Boom Drawing Sheet

Attached is the boom drawing sheet for download and printing
<a href="/files/boom_drawing.pdf">Download PDF</a>

Hinged Mast Bases

Hinged mast bases are designed for deck stepped masts to be used to help in the stepping process using a gin pole or on smaller masts, by hand. They are not designed to be used as tabernacle bases for temporarily lowering a mast to pass under a bridge or obstruction. For that use, we can custom make tabernacle bases that, along with mast and rigging modifications and using the boom as a gin pole, can make "on the fly" lowering possible.
We produce several sizes of hinge plates. The size is defined by the flat area of the plate that is available to mount the mast step or plug and mast section. The sizes follow:
HMB E27 5" X 3.5" Punched flanges 5 holes each side.
HMB SC27 6.75" X 4.25" No flanges.
HMB M30 6.5" X 4" Punched flanges 5 holes each side.
HMB 8055 8.0" X 5.5" Punched flanges 5 holes each side.
As you can see, the largest hinge plate has a flat area of 8" x 5.5". This will usually accommodate extrusion up to 8" x 5.5" and that is what we consider the largest section that can be safely stepped with a hinge plate. Larger sizes can use a custom tabernacle. The top plate of all of the tabernacles have fastener holes predrilled and countersunk. The base plates of all but the HMB E27 are left undrilled so that the existing bolt pattern in the deck can be match drilled. The holes will also have to be counter sunk. There are several methods of attaching the mast extrusion to the top plate. If the existing mast step casting is in good condition and with enough inherent strength to do the job, it can be attached to the top plate by machine screws , either with nuts or tapped into the step casting. The mast would be then attached to the mast step by drilling and tapping through the mast wall.
The second method is to make a plug out of thick aluminum (min. 3/4") that fits into the mast reasonably tightly. Small masts can use thick (3/4" +) Delrin or UHMW or similar plastic. The plug can then be attached to the top plate and the mast using the same method as with a casting. It is best to drill and tap all attachments since it usually works best to install the plug in the mast extrusion first and then attach it to the top plate.
With all methods of attachment , it is strongly recommended that thin plastic is installed between the mast , mast step or plug and the stainless steel top plate to inhibit galvanic corrosion. This is especially important if the boat is sailed in salt water. We can supply this material, optionally.
The base plate should be mounted on a flat on the boat deck that is at least as large as the base plate. It is important that the base plate is fully supported. Hard epoxy filler can be used if the buildup is not thicker than about 1/4". Thicker buildups should be done using fiberglass and resin laminations. G10 can also be shaped and glued to the deck with epoxy . The base plates are preferably bolted through the deck although long screws or lags can be used if the deck has sufficient thickness. Short screws or screws used in holes that are not close fitting and free from rot should not be used. Many manufacturers used plywood under the mast steps and through the years water may have penetrated the wood causing rot. This should be checked and repaired. The screws must grip very well if they are to be used instead of bolts. Use silicone sealer under the deck plate to seal the fasteners.
After the mast is stepped, the two hinge plates should be in full contact with the alignment pin fully engaged with the top plate. If this is not the case, the mast step under the bottom ss plate should be leveled. The alternative is to trim an angle in the butt of the mast extrusion. Many mast butts are not cut at 90 degrees in order to compensate for deck angle. If this is the case on your mast, this angle should be maintained and the plug or casting should be attached at that angle. In other words, if the mast is sitting down properly on the step before the hinging process is started, do not trim the base of the mast at a different angle. If you build up the boat under the step, be sure not to change the angle. If you do, the mast may need to be trimmed to accommodate the new mast/step angle.
