Mast Collar Thingy

[Foswick]

Currently, on my boat, no lines run from the mast to the cockpit. This spring, I am rigging halyards and reefing to do so. We have a deck-stepped mast and need to install blocks to make the 90-degree turn toward cockpit. The way I have most seen and liked was to use a deck plate and clip on whatever you like. I really don't want to unstep the mast for this, though.

The two other main options I have seen are to install turning blocks on the base of the mast or mount blocks directly to the deck. Both are OK viable options.

But, I recall seeing what I remember as a two-part clamp-on collar, of sorts - probably custom-made. It was (to the best of my recollection) about 5-6 inches wide/tall and was clamped very near the base. It might or might not have had a collar/boot attached.

Two questions:

• What is that called? It's not a super-common solution and I am having a hard time finding information about them. I mean ... I would probably end up just custom-making one (or having it done). I kind of thought someone like Rig Rite might do something like that but, not sure what it is called, and with their website short of photos, I don't know if they do or not.
• Anyone have experience and pros/cons to this approach? It seems like a why-not sort of approach since, it it doesn't work well it can just be removed.

Also, what about other options I am not considering?

 

[fred1diver]

Never seen anything like it personally, I am not sure about it without seeing it.
What kind of boat do you have?
Unstepping a mast is not that complicated, in my opinion it would be the best option as you could use the right gear for the job, let’s not forget that it needs to be really strong to support the loads needed.
I am not sure a clamped collar would have the strength needed, unless it is bolted to the mast itself

just my 2 cents

 

[Foswick]

I think they are mostly used on stayless masts. The main advantage there is you don't have to put a hole in your mast or deck - which is a greater consideration with stayless rigs. I think I might have seen it used on large wooden masts, too.

It should also be quite strong, as forces are well-distributed. In fact, that is actually one of the main reasons I took an interest - because it should be better than solutions that bolt/rivet directly to the mast or deck. A mast plate is a fine solution - I'm not against that. There's just a lot I find appealing about the collar/clamp idea.

I did find this brief reference to something similar: No Visible Means of Support

Though, the hardware in that article is considerably narrower than what I (sort of) recall seeing. I also just found this old post by @mermike: https://forums.sailboatowners.com/t...-the-base-of-the-mast.1249927492/post-1673517 Also a bit narrower than what I think I have seen.

So, the approach is not unheard of. I just can't find much information about it - just the occasional isolated use.

Here is a quick mock-up I just made to show what I think I recall. Something like ...

I will likely just end up unstepping and installing a mast plate. But, just looking at stresses, the collar is a stronger design and I love the idea of being able to remove, repair, inspect, and modify without unstepping.

 

[sailme88]

Forces in play... remember this term when you're narrowing your choices. The plates mounted under the mast are held down by the mast AND its shrouds. Halyards create lifting force. Many keel stepped masts have a hold down turnbuckle that is attached to the overhead and captured by a mast mounted pad eye. Since there is no mast on the cabin top, there is no down force. The turnbuckle holds the cabin top down against the upward pull of halyards.Attaching blocks to the cabin could work if you through drill the cabin top and use a robust backer plate. Attaching to the mast might also work if the block is thru bolted.You could have blocks on either side. Attaching to the bolts would require a tang of some sort. Again the tang needs to sized to overcome the forces against it. In the pic, the block collar looks to held in place buy compression. There is a possibility that the vertical forces might pull or allow the collar to slide up. To counter this, I'd suggest thru drilling and thur bolting in that area above the ledge in the casting.

 

[dLj]

I've only ever seen this done on wooden or steel masts. I've never seen it on aluminum masts. I suspect because if the clamping forces needed to hold it in place. What material is your mast?

In both cases on wooden and steel masts, they were custom made for the specific mast. I've made them for wooden masts. But only seen them on steel masts.

I don't know what they are called...

dj

 

[Joe]

Another source that I have had direct experience with is Garhauer Marine. Besides all the hardware displayed in their catalogue they will fabricate to your specs also. My projects were not new original designs, but rather modifications to existing products... customizing might be a better description. However, they do make a series of "mast plates" which, it you check the picture, could require a little modification for proper fitment. So creating a collar that would serve the same purpose as a mast plate might be in their wheelhouse. A phone call to the manager of that particular department.... sorry I can't remember his name... could be worth while.

The company is very much run like a family business, very informal and willing to help. Good luck.

 

[ShawnL]

I was going to suggest Garhauer, but @Joe beat me to it.

I used a couple of these on my boat. My loads aren't as great as yours probably are (smaller boat), I used large stainless fender washers on each fastener in the cabin. If my loads were greater, I'd probably fabricate a larger plate to use as a backing block.

 

[FastOlson]

I have seen a boat with a short (9" or so) piece of slotted track thru-bolted on each side of the mast base. Mine you, this would have to be a sturdy install with the attachment holes all epoxy filled and equal size backing plates underneath. As for a "clamped" ring with 'ears' for attaching blocks, C&C and Yamaha used to do something very similar to that back in the 70's, IIRC.
Note that anything you would clamp or cover over the mast will need to be well insulated from moisture which will potentially introduce salt water between the parts.

 

[rgranger]

These are designed to go around stanchions (search for stanchion turning block) and you could attach to the mast using SS hose clams (from the plumbing section of Lowes)

Pluse ..

...or...

 

[rgranger]

Also found this in the archives...

https://forums.sailboatowners.com/threads/installing-turning-blocks.1249924209/

 

[Project_Mayhem]

Two more potential fabricators.
Mast Collar | Eastport Spar & Rigging, LLC
Order Custom Stainless Boat Parts | White Water Marine

I saw some prefabbed ones available for Seldon masts and whomever Catalina uses for their spars

 

[Barnacle Bill]

So, my understanding is that you want to run halyards aft to the cockpit, right? Dwyer, who recently closed it's doors, offered a mast plate to attach blocks at the base of the mast to turn lines at 90 degrees to deck cheek blocks or multi deck organizers which start accommodating two lines and more to turn them around the companionway sliding hatch to the cockpit where the lines can be lead to a winch or cleats or stoppers (rope clutches) or both. This sort of hardware is offered by a number of manufacturers. Schaefer or Garhauer are two that come to mind. Harken makes deck organizers and a number of blocks as does Ronstan and a host of other manufacturers who supply deck hardware. You don't have to use an under mast deck plate to turn blocks at the base of the mast, but they are nice. You might want to check Garhauer.