6x6, etc.)
*Dual wheels or single wheels
*Airbags or steel springs
*How many axles are steered
*If the steered axles are friction or forced.
*Etc....
If you create an RV thats in the very large category with axle weights close to 10 tonnes, you will not be allowed to travel a lot of backroads and scenic routes, where you would most likely want to travel. Note: a lot of truck drivers do this anyway, and it leads to problems with damaged roads.

You can get all the info you need from this link for Norway as an example, (other countries have similar information offerings, usually in several languages): http://www.vegvesen.no/_attachment/...st_title=Donna+Diesel+Truckers+guide+(GB).pdf

Part of my decision to go for a Bimobil EX480 was the weight and dimensions. It's a 4x4 with less than 6 tonnes pr. axle and lower than 3,5 metres height. I can go just about anywhere without major problems, if I had a Unicat/Action Mobil from their medium size offerings I would be more limited. I would have loved to be able to afford one, yet would have had to plan my routes differently and not so freely as I do now.

For a global expedition vehicle an engine retarder/brake is also recommended. Where there are steep mountains (the Alps, Norway) you see trucks standing by the side of the road with smoke coming from the wheels/brakes, particularly in summer.

Lastly: vehicle width is calculated without the mirrors. Only the rigid "unfoldable" parts of the vehicle count.

The pdf link that Julius provides is very useful, and suggests that the maximum weight in most countries for a 3-axle vehicle will be 26 tons, not 30 tons; and in some countries, as low as 21/22 tons:




Given what Julius wrote, I am much more inclined to go with a 6x6 that is significantly “underweight” (say, just 20 or 18 or even 16 tons), than a 4x4 that comes in very near the two-axle weight limit, at 18 tons.

This then speaks to the question of “lifting” one of the axles. Like egn, I am inclined to think that lifting one of the axles is an unnecessary complication, especially if the vehicle is very near the two-axle limit, at 18 tons instead of 16 tons. I like the idea of “aiming” for 16 tons, but it’s hard to crunch all the numbers on the titanium half-height space frame, and carbon-fiber monocoque camper box, and all the other things I want to have inside, in order to figure out what the final weight will actually be.

You suggested thjakits, that if the TerraLiner is only 16 tons, why not go with two axles instead of three? After all, Mañana is 10.74 m long overall, and has two axles instead of three – see post #212, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page22 , and see http://www.thompsons.au.com/motorhome/ . But Mañana’s breakover angle seems quite bad, and Mañana really “pushed” the allowable two-axle weight limit of 18 tons. Given the extra “goodies” that I want inside, and the full-length pop-up and slide-outs (yes, I am still designing for a full-length pop-up!), I am prepared for the vehicle to finally weigh in at 18 or even 20 tons, instead of 16 tons.

So three axles, with none of them lifting, seems the way to go.


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22. Many Thanks to All Participants for Contributing!


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Finally, as for “taking over the TerraLiner design work”, by all means, please do!!! :coffeedrink:

Again, I am really an “interiors” and “styling” kind of guy, so I very much appreciate it when you guys “think out loud” all the engineering stuff in a very systematic and clear way. campo , Haf-E, egn, optimusprime, and thjakits, your dialogue about motors, batteries, axles, and so on has been simply brilliant, and it took all my willpower to just ignore the thread, and focus on my academic work.

Given the discussion that then unfolded, I am really glad that I did…..

All best wishes,


Biotect


PS – thjakits, just one small request. If possible, please embed videos and photographs. It's a bit tedious having to track down photos on websites that may or may not exist 6 months from now……

I know that it's quicker and easier to just say, “See post #746 on the pirate website”. But often on websites photos are only visible to registered participants. And that's a lot of work to place in the laps of others, especially when they just want to see a photo, and do not necessarily want to register with a completely new discussion forum.

In other words, your ability to “communicate” your ideas visually to the rest of us is somewhat constrained by your seeming aversion to posting photographs, to clarify what you mean. Everyone else posts lots of photos, so you could too….. ...Yes, this is putting “work” and “responsibility” back in your corner, but remember, I am not the only one reading your posts. You will save lots of other people lots of work, if you do the work instead….. Because I find your ideas interesting, I am willing to do the work to track down the links; it's just that others might not be so willing.

One of the reasons I enjoy participating in the Expedition Portal, is precisely because it has very sophisticated formatting tools, and excellent tools for embedding videos and photographs. So if possible, please try to use such tools…..

free radical, same suggestion to you: much nicer if you embed videos, and post photographs….

