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

biotect

Designer
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Given that SherpAlypto is a 6x6, for me it's a non issue. But my 2cents is that your design, while in the end could very well work out just fine, might be too expensive for even the audience. That's one of the reasons why things are as they are now. I have come to this simplified realization having just finished a year of design work with SherpAlypto. We started out with an idea and ended up with something, we thing anyway, that is very useable and somewhat 'cost effective.' my 2cents.

SherpAlypto is really interesting! Many thanks for the link to the thread, which I will need to read in full.

Fully agreed, my design will not seem "cost ineffective", at least at first. But the design agenda of the TerraLiner is different. The TerraLiner is not supposed to be a vehicle that is "cost-effective and buildable right now." Rather, the target is more like 2017 or 2018. Furthermore, the TerraLiner is a concept vehicle whose main purpose will be to "inspire" or "provoke thought". As suggested previously in the thread, it's often quite surprising what the eventual spin-offs of such blue-sky design exercises might be. See post #133 in particular, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page14 , which documents how a Nissan concept van inspired Danbury caravans to develop something similar, and more cost-effective.

Now in a thread on a website like ExPo, there is a natural enough expectation that all vehicle, engineering, and systems discussions should be "very realistic", i.e. "buildable right now". But a while back in the thread, thjakits, campo, dwh, and others helped clarify matters, recognizing that the TerraLiner should be "innovative", but not "futuristic", with a target date of 2017 or 2018. It should use technology that is in principle available right now, and perhaps even tried and tested in other application environments, but not yet in expedition motorhomes. For instance, diesel-electric hybrid transit buses do exist; there are now literally hundreds of them in operation around the world -- see http://en.wikipedia.org/wiki/Hybrid_electric_bus . So too, Oshkosh has designed and built off-road-capable military vehicles of all sizes that are diesel-electric. But nobody has yet designed and built a diesel-electric expedition motorhome.....:)

In short, even if nobody is willing to build something exactly like the TerraLiner in 2015, a few years down the road a manufacturer -- probably a mainstream motorhome manufacturer like Prevost, which is owned by Volvo -- might be inspired to build something similar -- see http://www.prevostcar.com and http://motorhome.prevostcar.com . Or perhaps an Australian company willing to experiment, like 4x4 Motorhomes, flush with venture capital from Australia's ongoing mining boom -- see http://www.4x4motorhomes.com.au , http://www.4x4motorhomes.com.au/vehicles/iveco-tonto6/motorhome , https://www.bus4x4.com.au/media/pdfs/vehicle-range/range-4x4motorhome.pdf , http://www.4x4motorhomes.com.au/vehicles/toyota-coaster/motorhome-build , http://www.4x4motorhomes.com.au/media/wysiwyg/gallery/index.html , and http://www.outbacktravelaustralia.com.au/buyers-guide-4x4-campervan/bus-4x4-coaster-4wd-campervan .

For reasons already suggested in post #883 and #884 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page89 , current market leaders in expedition motorhome like ActionMobil and UniCat in Europe, or Earthroamer in the United States, will probably not want to build a TerraLiner, because it would mess up their current business model in unpredictable ways. One might also say that these entrenched companies are smugly "self-satisfied" with their "just stick a box on the back of a pre-existing truck" solution. As such, they are probably immune to the criticism that the resulting interior space leaves much to be desired, at least when compared to current mainstream motorhomes. Whereas a mainstream motorhome manufacturer like Paradise Motorhomes in Australia was not immune to such complaints. It's then interesting that it was Paradise Motorhomes in Australia that was willing to build an expedition vehicle with a "one room design": with front seats that swivel, full-length slide-outs, and a drop-down deck. And not ActionMobil or UniCat. See post #879 to #884 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page88 and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page89 , and posts #912 to #914 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page92 .

Put another way, from the point of view of overall design, the most advanced expedition motorhomes built thus far have been Australian; and not German, Austrian or American.

All best wishes,



Biotect
 
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biotect

Designer
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Just for fun, and as a bit of a diversion from the central topic that's occupying this thread right now (i.e. straight axle versus independent suspension; 4x4 versus 6x6….), here are some examples of diesel-electric hybrid vehicles designed and built for difficult, very cold environments.


