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

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4. IVECO Factory-Based Customization?


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I tried researching IVECO's website a while back, to see if they offer any kind of similar "factory-made" customization, but could not seem to find anything equivalent to the PDFs above about MAN's MCC. But that doesn't mean that IVECO doesn't provide the service. Like MAN, IVECO is a very large, diversified company with various divisions, and just a cursory glance at the main "global" website suggests that at least its "IVECO-Astra" division would be very open to customization -- see http://www.iveco.com/corporate-en/company/pages/about.aspx and http://www.iveco.com/corporate-en/company/pages/iveco-astra.aspx .

Recall that the Tonto 6x6 is based on an IVECO "Trakker" chassis, which classifies as a commercial truck, albeit one designed for off-road use -- see http://www.iveco.com/corporate-en/company/pages/iveco-commercial-vehicles-.aspx , http://www.iveco.com/uk/products/pages/new-trakker-hi-reliability.aspx , and http://www.iveco.com/southafrica/products/pages/new-trakker-hi-reliability.aspx :



[video=youtube;B7E32lHXZI8]https://www.youtube.com/watch?v=B7E32lHXZI8&list=PLQTMxZgjMeTvKSn8ht70Ilnh xmC6kR0AY&index=1[/video] [video=youtube;a56O5l2GxBs]https://www.youtube.com/watch?v=a56O5l2GxBs&index=2&list=PLQTMxZgjMeTvKSn8 ht70IlnhxmC6kR0AY[/video]



However, on IVECO's "Trakker" webpages there does not seem to be anything to suggest that its 4x4 or 6x6 chassis frames are especially rigid -- see for instance http://www.iveco.com/en-us/press-room/kit/Pages/Trakker_ar_in_brief.aspx , http://www.iveco.com/en-us/press-room/kit/Pages/Trakker_ar_detail.aspx , http://www.iveco.com/en-us/press-room/kit/Pages/Trakker_ar_chassis_suspension.aspx , and http://www.iveco.com/uk/products/pages/new-trakker-robust-frame-in-high-yield-strength-steel.aspx . Whereas MAN with respect to its SX-series trucks in particular, and of course Tatra, do explicitly advertise ultra-rigidity as a virtue of their chassis frames.



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5. An Important Discovery: IVECO-Astra


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Now it's possible that what's wanted instead is an IVECO-Astra HD-9 (Heavy Duty) or HDD-9 (Heavy Heavy Duty) truck -- see http://www.iveco-astra.com/en/ , http://www.astraspa.com/en/hd9/ , http://www.astraspa.com/en/wp-content/uploads/2014/05/HD9-brochure-ITA-ENG.pdf , http://www.astraspa.com/en/wp-content/uploads/HD9-brochure-euro6-GB.pdf , http://www.astraspa.com/en/wp-content/uploads/HD9-sheet-chassis-euro3-6x6-GB.pdf , http://www.astraspa.com/en/wp-content/uploads/HD9-sheet-tractor-euro3-6x6-GB.pdf , http://www.astraspa.com/en/wp-content/uploads/HD9-sheet-chassis-euro5-6x6-GB.pdf , http://www.astraspa.com/en/wp-content/uploads/HD9-sheet-tractor-euro5-6x6-GB.pdf , http://www.astraspa.com/en/wp-content/uploads/HHD9-sheet-chassis-euro3-6x6-GB.pdf , http://www.astraspa.com/en/wp-content/uploads/HHD9-sheet-tractor-euro3-6x6-GB.pdf , and http://www.astraspa.com/en/technical-area/ :











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The previous PDF is useful in so far as it introduces the Astra HD9 truck, but the most interesting PDF by far is the one immediately following below, where we find written:

EXTRA STRONG

COMPONENTS

The HD9 features heavy-duty components designed to provide robustness and reliability for the most demanding off-road use, allowing for a total GVW up to 50 ton and over:

• A unique heavy-duty chassis: 820mm wide, made of sturdy high-tensile steel side members with large section dimensions (320x90x10mm) to ensure a high torsional stiffness, high stability and vehicle dynamic performance.The side members have constant and parallel section for the entire length of the frame to simplify body and components mounting operations.

• An exclusive “power-ring” rear tandem solution: designed with the highest safety standards for a limit of 40 ton to increase the strength and the rigidity of the entire chassis structure.

[video=youtube;EgZBPNvX7TI]https://www.youtube.com/watch?v=EgZBPNvX7TI [/video]



This is the very first time I've come across IVECO-Astra, and it's quite an eye-opener. Like Tatra and the MAN SX series, the Astra HD-9 is also advertised as having a chassis frame that's very torsionally stiff -- "up to 300 kN*m ".

This is a big revelation because up until now I had simply assumed that the only genuine players in the game of building 6x6 off-road vehicles with "Torsion Free-Frames" (recall the original motivating title of this thread....:sombrero, were Rheinmetall MAN, i.e. the military division of MAN, and Tatra. Seems that we can add IVECO-Astra to the short list. Also see http://www.iveco.com/corporate-en/company/pages/iveco-defence-vehicles.aspx , http://www.iveco.com/corporate-en/company/pages/magirus.aspx , and http://www.iveco.com/corporate-en/company/pages/iveco-bus-in-brief.aspx for other IVECO product lines, including a line of defence vehicles that needs to be researched further.....


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6. Torsional Rigidity in Rosenbauer Fire Trucks


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Another thought that occurred to me a very long while back, is that perhaps the best manufacturer for the TerraLiner's "bare bones" base-chassis might be Rosenbauer, a specialist in the manufacture of Fire-trucks. Fire-trucks are large vehicles, many of them much longer than the TerraLiner, that have substantial bodies, and like buses their bodies are fully integrated with their cabs. But unlike buses, firetrucks tend to be designed to cope with rougher terrain so that they can access difficult building sites, jump curbs easily, etc. They also have bodies that are "heavily perforated", with lots of doors, hatches, and lockers all over the vehicle behind which various kinds of equipment is stored.

The list of Fire-truck manufacturers is a long one: E-ONE, Ferrara, KME, MAN, Oshkosh (its Pierce Firetrucks division), Protec, Smeal, Spartan, etc. Many of these make specifically "wild-land" off-road Firetrucks, like the Spartan Wildland (see http://www.spartanerv.com/wildland/ and http://www.spartanerv.com/uploadedF...d_Marketing/Brochures/SpartanERV_Wildland.pdf ), or the Pierce Hawk Extreme Wildands truck (see post #330 at http://www.expeditionportal.com/for...ss-A-Crossover-w-6x6-Hybrid-Drivetrain/page33 , and http://www.piercemfg.com/getmedia/52dc909e-bce5-4790-a48b-d46a11346a71/HawkEX.pdf.aspx ). And then there are the various ARFF vehicles (Aircraft Rescue and Fire Fighting) made by Rosenbauer, Oshkosh, Ziegler, and others. The beginning of the thread has a gallery of Rosenbauer Panther images -- see posts #17 to #22 at http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=1562410#post1562410 to http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=1562467#post1562467 .

