bcbigfoot
Okanagan
Senior Member
Joined: 02/12/2006
View Profile
Good Sam RV Club Member
 Offline
|
sleepy wrote:bcbigfoot
the Lance is designed for a 6 point tiedown...
2 of the strut dampers provide the forward attachments
2 of the Happijacs provide the center attachments
2 of the happijacs provides the spring loaded rear attachments on the rear bumper
I'll take 6 point attachments over 4 point attachments any time
sleepy
Ok, and you did. (What's your point) As I might of as well if I owned a Lance that was engineered to use the happijac system however I don't.
I own a Bigfoot and the happijac tie down system would compromise the camper tie down mounts strength. The happijac pull in at a steep angle, under a situation were the camper were to try and separate from the truck, that angle would put force on (pull in, think lever) the side of the camper tie down mounting plate causing it to start ripping through the mounting structure on one side, like a claw hammer pulling a nail out, or pulling Velcro apart starting at a side or corner.
Pulling straight down (or less angle) on the camper mount tie down would load the mounting plate evenly across the mounting structure increasing it's ability to resist being pulled out much like pulling a nail strait out with a pair of plier's, or separating Velcro from the center. Basic engineering sleepy.
2002 Dodge 3500 2wd dually, cummins, 4.10 gears, 10500gvwr, Rancho 9000's shocks
2005 Bigfoot 259.6E, 80watt solar, eu2000 Honda gen., 2x group 31 AGM bats., 7100 btu aircond, electric rear step.
|
BradW
Mayor of Flat Rock
Senior Member
Joined: 10/29/2001
View Profile
|
Redsky wrote:I did a rough calculation of the wind force side load on my 845 camper and with a 50 MPH gust the force is about 844 lbs., which is not all that much and countered largely by the weight of the camper. But with a 70 MPH gust the side load nearly doubles to 1660 lbs. of force. It's the gusts that will get you.
The problem is that all that force needs to be resisted by the two windward hold downs on the camper. The turnbuckles are designed to provide 300 lbs. of holding force or 600 lbs. per side so even a 45 MPH gust could overwhelm them.
Just so no one is confused, 1,660 lbs side force does NOT translate into 1,660 lbs of force on the tie downs. The force on the tie downs would be MUCH less. I assume your calcs are based on the wind being exactly perpendicular to the camper side? What are the odds of that?
Also, if there had been 70 mph wind gusts, you would have seen a LOT more dust blowing around in those photos.
Brad
Wake Up America
2019 Lance 1062 and 2018 F-350 CC PSD 4X4 DRW
Tembrens, Rear Roadmaster Sway Bar, Torklift 48" Extention and 30K Superhitch
Our New Lance 1062 Truck Camper Unloading at Dealer Photos
|
CAJW
NorCal
Senior Member
Joined: 07/07/2012
View Profile
Offline
|
I'm no engineer, but I have stayed at a Holiday Inn (before we got our TC), but I agree with Jefe 4x4 in that centering guides may have helped prevent this.
Another thought to ponder is, would a DRW truck have helped keep the unit from tipping past the point of no return vs. the SRW the OP had? IMHO, it would have put the rotation point farther out and may have kept the truck from leaning over that last little bit to allow the camper enough lean over stressing that tie down mount to the failure point and fall out.
I'm in agreement that the OP (Nolan) was caught up in the perfect storm, literally. When teaching classroom for motorcycle training, we discuss accidents as having many links in a chain and if any link is broken (a contributing factor removed), the crash (accident) doesn't occur. In his case, it appears that Nolan was in the wrong place at the right time for all these things to come together to create this situation. Thankfully no one was hurt, which is the bottom line.
2013 AF 996, 2013 Chevy 3500 CC,LWB,4X4, Duramax, DRW, 3.73 rear, Torklift Stableloads & Tie-downs,Fast Guns, Ride Rite Air Bags, Superhitch w/ 32" extension.Big Wigs, Front Timbrens, TST TPMS-507,CubbyCam, Trimetric. TM & SC 2030 150W + 100W suitcase
|
bcbigfoot
Okanagan
Senior Member
Joined: 02/12/2006
View Profile
Good Sam RV Club Member
Offline
|
One would also likely need to calculate in the low pressure area generated on the leeward side of the camper, compounding the force of the wind.
In one of pictures there is dust blowing across the road/field. I lived in area's of Saskatchewan that is like that, one minute 40/50 mph wind gusts the next few minutes relatively calm. It's the nature of wind gusts in some locals.
As a armchair quarterback my guess is a combination of events to create a perfect storm. Wrong tie down system, typical poor truck camper tie down mount design/engineering, perhaps poor workmanship to boot. A big gust of wind and a little over correction of steering to keep the truck going straight (like skipro3 pointed out) and throw in a rut or two of soft powdery dirt. Walla the formulation for a 1 in a 1000000 flying camper. Or not?
|
wnjj
Cornelius, Oregon
Senior Member
Joined: 01/11/2007
View Profile
Offline
|
BradW wrote:Redsky wrote:I did a rough calculation of the wind force side load on my 845 camper and with a 50 MPH gust the force is about 844 lbs., which is not all that much and countered largely by the weight of the camper. But with a 70 MPH gust the side load nearly doubles to 1660 lbs. of force. It's the gusts that will get you.
The problem is that all that force needs to be resisted by the two windward hold downs on the camper. The turnbuckles are designed to provide 300 lbs. of holding force or 600 lbs. per side so even a 45 MPH gust could overwhelm them.