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1. Pisten Bully and Prinoth Snow Groomers in Antarctica


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Over in the “Thermal Engineering” thread, I posted the email exchange between myself and David Weimer, who has participated in a number of South Pole traverses, traverses that he documents beautifully on his blog, "Beyond the Backyard", at http://beyondthebackyard.com/category/polar-tractor-traversing/ and http://beyondthebackyard.com/2013/12/17/2013-2014-south-pole-traverse-day-41/ . David kindly gave me permission to repost his photographs on ExPo, and has already answered many of my questions about high-altitude/extreme-cold vehicles and heating – see posts #53 to #58, at http://www.expeditionportal.com/for...p-High-Altitude-Arctic-Antarctica-Tibet/page6 .

As already discussed in this thread, a go-anywhwere RTW motorhome needs a complete power train for all seasons, all altitudes, and all fuels. In addition to the range-extending engine/generator, other elements in the power-train also need to be "cold-hardened" and "altitude capable". For instance, how do Lithium-ion batteries hold up in extreme cold? And at extreme altitude? Do hybrid vehicles designed for extreme cold and high altitude yet exist?

Here the Hybrid Range Rovers that just recently crossed the Tibetan plateau might prove instructive, at least as far as altitude is concerned -- see posts #365 - #380, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page37 , http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page38 :


SilkTrail_Final_014_(70334).jpg large.jpg Range-Rovers-on-Silk-Trail-2013-5.jpg
RR_Silk_Trail_2013_Update_6_011013_08_(68742).jpg RR_Silk_Trail_2013_Update_6_011013_06_(68740).jpg RR_Silk_Trail_2013_Update_6_011013_13_(68747).jpg


However, for extreme cold, the only examples of hybrid power-trains that I've come across, so far, are vehicles designed for “snow grooming”: for preparing ski slopes in the winter. The two leading manufacturers are Pisten Bully and Prinoth, and these same vehicles have been used extensively in Antarctica.

In our correspondence, David Weimer mentioned that originally the “lead” or “front” vehicle of the South-Pole-Traverse – the vehicle equipped with “GPR” (ground-penetrating radar) – was a Pisten Bully. But they've since upgraded to a Prinoth BR 350. Although these snow-groomers are typically meant for more temperate winter climates, it seems they are ideally suited for the South Pole traverse, working as light-weight vehicles to detect crevasses in advance of the other vehicles, with GPR attached to long booms:


01aaaa-copy.jpg gpr.jpg




So I looked up both manufacturers.

Here are the links for Pisten Bully: http://www.pistenbully.com/en/company.html , http://www.pistenbully.com/en/products.html , http://www.pistenbully.com/en/products.html , http://www.pistenbully.com/en/download.html , http://www.pistenbully.com/en/download/brochures/pistenbully.html , http://www.pistenbully.com/en/products/pistenbully-600.html , http://www.pistenbully.com/en/products/pistenbully-600/scr.html , http://www.pistenbully.com/en/products/pistenbully-600/scr/engine.html , http://www.pistenbully.com/en/products/pistenbully-600/scr/datasheet.html , http://www.pistenbully.com/en/products/pistenbully-600/scr/pictures.html , http://www.pistenbully.com/en/products/pistenbully-600/polar-scr.html , http://www.pistenbully.com/en/products/pistenbully-600/polar-scr/engine.html , http://www.pistenbully.com/en/products/pistenbully-600/polar-scr/datasheet.html , http://www.pistenbully.com/en/products/pistenbully-600/polar-scr/pictures.html , and http://www.telemet.com/_pdf/KGF_PistenBullyselectGB.pdf .

And here are links for Prinoth: http://en.prinoth.com , http://en.prinoth.com/Company , http://en.prinoth.com/Company/History , http://en.prinoth.com/Snow-groomers , http://en.prinoth.com/Snow-groomers/Products/Snow-Groomers , http://en.prinoth.com/Snow-groomers/Products/Snow-Groomers/BR-350 , http://en.prinoth.com/content/download/19332/638782/version/4/file/Brochure_BR+350_EN_Final.pdf , and http://en.prinoth.com/content/download/18732/628273/version/4/file/Imagefolder_EN.pdf .