The Rosenbauer Panther is particularly interesting as s design precedent because it is very fast (it has to be; that's a basic requirement of an ARFF), it has AWD (either 4x4, 6x6, or 8x8), and the cab is fully integrated with the camper body. I strongly suspect that when MAN teamed up with Rosenbauer, also an Austrian company, to create the Panther, MAN relied on its in-house expertise in the creation of super-rigid, torsion-free frames, in order to create a completely unified and integrated cab/truck body. The Panther chassis underneath is no doubt not any kind ordinary MAN TGS chassis. Either it's the TGS chassis strengthened in order to not flex; or it's simply a civilian version of the military SX-44 or SX-45 chassis. Just watch the first videos below, to see how the whole Panther moves as a single unit. When driving over rough terrain or cornering, the cab does not go one way, and the truck body does not go the other way:






And see the Rosenbauer channel at https://www.youtube.com/channel/UCjNBEhBfl_NEiOjJKv7bbdw .

There was a reason why I posted all those images of the Panther at the beginning of the thread: because "conceptually" at least, it nicely illustrates what a fully integrated TerraLiner would move like when underway, even when driving over rough terrain. The Panther's engine is also rear-mounted, so the cab in front does not have to hinge forward, here again suggesting a precedent for a fully integrated design.

The thread has moved very far along from the place it began, when the concern was merely possible precedents for a "fully integrated design on a torsion-free frame". The Panther is also much too wide (well beyond the 2.5 m limit), and it's top-heavy with fire-fighting foam. But even still, the videos above are "suggestive", because they do show how I would like the TerraLiner to "move" and "handle".



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7. Rosenbauer and Aluminum


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I am also interested in how Rosenbauer contracts its more "regular" firetrucks. As near as I can tell, it creates a sub-chassis out of steel, with the option of one, two, or even three (!!) rails: and on top of that it then simply bolts a very rigid all-aluminum cab, and an equally rigid all-aluminum firetruck body:







Although stainless steel is available as a material for the body of one model, the preferred material for the fire-truck body seems to be aluminum -- see http://www.rosenbaueramerica.com , http://www.rosenbaueramerica.com/fire-trucks , http://www.rosenbaueramerica.com/fire-trucks/http-www.rosenbaueramerica.com-commander , http://www.rosenbaueramerica.com/fire-trucks/aerials , http://www.rosenbaueramerica.com/fire-trucks/pumpers , http://www.rosenbaueramerica.com/fire-trucks/rescues , http://www.rosenbaueramerica.com/fire-trucks/aircraft-rescue-fire-fighting , http://www.rosenbauer.com/en/rosenb...cles/panther.html?tx_rosenbauersprachmenu_pi2 , http://www.rosenbaueramerica.com/features/fire-truck-bodies , http://www.rosenbaueramerica.com/features/fire-truck-bodies/ext-heavy-duty-body , http://www.rosenbaueramerica.com/features/fire-truck-bodies/fx-fire-truck-body , http://www.rosenbaueramerica.com/features/fire-truck-bodies/ct-fire-truck-body , and http://www.rosenbaueramerica.com/fire-truck-brochures :









Here's an old pdf about the stainless-steel body option:







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Here are some older PDFs of Rosenbauer firetruck body construction, PDFs that contain some details not seen in the previous PDFs (those below are no longer available on-line). Again, the body is constructed in aluminum:









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What particularly interests me is just how incredibly rigid these aluminum firetruck bodies are (they need no support from the steel ladder-frame rails below), and yet how "porous" or perforated they are. They are literally packed with storage lockers and trays that slide out and down, especially the "Rescue" models of Rosenbauer firetrucks:









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8. Learning from Rosenbauer's Firetruck Aluminum-body Construction


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I am probably being completely impractical from a weight point of view when I say this, but images like those above get me wondering whether TerraLiner structural design might learn something from Rosenbauer firetrucks. I understand that up above the TerraLiner's aluminum space-frame will need to be kept as light as possible, constructed in much the same manner as Newell and Kimberley , with either a fiberglass shell or very light and thin aluminum skin on top of the space frame. The only really "heavy" pieces of metal will be steel roll-hoops, of the kind one sees in schematics of MAN bus construction (in red):







For extensive discussion of aluminum space-frame construction, see pages 73 and 74 earlier in the thread, posts #722 to #736 at http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=1672442#post1672442 and following.

But the interior of the TerraLiner will certainly have walls, partitions, a kitchen counter, perhaps other "built in" furniture, and so on. Also, the first half of the camper will ahave an internal "second floor" area much like a UniCat Pop-Up, where the bedroom will be. So I can't help but think that TerraLiner construction might learn a thing or two from how Rosenbauer uses aluminum to put together the bodies of its firetrucks. I wonder about the actual weight of Rosenbauer's aluminum firetruck bodies, independent of the rest of the vehicle (e.g. the steel ladder frame below), and when "empty" and not yet fitted out? They look very solid, much more solid than the tubular space-frame pictured immediately above. But I wonder what the weight difference might actually be, for a given amount of cubic volume?


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At least one expedition motorhome has been constructed out of the shell of an Oshkosh M1000 ARFF (Aircraft Rescue and Fire-Fighting), in other words, the shell of an airport fire-truck -- see posts #333 and #334 for many more images of this expedition motorhome, at http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=1604505#post1604505 :







Yes. this is how airport firetrucks once looked -- all boxy and snub-nosed.....








......until both Rosenbauer and Oshkosh came out with ARFFs that now look much more "dynamic", fast, and responsive; ARFFs like the Panther and the Oshkosh "Striker" -- see http://www.oshkoshairport.com/en/ARFFTrucks/NewStriker.aspx , http://www.oshkoshairport.com/en/ARFFTrucks/NewStriker/Striker3000-(1).aspx , and http://www.oshkoshairport.com/en/ARFFTrucks/NewStriker/Striker4500.aspx :






And see the YouTube channel at https://www.youtube.com/channel/UCCqdHFso1YSsBwNnqRa6uvw , for Oshkosh Airport Products.

So suggesting that TerraLiner construction might learn something from firetrucks, is actually not that crazy. :sombrero:



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9. The TerraLiner Cab Area: Sculpted in Aluminum by Rosenbauer?


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Finally, here's a full set of images of Rosenbauer's "Commander" fire-truck, images that show just how crush-proof the front cab is, even though it's made out of aluminum:









Needless to say, a motorhome's camper box can't be made this way, because it's just too heavy. But I'm no enthusiast for going in the opposite direction, merely constructing a rectilinear camper box out of FRP sandwich sheets that are just glued together. Instead, as already indicated, for long-term wearability and strength, Newell's way of doing things -- robust aluminum framing, covered by a welded aluminum skin, insulated, and all thermal bridges eliminated -- seems the way to go. But it's interesting that Rosenbauer builds its trucks in much the same way as Newell builds its motorhomes, or Kimberley builds its camper vans: steel for strength below, and then aluminum for the body on top, for lightness.

In addition, even though the whole camper box could not be built this way, I still wonder about the Cab Area specifically. Newell uses fiber-glass end-caps, because the front and back of its motorhomes have lovely curvilinear detailing designed by Porsche. No doubt Newell uses fiberglass because laying up fiberglass in a mold is much less expensive than hammering out the curves of each and every end cap in aluminum. But as I will suggest a bit further along in the thread, for the TerrraLiner's Cab Area something more like the Rosenbauer aluminum cab pictured above seems the way to go, structurally speaking. It's clear from these images that, in the right hands, the TerraLiner's aluminum end-caps could be beautifully curvilinear -- see post #2280 at http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=2001259#post2001259 and following, for further discussion.