Just so no one is confused, 1,660 lbs side force does NOT translate into 1,660 lbs of force on the tie downs. The force on the tie downs would be MUCH less. I assume your calcs are based on the wind being exactly perpendicular to the camper side? What are the odds of that?
Also, if there had been 70 mph wind gusts, you would have seen a LOT more dust blowing around in those photos.
Brad
Yep. Consider the lower left edge if the camper as it sits in the truck bed the pivot point. Multiply the wind force times the average height of the wall above that point (so maybe 1660 x 5 feet?). That's the rotational force hurting you. Now subtract off the weight of the camper pushing down at it's side-to-side center. I'll use a conservative (3000 x 2 feet).
1660 x 5 - 3000 x 2 = 2300 ft-lbs. This means a wind like that could start to tip over an unsecured camper.
Figuring the tiedowns in, they are about 6 feet horizontakly away from the left edge. That means even with only one tiedown, it need only hold 384 lbs to stop 2300 ft-lbs.
The truck was either tilted, bouncing or that tiedown was already compromised before the wind hit or some combination of these.
|
|
|
sleepy
Oak Ridge,Tennessee
Senior Member
Joined: 04/07/2003
View Profile
|
This has been a good discussion...
1)so far I've been reminded that I can't spell I'll bet that 99.44% of the Truck camper regulars knew it already
2) and that I'm not an engineery that's right, I'm a retiree
3) I read that some one else noticed the lack of wind blown dust in the air in the pictures But Janet and I, while in bed in our TC survived a 108 mph down draft straight line shear wind in Sandusky, Ohio. it hit us in the rear drivers side corner... for a miniute or so it shook us in every concievable way. The happijac's held. (I posted on it at the time... it was fall of 2005)
What the OP could have had is a sheer wind that was over in seconds.
Since we don't have a wind tunnel to repeat the same conditions over and over making only one change at a time using different tie down systems we can't say with any certainity what is best, or if there is any difference in the tiedons at all... at this point it is just conjecture.
I do understand research methadology. And I understand when a guy claims to be a quarterback... armchair of course.
Even an educated guess... is still a guess!
sleepy
2003 Lance 1161,/slideout/AGM batteries/255W Solar/propane generator/Sat dish/2 Fantastic Fans/AC/winter pkg
AirFoil, Trimetric, LED lights, Platcat vent heat
2003GMC K3500 LT/Crewcab/duramax diesel/allison/dually/4x4/OnStar/front reciever mounted spare
|
anutami
Ramona
Senior Member
Joined: 12/15/2012
View Profile
|
Well, I have been searching high and low for "the perfect rig" to replace my 2012 wolf creek 850 and I keep going back to the wolf creek. This camper seems perfect for a family of 4 that prefers 4wd roads. It is hard to beat a hard side non slide 8' camper with an aluminum frame structure, larger holding tanks, light weight, huge dinette, beautiful interior, perfect fold down bunk for my 5 year old, massive storage cabinets, that you can take off road to almost as many places as a pop up camper. Is there another 8' camper that can compete? My only beef is with the tie down anchors. Northwood agreed to reinforce the tie down anchors on a new custom build 2014 wolf creek 850 and I pulled the trigger. Props to Kevin Baker owner of apache camping center in portland as he negotiated on my behalf. The wolf creek held up great rolling out of my truck and holding up even better when the tow truck driver rolled it back upright, so the frame and structure are obviously above par.. Northwood has been great on helping me out and I can't wait to get on the road again. I guess I have what you you call the truck camper blues as it is prime desert season right now in so cal and looking forward to feeling free again. I am going with the new torklift talon tie downs so I should have no more worries of my camper becoming separated from my truck.
2001 Ford F350 LB Diesel 4x4 CrewCab Stick
2015 Wolf Creek 850 Thermal Pane Windows, Oven, Reinforced Anchor Bolts, 200w Solar, Torklift Tie Downs, Fastguns, Stableloads
|
kerry4951
East Central Pennsylvania
Senior Member
Joined: 12/16/2009
View Profile
Offline
|
anutami wrote: Northwood agreed to reinforce the tie down anchors on a new custom build 2014 wolf creek 850 and I pulled the trigger.
It may be in their best interest to start doing this to all their new campers from this point forward. No need to do just one. Anyway, glad you have your new TC ordered and overall Northwood builds a great product.
2009 Silverado 3500 dually D/A, Supersprings, Stable Loads, Bilsteins, Hellwig Sway Bar.
2010 Arctic Fox 1140 DB, 220 watts solar, custom 4 in 1 "U" shaped dinette/couch, baseboard and Cat 3 heat, 2nd dinette TV, cabover headboard storage, 67 TC mods
|
abslayer
Canada
Full Member
Joined: 10/06/2010
View Profile
|
BradW wrote:Mello Mike wrote: So in this case a frame-mounted tie down on the rear probably would have saved this camper from going airborne.
Maybe. Or maybe the rear camper tie-down eyelet may have failed.
Regardless, I wasn’t there and I ain’t go no video evidence, but I don’t find it credible that a violent camper ejection like this was all cause by a crosswind while driving at only 25 mph. JMO.
Brad
Took the words right out of my mouth![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/scratchead.gif "scratchead")
|
Rbertalotto
Massachusetts
Senior Member
Joined: 06/02/2005
View Profile
Good Sam RV Club Member
Offline
|
Good for you! Sounds like they are taking care of you. Good Luck with it!
RoyB
Dartmouth, MA
2021 RAM 2500 4X4 6.4L
2011 Forest River Grey Wolf Cherokee 19RR
520 w solar-200ah Renogy Li-Epever MPPT
|
|
|
|