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CONTINUED IN NEXT POST
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biotect

Designer
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CONTINUED FROM PREVIOUS NEXT POST
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For Prinoth, it’s the Husky E-motion – see http://en.prinoth.com/Snow-groomers/Products/Snow-Groomers/HUSKY , http://en.prinoth.com/content/download/19331/638774/version/7/file/Husky_Eng_Low_Pdf.pdf ,
http://en.prinoth.com/content/downl...ion/14/file/Info+Folder+HUSKY+E-motion_EN.pdf , http://en.prinoth.com/Company/Environment , http://www.trakkemaskin.no/default.asp?cid=1&nid=1628 , http://www.camese.org/news.cfm?itemid=9522 , http://www.seilbahn.net/sn/index.ph...nd innovative -the new PRINOTH Husky E-motion , http://www.ideegreen.it/alto-adige-green-13821.html , http://www.seilbahn.net/sn/index.php?i=62&news=3285&titel=Tilling Technology for World Champions :


298_900.jpg 296_900.jpg 297_900.jpg
Untitled-1.jpg Husky-E-motion-in-Antholz_fullscreen.jpg HUSKY-E-motion_gallery_widget_full.jpg


I decided to post this information here, instead of the “Thermal Engineering” thread, because the latter is really a thread about heating and air-conditioning in extreme environments. Whereas this thread has generated a great deal of interest in the possibility of diesel-electric powertrains for expedition motorhomes in general, and the TerraLiner in particular.

These Prinoth and Pisten Bully diesel-electric hybrid snow-groomers demonstrate that the transition to diesel-electric hybrid technology across a wide range of vehicle types is happening faster than many people realize. Like the Ranger Rover hybrids, or Oshkosh hybrids, these are not vehicles designed for “easy” applications in urban centers. These are work vehicles that have to do a job in tough conditions: extreme-terrain, extreme altitude, and extreme weather.

All best wishes,


Biotect
 
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LoRoad

Adventurer
So LoRoad, I was just wondering: was your vehicle equipped with this sort of exterior protective piping? If your vehicle was not so equipped, do you think that such piping might have made a difference, and protected your camper box from severe damage?
I have wondered the same thing. While an external roll bar might have helped mitigate the damage to the shower dome, I do not think it would have done anything to have kept the entire unit from tweaking, and that is ultimately what did the unit in. From my personal experience, such roll cage/bar(s) are used to ultimately protect the occupant - though having a good brush guard is always nice. Having said that though, the cage does offer protection to the unit, but remember that is not its primary purpose, typically.
 
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campo

Adventurer
I do like the e-hybrid Pistenbully but I can not find the battery pack between generator and e-engines on the schematic
Would it be 24V or 400VDC ?

In my dream version for the 6x6 Terraliner axle 1 and 3 would be electrical and axle 2 diesel engine direct.
If to difficult to realise I would make a classic 6x4 diesel mechanic axle 2+3 with an extra electric engine in line or on the diesel engine
and only the front axle e-engine driven.

What I would certainly do is try to combine and only use 1 battery LIPO pack both for driving and living.
 

biotect

Designer
..
I do like the e-hybrid Pistenbully but I can not find the battery pack between generator and e-engines on the schematic
Would it be 24V or 400VDC ?

Hi campo,

The third image that I posted from the pdf suggests that batteries are planned for the Pisten Bully 600 E+, but batteries are not yet implemented -- see http://www.e-mobilbw.de/files/e-mob...chnologietag 2013/TT 2013_H4_Michael Kuhn.pdf :

7.jpg

At present, it seems that the diesel engine in the 600 E+ drives a generator that directly powers the electric motors, without the intervention of a battery. But my guess is that the long grey boxes in the schematic, which seem to be the diesel fuel tanks, are the ultimate intended locations of the batteries as well. It would seem to make "spatial sense" to install the batteries on platforms located just above these long diesel fuel tanks:

14 copy.jpg

But I could be wrong. Until Pisten Bully finalizes its product development sequence of the 600 E+, we can only guess where it will choose to locate the batteries.