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10. Structural Design Conservatism


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I know that thjaktis and campo think that the TerraLiner should be designed "from the ground up" as a semi-monocoque space-frame, one in which the whole camper body contributes to the torsional stiffness required. But there are just so many advantages to having a Tatra backbone tube, a more conventional ladder-frame, or a steel-truss bridge-like structure, do most "work" of providing torsional stiffness for the vehicle instead down below, with the camper box framed more lightly in aluminum above. That aluminum framing above can also contribute torsional stiffness, too; but the main work gets done by the steel below.

For instance, this concentrates the structural weight of heavy steel low down in the vehicle, thereby allowing the upper part of the vehicle, i.e. the fully integrated camper shell proper, to be much lighter, and the TerraLiner then has a much lower center of gravity. I've written quite a bit on this topic that I don't want to post just yet. But for now suffice it to say that a "Titanium Space Frame" is a complete non-starter, because the huge barometric chamber that would be required to weld such a large frame simply does not exist, and is unlikely to be created any time soon. I don't want to go into the details at present, but it seems to me that Kimberley's "Hybrid steel-aluminum" chassis gets the mix of materials and overall engineering right -- see http://info.kimberleykaravans.com/b...onsumption-with-Lightweight-Off-road-Caravans , http://info.kimberleykruiser.com/improve-your-fuel-consumption-with-lightweight-off-road-caravans/ , and http://www.kimberleygroup.com.au/im...-caravans-Brochure-pages-20052015-low-res.pdf . The frame underneath that's designed to absorb all the stress of road travel should be made of steel, and not aluminum, for a number of good reasons. And then on top of that the fully integrated camper shell should built out of combination of aluminum and fiberglass, for a number of additional good reasons.

Granted lots of other possibilities exist, like an aluminum skin on a galvanized steel frame, or FRP construction; see in particular the very interesting discussion at http://www.expeditionportal.com/forum/threads/146453-ALU-skin-on-galvanized-STEEL-frame . There's also MAN's innovative "segmented side-wall" system implemented in its "Lion City" transit buses, which allows just individual segments to be repaired/replaced "quickly and inexpensively by the customer without the use of special tools" -- see http://www.bus.man.eu/global/en/city-buses/man-lions-city/efficiency/Efficiency.html , http://www.bus.man.eu/global/en/city-buses/man-lions-city-hybrid/efficiency/Efficiency.html , http://www.bus.man.eu/man/media/en/content_medien/doc/business_website_bus_master_1/Lions_City.pdf ,http://m.man-mn.com/system/product_..._LionsCity_Broschuere_2012_ENG.pdf?1354107166 , and http://www.neoplan.se/uploads/files/lions_city_2014_en.pdf . And sure, the camper shell will also need to incorporate steel roll-hoops. But otherwise, the TerraLiner's fully integrated camper shell should just be framed in aluminum. And once one begins thinking along such lines, then the search for a manufacturer that can provide a torsion-free steel "basis chassis" resumes.

For me it's also important to imagine the TerraLiner as a vehicle that might actually get built. However, when one imagines the TerraLiner constructed as a single monocoque space-frame, the immediate question arises: who could or would possibly build such a thing? Theoretically speaking, it is possible that MAN could do so: it advertises its most recent and advanced Lion City buses as having "Torsion-Proof skeleton frames" -- see http://www.bus.man.eu/global/en/city-buses/man-lions-city/safety/Safety.html and http://www.bus.man.eu/global/en/city-buses/man-lions-city-hybrid/safety/Safety.html . Newell and Provost also build their chassis + camper-boxes as "vertically integrated" wholes; see the extensive discussion in posts #732 - #736, on page 74 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page74, or at http://www.expeditionportal.com/for...igid-Torsion-Free-Frame?p=1672458#post1672458 and following.

But building a "Torsion-Proof skeleton frame" for a bus or motorhome that travels on good roads in the First World is one thing; building one that can remain "Torsion-Proof" on bad roads or off-road in Second- or Third-World contexts is another. A manufacturer like MAN gradually built up its knowledge of how to optimize space-frame construction for buses traveling on First-World roads through decades of trial-and-error. No doubt Newell and Provost have gone through a similar trial-and-error learning process. Indeed, they've thrown 4 big slide-outs into the mix, which complicates things further, because structurally speaking big slide-outs are huge "perforations" or "holes" in the tubular space-frame shell. So coming up with an equivalent space-frame for a fully-integrated bad-road-capable motorhome seems like it would involve a considerable amount of guess-work. And what if one guesses wrong?

Whereas if instead one imagines the TerraLiner built up along lines similar to the Tonto -- a shell placed on top a pre-existing off-road-capable 6x6 chassis -- it's much easier to hope that the TerraLiner might see the light of day, and that the resulting vehicle's chassis won't hold many surprises. The off-road capable, torsion-free chassis-frames developed by MAN, Tatra, and IVECO-Astra, are proven technology: they are chassis-frames that have gone through decades of development and refinement.

Such considerations are once again inclining me to reconsider the Tatra backbone tube, no doubt much to the chagrin of thjakits and campo as they read this…..:sombrero: ..Heavy? Yes. But strong as hell, and absolutely stiff? You betcha.



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Actually, I just wrote that to provoke thjakits and campo.....:smileeek:

In truth, the Tatra backbone tube is not a good idea for a serial-hybrid TerraLiner, for exactly the reasons stated by thjaktis in post #1163 at http://www.expeditionportal.com/for...igid-Torsion-Free-Frame?p=1740093#post1740093 :

IF you keep the complete TATRA drivetrain - you are just adding the in-efficiency part of generating e-power to run the same-old-same-old with a e-motor!!

You lose twice! (generating loss and using loss) Might as well keep the Diesel drive a trans and transfer....

I think you cannot get any lower in motor count than on/per axle before you lose all advantages of the hybrid idea....

However, six electric hub-motors, or three electric motors driving three axles, is perfectly compatible with a torsion-free ladder frame of the kind made by MAN or IVECO-Astra. Tatra is not the only manufacturer that promises a torsion-free "base chassis". And given that in the case of Tatra, "torsion free" goes hand-in-hand with purchasing its very particular backbone-tube drive train, it would seem wise to opt instead for a solution where "chassis frame" and "drive train" are not so profoundly fused.

For a prior, point-by-point account of my reasoning, written mainly in response to campo, see post #740 at http://www.expeditionportal.com/for...igid-Torsion-Free-Frame?p=1672849#post1672849 .

To that prior list of considerations, I'd then like to the add the following point, one that I think really does clinch the argument.



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11. The Mercedes G-Wagen as Design Inspiration


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On my own view, it's a bit mono-dimensional to think that all aspects of TerraLiner design have to be completely revolutionary. Sure, it's more fun if as much of the design is as revolutionary as possible. But on my own view, there are certain aspects of TerraLiner design that ideally should remain as conservative as possible, and one of those is structural.

