Bow/Stern tie down points
In all this discussion, I did not see anyone comment on the actual connect point on the kayak bow and stern. For me it would have to be the kayak carrying handles and to me these will fail immmediately under any stress from the force of a rack failing. Has anyone added a bow/stern tie down on the kayak itself that would be better than the handles?
Tom
The bow…
and stern line and the carry handles should be strength tested to at least hold the weight of the boat. Obviously some people carry their boats with them,or drag the weight plus gear with them, emptied swamped boat with them,use as rescue grips,etc. I most cases I believe the carry handles have more tensil strength then the weight of the boat. However the attach point may or may not be the strongest link.
From my exerience with lines I use the smallest diameter rope that carries a tensile strength of twice the boat weight. A 1/8" diameter rope carries a tensile strength of aproximatly 90 lbs,3/16" about 115lbs. A 1" wide nylon strap type tie down is almost capable of towing a small car in strength.
In my experience the bow and stern lines help against lift of the boat from driving speed winds,or gust winds generated by trucks,or crosswinds. It relieves the extra stresses on the rack mounts and straps helping avoid rack release or failure.Like someone mentioned you can see if there is a problem by the tension on the lines. In some rare cases it may also help hold up against a dislodged rack,or a loose rack,and like all above agree add the extra measure of safety.
I don’t think bow & stern line make much difference when it comes to a head on, or rear end collisions,due to forces exceeding rack,ties,vehicle,or boat attach point strengths for the excessive inertia forces generated by impact. However they may act as a retarder of the forces that caused the release to slow down the ejection. However I am not willing to try that theory with my car or boats,are you?
Just for my piece of mind I use them,and the 10 minutes it takes to put them on may save me or someone else damage or injury.
billinpa
not to belabor this worn out thread, but
Bill, what does the static weight of the boat have to do with the strength of the line used to secure it to a roof?
I would think almost nothing. But I’m not an engineer either.
You would
– Last Updated: Jun-25-09 4:46 PM EST –
want the line to carry the weight of the boat plus any wind forces generated. Hence twice the weight of the boat. Years ago I read that somewhere and am just coveying it as I remember. Common sense would tell me if the rack released and the weight of the boat,and wind forces are pulling on the lines you would want the lines to be able to carry the weight of the boat,rack,and wind forces until you slow down. Otherwise use sewing thread for lines,Hummmm?
billinpa
freaking engineers
We’ll all be using 2# cable once the engineers get involved (just pulling your chain, I’m an engineer wannabe).
I guess what I’m getting at is
… mason line is like 200++lb test. But I sure wouldn’t use it to secure a 65 pound boat.
Dynamic loads far exceed static loads
– Last Updated: Jun-25-09 5:51 PM EST –
Ah' too had some fizziks in reform school.
Fer example... iffin' me sweetie pie - Miss Crabtree waar ta find me spoonin' wit o' let's say... Emma Peel - if her fist waar just restin' on me nose it would exert a force... o' lets say 1 PSI. Now, iffin' she'd haul back an' really land a round-house punch on me schnoz ah' wood reckon it'll be at least a couple hundred PSI an' one busted proboscis. Tough dame dat Miss Crabtree.
Wat in tar-nation be ah' jabberin' about???
Oh yeah, a movin' (relative ta a stationary object. ie. mounting point, rope, strap, rack, car, etc.) 50lb. boat is gonna exert a much greater force (inertia) than would a static or stationary oobject (ie. boat).
FE
Short and wide?
Bow and stern lines are considered a good idea but aren’t absolutely necessary. It depends on the boat and how secure the main tiedowns are. For shorter boats you can usually just tie the endloops back to the rack bars for some extra security.
But wat if de rack fails?
– Last Updated: Jun-25-09 6:02 PM EST –
Dat yer jus' tied onto???
FE
96 Sienna ???
I believe 98 was the first year the Sienna was made.