As for 24V or 400VDC: the pdf seems to suggest that the generator in the Pisten Bully 600 E+ produces 140 KW, at 650V:


Untitled-1.jpg


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In my dream version for the 6x6 Terraliner axle 1 and 3 would be electrical and axle 2 diesel engine direct.
If to difficult to realise I would make a classic 6x4 diesel mechanic axle 2+3 with an extra electric engine in line or on the diesel engine
and only the front axle e-engine driven.

What I would certainly do is try to combine and only use 1 battery LIPO pack both for driving and living.

Campo, here you seem to be proposing some kind of "Parallel Hybrid" arrangement, in which the diesel engine can still power the wheels directly; as opposed to a pure serial-hybrid arrangement, as per the Pisten Bully 600 E+.

My own inclination is very strongly in favor of pure serial hybrid, for reasons clearly spelled out in an article written by U.S. Army specialists. I already referenced this article earlier in the thread, in post #674, at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page68 . On my own view, this article should be mandatory reading for anyone interested in hybrid expedition motorhomes:


.......with only a few exceptions (for instance, the MillenWorks Light Utility Vehicle or "LUV"), almost all of the hybrid prototypes developed by the U.S. military over the last decade have been serial hybrids, not parallel hybrids. There seem to be very good reasons for this. For a really interesting recent paper (2012) that advocates “no half measures”, and full serial hybrid or IHED – “In-Hub Electric Drive” – for all U.S. Army vehicles, see http://www.benning.army.mil/armor/e...012/SEP_OCT/Articles/DuVall_Hoeltzel_SO12.pdf and http://www.benning.army.mil/armor/eARMOR/content/issues/2012/SEP_OCT/DuVall_Hoeltzel.html .

Here is a long quote from the article. Wherever it writes “IHED”, just substitute “Serial Hybrid”:


The IHED [i.e. a serial hybrid solution] consists of a diesel engine that drives a generator that provides electric power to wheel motors (mounted inside the wheel hub with a gearbox) that provides motive power to the tires, eliminating the entire mechanical drive train. The e-drive can be augmented (the optional hybrid portion) with a battery pack and battery-power converter, providing power for burst acceleration, periods of silent watch (six to 12 hours), silent movement (up to 20 miles on level terrain), power recovery/storage from regenerative braking, a second source of power and mobile-power-generation capability with an uninterrupted power source.

What does IHED provide vs. conventional mechanical drive? It provides very large quantities of electric power for on- vehicle and export uses. These include communications; navigation; command, control, communications, computers and intelligence / battlefield information; reconnaissance-surveillance-targeting; sensors; unmanned aerial vehicle / unmanned ground vehicle control; electric-powered weapons; electric armor and countermeasures; electric tools; and portable-device battery recharge. It also augments/eliminates trailer-mounted generators.

IHED improves system reliability. The total system-parts count is greatly reduced by 30 percent to 45 percent. (If it isn't on the vehicle, it can't break or fail.) E-drive has very few friction points and some bearings on shafts; all else are magnetically coupled – no friction, no heat, no wear points…..

IHED increases mobility because having no half-shafts allows uncomplicated, very large wheel travel. The suspension increases cross-country speed, reduces crew/vehicle fatigue and increases weapons effectiveness and survivability. IHED raises the vehicle's ground clearance by eliminating the mechanical drive train and, in many cases, increases stability and safety. It also provides for computer-controlled all-wheel traction control, anti-lock braking system and stability control.

IHED improves logistics and reduces the expeditionary footprint. Analyses based on Aberdeen Proving Ground, MD, testing shows that a reduction in fuel consumption of greater than 40 percent is possible. The longer silent-watch periods reduce fuel use as well as increasing survivability and stealth. On an IHED system, all wheel stations and supporting electronics are common parts, reducing system-part count and spares by eliminating the mechanical drive train (for example, greater than 42 percent less line-replaceable units on the e-drive Stryker vs. the present Stryker).

IHED can lower system lifecycle costs 40 percent to 50 percent based on the United Kingdom's Future Rapid Effects System Study, which com- pared the Light Armored Vehicle III to an 8x8 IHED vehicle. Reliability is raised by eliminating so many parts and using proven electric technology. IHED's modular nature provides easy upgrade when enhanced or new technology appears. IHED also allows the system designer to easily integrate the drive system and exploit a family-of-vehicles concept. It simplifies and reduces maintenance workload and times (fewer parts). It reduces training for operators and maintainers (system simplicity and commonality, not complexity).