There are a number of methods of raising the mast with a hinge base. Some use A frames, others step by hand and I like to use a gin pole set up. I believe that the gin pole method is the safest and fastest method to step a mast. The method employs a dedicated gin pole (some people use their spinnaker pole) which attaches to the mast and has a couple of lines that go from the deck to its tip, athwartships to support it side to side. A dead ended halyard goes over the tip of the gin pole an attaches to either a block and tackle attached to the bow or to the trailer winch in the case of a trailer boat. The mast needs a sideways support line from each side of the boat go keep it from falling sideways during the lift. These support lines or wires should attach to the boat at about the same vertical height as the hinge pin so that their lengths remain the same over most of the lift.
To lift the mast, usually the upper shrouds are not attached since they do not have enough range to go through the arc of the lift. The backstay should be attached and the aft lowers (if the boat has them) should be attached along with the gin pole guides lines and mast lifting wires. The halyard that is over the gin pole is tensioned, after clearing all bystanders from the fall zone of the mast, and the lift begins by cranking the trailer winch or pulling on the block and tackle. The mast will come up and it is important to clear all of the shrouds as it does. Never should anyone stand or sit in the fall zone of the mast. As the mast reaches its full up postion, the upper shrouds and forward lowers can be attached and tightened, and the headstay attached and tightened. When the mast is up and the wires tensioned, the lifting gear can be removed.
Safety tips:
<ol>
<li>NEVER, NEVER, NEVER allow anyone to be in the fall zone of the mast when raising the mast.</li>
<li>All parts of the raising gear should be first class, fully rated hardware. No cheap hardware store clips or other parts that can bend or break. Rated screw shackles are the best to use. Galvanized is fine and less expensive than stainless. No snap hooks, use rated snapshackles or rated locking carabineers if quick release is desired.</li>
<li>Extreme care should always be used. Go slowly and stop if something does not seem right. Watch the rigging as the mast is raised to be sure that nothing has snagged or that turnbuckles are leading properly.</li>
<li>Inspect all of the raising gear before attempting to step the mast. Inspect all connections before lifting.</li>
<li>Never try to catch the mast if it starts to fall. It may seem counterintuitive to say this, but the natural reaction is to try to catch the mast. Stay out of the fall zone when lifting.</li>
<li>Attempting to step the mast in high winds or on the water when the boat is rolling due to wave action is not safe.</li>
</ol>
No one set up will work with all boats. I have outlined a method that has worked on a number of boats that I have set up. It allows for the operator to be at the bow of the boat, in the safest spot. There are other methods that use the boom for a gin pole and lift the mast from the bow. The boom must be fixed in position and not on a sliding gooseneck. This method works well and is the preferred method when a tabernacle step is used for "on the fly" mast lowering for bridges. The tabernacle system uses a custom designed mast base and requires that the bottom of the mast be modified . The standing rigging has to be modified as well so that the rigging can remain attached and relatively tight as the mast is lowered. Again, the hinge base is not designed for this type of mast lowering. The hinged mast base can, however, be reversed with the hinge forward so that the mast can be raised from the bow using the boom as a gin pole. This is not for lowering the mast on the go, but for mast stepping under controlled conditions.
This article is for informational purposes only. Ballenger Spar Systems, Inc. will not be held liable for the use or misuse of the information in this article. This article is not to be reproduced or used in any way without prior consent.

