Wind-Induced Uplift a Problem?

N

Nailhead

basset hound
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I read a classified on the Alaskan website from a seller offering for sale the "BOTTOM HALF ONLY" (his caps) of an 8' CO. Top half lifted off while driving in the wind. Located in Wyoming. Whodathunkit.

This got me thinking. I lived in WY for quite a while, so I still visit frequently, which means I cannot avoid driving the Alaskan through strong winds. Like last Saturday, when we drove past a UPS dry box in the median on I-25.

Is wind-induced uplift a problem with these? I know you pin them up when raised, but can you pin them down?

If not, anyone got any ideas for securing the top half down while traveling (other than ratchet straps)?

Happy New Year!
 
My Alaskan came with a set of holes in the top and bottom that lined up when the top was down. Located at the front bottom corner of the camper. Inserting a pin locks the two halves together. It wasn't enough for Montana winds so I put a matching set on the passenger side. With both sides pinned I am good for about 95% of the time. The other five percent gets a ratchet strap over the top and hooked to both of the jack mounts at the front of the camper. That has worked, even when watching an f250 towing a hard sided camper get blown off the road ahead of me at Judith Gap.

A quartering cross wind seems to be the worst.

Good luck
 
Thank you for the information, very helpful.

Judith Gap: that rings a bell, like I've been through there, just can't remember where it is.
 
Central Montana, south of Lewistown

Montana's first big wind farm 20 years ago, big surprise, windiest place I know of.
 
I think the problem with lift may also be exacerbated if you have a fair amount of SPACE between the top and the roof of your truck. The larger the area of inflow of air, the greater the lift. That would be something for physics majors and I'm not one, but I think you can also prevent that by simple adding one of those wind diverting thing-a-ma-bobs to the front edge of the truck roof drip channels that prevents the winds from getting between camper and truck roof. Something like an air dam I guess.

Getting the camper to fit into your later model truck with higher tub sidewalls means the C/O will ride higher as well and then the height of the cab comes into the equation...meaning once you raise up the camper to fit the tub, you may have allowed a LOT more wind force between the camper and the truck roof which would provide more lifting force.

My C/O hasn't experienced any lift that I have seen yet but it has a fairly small distance between cab and C/O.

Anyone here a math major that can confirm/deny this theory for us?
 
I think we have two different problems being discussed. The original question dealt with the top half of an Alaskan separating from the bottom half. On an Alaskan the bottom half of the cabover, where the bedding is, is part of the lower half of the camper, When you get any separation between the top half of the cabover and the bottom half at highway speeds it tends to make the top half a wing and want to lift up and off, thus the reason to pin the two halves together when traveling or adding the strap to further mechanically prevent the lifting between the sections.
The wind effect between the cab roof and the bottom of the cabover is an entirely different issue, I ran a pool noodle as an air dam between the cab roof and the cabover bottom for a while, fit nice, looked ok, kept the bugs from hitting the camper wall behind the cab but didn't do anything for mileage or handling that I could quantify, but my camper fits fairly well.

It really isn't a big issue if you plan for it and I probably have driven in some of the windiest places in the West.
 
PackRat said:
I think the problem with lift may also be exacerbated if you have a fair amount of SPACE between the top and the roof of your truck. The larger the area of inflow of air, the greater the lift. That would be something for physics majors and I'm not one, but I think you can also prevent that by simple adding one of those wind diverting thing-a-ma-bobs to the front edge of the truck roof drip channels that prevents the winds from getting between camper and truck roof. Something like an air dam I guess.

Getting the camper to fit into your later model truck with higher tub sidewalls means the C/O will ride higher as well and then the height of the cab comes into the equation...meaning once you raise up the camper to fit the tub, you may have allowed a LOT more wind force between the camper and the truck roof which would provide more lifting force.

My C/O hasn't experienced any lift that I have seen yet but it has a fairly small distance between cab and C/O.

Anyone here a math major that can confirm/deny this theory for us?
Click to expand...
That cab-to-camper distance will be factored in when we mount the camper to the '72 IH 4x4 dually I have. We'll be able to set it to any clearance we want (within reason).
wcj said:
It really isn't a big issue if you plan for it and I probably have driven in some of the windiest places in the West.
Click to expand...
Amen, brother: I lived in SE WY for 18 years. The name "Bordeaux" is the "Judith Gap" of the area, inspiring respect and discomfort in anyone living locally.
 
Nailhead: My 2018 10 ft Alaskan cabover has what they call a "travel bolt" which in essence is a carriage bolt that runs thru both haves of the camper and is located on the forward wall on the driver's side. I've driven all over Wyoming and Montana with no problems but I can understand your point perfectly.
 
Is this wind lift a problem primarily - or only? - with cabovers? I'm planning to buy a non-cabover, so will this be a non-problem for me?
 
I'm in SW Alberta where wind can be an issue at times, (110 - 120 mph)
I lost the top of a 70's vintage C/O Alaskan.
My current Alaskan, 2003 10 ft C/O, came with the lock-down bolt on driver's side. I added one to passenger's side when I saw that it trying to lift. (2 - 3")
Since then, I've also added pins to the leading edge of the C/O since it had a tendency to flutter/vibrate up and down.
If needed have some suggestions on avoiding lifting of older Alaskans with lower side bed layout.
I'll try to learn how to add some pictures.
RJ
 
Rodeor said:
I'm in SW Alberta where wind can be an issue at times, (110 - 120 mph)
I lost the top of a 70's vintage C/O Alaskan.
My current Alaskan, 2003 10 ft C/O, came with the lock-down bolt on driver's side. I added one to passenger's side when I saw that it trying to lift. (2 - 3")
Since then, I've also added pins to the leading edge of the C/O since it had a tendency to flutter/vibrate up and down.
If needed have some suggestions on avoiding lifting of older Alaskans with lower side bed layout.
I'll try to learn how to add some pictures.
RJ
Click to expand...
These might help with photos.

http://www.wanderthewest.com/forum/topic/13441-uploading-photos-to-comments-and-gallery/

http://www.wanderthewest.com/forum/topic/2349-photo-attachment-explanation/
 
popRoid said:
Nailhead: My 2018 10 ft Alaskan cabover has what they call a "travel bolt" which in essence is a carriage bolt that runs thru both haves of the camper and is located on the forward wall on the driver's side. I've driven all over Wyoming and Montana with no problems but I can understand your point perfectly.
Click to expand...
Hmmm, ok. Interesting.

Thank you very much for mentioning that.

I’ve located a camper, and am going to go pick it up in a few weeks, and I’ll be damned if I’m gonna have it come undone on me on the way back home. If it doesn’t have that bolt, I’ll ratchet-strap it from the front jack brackets down to the rock rail on the truck, and then modify the camper as above later on.
 
Rodeor said:
I'm in SW Alberta where wind can be an issue at times, (110 - 120 mph)
I lost the top of a 70's vintage C/O Alaskan.
My current Alaskan, 2003 10 ft C/O, came with the lock-down bolt on driver's side. I added one to passenger's side when I saw that it trying to lift. (2 - 3")
Since then, I've also added pins to the leading edge of the C/O since it had a tendency to flutter/vibrate up and down.
If needed have some suggestions on avoiding lifting of older Alaskans with lower side bed layout.
I'll try to learn how to add some pictures.
RJ
Click to expand...
This also makes sense. Thanks for the ideas.

Hope you’re able to figure the pic procedure out— too complicated for me.
 
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