The high-wheel travel suspension allows the vehicle to move at greater speed over broken terrain while keeping crew ride within a tolerable level. The addition of an active component keeps the wheel in contact with the ground for greater periods of time, increasing driver control of change of direction and braking. It will also provide energy recovery that can be put back into the power-budget system. The new tread patterns being applied to military tires, coupled with a CTIS, have led to dramatic increases in wheeled-vehicle mobility.

Several IHED 4x4 vehicles have under- gone testing at Aberdeen Proving Grounds. They also have a number of user evaluations from Regular Army and Marine units, as well as Special Operations Forces, at Yuma Proving Grounds and Fort Benning, GA. Test reports have confirmed that vehicles equipped in the manner described have much greater mobility than current vehicles……

Having participated in all the demonstrations of these vehicles, the authors heard experienced tracked-vehicle officers from the U.S. Army, Canada, Great Britain, Germany and Australia state that they had been driven in IHED vehicles across terrain they wouldn't have tried with their tracked vehicles.


No half-measures

The benefits are many, but beware of those who would take half-measures. Adding a generator and replacing a drop- box or differential with a motor in the mistaken belief it reduces risk is incorrect. If the electric system is layered over the mechanical system, all the mechanical system's drawbacks and weaknesses are still there. The risk factor has gone up, not down. The Humvee is an example; all four half-shafts are different and are the mechanical fuse in the system. They break to save more expensive parts from breaking. The SOF teams informed the authors that they take four or five sets of half- shafts with them because they break so often.

If an electric motor is substituted for the differential, the half-shaft problem remains. In the world of reliability, the numbers would not get better – they would get worse. IHED drive trains are magnetically coupled and can't break; a strong gearbox can take punishment, as this magnetic coupling feature provides protection. Eliminating the mechanical system for an IHED drive train reduces the number of LRU 30 percent to 45 percent; if an LRU is not on the vehicle, it can't break or fail.
So the question is, with so many compel- ling benefits, why hasn't IHED been put into military service? The answer, up to recently, has been performance risk and lack of an adequate production base. The remaining technical risk of electromagnetic-impulse compatibility has been successfully addressed in recent component/ subsystem-level qualification testing.

The final barrier to production and fielding of IHED is availability of an adequate U.S. production base. This barrier is being rapidly eliminated with substantial U.S. investment in electric traction motors, power electronics and battery-production facilities for hybrid electric cars. This production base will very soon accommodate military needs with a minimum of investment and risk, and will provide enough competition at the component level to assure affordability.
Anyone interested in hybrid solutions for large expedition vehicles should read this article in full. It is simply terrific.

The main point of this U.S. Army article is that even though a parallel hybrid solution might seem "simpler" or "safer" or "less potentially problematic", exactly the opposite will be true. A parallel hybrid system will combine the worst of two worlds, not the best. It will be more complex and more difficult to maintain than either a pure serial hybrid solution, or a more traditional diesel-motor-only solution.

Campo, would be great if you could find some time to read this pdf article, and post your reactions to it. The article is in English, of course, and written using the kind of acronym-packed rhetoric that U.S. Army types love. But you could just cut-and-paste the text into "Google Translate", and then read it in Dutch. It's really worth reading, and it would be great to see what your response might be.....:)

All best wishes,



Biotect
 
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biotect

Designer
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I have wondered the same thing. While an external roll bar might have helped mitigate the damage to the shower dome, I do not think it would have done anything to have kept the entire unit from tweaking, and that is ultimately what did the unit in. From my personal experience, such roll cage/bar(s) are used to ultimately protect the occupant - though having a good brush guard is always nice. Having said that though, the cage does offer protection to the unit, but remember that is not its primary purpose, typically.

Hi Loroad,

Many thanks for your candid and brave response to a question that may have hit an emotional nerve. When something like this happens to a camper, one can easily imagine the frustration, anger, bitterness, and self-recrimination such an accident would generate. I have a Buddhist meditative practice that might help, somewhat. But I would still be kicking myself months later. So again, my condolences.