Mast Assembly Instructions

Please read before attempting to assemble mast.
Unpack mast carefully and check to be sure that you have received all necessary parts. if there is any hidden damage, it must be reported to the trucking company and Ballenger Spar Systems immediately (see shipping damage info sticker on package).
All painted spars must be unwrapped immediately upon receipt and never wrapped in plastic or laid on any wet, non porous surfaces or blistering of the paint may result. This occurrence is not covered by our warranty. anodized surfaces must never be washed with any strong base solutions (caustic soda, some paint strippers, some bilge cleaners, etc.) or the anodize may be stripped from the surface of the spar. this is also not covered by our warranty.
<h3>Mechanical Splice Assembly</h3>
Some masts are shipped with the mechanical splice disassembled for shipping reasons. Assembly is quite simple. One side of the splice is shipped assembled and can be used as a guide. Sometimes there are different length screws used in the front of the mast versus the sides so be aware of that. One can double check by removing a screw from the assembled splice side to double check.
Both sections should be placed on a relatively level surface such as saw horses. Line them both up and tie the corresponding halyard tag lines together. There is a PVC splice piece in the electrical tube that helps to guide the joint together. Slowly slide the two mast pieces together making sure that the PVC splice connects and that the tag lines don’t get pinched in the splice. It helps to tighten the tag lines as the splice is pulled together. A ratchet strap or block and tackle can be used to pull the mast sections together, but usually this is unnecessary. Once the two mast sections meet, start to install screws in the front of the mast first. Use Loctite, 5200 or silicone on the screw threads and under the heads. Tighten each of the screws. After the front row (s) are installed, go to the next row aft on one side. After that row go to the same row on the opposite side and complete that row. Follow the same sequence, alternating port and starboard, working aft until all of the screws are installed. There are usually a couple of aluminum bars on the aft face. Those should be the last to be screwed together. Check for alignment by sighting the sail track. The splice screws can be loosened and the re tightened if required to help realign the sections. In some cases installing the aft bars first will help align the sail track.
<h3>Spreader assembly</h3>
The mast is easiest to assemble if it is lying track side down on saw horses. the first step is to install the spreader bars. They are usually marked with their position and direction forward. they are pre fitted at the shop before painting or anodizing. the bars are installed from the starboard side of the mast with the angle in the bar up and they should be a very snug fit. It may require tapping into place with a rubber mallet. do not use a steel hammer- it will mushroom the end of the bar and make the spreader fit impossible. sometimes a tiny amount of filing is required to remove some of the paint or anodize buildup around the hole. Do this very carefully and keep it to an absolute minimum because you want a very tight spreader bar fit. the halyards should all be behind (aft) of the spreader bars. the only exception is when a pole lift or staysail halyard is very close to a spreader bar. be very careful not to snag or pinch one of the tag lines or halyards when installing the spreader bars.
On all but the smallest spreaders, spreader keys are used on the spreader bars to fill the space between the bar and spreader. the 3.25" wide spreaders use one in the front and the back and the 4.75" wide spreaders use only one in the front of the bar. these again were prefit at the factory and should be used in the position in which they were installed on the spreader bar. lubricate the bar and keys with lanocote and slide one of the spreaders on the bar until the bolt hole align and bolt in place. if the bolt holes don't line up, you may have the bar backwards. coat the bolts with lanocote and install. make sure that the first spreader installed is flush against the mast and install the second on the other side. you will probably notice that the bolt holes on the second side to not exactly line up athwartships. this is intentional, do not drill them out. this slight mis alignment insures that the system will be tight after it is bolted. use either a clamp to compress the mast athwartships or use a drift pin in one of the bolt holes to align the holes. bolt as before.
<h3>Rigging assembly</h3>
Install the shrouds and stays on the mast. there are many different terminations for standing rigging, especially with rod rigging. the two most common with wire rigging are t tangs and external tangs. external tangs require pinning with the clevis and cotter pins supplied. bend the cotter pins open a minimum of 30 degrees. It is best to have the cotter pins on the inside of the tang. be sure that the cotter pins are large enough and that the clevis pins are long enough so that the cotter is not bearing hard on the tang. the wearing of the cotter on the tang can cause the cotter to fail.
