I see threads arising frequently on this site about cartopping, often with unnecessarily acerbic discussions about tiedowns for the bow and stern.
This got me thinking that I don't think I have ever seen end tiedowns at the outrigger events I have attended or at the rowing shell events in my town. So, I looked at what the rowers seem to be using and also found a picture on ocpaddler.com. The answer is that long hull paddlers try to get 6-8 feet between their cartop bars and use racks they trust.
I get 6+ feet between bars on the top of my van. A popular rack extender for small vehicles seems to be the Burnham boat sling:
http://www.burnhamboatslings.com/StoreFront.bok
Here is a picture, which you can magnify, of a Huki outrigger on a compact car using a Burnham:
http://www.ocpaddler.com/files/P1000088_0.jpg
Although I have never seen it for outriggers or rowing shells, you could extend vertical tiedowns from the trunk and hood to supplement the rack straps. However, you would have to be very careful not to crack these fragile hulls with down pressure leverage.
Here is the rig that I made for
our 23 foot long tandem kayak out of EMT.
It wasn’t for support as much as for stabilizing the long delicate front from cross winds.
[URL=http://good-times.webshots.com/photo/2182228210088080270HHajAE
URL=http://good-times.webshots.com/photo/2857696520088080270BHMWSA
Material cost - less than 20 dollars, not counting the Yakama stuff
Cheers,
jackL
Nice looking system
The Burnham slings look like a good system, although they look too narrow for most kayaks. I get a similar effect using an EZ-Vee carrier by Kayakpro (a p-net sponsor). The Vees are 8 feet apart on my version, vs. only a 29" spread on the factory racks. I had to make adapters and added a little pipe insulation and it’s a great system, if pricey. The EZ-Vee looks a little beefier (the bars have an internal X reinforcement, the Vees are welded). Both good systems to my eye.
http://i97.photobucket.com/albums/l234/carldelo/Pachena%20on%20Mini/Pachena005.jpg?t=1248649269
When I transported my 27’ scull,
I built a custom rack with cradles for it. The rack was supported by old-time rain gutter grabbing uprights spaced as wide as a full-size Chevy wagon would allow. This arrangement was sufficiently solid that I did not use front and rear ties.
However, that does not apply to present reality. Rain gutters are gone. Rack crossbar spacing is down to less than a yard on many vehicles, including our '08 Accord. Attachment via Yakima or Thule towers cannot be considered as secure as Quick ‘n’ Easy towers on rain gutters.
Every boat toting situation is unique, but most will require front and rear tie downs for a good measure of safety. You can cut corners. Maybe you can cut corners for a long, long time. Or, you can wait until enough loose boat incidents cause busybody state legislators to TELL you to use front and rear ties.
Misc. comments
Another long hull rack extender is the Adirondack Rowing shell rack:
http://www.adirondackrowing.com/economy_shell_rack.htm
Full size vans still have rain gutters. And as an extra bonus, some, like mine, can get as much as 10 gas stations per mile.
One tie down safety trick used by some outrigger paddlers is to secure the front rack (rather than the boat) to the vehicle by an additional, redundant method. One such method is to wind a long strap around the front rack bar multiple times and pass it through the tops of the front door openings into the vehicle. The doors of most vehicles should close right over the straps.
Their shell rack is similar to what
I built for myself back in 1965. I used slings rather than pressure pads because our shells then were skinned with western red cedar, and would split very easily.
If I used a rack like that on a sedan like our Accord, I would use safety lines from the front and rear of the rack to strong points on the car. I think I did a good job mounting my Yakima towers and clips, and I have the front and rear bars linked strongly for additional safety, but I just can’t trust clips as much as I trusted rain gutters.
nice links
Keep in mind, the picture with the BMW still shows regular rack with very short spread. The kayak is sitting in a very nice cradle, so major stress points are removed from the kayak. Unfortunately, the points were stress/forces are transferred to the car are absolutely the same to what would happen with your run of the mill saddles or what not.
Yakima/Thule solution
Starting from a basic Yakima or Thule rack setup on a short roof, you can add a set of 72" bars running fore and aft, connected via two sets of Yakima connectors (90 degrees to each other and bolted together), then another set of crossbars out at the ends of the long bars connected via the same system. Doesn’t change how the load is transferred to the car roof, but does support the long hull better against crosswinds and rocking over bumps. Brainchild of a guy I know here (AFAIK) and starting to show up a lot locally.
Quite right, Surinam.
At highway speeds, the leverage forces are there and will either be applied to the boat, vehicle, or divided between the two.
It is up to the boater to decide how to deal with these forces. Allow the boat to move up/down/sideways? Let the rack & cradle system twist? With a long boat I will always use bow & stern “V’s” to limit movement and add a degree of redundancy. As g2d pointed out, you may have no problems for years and years, and then you experience The Big Whoops.
Jim