Here my thinking has become almost “anti-progressive”, a bit like the thinking of those responsible for the Mecedes G-wagen. The argument goes that it is precisely because the G-wagen's basic mechanical layout has changed very little in more than 30 years, and the G-wagen is still such a heavy machine made out of steel, with solid axles, antiquated steering and suspension, permanent all-wheel drive, a ladder-frame construction, etc. etc., that it has proven such a reliable vehicle, able to log a million miles or more in military use, and sometimes even civilian use – see http://www.army-technology.com/projects/mercedesgwagon/ , http://www.highsnobiety.com/2014/11/10/mercedes-benz-g-class-anniversary/ , and http://www.autocar.co.uk/car-review/mercedes-benz/g-class :



[video=youtube;eEjY1FPUrGU]https://www.youtube.com/watch?v=eEjY1FPUrGU [/video] [video=youtube;6eODBPgE6Mc]https://www.youtube.com/watch?v=6eODBPgE6Mc [/video]



Sure, the civilian version of the G-wagen has added all kinds of whiz-bang ultra-luxe gizmos like cruise control that uses radar, comprehensive entertainment, navigation, and communictation systems, custom leather, and so on – see http://www.quora.com/What-makes-Mercedes-Benz-G-Class-so-expensive-in-spite-of-such-ugly-looks . But otherwise, Mercedes has avoided tampering with the underyling mechanical design, because it is so proven and tested.

When I think of things that could go wrong with the TerraLiner, it's not the fancy, state-of-the-art Watermaker or AWGs breaking down that worry me, or a solar panel or two ceasing to function on the roof. If there is less solar electricity available for a few days, then so be it; the TerraLiner will use a diesel generator instead. If there's no new water actively being made by the AWG from humidity, then so be it; the TerraLiner will still have a large freshwater tank in reserve, there is still rainwater collection, and the TerraLiner will still have other filtering systems, e.g. a Seagull attached to the tap in the kitchen. Most systems in the TerraLiner will be more or less redundant, including the diesel generators and electric motors. And most systems on the TerraLiner will be potentially replaceable/upgradeable as technology advances, especially the Jenoptik/Steyer diesel generators, lithium battery banks, ultra-capacitors, and electric motors. As already discussed in the thread, I've been imagining the TerraLiner as a bit like an M-1 Abrams tank, which the U.S. Army does not construct completely new, but rather, constantly refurbishes at a special factory – see post #516 on page 52 at http://www.expeditionportal.com/for...igid-Torsion-Free-Frame?p=1653134#post1653134 .

However, the most basic mechanical drive elements of the TerraLiner, and its total “container” or frame, these will not be redundant. For instance, suppose the TerrraLiner had two electric motors, one driving the tandem axles in front (Chinese Six format), and the other driving a single axle in the rear. if the drive-train for the tandem axles in front stops working, even if the single axle in back were still powered by an independent electric motor, the vehicle might be seriously compromised. So whatever drive train is used in front, had better be rock-solid and indestructible.

OF course this is also a good argument for having three electric motors instead of two, and no drive-train up front. Indeed, this may also eliminate any need for an inter-axle differential between the front two axles? A while back Haf-E had something useful to say on this topic:

I think one detail missed on the "chinese six" configuration when used on a 6x6 vehicle is that with the dual steering axles an inter-axle differential is necessary - while with the traditional single steering axle the back two axles do not include an inter-axle differential. This reduces the cost and complexity involved.

Most of the older trucks where not 6x6 but just had the single rear drive axle powered. Adding a second front steering axle was an inexpensive way to increase the payload capacity since it is not a powered axles. Since each of the four front wheels is allowed to rotate as required, tire scrubbing is minimized compared to having a tandem rear drive axle setup which will scrub tires since only cross axle differentials are included.

If the vehicle is designed for low traction surfaces only (like a truck trials rig or a snow rig) then the benefit of the dual steering axles would be substantial and a inter-axle differential is not needed (or even perhaps desirable).

I think that Tatra's include interaxle differentials between the two forward and the two rear axles - not sure what is done on a MAN type truck - anyone know if they are different?

Honestly, I am not clear about the automotive engineering issues here, and how they would translate when using three electric motors to power three axles, with a view to also eliminating tire-scrubbing. But that's the whole point: the engineering of a torsion-free, bad-road/off-road capable, 6x6 "base chassis" is a complicated affair, and might become even more complicated -- or at least just as complicated -- once one throws in a demand for a hybrid drive-train, electric motors, and so on. This is something quite specialized, something best left up to specialists that have decades of experience, and who are habituated to engineering very robust off-road trucks.

With such considerations in mind, it seems to me that the following are the most basic elements of the TerraLiner that one might want to keep “fixed”, and engineered to be well-nigh indestructible:


(a) the axles and the drive-train

(b) the steering assemblies for all-wheel steering

(c) the frame of the sub-chassis

(d) the frame and walls of the camper shell.


“Fixed”, in the sense that they should be designed for a very long service life. Rheinmetall MAN military has specified that SX series trucks should have an operational life of 30 years, and I am thinking that something similar should be true of the most “basic” or “foundational” mechanical and structural elements of the TerraLiner.

So I've been thinking that these elements should be designed as conservatively as possible, from an engineering point of view, so that they are utterly mechanically reliable, rugged, and durable. Designed so well and so conservatively that precisely because they are not duplicated elements, they won't have to be replaced for decades. Sure, this might entail revisiting straight-axle as opposed to independent suspension, and the G-wagen does have straight-axles. The actual suspension technology is another matter, which I will address a bit further along, because there are significant design reasons why I would want the TerraLiner to experiment with “active suspension” or “hydro-pneumatic” shock/struts, as opposed to progressive coil springs or airbag suspension.

Yes, I still want the exterior appearance of the TerraLiner to be curvilinear. But throughout the thread we've seen that in the case of Kimberley, this is perfectly compatible with robust aluminum alloy-framing for the camper shell, covered by fiberglass. And a curvilinear aesthetic would also be perfectly compatible with a “hybrid” steel-aluminum combination, where the camper shell was mostly framed in aluminum (the exception would be steel roll-bars), but the "base chassis" is made out of steel, and all drive-train elements, axles, steering assemblies, etc. are made out of steel.

As must be clear from this posting series, I am now thoroughly committed to the idea of the TerraLiner being completely revolutionary in other ways, for instance, its deployment of massive solar via enormous side-awnings. Or its hybrid diesel-electric drive-train. But the most basic, “foundational” elements of the house, I think, need to be designed to handle very traditional kinds of mechanical stress and wear-and-tear, and so they need to be more conservatively designed.




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12. Serial or Parallel Hybrid?


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It also seems wise to want as much of the chassis-manufature as possible to be handled by a single company.

Now granted, if the power-train were serial-hybrid, then this would something a bit exotic, especially in a bad-road and globally capable motorhome. So perhaps the powetrain would have to be sourced from Oshkosh, or perhaps put together by an even more specialized company.