T tangs are very easy to install. turn the tang 90 degrees to its normal position and insert in the tang backer. install the appropriate rubber t tang plug above the tang. a small amount of clear silicone will insure that it stays in place. the plugs are not necessary, but they do help to keep water out of the mast and the shrouds in place when stepping the mast.
Since there are so many different terminations for rod rigging, it is best to check with the factory for instructions on specific installations.
Install the shrouds in the spreader tips. use lanocote liberally on all of the bearing surfaces and threads. tape and boot the spreader tips. use caution in protecting the spreader ends. make sure that the tips can drain so that water will not be trapped around the spreader tip. The combination of stainless, aluminum or carbon, and salt water make a powerful battery and galvanic corrosion will cause rapid deterioration of the spreader tip. leather boots or the molded rubber ones work well. teflon tape on the extreme ends of the tip are many times enough.
Lubricate the threads of the turnbuckles with lanocote, tef-gel or lithium grease. this is important to prevent galling when the turnbuckles are adjusted. be sure that there are no damaged threads or burrs on the cotter pin hole when assembling the turnbuckles. do not force the turnbuckles if they are binding, this will only damage the threads and compromise the strength of the turnbuckle. call the factory if you are having problems with thread fit.
If mechanical fittings are to be installed on the shrouds be sure to read our instructions on installing them. we will not warranty galled fittings unless our instructions are read and followed. please call the factory if you do not have a copy.
<h3>Installation of electronics</h3>
The mast mounted lights and wiring are tested at the factory but transportation can vibrate bulbs loose or destroy filaments so it is important to check the lighting before installation of the mast. Care should be taken to insure that the masthead instruments will not be damaged by the crane or hoist when stepping the mast. It is best to check with the yard for advice on weather to install masthead and other electronics before the mast is stepped. The wiring at the base of the mast should be arranged so that there is no danger of damage when stepping the mast.
<h3>Lifting the mast</h3>
The mast should always be lifted on the long axis of the extrusion, never sideways. the mast is strongest in the fore and aft dimension and may be damaged if lifted sideways. Lines on each spreader tip can be used to stabilize the mast during the initial lifting procedure. once the mast is vertical, it can be rotated to its required orientation.
Never stand directly under a lifted mast or put appendages under the butt.
<h3>Important:</h3>
Never modify, drill holes, or cut openings in the spar without first checking with the factory. Tthis is an engineered spar system and any unauthorized modification of the spars or rigging will void the warranty and may compromise the integrity of the system. Property damage and personal injury or death can result from improperly executed modifications. Consult with the factory before attempting any modification or addition to the spar system.
<h3>Other helpful tips:</h3>
<ol>
<li>
Use rags around the mast collar to protect the mast as it is passed through the deck collar.
</li>
<li>
Set the center of the mast step slightly aft of directly below the center of the deck collar to allow for prebend in the mast.
</li>
<li>
When the mast is on the step be sure that the butt of the mast comes in contact with the mast step evenly. the mast should be sitting on the step with full contact when the headstay is made to length. if the mast doesn't contact the step evenly, there is danger of damage to the mast and or the step. some bendy masts have a slight "rocker" cut into the front edge so that it will bend and not point load the front of the mast. this configuration will show a slight gap on the forward face of the mast and is normal.
</li>
<li>
Be sure to pin a tape the turnbuckles after tuning the mast. this is very important because cotter pins are quite sharp and can cause injury unless they are bent so that the sharp edges are buried in the turnbuckle body and taped over. use plastic rigging tape.
</li>
<li>
Using Lanocote or TefGel inside the base of the mast can help reduce corrosion at the butt. also coating the step bolts with Lanocote will make expedite later removal.
</li>
<li>
Chock the mast with rubber chocking or Spartite and make sure that the mast is not point loaded in the collar. Use Spartite only on carbon masts .
</li>
<li>
New rigging will stretch after a few sails and will need to be re tuned. make sure that this is done as soon as excessive play is evident in the leeward shrouds when sailing .
</li>
<li>
We coat our anodized masts with a clear acrylic sealer before shipping. This wipe on finish can be reapplied yearly and will help protect the surface and keep it looking good. It is also helpful in restoring old anodized finishes. Spar Seal is available from the factory.
</li>
<li>
Any questions? Please call or email.
</li>
</ol>