I had a 98 and there are towing hooks underneath the vehicle that work for tied downs. I cant remember but they are not symmetric front and back …one in the front I believe, two in the back.
If your boat is longer than about 11 ft. I would do front and rear tie downs.
CD pachena "in flight"
See the December, 2006 review of the Pachena by Current Designs. A quality rack failed, and the kayak went airborne on the highway. Systems fail, that is why a backup is necessary.
"Layers of Safety"
Up-a-creek hit the nail on the head. Some folks are belt folks. Some are suspender folks. And some are belt-and-suspender folks, just to be sure.
I am involved in industrial safety at work. One thing I was taught, and firmly believe in, is that individuals can become habitualized at performing a job in an unsafe manner - as long as there are no negative consequences. So it is best to habitualize that individual with SAFE techniques so that if and when the feces hits the ventilator at least he or she is acting safely.
Only a handful in this thread have witnessed an airborn boat. I have. And I have seen the results of several other flights. As such, I do not wish to experience any more.
Jim
Belt & suspenders guy.
LONG LIVE THIS THREAD!!!
a classic pnet review
it was 12-26-05 by dlinnane for the Pachena - and worth reading again.
light not heat
very nice post. it is important to understand things like this that are like many aspects of kayaking, counter intuitive.
perceived vs actual danger is a common reason for many dangerous events not being understood.
for example, driving a car or crossing a busy city street are far more dangerous, i.e., probability of getting hurt and seriously hurt DRAMATICALLY higher than flying on a commercial plane. But many people area totally blase about driving but scared about flying.
I have a permanent rack on my car and use double tie downs, the equivalent to a removable rack and tie downs. In reading your post though, I am going to start using tie downs also.
Thank you!!!
In the event of an accident
Ok…What about a surf ski?
Surf ski’s don’t have any attachment points for bow or stern lines.
Typically what I do for a long trip is along with the straps, I’ll put on my lasoo locks. They prevent the boats from sliding forward or backward in case the straps fail.
Most important to me is trust in my rack. I make sure it’s secure and not about to fall off or fail. And during any stop I make, I check the straps and tighten as needed.
I showed my set up to Miss Crabtree and she gave me a stamp of approval.
only for me
only for me, NOT you. I have decided to be self honest finally. My not using tie downs was purely selfish. Just did not want to bother. Easier form me to rationalize.
Ethics is about responsibility to others not self. So I decided this thing should not be about me, which I have been doing. It is about not having this stuff sail off my car and hurt someone.
Again, for me. Each person decides for themselves : > )
Stay off the Maine Pike today!!!
I’ve got a canoe on my roof and it might have your name on it!
The sucker’s tied on there every which way but loose,… but you never know.
broken racks and flying boats
– Last Updated: Jun-27-09 7:38 PM EST –
I imagine that the percentage of times a boat flies off a vehicle relative to the number of times a boat is cartopped is indeed small, and one can probably go a lifetime without using a bow tie down without having this experience. But I have known 3 people who have had this experience and the mechanism in all 3 cases was almost indentical to an incident described in Lou Glaros' and Charlie Wilson's book "Freestyle Canoeing".
In all instances long boats were being cartopped with 2 belly straps or ropes across the hull, one at each rack crossbar, but no bow line was used. For various reasons the strap or rope across the hull at the front crossbar failed, either due to failure of a cam device, a broken strap, a knot coming undone, or a tied rope walking off the end of the crossbar. Immediately, the wind force lifted the bow of the boat with great force, snapped the rear crossbar off of the towers, and the boat took off with the rear crossbar still attached.
This might not occur with a short kayak and if you are absolutely certain that your ropes, cams, straps, or knots will never, ever fail, then you can dispense with the bow tie-down. I find, however, that a triangulated bow tie-down does help prevent the front of a long boat from yawing back and forth in response to crosswinds, in addition to providing a visual reminder that a boat is up there.
you still here kricky?
Wonder if the OP is still here, or if maybe they sold the kayak and bought bicycles instead after reading this thread.