Originally Posted by Pblais
You don't haul up an anchor. You lift it out. . . .
The real load would be breaking out the anchor and that usually is not a shock load as you are moving the boat slowly to use the mass of the boat to unset the anchor. Again the bow roller is not carrying the load. . .
SlugmasterP Would the twisting and lateral movement be an issue if I'm only using it to drop the anchor and lift it out? The rest of the time while at anchor I'll have the nylon rode running through chocks and cleated off.
Pblais I think that's what your getting at right? That the roller isn't meant to be used while at anchor. If that is taking the stress from the movements of the boat I could see how there could be problems with bending and twisting.
Here is where reality and theory clash. When "at anchor" you normally have a bridle
attached to the anchor rode and also attached to either the bow cleats
or a Samson
post so that loads imposed by wind/waves or current
are not directed through the portion of the anchor rode between the "bridle" and the windlass but instead transferred to said Samson
post or bow cleats
Then comes "weighing anchor" or "up the hook" time. The bridle
is removed and the anchor rode is established back over the anchor chock roller assembly. Then the anchor rode is hauled in by "whatever" means until the anchor is nestled back in the chocks.
Except - when the anchor is firmly and dastardly buried in the sea bottom, usually in clay or some seriously deep mud. [This happens about 2 or 3 times per year to me]. Also things can get really nasty when the anchor get tangled in sunken boat wreckage or abandoned mooring
chains. Then retrieving the anchor becomes an extreme ordeal and loads are imparted to that commercially made bow anchor chock/roller system that it is simply not strong enough to handle.
Typically, veering is employed - driving the boat over the anchor and off in a side direction - to try to dislodge or loosen the anchor. Here is where the side loads generated in this maneuver twist and bend the thin side plates.
Or, you drive the boat over the top of the anchor and straight ahead attempting to rotate the anchor vertically to the opposite direction and break it free. Here the buoyancy of the boat is used to cause the bow to "dip" and then yank vertically on the anchor rode/anchor. Here is where the weak side plates and even the bottom plate and bow attachment bolts are stressed and bent.
On smaller boat - under 35 ft (12m) I have seen quite a few bent and twisted bow anchor chocks. The frustration of not being able to promptly raise the anchor when "it is time to go" frequently results in these less than optimal techniques for retrieving a stuck/buried anchor being employed.
Patiently putting a vertical load on the anchor rode with gentle boat movement (sort of, wiggling around) over time will work
the anchor free except when it is caught in sunken debris. I have spent as much as an hour and a half working an anchor out of the mud in Luperon, D.R. after it has been "down there" for several months. One way to put a vertical load on the anchor rode and not on the anchor chock/roller is to use a spare fore halyard
from the main mast
and attach it to the anchor rode. Then winching in the halyard
puts a purely vertical pull on the anchor rode and with time wiggles the anchor free - or even in one case, raises the sunken vessel part that your anchor has grown an intimate attraction for.
So yes, you can go years without overloading one of those commercially made anchor chock/roller systems - or - you can twist the heck out of it during one frantic "got to go now" moment.