Mast Info Sheet

Below is the Mast Information Sheet for download and printing.
<a href="/files/mast_info_sheet_2006.pdf">Download PDF</a>
Download PDF

Mast Maintenance

Or how to avoid turning your sailboat into a powerboat.
The single greatest cause of sailors becoming power boaters is the lack of maintenance given to their spars and rigging. many sailors simply sail their boats until the rig falls down. this practice is great for our business but bad for both insurance companies and boat owners. a simple inspection and replacement program can save a summers sailing, the crews' safety, and maybe the club championship.
The simplest and most important maintenance priority involves wash down, inspection and lubrication. hosing down the spars after use, especially in salt water, rinses away salt and grime that degrades the surface of the spar and helps promote galvanic corrosion between dissimilar metals. the boom is especially prone to problems since many times it is wrapped in a wet mainsail and a sail cover to bake in the hot sun. fresh, clean water will be a lot less harmful than salt or lake water would be.
While cleaning the spars, inspect the hardware, look for points of wear and other potential problems. high load areas such as the gooseneck and vang swivels or bails on the mast, and vang mainsheet and outhaul areas on the boom should receive special attention. look for excessive corrosion, small cracks, deformation or other tell tale signs of potential problems. at least every six months enjoy the view from the top of your mast and go aloft to inspect and lubricate the masthead sheaves. inspect all of the hardware along the mast including the spreader bases, shroud tangs, spreader tips and chafe protection, and masthead sheaves. this is also a great time to replace the anchor light bulb that has been out for the last two seasons. check for cracks at any of the forward sheave boxes, such as the pole lift or staysail sheave, and at the hounds box on fractional rigs. these are areas that show fatigue first. check the hardware for small cracks, excessive corrosion, and deformation. check for halyard wear on the forward edges of the spreaders.
Mast tangs are usually either external type with a compression tube and bolt fixing them to the mast, or one of a variety of newer types including "t tangs" for wire or stemball tangs for rod and wire or screw together type rod tangs. all the types of tangs should be checked for corrosion, articulation, and proper mast wall bearing. stress and corrosion can cause the tangs to crack or in some cases cause the attaching fasteners to become loose or ineffective. corrosion can also cause the tangs to lose their ability to articulate as the mast moves which is a sure fatigue inducer in the shrouds. all tangs bear on the mast wall and the bearing point shoud be inspected to be sure that the tang is not "dragging" through the wall of the mast. compression tubes and bolts should be inspected regularly, but this will require disassembly of the tangs and that is usually best done with the mast out of the boat. i have seen many compression tubes, bolts and tie rods nearly cut in half from improperly lead wire to rope halyards. i would plan to pull your mast for a thorough inspection every five years or less.
After battling the seagulls for room at the masthead, inspect the headstay and backstay toggles, chafe guards, and sheaves. the sheaves should be lubricated with a heavy lubricant. we recommend using heavy lubricants (lanocote, or lithium grease or a combination of both) instead of light lubricants due to their ability to stand up under high loads and to prevent galling. both lanocote and lithium grease are available in aerosol cans with long plastic "noses" that can get to the center of the sheaves without disassembly. the exception is harken sheaves which should be washed out with water and lightly lubricated. wd-40 is not a good lubricant for any use on spars, in fact it becomes glue like in salt water. i doubt that this dismissal will affect their stock price or their sales to unsuspecting sailors.
Lanocote has proven to be a miracle product for protecting from galvanic corrosion and galling. we use it on any parts that have to come apart again, such as spreader tips, spreader bolts, sheave pins and sheaves. it is made of lanolin and is pleasant to use and isn't messy like never-seize used to be. we call it "sheep dip" at our shop since lanolin is a component of sheep wool. in fact, for many years we had a border collie named "mac" who used to sniff at an open tub of lanocote with great excitement. he was so excited one day that he stepped in a tub and wore it for several laps around the shop before it fell off. 'tef-gel' is another widely used and very effective lubricant/corrosion prohibitor.
Standing rigging
