I’ve talked with several RG65 sailors and it seems some use shrouds and some don’t. How does one determine whether or not shrouds are necessary? And if they are, where should they attach to the mast? (My instinct on the latter is 85-90% of the distance from the deck to the forestay attachment point – but that’s just a guess.)
BTW, this is for an MXP RG65.
I will assume you use a sloop/traditional rig, where the mast stands on a mast step, and suported laterally by shrouds and longitudinally by the jib and back-stay.
If you go shroudless, then the mast must be inserted in a tube that goes all the way down to the bottom of the hull for proper lateral and longitudinal support. Adjusting rake is tricky here! I’ve seen three methods for this:
In my case I use swing rig, and it cannot have shrouds anyway…
Ok, just noticed I did not answer your question!!
—>Are shrouds necessary?
Shrouds are just some means to support the mast in upright position. Our RG65 masts are only 110cm long, and a good quality 6mm diameter carbon fiber rod is stiff enough to support itself. So no, they are no necessary. And even if you use shrouds, spreaders are optional, too.
—>Why do some use shrouds and some don’t?
Its a matter of taste. I prefer the lighter construction on shroudless swing rig (no hull reinforcements needed for supporting jib and back stay!). Others prefer the flexibillity of being able to adjust mast rake. It’s up to you: what is your priority?
Dean,
I use shrouds.
It does make for more tangles and longer rig swaps.
if you go shroud-less, your mast tube alignment and placement must be perfect. if its off, just like if your keel and rudder were off kilter it woudl make for a potentially poor sailing boat.
nice thing about a shrouds and a deck stepped mast is the ability to really play with the masts position and alignment. I’ve had the same rig and sails on my multiple rgs now for about 3 years. So not having to make new rigs for each boat or new sails to account for the CE/CLR positions is a nice plus…
Hint for faster set-up and rig swaps. Taken from my 18 Square Meter catamaran days (2 forestays and two side shrouds - 1 on each side plus 2 trap wires - one on each side).
I used red & green electrical tape and if used on an r/c sized boat cut a piece about an inch long and split it lengthwise. Then wrap it around the shroud on each side of the boat. One piece for forward shrouds, and two pieces (one above the other) for aft shrouds. East to see and find the side you want. DOES NOT prevent tangles and wraps…Only identifies the line you are looking for.
Dick
For the Goth RG65 MXP (designed by Frank Russell, built by MX Components) the mast steps are tubes that extend near to the bottom of the hull. The forward tube is 9mm diameter and, of course, is intended for the swing rig. The aft tube is 9.8mm diameter at the base and increases to 10.0 x 13.7mm at the deck. The latter allows the mast to be raked.
I can easily design and build a mast ram that will attach to the keel bolt (M3 screw about 39mm aft of the mast tube). I know that a mast ram is normally attached forward of the mast and is pushing against the leading edge. In this case, the ram would connect to the mast using a ring so it could pull, rather than push, on the mast. (Whether I need a ram or not is still an open question. The point is I can add a ram later if I want.)
My mast is 7.95mm diameter at the base (ground to fit the 8.0mm ID of the SailsEtc 012RG or Breaking Winds ball bearing gooseneck). My current thinking is to make a small ring that fits to the base of the mast. The purpose of that ring will be to hold the position of the base inside the mast tube, and yet allow the mast to be raked (and even allow small adjustments laterally).
Then I plan to use shrouds (0.27mm = 0.0105in stainless steel wire, American Fishing Wire #02, 12kg = 27lb test, available on Amazon.com). M2 rigging screws will be used to attached the shrouds to the MXP’s chainplates (already installed – thanks, Maurizio!). I’m working on the means for attachment to the mast; I would prefer to terminate the shrouds at the masthead crane and hope to avoid the need to drill holes in the mast. (By running the shrouds up to the masthead I keep the mast loaded fully in compression. By avoiding holes in the mast I minimize the chance of creating a weak spot and a mast failure.)
The deciding factor was Marc’s comment above:
If you go shroud-less, your mast tube alignment and placement must be perfect.
The flexibility I get (as far as rig tuning) seems to outweigh the complexity and added wind resistance. I am very comfortable with performing rig swaps on a boat with shrouds; after all, most RC boats do use at least one set of shrouds!
Thanks for the suggestions, guys!
Hi,
with an 8mm carbon tube as a mast regardless of cylindrical or conical there is no need at all to use shrouds. For my swing rigs I use usually Skyshark PT5 or PT7 tubes which are quite stiff, the PT7 even too stiff for light winds. Using shrouds looks quite nice but for my experience it is too dangerous during races. The risk that to boats will hook up each with their rigs is much higher when using shrouds. For trimming, back- and forestay are enough.
btw, for the lower part I am using 6mm EXCEL tubes. The swing boom ist glued to this 6mm tube and the PT 5 or 7 is plugged on to the upper part which is about 10 or 12cm long. I am using plastic bearings (iglidur) with no disadvantege compered to ball bearings (more info here: http://p-sails.blogspot.de/2013/09/swing-rigg-2013.html#more)
Back to the drawing board! (Again, I fully understand that with a swing rig one does not, cannot, use shrouds!)
For trimming, back- and forestay are enough.
Joachim: Are you assuming that there is a mast ram? Or is that not even necessary?
I believe that I can make the mast tube placement and alignment as close to perfect as necessary. One nice feature of a shroud-less rig is that I don’t need to worry about where to attach the shrouds!
Dean
IRL 007
Looks you need some pictures. Here are some of my swing-rigs. All my RG65 build photos here (how to build): https://www.flickr.com/photos/thomasarmstrong/sets/72157639976683944/
Note that fore- and back-stay are integral part of the rig. They do not connect to the hull! They serve to give the rig tension, and to curve the mast to fit the main.