What do others think? Would the abundant piping that seems to completely surround Romuald Koperski's MAN-KAT, shown in posts #928 - #932 immediately above, prevent similar damage, if Koperski had backed into a tree in the middle of Siberia?

All best wishes,



Biotect
 
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egn

Adventurer
The main point of this U.S. Army article is that even though a parallel hybrid solution might seem "simpler" or "safer" or "less potentially problematic", exactly the opposite will be true. A parallel hybrid system will combine the worst of two worlds, not the best. It will be more complex and more difficult to maintain than either a pure serial hybrid solution, or a more traditional diesel-motor-only solution.
BMW i8 shows how good such a parallel hybrid can work.



I also favor the serial hybrid, but the parallel hybrid has its advantages too. I.E. you don't need an extra electric generator to charge the battery, as the engine can do this indirectly through the electric motor of the other axle(s) coupled by the road. The fuel efficiency may also be higher because you don't have to go through the generation step.

What I find interesting is the very small i8 engine with the high power (231hp). You can probably install one at 2 of the 3 axles of an 6x6 and electric motor at one axle with a total of more than 600hp.

Would a clean LPG/CNG version of such an engine be an alternative to a diesel engine?
 
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LoRoad

Adventurer
Hi Loroad,

Many thanks for your candid and brave response to a question that may have hit an emotional nerve. When something like this happens to a camper, one can easily imagine the frustration, anger, bitterness, and self-recrimination such an accident would generate. I have a Buddhist meditative practice that might help, somewhat. But I would still be kicking myself months later. So again, my condolences.
Dude - you thinkest me more sensitive than I really am ... It's just a piece of equipment for me. Stuff breaks, wears out, gets set to the side over time. Not unlike a pair of hiking boots - which btw also wear out. ;-) no one got hurt = no tears
 

biotect

Designer
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Dude - you thinkest me more sensitive than I really am ... It's just a piece of equipment for me.
Hi LoRoad,

Good to hear it. I wanted to err on the side of caution, because some participants are more "thin-skinned" than others.....:sombrero:

Even still, I'd like to hear from everyone else: Would the abundant piping that seems to completely surround Romuald Koperski's MAN-KAT, shown in posts #928 - #932 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page93 and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page94, prevent similar damage?

If Koperski had backed into a tree in the middle of Siberia, would his camper box have been spared the force of impact?

All best wishes,



Biotect
 

biotect

Designer
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I also favor the serial hybrid, but the parallel hybrid has its advantages too......

Would a clean LPG/CNG version of such an engine be an alternative to a diesel engine?

Hi egn,

Perhaps the main reason not to go with LPG/CNG, would be fuel tank size. As you wrote a long while back, maximum LPG tank size would be 333 Liters, whereas a diesel tank could be 1500 Liters. Also, there is the question whether good LPG/CNG fuel would be available in the Third World.

The BMW i8 is "über-cool", a truly spectacular piece of design and engineering. Not only well-engineered, but so too, unbelievably beautiful. I really loved the second video in particular, because his background commentary speaks to any number of larger issues. For instance, he emphasize that the BMW i8 accelerates and actually goes faster than most Porsche 911's. But 10 years from now, the point will be moot, because 911's probably won't even be allowed on the roads anymore, because of emissions standards. He drives home the point that hybrid vehicles constructed out of carbon fiber are not just "the future", they are the inevitable future, the future that is completely unavoidable:




And needless to say, it's one thing for a start-up company like Tesla to sell an experimental Sports Car. It's another thing for BMW to get into the game. He states that the BMW i8 will probably prove the most important Sports Car of the decade. So for everyone else reading this: this video referenced by egn is really worth watching.

What he says about Sports Cars applies to all vehicle categories, and one consequence seems equally inevitable: the days of "fix it yourself" engines are over. One can only imagine just how complicated the BMW i8 drive train must be, in order to co-ordinate electric motors and a petrol engine accelerating the car simultaneously. And the i8 drivetrain is definitely not something that anyone except a trained mechanical engineer or mechanic could fix themselves. So as suggested earlier, if hybrid is the future, then for RTW expedition motorhomes redundancy is the future as well, and not self-repairability.


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With all of that said, I am still going to plump for serial hybrid.....

