Anchor from Bow or Bridgedeck?

[mikereed100]

As I refit my cat I am coming to the stage where I have to decide whether to deploy the anchor from a roller on the crossarm or straight from the bridgedeck. Originally I had thought that the bow option would be better as the anchors and chain are more accessible. However I now sort of lean to the bridgedeck as this would take the strain off the crossarm and the weight of the anchors and chain off the bow. Any thoughts/rants/biased opinions on this matter?

[ScratchBC]

I once crewed on a a fountian Pajor Bahia (46' sailing cat)

On that boat there was a lazeret on the bridgedeck where the anchor, winch, and chain was stowed. The anchor was a danforce and had all chain. We hooked a bridal attached to the bows to the chain, such that all of the tension was on the bridal. That set up worked great! The line was always way infront of the boat thanks to the bridal, but we allways had the chain and winch hidden and out of the way.

Hope that helped.

-Alex

[Vasco]

I'm a monohull sailor so the following is based only on observation. The problem with bridge deck deployment is that in poor conditions (very rough) or where the wind is against the current the rode can quickly go under one of the hulls when anchoring. I've seen this happen with both nylon and all chain and it happens before you can go forward to put the bridle on. The same thing can happen when weighing anchor if the coordination between the helmsperson and the "anchorer" is a bit off. Also if , heavens forbid, you ever get hung up on something, your rode will be between the hulls and again susceptible to going against or under one of the hulls instead of off the bow. OK, you catamaran sailors who have a bridge deck deployed anchors, what's been your experience?

[GordMay]

As I envision your situation:
~ the bridgedeck stops short of the bows, with a gap (perhaps a trampoline) between it and the forward beam (crossarm).

You may deploy (launch) your anchor from a centrally located (on the fwd beam) roller, but never secure it there. Catamarans should always use a bridle.

A bridle is a wye-shaped rope, attached at the single end to the anchor rode, and at each ama bow on the double ends. The main rode is then secured amidships (to bridgedeck or mast), such that it is normally “slack”. The bridle takes the normal loading, and may be adjusted asymmetrically to prevent skating or horsing.

On some catamarans, where there is a solid foredeck (notably Privilege and Prout), the bridle is slightly less critical, though still useful in preventing “horsing”.

[Tropic Cat]

Gord,

I'm trying to envision your bridle configuration. If the hulls take the normal loading via the bridle, why extend the rode to the mast?

Rick in Florida

[GordMay]

Extend the rode to a strongback (mast, nacelle, bridgdeck, etc), for the same purposes as we do on a monohull - ultimate rode connection.
The Bridle takes the normal anchoring loads, but the rode must still be independently connected to the boat.
BTW - I prefer the bridle or smaller diameter than the rode.

[henryv]

On my PDQ32 the anchors are deployed from the bows. On my Leopard the anchor is deployed from the bridge deck. Either way you need a bridle in place once the anchor is set.
Deployment from the bows works a little better if you are setting two anchors. Deployment from the bridge deck puts the chain well back between the hulls so you need to take care during setting not to get the boat pulling off to one side as the chain will contact the hulls.
I think both options have some advantages but in the end it is probably more an issue of where things tend to fit in better - that said I probably prefer the set up with an anchor on each bow.

[Tropic Cat]

I am curious as to what people are using for anchoring setups on cats. Hurricane season is officially upon us and it's only natural to revisit the subject.

Rick in Florida

[gosstyla]

I have no experience with a bridge deck setup but during the design stage of my current boat I seriously considered that arrangement. Ultimately I went with rollers on the bow because of the likelyhood of the bridle and rode sailing over the hulls when deploying from the bridge deck.

My "first down" anchor is a Fortress Fx-55 with 30ft of chain connected to the 66lb Bruce main anchor.

[colemj]

I chartered a cat with the anchoring system at the bridgedeck. You still attach a bridle to each hull, though. I found the problem mentioned above where the boat would bear off while dropping anchor before attaching the bridle and the chain would come up tight underneath and against a hull. If it is windy, it can come up very tight and "saw" against the hull. Also, the windlass is now taking the full load with no way to easily release it or put on a stopper. It had the added disadvantage of not being able to work on the anchor system easily.

Mark

[markpj23]

FWIW, another option may be what I saw on a cat at the Oakland Strictly Sail show this year - unfortunately I do not remember the manufacturer of the cat, but it was in the mid-30ft range.

A single anchor located on-centerline on the cross-brace in a traditional roller housing. The chain ran back to the windlass located in a bridge deck nacelle. Some basic disadvantages I saw was that the chain ran back to the windlass in an open tray vice a closed or partially covered conduit. I could envision the chain jumping around dangerously during a free-fall deployment, but I guess if you used a reversing windlass that issue could be avoided. Not sure how you'd mitigate the noise of that chain sliding all that way through the tray though - or underway as you hobby-horse to windward...

Also I don't remember if the chain went over the roller through a closed chock, but if it wasn't closed that would be horrible, since any side pull would yank the chain out of the tray on its way to making a straight line back to the windlass.

I can see merits in this arrangement - if there was a reliable way to keep the chain in the tray. You would avoid the chain sliding under one of the hulls prior to getting the bridle on anyway.... And if side-pull did happen, you'd only slice off structure ABOVE the waterline ..

[mikereed100]

Rick and Henry raise a good point echoed by Chuck Kantor in his "Cruising in Catamarans", that of the possibility of contact between the hull and the rode during deployment/retrieval. If the wind were up (katabatic winds of 40-50kts sustained are not uncommon in my area) it would take some fancy helmwork to keep the bows from falling off and contacting the rode while setting anchor.
On the other hand, severe vertical forces can be generated while trying to retrieve reluctant ground tackle. In cases such as this deployment from the crossarm places much strain on the spar itself as well as the rig through the forestay.
Deployment from the bows as Henry suggests makes good sense and solves both these problems. Unfortunately my bows have a "reverse rake" from mid-hull up which would make this difficult.
Probably end up deploying off the bow in deference to my gelcoat and just pay close attention when breaking out well set anchors. Thanks for all the replies.

Mike

[sandy daugherty]

Re-reading this I realize no one mentioned the difficulty in attaching the bridle to the rode from a central bridge deck winch. I chartered a Moorings 4700 that had a handy hatch to reach the rode, but it was still awkward.

In shallow water on my PDQ (with a windlass on the stbd bow, a 30' chain to 170' 3-strand 9/16" rope) I frequently can set a bridal with a single line from the other bow, attached to the chain rode with a locking chain hook then let out more rode to equalize the sides. In deeper water I tie the single line from the other bow to the rope section of the rode with rolling hitches, good enough to hold and still easy to untie. If there is going to be some action with current and wind, I use a clove hitch (which weakens the rode. All this I can do singlehanded. The 4700 took three people.