Another important area of inspection is the standing rigging. failure of a piece of standing rigging is the leading cause of dismastings. a system of inspection and systematic replacement is the surest way to prevent the "powerboat syndrome."
Both rod and wire rigging have finite lives. they both fall prey to fatigue and corrosion over time. wire rigging due to its construction and method of attaching fittings will probably fail from corrosion where as rod riggings' nemesis is primarily fatigue.
Corrosion in standing rigging is primarily "chloride type" corrosion where salt water in an oxygen free environment will activate the stainless steel and cause it to eat itself. this happens inside swage fittings with little obvious evidence until the wire and fitting part. sometimes small crack will be apparent in the swage fitting from the corrosion expanding the parts, and sometimes not. careful inspection can many times find problems, and if any wire strands are broken at the shank of the swage, the wire should be replaced immediately. type 316 stainless steel is only marginally better protection from this "active" type corrosion than 302/304 stainless. nitronic 50 rod, which is the alloy used for most rod rigging is quite corrosion resistant and most of the fittings are designed to drain, thus avoiding the problem. i do wish that navtec would drill drain holes in their tip cups; they are always full with water when i inspect them.
Anaerobic corrosion also causes surface discoloration on the wire itself. any type of coating on the wire surface (dirt, oil, and other surface contaminates) can keep oxygen from coming in contact with the surface of the stainless steel. if oxygen can not reach the surface of the stainless steel, the surface can not "passivate" itself and corrosion or staining can occur. i have seen this type of staining in all types (316 and 302/304 ss) and sources (us and imported) of stainless steel wire. the only way to avoid this staining is to keep the wire clean. i've often thought that calling a steel stainless on a sailboat was a marketing ploy.
Fatigue is many times less evident than corrosion but equally deadly to the vertical orientation of the rig. wire is superior in indicating fatigue in that one or more stands will usually break before the entire bundle fails. rod, on the other hand, consists of only one strand and is either continuous or broken. i have never found a piece of rod that is cracked and not broken. fatigue usually occurs during use of the boat, but a loose stay or shroud flogging in the wind at the dock is also a prime candidate. trailering a boat can also cause premature failure if the shrouds are not kept from bouncing around. the best prevention is to remove the wires from the mast before trailering. if that is not possible, they should be strapped tightly to the mast.
The areas that have been the most common sites for rod failure have been at the spreader tips (above or below the spreader bend on intermediate shrouds) and at the top fitting of the headstay. the headstay and intermediates are usually the first candidates for replacement, although replacing all of the rigging at once is usually the smartest plan. although all boats are different, i would say that rod and wire rigging becomes suspect after about seven years of normal use.
Running rigging
The current trend in halyards is away from rope to wire halyards and toward all rope halyards. the rope halyards are usually lighter, and more kind to hands and the mast. they are, however, much more prone to chafe than wire halyards. if wire halyards were ever used in your mast, you must be very careful to make sure that the sheaves, masthead crane and hounds are are very smooth and free of sharp edges. sometimes, chafe guards should be installed to protect the line, especially the main halyard. a few minutes with a file and sandpaper can save many dollars in new rope halyards. a sharp edge can ruin a new halyard in a matter of minutes.
Carefully check all of the halyards themselves. wire halyards should be checked for breaks, "meat hooks," and integrity of the splice and nicopress . rope halyards should be checked for chafe spots, cover bunching, and the integrity of the splice. all the shackles should be very carefully inspected, with a magnifying glass (for us old guys), to look for corrosion and cracking, especially in the hinge pin area. i do have one obvious suggestion, check the halyards before you go aloft on one to inspect the masthead. also never trust just the shackle on the bosun's chair; always backup the shackle with a line laced through the spliced eye, or better yet, tie a bowline in the halyard and tie to that. you don't get second chances at the masthead.
With a little common sense and a few hours a year, sailing can be made safer and more enjoyable. i hope that this article has helped make both of these goals more attainable.
Good sailing,
Buzz Ballenger, Ballenger Spar Systems, Inc.