However, here it's worth briefly noting that MAN has been making significant strides in various kinds of Hybrid technology: serial hybrid in its "Lion City" buses, and parallel hybrid for its TGX line of long-haul trucks. See http://www.bus.man.eu/global/en/city-buses/man-lions-city-hybrid/overview/Overview.html , http://www.bus.man.eu/global/en/cit...and-transmission/Engine-and-transmission.html , http://www.bus.man.eu/global/en/city-buses/man-lions-city-hybrid/cockpit/Cockpit.html , http://www.bus.man.eu/global/en/cit...senger-compartment/Passenger-compartment.html , http://www.bus.man.eu/global/en/city-buses/man-lions-city-hybrid/safety/Safety.html , http://www.bus.man.eu/global/en/city-buses/man-lions-city-hybrid/efficiency/Efficiency.html , http://www.bus.man.eu/man/media/en/...ss_website_bus_master_1/Lions_City_Hybrid.pdf , http://bildarchiv.man.de/index.php/main?level=0&catId=2934&mainCatId=530&catName=MAN+Lion's+City+Hybrid&countPerPage=96 http://www.corporate.man.eu/en/pres...ard-for-the-MAN-Lion_s-City-Hybrid-41734.html , https://en.wikipedia.org/wiki/MAN_Lion's_City , http://archive.is/9Foj , http://www.neoplan.se/uploads/files/hybrid_eng.pdf , http://www.civitas.eu/sites/default/files/2a_hybrid_bus_neugebauer.pdf , http://mantruck.co.kr/nhc/index/BusCatalogue_City Bus.pdf , http://www.volkswagenag.com/content/vwcorp/info_center/en/news/2014/03/sweden.html , https://translate.google.co.uk/tran...e/MAN/lions-city-hybrid-2010.html&prev=search , http://www.corporate.man.eu/man/med...ppe_en/13_140924_MAN_IAA_Portfolio_Bus_EN.pdf , http://www.corporate.man.eu/man/med...015_Busworld_2015_Lions_City_Evolution_EN.pdf , and http://kortrijk.busworld.org/uploads/exhibitors_releases/97/150608-UITP-EN.pdf ; http://www.corporate.man.eu/en/pres...ere-of-the-MAN-TGX-hybrid-concept-163584.html , http://www.greencarcongress.com/2014/09/20140928-maniaa.html , http://www.volkswagenag.com/content/vwcorp/info_center/en/themes/2014/09/MAN_at_the_IAA_2014.html , and https://translate.google.co.uk/tran...trieb-im-Fernverkehrs-Lkw-MAN-TGX&prev=search :



[video=youtube;ff1v9y-iRUI]https://www.youtube.com/watch?v=ff1v9y-iRUI [/video] [video=youtube;8VrjSZP2l9U]https://www.youtube.com/watch?v=8VrjSZP2l9U [/video]



After some further research, it has become a bit of a puzzle for me what might be the best hybrid technology for a bad-road capable motorhome that also has massive solar. I am honestly not clear whether serial hybrid as implemented so far in city buses, or parallel hybrid as is now being developed for long-distance trucking, is the most telling precedent.

Many Class-A American high-end motorhomes are really just converted bus-shells, for instance, the premium Class-A motorhomes that use a Prevost chassis as their base. But bad-road and off-road capable motorhomes of the kind made by Action-Mobil will typically use a MAN truck as their base. Yes, a globally capable motorhome will be a "long distance" transport application, so perhaps parallel hybrid would be the best fit. But MAN, Volvo, and others are also thinking this way because they are mostly designing tractors that haul separate trailers. Their trucks won't have a guaranteed source of supplementary solar power on the roof, one that might more than make up for the comparatively low power-to-weight ratio of batteries in comparison to diesel. If the TerraLiner had truly massive solar, more than what's needed to power its camper systems, then the TerraLiner would in effect be constantly "tanking up" every time there's sunshine. And that might out-weigh the low power-to-weight ratio of batteries. And then there's the matter of electric motors providing instant torque, a not-so-trivial consideration when bad-road or off-road driving, which is perhaps the main reason why Oshkosh is developing full diesel-electric hybrid so aggressively, even for trucks engaged in "military long haul".



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CONTINUED IN NEXT POST
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[biotect]

.
CONTINUED FROM PREVIOUS POST

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13. A single manufacturer for basic mechanical and structural integration


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In any case, I will re-address the question of serial versus parallel hybrid in a future posting series. But ideally everything else -- the stiffened frame, the axles (whether straight or IS), the suspension technology, the all-wheel steering, etc. -- should be put together by a single manufacturer. And if a company like MAN could also handle the hybrid power-train, all the better. Because clearly, having a single "big name" manufacturer handle the total systems integration of the chassis and power-train would be strongly preferable to a completely bespoke creation.

So I find myself returning again and again to the simple idea that the TerraLiner's "base-chassis" should made by Tatra, MAN, or IVECO-Astra, with the fully integrated camper shell then built on top of that. As the previous posts demonstrate, all of these manufacturers now have business models in which the creation of one-off custom vehicles is nothing special, and no problem at all. One doesn't have to order 10 five-axle trucks from MAN's Modification Competence Center in order to get a reasonably good price. And it should be perfectly possible to order a 6x6 "Chinese-Six", tandem-axle-forward base-chassis from either MAN or IVECO-Astra, for not too much of a price-premium. Automotive manufacturing has radically changed over the last few decades, and not only have automotive companies been moving towards more of a "batch-manufacturing" model, they have also been deliberately designing wide latitude for individualized customization into their production systems.

Now granted, what's needed for the TerraLiner is not a super-robust, very heavy chassis frame built for a mining truck that can haul tons and tons of rocks. But what is wanted is the expertise of a company like IVECO-Astra in creating torsionally super-rigid truck frames that will not flex in bad-road and off-road conditions, such that a fully integrated camper shell can be constructed on top. If any companies could come up with a well-engineered, light-weight version of a torsionally rigid frame, a frame designed to carry the weight of the TerraLiner camper shell and its various fuel and water tanks, and not much more, it would be companies like MAN, Tatra, or IVECO-Astra.

Here it should also be emphasized that factory-customization is very desirable, because work done by MAN or ASTRA-Iveco would be guaranteed worldwide by these companies themselves. Whereas if a Malaysian company is stiffening IVECO 4x4 and 6x6 Trakker chassis frames which are then sold as "Tonto" mining buses in Australia, by another company acting merely as distributor......? Well, who is ultimately responsible if something goes wrong? Does the chassis-modification work of the Malaysian company void IVECO's warranty?

In any case, many thanks 93Canter for posting about the Tonto, and encouraging a revisit of IVECO's website. The ASTRA-Iveco HD-9 is a very big surprise, and if you hadn't posted about the Tonto, I wouldn't have come across it!!



****************************************


14. Australian Transportation Design and Manufacturing Excellence


****************************************


In closing, just curious: how did you come by an opportunity to photograph the underside of a Tonto? Are you based in Australia?

If you are, just wanted to add that Australia does some really cool things in transportation design. Which is a bit surprising, because Australia is a comparatively small country, whose economy is based mainly on resource-extraction and not manufacturing. For instance, have you heard of Australia's Austal fast catamarans, both civilian passenger/vehicle ferries and large military vessels? See http://www.austal.com/en/Home.aspx , http://www.austal.com/en/about-austal/Overview.aspx , http://www.austal.com/en/about-austal/the-austal-story.aspx , http://www.austal.com/en/about-austal/production-facilities.aspx , and http://www.austal.com/en/products-and-services/commercial-products/ferries-vehicle-passenger.aspx:






Even though Austal began as an Australian company, it now seems to be poised to supply at least 20 % of the U.S. Navy's future ships, because it's so creative, technology-driven, and innovative. It's all the more remarkable that Austal was founded only in 1988.

At the other end of the size-spectrum there are Weta trimarans, designed and made in New Zealand -- see http://www.wetamarine.com , http://www.wetamarine.com/why-weta/ , http://www.wetamarine.com/our-story/ , http://www.wetamarine.com/the-boat/, and http://www.wetamarine.com/weta-in-action/:






These are just two examples, and earlier in the thread I've also discussed Kimberley's T3 off-road trailers (Australia), Paradise Motorhomes (Australia), FPB Fast Patrol Boats (New Zealand), and many others, including the Australian company that distributes the Tonto -- see http://www.kimberleykruiser.com , http://www.kimberleykruiser.com/offroad-caravan-model-summary-3-models , http://www.paradisemotorhomes.com.au , http://www.setsail.com , http://www.setsail.com/intro-to-fpb-program/ , http://www.setsail.com/fpb-64/, etc.