One of the most fundamental reasons why I favor serial hybrid, is the design flexibility it allows. I no longer have to install a big engine that's permanently fixed to a big transmission directly driving the wheels. Instead, I can locate an engine + generator wherever I like, because the latter generates electricity that goes down flexible electrical wires to wherever it's needed. So it becomes possible to imagine putting the engine + generator on a big slide-out tray, providing 360 degree access for servicing, without needing the cab area to lift:


Gen7 copy.jpg


Again, this was suggested by dwh in a private message:

OR, put everything on a slide out the front, similar to the way they do generators on some of the larger motorhomes:

http://www.rvst.org/candidate/Images/Gen7.png

Open the floor up, disconnect a few bits here and there, and then just slide the whole works out. You could probably rig it so the battery bank slides out the rear as well.
It's the perfect solution, and saves me many, many design headaches.....:sombrero: ,,,It's simply brilliant, and at one stroke this solves a problem that was vexing me for months: that COE placement with a tilting cab undermines the possibility of a fully integrated design.

Recall that this problem was discussed at considerable length earlier in the thread -- see posts #110 - #114 , #119 - #120 - #127 ,
at http://www.expeditionportal.com/foru...e-Frame/page11 , http://www.expeditionportal.com/foru...e-Frame/page12 , and http://www.expeditionportal.com/foru...e-Frame/page13 (standard ExPo pagination). In particular, recall your deft summary of the various disadvantages of different kinds of engine placement on page 13, post #127, athttp://www.expeditionportal.com/foru...e-Frame/page13 .

The same problem vexed the designers of the Paradise Motorhomes expedition vehicle shown earlier in the thread -- see
http://www.caravancampingsales.com.au/content/reviews/2011/motorhomes-and-campers/paradise/paradise-motor-homes-mansion-4x4-24919 and http://4wdmotorhome.com.au . They seem to have left the forward-tilting cab as it is, still able to tilt. They did not completely remove it, as per Mañana. But when lowered the Paradise Motorhomes cab locks to the camper box with a super-tight bendy-bus sort of rubber seal:


ge5047381741861201973.jpg ge4911720830504722700.jpg
ge5320198109348685494.jpg ge4834395816147242643.jpg


And they made the opening at the back of the cab large enough so that the seats could swivel around, giving the illusion that they are part of the "one-room design" of the camper as a whole -- see posts #879 to #884 at http://www.expeditionportal.com/forum/threads/124789-Fully-Integrated-MAN-or-TATRA-6x6-or-8x8-Expedition-RV-w-Rigid-Torsion-Free-Frame/page88 and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page89 ; and posts #912 to #914 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page92 :


ge5400883145854283157.jpg


In other words, although the Paradise Motorhomes vehicle seems "fully integrated" when the cab is down, in truth it's not: it's still a non-integrated design. And when the cab is up and tilted forward, it will look something like this:


7784352_orig.jpg 5177853_orig.jpg
__daf_tilt_cab_3.jpg _daf_tilt_cab.jpg


With the complete insides of the camper box exposed to the elements, and/or to theft.....

Notice how on the "sell" websites for this Paradise Motorhomes expedition vehicle there is not a single picture of its cab tilting forward, although the product literature clearly states that it does so. Because if potential customers saw images like the ones directly above, they would immediately react with some degree of caution and reluctance. These are not "nice" or "promising" images, and they do not suggest a fully integrated design. Instead, they suggest a half-measure "fix". Although the Paradise Motorhomes expedition vehicle is spacious, has fantastic double slide-outs, and has a great drop-down deck, at the end of the day it too is a half-measure "fix". It is not a fully integrated design.

Whereas one key objective of "fully integrated" motorhome design, is precisely to eliminate this "motorhome split in half" problem, that arises when one uses a COE truck chassis with a cab that tilts forward.