However, if the two of you have some principled reason for not wanting to embed videos or post photographs, then no worries, just ignore the above. It's just a suggestion.

 

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13. Poll: Fully Independent Suspension versus Solid Straight Axle



At this point, I am tempted to run a poll: who seems in favor of straight-axle, and who seems in favor of independent suspension all round? So far, my guess would be:

(1) Independent Suspension, or Tatra Swing-Axle: campo, free radical

(2) Solid straight Axle: thjakits, egn

If anyone else reading this wants to chime in with their preference, and explain why they prefer one as opposed to the other, please add your thoughts to the thread!

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My vote is for long-travel IS, especially if you're wanting to use electric motors.

 

[campo]

Hi Biotect

Great Post ! go on and thanks to god that you seem to survive in your scolar environment.
You make some extra statements about your point of views for the Terraliner.
That is good and helps a lot for the overall orientation of this discussion.
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Trying to make a résumé of your Terraliner conclusions and statements I am still missing a really reason for
not using a 4x4 base instead of your 6x6 proposal.
Even at an overall weight of 18 T (pop up?) instead of my more conservative 12 to 16 ton lightweight ideas it is still
possible with 4x4 .
The only real point of advantage you mention are the attaque angles with the 6x6 vs 4x4.
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So I suppose that your idea for 6x6 instead of 4x4 must come from a designer or marketing presentation point of view. I do accept then.
Although if you (we) want to market the Terraliner concept in a later phase it will be easier to find 10 times more customers
for the "soft" 4x4 than for the "hard" 6x6
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Regards Campo
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About marketing:
You mention that the “Integrated monocoque” 4x4 concept is not on the discussion table in classical trucker
companies like Unicat and Action Mobile. Are you sure ? Maybe I need to speak with them somewhere in the next months
in order to get this confirmed.
I will also try to find out if there is the possibility that one of the existing bus and coach builders would like to (transform
the today 4x2 with back engine) build a for them 4x4 heavy off road version of an existing “monocoque or tubular frame” 9m bus.
I have a friend who dreams to replace his today heavy 6x6 RV by an integrated 4x4 RV bus/coach based “on road version”.
Because of his age.
If ever I build a next RV than I would also like to go for an integrated heavy 4x4 but in the compact 7 m length class, with side pop
out, and also < 11,9 T
So there seems to be a demand...
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Regards Campo

 

[dwh]

Heya. I'm still following along.

As to straight axle vs. independent - if you are using a portal design with drive motors at each wheel, then there is no straight axle anyway. Tying the independent drive motor/portal assemblies together with a tube across the chassis from one side to the other just seems silly to me. (Except for a steering tie rod of course.) You only need to even consider the point if you decide to go with a one drive motor per axle setup, in which case I'd still vote for independent. An independent suspension is only going to have a limited amount of travel, and will eventually encounter the bump stops, which will end up lifting the chassis just as a straight axle would. It would just happen a bit earlier with the straight axle.



As to moving the center axle forward, the issue you'll encounter is steering. As you turn the vehicle, either the center or rear axle is going to slide or "scrub", dragging the tires sideways. To have the center axle actually in the center, you'll need steering at both ends to allow the vehicle to sort of "pivot around" the center axle.

 

[Gatsma]

As to moving the center axle forward, the issue you'll encounter is steering. As you turn the vehicle, either the center or rear axle is going to slide or "scrub", dragging the tires sideways. To have the center axle actually in the center, you'll need steering at both ends to allow the vehicle to sort of "pivot around" the center axle.

OR, BOTH the center and front axles could steer, which would be better on streets so the rear won't swing out as much while turning. My .02!

 

[optimusprime]

With a 6x6 configuration, as opposed to 4x4, one big benefit would be the advantage of having the vehicles mass spread through six wheels,which would be an advantage in softer ground.
I know we're not talking about 'real off road' but imagine traversing a grassy field after heavy rain.
I know what i'd rather have,esp if the weight is kept down to say 10 -12 ton.
( i've seen the mess my 4 wheel 18 ton truck makes .........)


if you are going with electric hub motors ( for want of better terminology) then independent suspension is the way to go.
Fit air suspension, so you can raise/ lower it to the travelling conditions.

 

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Poll: Fully Independent Suspension, versus Solid Straight Axle


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(1) Independent Suspension, or Tatra Swing-Axle: campo, free radical, dwh, NeverEnough

(2) Solid straight Axle:thjakits, egn


According to dwh, the "rocks or mud messing things up in the center line of the vehicle" argument doesn't carry much weight, because eventually the center of the vehicle will lift with independent suspension, too:

Heya. I'm still following along.

