Bolt Rope or Jack Line?

OK… which is it… which do you prefer… the Jack line method, or the bolt rope method… Both had been around for some time. The jack line is supposed to be easier to set the shape of the sail than the old standby bolt rope method. Jack line was previously used a great deal simply by boats that did not have an airfoil traditionaly shaped mast with a sail slot. Particularly when carbon fiber masts were getting popular and were either homemade or made from already existing products (such as fishing rods) tell me what you think… what you use and why. Would you buy a new suit of sails with a jackline system in lieu of your old bolt rope main because you think it is that much of an advantage? Would you pay extra for a jack line style mast if a slotted main were available? Let me know what general consensus is. Thanks!

Larry -

given some of the experimentation that Lester Gilbert and others have done/are doing, the third option is circular mast (carbon) with main tied to the mast - but allowing a gap of up to 3/8 inch as I recall) which has tendency to keep the luff straight, yet offers a very thin leading edge to the wind, and also moves it out and away from the turbulence caused by the round, carbon fiber mast cross section.

I intend to use/try this method on my MultiONE 1 Meter. In theory, and based on what they have seen, much improvement is to be gained.

Of the other two - I would select a bolt rope IF my mast section were foil shaped and allowed to rotate. Without rotation, I think either have little benefits over the other (bolt rope versus jackline).

I use the jackline although recessed into the back of the mast, for boats where I want to be able to change sails without removing and restepping the mast. For this I use simple bra hooks attached to the luff of the mainsail, hooking them on to the fixed jackwire on the mast. I recall how much trouble it was unhooking bra hooks when (ummmm) much younger, [:-eyebrows] so always feel confident they won’t come off unless I work at it!

Note that my jackline concept is the line is attached to the mast - not inside the mainsail luff!

BTW - where in Florida are you located - and what fleets are nearby that are active if you don’t mind the question?

ok if you ask me
i perfer the jackline/ i used to just tie the main onto the mast with rope. then a friend shouwd me the jackline method. and it imorive the sail performance. think of it like a huge door hinge. the bolt rope is a good idea also . but in order to use the bolt rope . you have to have a groovy tube. mast
and for that money. it would be worth it.
i will still use the jackline myself
long live the cup

On some of my boats I use a wire run down the luff of the main with notches cutout of the main luff pocket every 7" for.5" double side velcro. Allows adjustment of the main distance from the mast, easy removal of the velcro to allow the sail to slide down for reefing and allows the sail to rotate to the lee side of the mast.

Doug Lord
–High Technology Sailing/Racing

Current best practice is either sail ties (string or wire) around a round mast or a “bolt rope” in a groovy or aeromast. Doug Lord’s velcro is a solution unique to him and not used by any other sail or rig maker in r/c sailing.

Actually I am in Texas (home)now, near San Antonio. I have both masts available, but I am about to have a die struck for aluminum extruded masts. I was going to be able to offer a 6’ mast and 2’ boom for about $22.50 which I thought was pretty reasonable. I am hearing from other people that the jack line method is preferable, but I had never seen that used with a slotted mast… it almost seemed redundant.

I understand about the flexibility of the mainsail, and even the option (as mentioned above) for allowing it to clear the turbulent air coming around the mast… both valid and understandable points… but what I am curious about is should I pursue the airfoil shape annodized mast, if that is really not what people want. (in other words, do I want to buy 1000 of them if no one is going to want them) I always thought that they were a lock. I might have to live to be 100 to get rid of them all… maybe schooners will make a comeback… hehehe with 3 or 4 masts each [:-boggled]

<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by Larry Ludwig

I am about to have a die struck for aluminum extruded masts<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
Hi Larry

Sounds very interesting! What grade of Al were you thinking about? 7075? 6061? What wall thickness? Diameter? Weight per unit length?

<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>I was going to be able to offer a 6’ mast<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
What is the maximum length that your postal service will accept?

<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>should I pursue the airfoil shape annodized mast<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
Some classes, such as the IOM, restrict the mast to a circular section. The downside of an aerofoil section mast is that it needs to be able to rotate to be effective. This means some pretty fancy hardware for the mast step, the masthead, the spreaders, and possibly the jib hoist if a fractional rig. It also has some implications for mast bend and mainsail luff curve, and the arrangement you want for the gooseneck and associated fittings.

Lester Gilbert

has any one tapered an aluminum mast? if so how did it work and was it worh doing? if not is there ny point in such a small section?

When the Apprentice knows more than the Mentor its time to quit!