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biotect

Designer
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In its mainstream, conventional designs, Paradise Motorhomes avoids this problem by creating campers based on CBE platforms, where there is no need for the cab to tilt. The engine can be accessed just by lifting the bonnet -- see http://www.paradisemotorhomes.com.au/independence-series/exterior , http://www.paradisemotorhomes.com.au/liberation-series/exterior , and http://www.paradisemotorhomes.com.au/inspiration-series-2013/exterior :


independence_6797.jpg 8778.jpg independence_6810.jpg
independence.jpg insiration_ultra.jpg inspiration_4x4_1_0.jpg
inspiration_4x4_3.jpg inspiration_4x4_2_0.jpg awning_0.jpg


But egn, you are on record as not liking CBE designs. So if the TerraLiner were a parallel hybrid, where would you put the engine that directly drives the wheels??? The only possible option left is rear pusher placement. But this then makes a Caravisio-type of rear deck impossible:


Caravisio_01.jpg


So that's why I was so enthusiastic about dwh's proposal: a serial hybrid engine/generator, that pulls out of the front of the vehicle, on a slide-out tray for full 360-degree servicing......

For more detailed discussion, see post #492 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page50 .

All best wishes,



Biotect
 
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nick disjunkt

Adventurer
I inherited the semi integrated cab-over format from Jim’s previous life as a cash in transit truck. The cab has a welded in-situ internal steel lining that prevents the driver or passenger from easily getting out of the cab doors. The original builder therefore had to make entry and exit via the box body pretty easy.I've attached some photos which might be of intest to you. The first shows the disconcerting view looking forward with the cab tilted. Instead of seeing the driver and passenger seat, all you can see is the hydraulic gear shift system sticking out of the bottom of the cab.

The cab on Jim tilts as normal using a manual hydraulic pump, but it is then locked to the body using 4 large bolts on each side. These compress an internal and an external seal. It takes a little longer to tilt the cab than on a standard truck, but it with the number of times I have to do it, it’s not a problem for me.

I wouldn’t recommend this solution for an extreme weather camper, as with the best will in the world, it is not possible to effectively insulate the original cab. The cab on my truck is no worse that what you might find on an American A-class RV, but these are not really designed for extreme conditions. In hot weather, a lot of thermal gain comes through the front windscreen, and in cold weather you can feel a noticeable convection current bringing cold air onto your feet when you are sitting on the front benches. The poor thermal insulation is not a problem in truck cabs as most of the time they are occupied with the heating or AC running, but trying to make the space work as part of a motorhome is far from ideal. I have thick curtains to separate the two areas, but earthroamers solution of having thick padded cushions that easily stow away is better thermally.






 

dwh

Tail-End Charlie
Even still, I'd like to hear from everyone else: Would the abundant piping that seems to completely surround Romuald Koperski's MAN-KAT, shown in posts #928 - #932 at http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page93 and http://www.expeditionportal.com/for...pedition-RV-w-Rigid-Torsion-Free-Frame/page94, prevent similar damage?

If Koperski had backed into a tree in the middle of Siberia, would his camper box have been spared the force of impact?
Depends. In that vid I posed a few posts back, you can see that those trucks are protected by the external roll cages. They get sideways in ditches, roll over and just use a crane to put it back on its feet and keep on going.

"Proper" roll cages don't just attach to the bodywork. They usually have one section which cages the bodywork and another section which attaches to the frame, and then the two "sandwich" the body panel, or a hole is cut through the body so the cage can tie to the frame:






If, for instance, that MAN KAT had an external roll cage around the camper box, but the cage was NOT tied to the frame, then backing into a tree could easily prevent damage to the box - BUT could transfer the shock to the mounts and damage the mounts and/or frame attachment points.

For a project like yours, I wouldn't even consider an external roll cage - a.k.a., "Rhino Bars". Too ugly, too much aerodynamic laminar flow disruption, and not really needed anyway.

A couple of beefy front and rear bumpers, and perhaps a few strategically placed brush guards should be adequate protection for the bodywork. The structure itself protected by the ribs and stringers of the bodywork, like the pics you've posted of buses.

I doubt if anyone is going to tip your truck over on its side. And if they do...they'll probably just ship the truck somewhere to get it fixed and catch a flight home.



OR...

You could include an internal cage into the body, and have attachment points so that protection bars or plates could be bolted through the body to the cage, so that the force of external hits would be transferred to the cage. I'm picturing something like I saw on a pic of a modern Airstream trailer, though perhaps not as large:


airstream-flying-cloud-exterior.jpg
 

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