As to straight axle vs. independent - if you are using a portal design with drive motors at each wheel, then there is no straight axle anyway. Tying the independent drive motor/portal assemblies together with a tube across the chassis from one side to the other just seems silly to me. (Except for a steering tie rod of course.) You only need to even consider the point if you decide to go with a one drive motor per axle setup, in which case I'd still vote for independent. An independent suspension is only going to have a limited amount of travel, and will eventually encounter the bump stops, which will end up lifting the chassis just as a straight axle would. It would just happen a bit earlier with the straight axle.

Neverenough, you proposed "long travel" independent suspension, but here you are probably imagining a progressive coil set up, so that fairly early on the center line of the chassis will also lift, as dwh just described?

thjakits and egn: how would you respond to these arguments? And how would you respond to my "devil's advocate" arguments in post #855, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page89 (standard ExPo pagination)?All best wishes,


Biotect

 

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Why 6x6 and not 4x4


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Hi campo,

Really good to be corresponding with you again! I very much missed participating here on ExPo, where everything focuses on a limited class of vehicles.

I can see your “marketing point” about wider enthusiasm for a 4x4 instead of a 6x6, although to be honest, I don’t quite understand that enthusiasm. There are just so many good arguments in favor of 6x6, even for a “shorter” vehicle that’s only 7 or 8 m long:

· Much greater ride comfort over rocky terrain and bad roads, like the G219 in China, or the Tanami trail in Australia (egn’s argument)
· Better ability to handle mud (egn’s argument)
· More wheels on the ground, so the vehicle’s mass spreads across six wheels instead of four, which would also be an advantage when wheels are deflated, crossing sand (optimusprime’s argument)
· Greater redundancy: one tire can blow, and the vehicle will still be able to continue travelling for a limited period
· Wider wheel base possible, allowing better arrival and departure angles
· Reduced inter-axle distance, so better “break-over angle”, and less possibility of the vehicle “turtling”, especially in an arrangement where the three axles are spaced evenly, and the inter-axle distance remains less than 3.5 m
· With three axles, the TerraLiner body becomes massively underweight relative to allowable weight: three axles allows 26 tons, but the vehicle will be only 18 or 20 tons. Whereas with two axles, the TerraLiner body would weigh very near the limit of 18 tons. And this does seem to be “pushing things” a bit too close….

See post #886, “Axle Locations”, post #891, “Why 6x6 and not 4x4”, and post #892, “Overall Weight”, all just above.

And no doubt there are additional arguments…..

Anyway, it’s good to be engaged here again for a few weeks (until Christmas), and to see such an immediate response. Now just waiting to hear from egn, Haf-E, and especially thjakits, because I took thjakits to task on a few key important issues, like TerraLiner windshield design…..:sport_box (see posts #871 to #875, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page88 ).

:sombrero:


All best wishes,


Biotect

PS -- campo, your images and/or links for Volvo’s new independent front axle suspension in post #828 did not work; see http://www.expeditionportal.com/forum/threads/124789-Fully-Integrated-MAN-or-TATRA-6x6-or-8x8-Expedition-RV-w-Rigid-Torsion-Free-Frame/page83 . Would you be willing to post these images again? But great images in post #829 of the independent suspension for the Dakar GINAF.....
...

 

[dwh]

From what I see, Tatra (and Mogs) generally don't have a lot of *up* travel in the suspension. But they do a fantastic job of allowing the wheels to "droop" and remain in contact with the ground. That's perfect for normal use, going slow and crawling. For racing, trucks need more up travel to soak up bumps at speed.

For a rather extreme example of what I was saying about encountering the bump stop and lifting the frame, see the zebra striped truck at 5:24 in this vid:

 

[NeverEnough]

you proposed "long travel" independent suspension, but here you are probably imagining a progressive coil set up, so that fairly early on the center line of the chassis will also lift, as dwh just described?

Biotect

"Long travel" is relative and given the theoretical nature of this thread, best not to take anything I say too literally because I'm just shooting from the hip. I consider systems like the TAK 4 to be long travel for a heavy truck. Customization doesn't seem to be a limiting factor for this theoretical build, so I figured the same goes for the suspension, complete with an electronically air-adjusted coil-over assembly.

And a little fun trivia: my buddy was flying the chopper for the Top Speed unmanned MTVR vs. Range Rover episode. That's a cool machine!