I am partly Canadian, and Canada has a population about 35 % larger than Australia's. But if memory serves, in this thread I have discussed only one Canadian-made transportation product at length, namely, the Foremost TerraBus -- see http://foremost.ca/foremost-mobile-equipment/wheeled-vehicles/terra-bus/ . The passenger cars on the Qinghai-Tibet railway are made by Bombardier, also a Canadian company.

In short, for a transportation designer, Australia and neighboring New Zealand sure do seem like exceptionally cool countries.....:ylsmoke:

All best wishes,



Biotect
,,,

 

[thjakits]

Heeey Bio!

How is it goin'?!!


IT seems we come full circle on the chassis stuff!!

- Tatra is no good for what you need - UNIQUE system - NO good for 3rd/4th world "fixit" situation....

- Whatever the newest ladder frame available, it will NOT be "Fully Integrated, ....Rigid, Torsion-Free ..."
[I even bet, it is actually designed with a calculated flex!]

About 20000 posts ago I suggested to look at "Fully Rigid Box, incl. Drive Cabin on top of Semi-High Flex frame a la Unimog"
- the ONLY "RIGID, TORSION-FREE" frame is via Space frame and or Spaced Composite (Honeycomb) or some combination off this, anything else WILL have flex to some degree - I don't say you can't change your mind, but what it heads towards now is far off from what you put up as "doctrine" - 20000 posts ago.....

- Also, you mentioned I have gone silent on the solid axle - ...well, I argued the reasons FOR a solid axle and I still believe it is a better/simpler solution for what you need for Terraliner - just no use repeating the same arguments. You believe it has to be independent for comfort, because people who actually have a truck with solid axles suggested independent - just the same people do NOT have AIR SUSPENSION! ....go and try out both and you will find NO difference in comfort at the speeds expected for Terraliner - just WAY less moving parts and points for the solid axles (....or an electric drive "copy" solid axle) - plus, I probably would have some air/hydro hybrid suspension designed, with "expanded flex-mode capabilities"

Even if I would have a separate e-motor for each wheel or axle and prefer to chassis-mount the motor, I STILL would get a DeDion axle to simulate the solid axle, simply because I believe it is the better suspension design for a Worldcruiser of this size.... (IF there is
advantage to driving or driving safety with a independent suspension - to me the simplicity of the solid design is worth it over the complexity of the IS)

I know you keep listing revised End User Targets - but again (like I said 20000 posts ago), as you keep "softening" the capability requirements, you also eliminate the need for most of the drivetrain and off-road capabilities. The same goes for 3rd world repair and "fix-ability" - you mention a dealer and service network.
[We are now down to "elderly couples looking for full comfort travel and surf fans" - by now you need AWD ONLY, because you need the re-gen capability, not really the off/dirt road capability anymore - most dirt roads you won't need AWD to drive them..... Yeah you got a jet-RIB planned now too - well, you mostly WON'T launch it unless you have a boat ramp, no need for AWD...]

Well - where I would want to go, I'd be happy to find a simple tire-shop with a welder within 300 km..... let alone a Terraliner Service Station....
[Again, don't get me wrong - YOU build Terraliner for what YOU want!! Does it still have anything to do with the initial requirements list?? You tell me...]



NOW - the REAL reason for this post:

I remember, ALSO 20000 posts ago, that we discussed parallel and serial hybrid, batteries and how big a Gen-Set the Terraliner will need.

It seems my (...our collective) opinion on the state of electric power storage is a little behind the curve!


Check this: http://onestepoffthegrid.com.au/all...in-melbourne-heading-to-sydney-on-one-charge/



IF these guys can pull off a 1000km+ range full size bus - charging time won't really matter anymore, as long as you can do it within 8 hours or so.
[YOU, the owner/driver will probably need re-charging before the truck does!]

In Europe you won't legally do more than 800 km per driver/day - even with more than one driver - not much purpose to haul more than 10 hrs at a time in a PLEASURE vehicle!
[And you STILL could extend the range by keeping the SMALL gen-set running all day....]

SO - what are the implications for the Terraliner Powertrain, should you decide to pursue the FULL-ELECTRIC route?

Actual battery charge levels and speed pending, you should get away with a rather very small gen-set for a 8-hour full recharge of the 1000km+ range battery set - WHAT is the MAX, worst case scenario for the Terraliner power needs?

Pitchblack night/ total overcast
NO breeze whatsoever
-50°C
NO energies stored (hot water, battery)

To run all this at once (plus electronics and white line) - would that same power be enough to charge the battery pack in 8 hrs too?

[Remember, you hardly ever would face this situation - you won't run the washing machine and dryer when you are dead in the cold, have empty batteries and need to heat water, you also would probably see some sun light eventually and/or have some air moving]

At what I get is - you really won't need a 360-500hp to "serial drive" the Terraliner - you only need enough to charge within 8 hrs + in the worse case run a few utilities at the same time, should be nowhere near the above power-level.....


Damn! You think you got it figured out and then someone comes with this 1000+ range Electric Bus! :sombrero::sombrero:



I'd say, call your engineering buddies and tell them to go back to the drive train drawing board!!
[You might want to get an electric engineer on board asap, IC engineers become obsolete FAST:smileeek:]




Cheers all,

thjakits

 

[biotect]

Hi thjakits,

Good to hear from you!

I've got to run, but wanted to get in a quick reply on the chassis issue. The difference between our views about the chassis probably comes down to the fact that I am now thinking about the TerraLiner moving beyond the mere vaporware phase. I am asking myself practical questions like, "Who will build it? And once built, who will repair it?"

I am also thinking in terms of a two-fold classification of design elements: those that can be and will be replaced, versus those that need to be designed to last 30 years. Please see post #1886 directly above, in which I discuss the virtues of "Structural Design Conservatism" with regard to the basic chassis, and the most basic mechanical systems. Here the G-wagen should serve as useful precedent. The TerraLiner can only be "upgradeable", with the capacity to incorporate new technological innovations as they arise -- for instance, new diesel generators, new batteries, new solar panels, etc. -- if the underlying "scaffolding" is rock-solid, and still is in good working order 30 years later.

So either you agree with this fundamental point made in post #1886, or you don't. If you still don't agree, then no worries, we can just agree to disagree. But also try re-reading post #740 again, at http://www.expeditionportal.com/for...igid-Torsion-Free-Frame?p=1672849#post1672849 . I just re-read it myself, and the points made in that post sound even stronger now than when I first wrote it.....:sombrero: ..It provides a whole list of cogent arguments in favor of some kind of combination of a steel sub-chassis + aluminum/fiberglass shell, arguments that neither you nor campo ever responded to directly. They are really good arguments, thjakits, and on my own view, they kind of deserve a measured, reasonable, and equally cogent response. Wouldn't you agree?

Now you can just re-assert that TerraLiner structural design must by hyper-innovative, and that it must be a tubular space-frame. But merely re-asserting your point of view is not the same thing as providing arguments to back up your position. Mere re-assertion is kind of dogmatic/aggressive, and some would say even quasi-Fascistic. Whereas argument is more "dialectical". When one commits oneself to arguing instead of merely asserting, one commits oneself to doing the hard work (and often it is hard work) of figuring out the reasons why one thinks the way that one does; and then trying to communicate those reasons to others. And in more discursive, dialectical argument and counter-argument, one commits to truly listening to the reasons that others give for their contrary point of view, and responding to those reasons with additional, carefully reasoned, well-articulated arguments. Merely re-asserting one's position is not counter-argument. It's just dogmatic stubbornness.....