If you are using the mast for a large heavy boat you could ust one straight piece of heavy guage aluminum and splice a ski pole tip to it. One guy up here uses it on a J class boat. It is heavy and probably not practical for most classes. Another solution if the class permits it is a carbon skipole or carbon fishing rod blank used to catch large fish like tuna sharks or halibut. If you need to save weight and or want some control of the mast bend the standard aluminum or carbon masts offered by the various manufacturers are your best most cost effective way to go.

Hi Bob -

I would second your recommendation regarding ski poles. I have hooked up with one manufacturer who is willing to send me any amount I want - and doesn’t even charge postage. Most are of the professional versions used for cross country skiing. These are taperd and very (VERY) stiff. My first use will be on my 1 Meter multi, and so far it looks like all I will need is a forestay and two side shrouds. Doesn’t even look like diamonds will be required. Main was cut to this very stiff mast section. Because of the way the filliments are wound, it was designed to take a great deal of compression load (when skiier double-poles or pushes himself) This feature is what helps to prevent bend/distortion. Most have had tips broken, so the larger taped section is intact and useable.

Would suggest contacting your local ski shops and ask for warranty returns. If they return to manufacturer, contact that manufacturer. Base on my mast is about.625 (5/8" diameter) and tapers from there. Might be too big for smaller boats however. But if you canuse them, an excellent way to save some money. Since we allow advertising in the multi classes, their product name will be showing - for sure.

As a general matter, for any racing class that permits carbon fiber masts, aluminum has been abandoned. As to an aero aluminum mast, Lester hits the issue right on the head–many classes (such as the IOM) that prohibit carbon masts also mandate round spars.

Also, as with carbon fiber tubes, there is aluminum and there is aluminum. The alloy, wall thickness and diameter used in a proposed mast can make a vast difference in its performance and desireability.

I would think therefore that it might be quite difficult to sell 1000 aero aluminum spars.

We place thin plastic tubing on to ripstop sail repair tape. Each piece of tape is about 1" wide. This is stuck to the main. A wire is attached to the mast around the gooseneck position. It is then threaded through the plastic tubing. Pulled tight and attached to the top of the mast. Electrical cable ties(very small ones) are then used to keep the wire attached to the mast at intervals up the mast.
Naturally this system is used on the multihull fleet, when using round masts. Some of the boats are now using carbon tapered airfoil sections (Home produced by one of our members)and these boats have a bolt rope.

I have been told of one lady over here producing tapered aluminium masts. She uses a 16mm, 1mm wall aluminium tube. It is cut and re-welded. I can’t comment on what they look like, or the weight of them,
as to date I haven’t seen one.

As to the aluminum thickness, we are still debating, but I will probably go with what has been on the market for all these years. They were popular on the EC-12 and S/B and Soling M.

Quite correct, any class that has allowed carbon uses carbon, so we are looking into how expensive it will be to make the slotted masts from those materials.

For “J” boats the masts are all custom made from hardwoods and are a work of art. Internal halyards? heheheh you betcha if that is what you like. They are 10’ and considerable larger in diameter.

Hi All,
i’ve been reading this site with interest for a while and finally decided to post as i actually have something to contribute. i sail out of the same club as Peter Birch and have been making carbon fibre masts for a few years. i make them off a single sided female mould and then joing them once the 2 parts have cured. i use uni carbon (150g/m^2) as the first layer and then add a layer of 80g woven fibreglass to hold it together somewhat. the section ends up being about 1mm thick and the entire mast (2.5m) is maybe 150g. this makes it lighter than most aluminium sections. the chord length is 30mm and width is about 12mm with the leading and trailing edges pointed. i realise this is probably not the best aerofoil section but my under-the-house construction methods are also not the best. my first attempt at this mast was on a 1.8m B rig that i still use. the sail is attached with sticky-back sail cloth, which does not allow any luff changes. it only has 1 attachment point and therefore no lowers or uppers or triangles or any such drag raising appendages. i have found that it bends very little fore and aft (less than 5mm under 5kg) and about 30mm sideways at the tip when sailing. this is also far superior to any aluminium masts i’ve ever seen.

Recently i have added a track to a new B mast by gluing a 5.5mm hollow carbon tube inside the mast on the trailing edge. the track wsa then cut out using a Dremel with a very thin cutting blade. The mast is a bit heavier due to the tubes, but the bending characteristics have improved even more, suggesting that the laminate may be reduced. The sail now has about 10 pieces of bolt rope to attach it and the overall manageability and speed of the boat has improved. i’m still working on a better way to aid the rotation of the mast and control it. i have thought about fixing it to the boom to help it rotate, but light wind performance will suffer due to the inherent stiffness of the shroud fitting. any suggestions as to a way of fitting roller bearings (thrust or journal) would be greatly appreciated?