A Mast Tuning Guide - The Light Version

Mast tuning is simple if you remember a couple of basic principles. If you understand these principles, you can tune just about any mast.
The first principle, and probably the most important, concerns tuning the mast athwart ships. the diagonal shrouds, lowers and intermediates, always pull the mast to weather at the spreader where they terminate. The spreaders, on the other hand, due to the compression from the wires going over their tips, push the mast to leeward. in order to tune a mast, you need to establish a dynamic balance between "pull" of the diagonal and the "push" of the spreader.
The second principle is that the length of the headstay controls the rake of the mast, i.e., the amount that the mast is aft of plumb in the boat. masts, in general, should always have at least a small amount of rake, they are usually designed for one to two degrees of rake. the feel of the helm is the ultimate test of the rake. Making a mast more vertical will help weather helm and more rake will help to correct lee helm. this is a bit of a simplification, but after all this is the "light" version of mast tuning.
The third principle is that most masts should have a slight "prebend" over their length with the headstay firm from a minimum of backstay load. prebend can be visualized best by stretching the main halyard down the aft face of the mast. the maximum distance that the back of the mast is in front of the halyard is the prebend (you should take into account any offset that the position of the main halyard sheave causes). prebend can be attained by tightening forward lowers, chocking the mast forward in the collar at the deck, moving the mast step aft (on a keel stepped mast), or lengthening the headstay. the amount of prebend varies from about 1" for a single spreader deck stepped mast to 6" for larger keel stepped spars.
The last principle concerns the amount of tension in the rigging. as a general rule, when the rig is fully loaded up (top end of the #1), the leeward shrouds should be beginning to appear to slacken. they can be deflected by hand, but not swinging loose. This will approach optimum general rig tension for most normal boats. individually the wire tensions should be higher in the lowers and uppers than in any of the intermediates.
The tuning sequence that has worked the best for us is to start by centering the spar in the boat athwartships with the uppers. we tighten the uppers slightly. next the lowers are adjusted so that the mast at the lower spreader is centered on the masthead. sighting up the sail track is the best way to determine this. if the mast has multiple sets of spreaders, then the intermediates are adjusted next starting at the upper spreader. when the mast looks to be in column from the deck to the tip, then rig tension can be applied (chock the mast sideways and fore and aft now if it is a keel stepped mast- make sure the step position is correct for the required prebend). We add additional tension by adding equal numbers of turns to each side of the turnbuckles in the same sequence that we first used. make sure that the turnbuckles are lubricated with heavy lubricant to prevent galling and damage to the threads. check to see if additional adjusting of the shrouds is necessary as you add tension to the rig. check the headstay to see if the rake of the mast is correct. check the prebend. tension the backstay and see if the mast remains straight under load. that should conclude the dock tune portion of the setup.
<h3>Some hints:</h3>
<ol>
<li>
If the tip of your mast seems to fall off, and your uppers are fairly tight, try loosening the intermediates.
</li>
<li>
Check the rake of a mast by tying a heavy object to the main halyard and measuring the offset from the back of the mast. subtract any sheave offset present.
</li>
<li>
Make sure to do the final tuning of the mast when sailing. make sure that the mast remains straight athwart ships. check that the mast bends forward in the center (the reason for prebend).
</li>
<li>
Check to make sure that the bottom of the mast is square athwart ships, and for a keel stepped mast that the mast is straight through the deck. if it is not, the mast will be forced into an s bend that is impossible to tune out. we usually tune a keel stepped mast with the deck chocks out and shim the mast sideways after the mast is straight athwart ships. mast steps and mast collars are rarely exactly on the centerline of the boat.
</li>
<li>
Use a steel tape run up the pole lift or main halyard to get the mast vertical in the boat.
</li>
<li>
Always pin and tape turnbuckles and cotter pins after tuning. be sure the cotter pins are taped so that the sharp ends are covered to protect people and sails.
</li>
</ol>
Well, there it is, forty-five years of experience condensed into one and one-half pages. now you should be ready to tackle tuning any mast. in fact, I hear there are some openings for riggers for the next America's Cup.
Buzz Ballenger, Pres.

Guides

A Mast Tuning Guide - The Light Version

Boom Drawing Sheet

Hinged Mast Bases

Mast Assembly Instructions

Mast Info Sheet

Mast Maintenance