Also, please note that I am not thinking of just taking an SX-44 6x6 chassis and throwing a camper box on top. I spent quite a bit of time in the previous 20 posts or so discussing the "open-ness" to customization of both MAN and IVECO-Astra, in order to underscore the idea that both companies would be very amenable to manufacturing a custom TerraLiner subframe. MAN is exceptionally clear on this issue: MAN will create just about any chassis you like, narrower, wider, shorter, longer, as well as more robust and more torsion free. I figure that because MAN has so much experience with the MAN-KAT and the SX series of military trucks, all that would be required is for MAN to source design and engineering expertise already available in-house, in order to come up with a torsion-free chassis frame that is optimized for the camper weight-load of the TerraLiner.

Again, I completely agree with you that there is no need for an SX-44 frame that has the potential to carry a very heavy payload. But where you and I disagree, is that I see an option that perhaps you do not see: the option of a much lighter but still torsion-free version of the SX-44 frame, custom-built by MAN's commercial division, and custom-built for not that much of a price premium, because custom-manufacturing is standard operating procedure for MAN. And I get the feeling that IVECO-Astra would be wiling to provide the same service. To emphasize, so that this really sinks in: in both cases, both companies are already set up to provide a highly customized sort of service. This level of customization is part of their standard business model, and it's nothing exceptional for them. They want to do this kind of work, and MAN very actively advertises its customization capabilities.

Granted, one would have to pay more for customization, but I would be curious to know how much more. And I'd like to know if it's really all that much more. It would be interesting to know the price difference between a "standard" TGS 6x6 chassis (if there even is such a thing!!), versus a "standard" SX-44 chassis, versus a chassis of the kind that the TerraLiner would need.


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Here's one more reason why it might be desirable to structurally separate the camper box from the chassis sub-frame: aesthetic.

As I suggested in post #742, when one uses a metal frame for the camper box, there arises the problem of thermal bridges -- again, see http://www.expeditionportal.com/for...igid-Torsion-Free-Frame?p=1672849#post1672849 . Blissmobil recognizes this problem when it proposes a camper box framed in steel, and it proposes a solution: Aerogel insulation. See http://www.blissmobil.com/en/produc...the-body-18ft/232-thermal-bridge-free-21.html :







But investigate Aerogel technology a bit more deeply, and it becomes a bit worrying in contexts where the gel is subject to constant vibration. Aerogel has never really worked in clothing, because after a year or so the gel turns to powder. Sure, flexible Aerogel now exists that can be wrapped around pipes to insulate them in industrial or home-improvement contexts. But it gets wrapped once, and then it's left alone, around a pipe that remains stationary and doesn't shake (assuming the pipe is not in California, i.e. in a place that has earthquakes....:sombrero: ). Whereas in the context of an expedition motorhome, the Aerogel in a Blssmobil box just will get shaken, a lot. I am not certain about how well it will or will not hold up. But I know that there's a "question mark" here. For a reasonably full discussion, see posts #156 and #157 on page 16, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page16, or beginning at http://www.expeditionportal.com/for...igid-Torsion-Free-Frame?p=1570369#post1570369 and following.

So is the solution to go instead with FRP (Fiberglass Reinforced Plastic) sandwich panels, simply glued together, as per ActionMobil or Unicat? Personally, I've always been a bit skeptical of FRP too. It was just a "feeling", a sculptor's intuition that this type of construction should be doubted. I was then happy when I read Iain_U1250's good reasons as to why FRP is a bad idea:

My camper is aluminium skin on a steel frame. I used 2mm aluminium, which is pretty strong, and whilst it may dent, a field repair is very easy and it won't crack like FPR, which would very difficult to repair in the field, or even the workshop properly.

I had two main reasons for not going with FRP for the camper, first was I plan to use the two seats in the rear to allow extra passengers, and according to the Australian Design Rules, in order to do so, I need the rear to be "substantial" and was directed by an Engineer to the ADR for buses - steel frames at various centres as a minimum. Given I need a steel frame, then aluminium became the easiest option for me.

On my build thread I have a lot of photos of how I isolated the skin from the frame, but I glued the aluminium on using Sikaflex 252, and to ensure I had a 3mm layer of Sikaflex to get maximum strength, I used 3mm rubber tabs as spacers, then as the Sikaflex started to harden, pulled the rubber out and squeezed in more Sikaflex. You need to design the frame to match the aluminium sheeting size, and I always had and extra layer of aluminium over each horizontal joint where water could pool to minimise the risk of water leaks.







My camper box (bare) including the OEM very heavy duty four point mounting frame only weighted about 440kg. I only bought 100kg of aluminium and 100kg of steel to build the box, and had a a fair amount of off-cuts. My camper walls are almost 100mm thick, with multiple layers of insulation and is full lined with a composite panel. The weight of the insulation and lining is around 100kg as well. My floor is a Aluminium /aerogel/plywood/wood composite, about 25mm thick and is also very light weight.







My camper shape was also fairly complex by comparison to the majority of square box camper people build, with a lot of angles.







The other main reason for not going with FPR panels has been the long term experience of a few owners with FRP skinned vehicles, that complain of water leaks into the FRP caused by the joints cracking on the roof caused by hitting tree branches etc, which to me is inevitable. DIY FRP is difficult, it takes a lot of experience and proper equipment, or you end up with a long term problem with the curing of the resin, if it is not 100%, then de-lamination will occur some time in the future, and I was not confident I could ensure proper curing etc. I doubt I would have been able to build.

Here you have some excellent arguments in a nutshell, about why boxy-square FRP construction might be a mistake.

For me one of the most telling reasons that Iain_U1250 briefly mentions, but does not elaborate at length, is that FRP as a construction technique only lends itself to a very boxy-square aesthetic. Indeed, FRP is a construction technique that positively determines that a rectilinear aesthetic will be the outcome for a camper box. If one doesn't want that outcome, then like Iain_U1250 and myself, one has to look elsewhere.

I would then merely repeat that I am interested in a more "shaped" camper box, more curvilinear, in the sense that a KimberleyKrusiser T3 is curvilinear:








So one of the questions I have been asking myself is,

"How could I get a fabricator to create a more curvilinear camper shell?"

There would be no point in asking Actionmobil or UniCat to do so, because their engineering commitment to FRP camper-box construction automatically necessitates commitment to rectilinear aesthetics. So too, imagine trying to get MAN or IVECO-Astra to create a custom, curvilinear, aluminum + fiberglass camper shell, as per the KimberleyKruiser T3...... Even if they were willing to do the work, it might cost a fortune. Creating shaped motorhome camper shells is simply not MAN's nor IVECO-Astra's area of competence.

Just as creating torsion-free 6x6 subframes is not Kimberley's area of competence. Or, for that matter, the area of competence of any current motorhome manufacturer. Creating torsion-free 6x6 subframes is the competence of MAN, IVECO-Astra, and Tatra, and that's about it. Creating a torsion-free 6x6 subframe, with a 6x6 mechanical assembly and drive-train, is something that Prevost or Newell just don't build, even though they do build their motorhomes from scratch. And this is also something that one would probably not want Prevost or Newell to build, because it is simply beyond their area of competence.

Now if that's true, then one could then say all the more emphatically that no motorhome manufacturer anywhere is competent to produce a torsion-free tubular space-frame shell for a bad-road/off-road motorhome. No motorhome manufacturer anywhere is competent to create a complete tubular-space-frame shell that would eliminate the need for "base chassis" from MAN, IVECO-Astra, or Tatra. Motorhome fabricators like Prevost and Newell are only competent to produce tubular space-frame shells for Class-A motorhomes that travel paved roads in the United States. Asking them to do more than this, would be asking for trouble, especially if they said "yes".

So it seems to me, given my design preferences and concerns about practical "build-ability", that it would make the most sense to have a chassis-specialist like MAN, IVECO-Astra, or Tatra create the "bottom" or "base chassis" of the vehicle. While another completely different manufacturer -- one that has experience creating integrated motorhome layouts; one that has experience with pop-ups and slide-outs; one that knows how to combine aluminum framing with fiberglass, insulation, and the reliable insulation of all thermal bridges.... for instance, a manufacturer like Newell -- would fabricate the fully integrated camper shell on top. In many ways the TerraLiner might be a very natural product-experiment for Newell, because Newell is already so specialized in high-end Class-A motorhomes that travel the United States. The TerraLiner would extend the possible territorial reach of a Newell to the whole planet. And unlike UniCat or Actionmobil, Newell is not terrified of curvilinear design, neither on the exterior of its motorhomes, nor the interiors. Just compare http://www.actionmobil.com and http://www.actionmobil.com/3-achser/globecruiser , to http://www.newellcoach.com and http://www.newellcoach.com/the-coaches/photo-gallery/ , and the images alone make the argument. Newell is very competent in the creation of shaped, curvilinear motorhome shells, shells made out of aluminum framing, with aluminum skins and fiberglass end-caps, composite insulation, and all thermal bridges reliably covered and insulated:






But the one thing that Newell could not be expected to make, is a very robust "base chassis" that can handle bad roads, and do some off-roading as well. In this video Newell emphasizes that it builds a particularly rigid "base chassis" for its motorhome, so that the camper body can be perforated by no less than four slide-outs, and remain stable and not twist. But even a Newell base chassis will not be quite the same thing as a MAN or IVECO-Astra torsion-free frame, designed to remain rigid in demanding, off-road conditions.

Now granted, as long as the TerraLiner remains mere vaporware, I can design whatever I like, and just fantasize about a rich person wanting to build it, and a manufacturer able to build it. But once we leave the imaginatively expansive vales of vaporware, and once we begin to think about actual current manufacturing capabilities and non-overlapping competences, the picture changes completely.

Furthermore thjakits, you don't seem to care about aesthetics that much, and you've made it clear that curvilinear interior and exterior design is not a value for you. So if MAN or IVECO were wiling to create a compete tubular space frame, but for cost reasons that space-frame would have to be utterly "boxy", you'd have no problem with that, from an aesthetic point of view. But I would have a problem with that.

Actually, because both IVECO and MAN have large bus divisions in which they design and construct tubular space-frames for buses all the time, I suspect that both might rather enjoy the challenge of combining the design and structural knowledge of their bus divisions, with the design and structural knowledge of their truck divisions. In other words, both MAN and IVECO-Astra may in fact jump at the chance to create the aluminum-framed fiberglass shell for the TerraLiner on top as well, and one that's curvilinear to boot, just like their bus shells. But I would remain concerned about the possible price, because although MAN and IVECO-Astra are set up for bespoke truck chassis-frame construction, I doubt they are set up for bespoke bus-shell construction. Whereas the whole manufacturing process at Newell is much more artiginal to begin with. There also remains the fact that neither MAN nor IVECO-Astra has much experience creating motorhome interiors, only bus interiors. And neither one would have much experience with slide-outs or drop-down decks, for instance.

So I've been figuring that for aesthetic as well as engineering reasons, it would be best to leave the "base chassis" to MAN or IVECO-Astra, and imagine a company like Newell doing the fully integrated camper shell on top, a camper shell that will be curvilinear, aluminum framed, with either a fiberglass or shaped aluminum skin. That way each company would be charged with doing what it does best, and would not be asked to take wild leaps into the dark, into areas that it knows little about.

All best wishes,



Biotect

 

[thjakits]

Bio .....what you call a quick reply:wings::wings::wings: (forgot that you type at hyper-speed...)

Okay - just to clear it up - the space-frame "insistence" came about ONLY because of the discussion HOW to make the thing torsional rigid.

MY approach was always via a flexible chassis. Even though IVECO and MAN (....and certainly ALL the other truck manufacturers too, Renault, Mercedes, Volvo , Scania, etc...) will build you whatever you want - they advertise stiffer or softer frames - it comes down to the proposed end-use.
[Today it really comes down to find the optimum way to reduce weight - trucks are limited to nominal 80km/h today, buses to 100km/h - so no use to invent a chassis that goes faster than 120km/h, chassis development is NOT about race-speed suspensions, it is about ECONOMY and economy ONLY - if the chassis get stiffer, it is because they can safe weight on the structure above - most likely a higher grade steel in the chassis, that does NOT need an increase in size, but because of the higher grade it is stiffer. They could have done that in the past, but possibly had trouble with fatigue cracks - of course they will sell the new product with whatever reasoning sells best! BUT at the end the MASTER-monster-über offroad truck is still the Unimog - the Unimog STILL uses a super flexible chassis....probably NOT a good idea to bolt a rigid box to it - so we are back to triangular or diamond moving joints suspension]


Here is another option - pending on the engineering advise regarding the selected chassis:

Select the chassis you want and then BOLT a Space-Frame box to it and you should also get a super-rigid structure (if this is still the goal....)

You want to make the space frame as simple as possible (straight lines) and add-on curvy-linear stuff (let the space frame carry the loads and the curves do the aerodynamics and good looks).
[Just DON'T use the above mentioned Unimog chassis!! THe Unimog chassis IS really part of the moving suspension!!]


IF you still want a rigid structure - talk to the truck makers (MAN and IVECO are your favorites at this time, but it really doesn't matter, they ALL make the same with a different flavour), they will tell you too, NO ladder frame will ever get you the stiffness of a space frame - simple engineering principles.
[YES they can make a stiffer frame/box combo, but not at the same weight]

Suspension: I have no more arguments FOR the solid axles (or in light of the powertrain I'd rather call it "solid axle like acting" - suspension).

We already saw that IS has good ground-clearance these days, KAMAZ has a nice new rig with IS and chinese-6 configuration - as posted earlier.

SIMPLICITY over COMPLEXITY for the task at hand - in this particular case, SOLID axle wins - no more to argue.....



Did you check on the link with the 1000km+ Bus?



Cheers,

thjakits


PS: I don't know about the other guys following this thread - but I am thoroughly lost by now!

I don't know what could be done about it, because:

1] TOO much general information trailing off to out of the way disciplines (trains, ships, sailboats, etc....)

2] LOTS of excellent general information of out of the way disciplines (trains, ships, sailboats, etc....)

--- I have this thread marked for ALL OVER THE PLACE references - no other source where there is so much reference in one place on a load of different things!!! ---- ...just doesn't help much with keeping focused on the Terraliner itself....

:sombrero: :sombrero::sombrero:

 

[thjakits]

Wothahellizat Mark I - rear deck:


...probably so it doesn't tip over backwards when there is a heavy party on deck! 3