Capt. Don Boom Brake

Capt. Don  Boom Brakes. Sail any size boat with confidence.
If your traveler shackle bolt is 1/2" diameter or less then you will have no problems using our boom brake since the traveler is under far higher loading than the brake will  ever encounter.

NEW: 2019 version #2 is now thicker at 14mm, so stronger for larger boats.



© Don Green 2013

PleaseContact us for non US orders as they cannot be processed on our web site due to shipping charges being significantly different depending on destination country and your preferred method.

As seen in:
1/ http://www.sailingtoday.co.uk/gear/gear-on-test/boom-brakes-group-gear-test/
2/ SAIL magazine Dec 2016 on page 22.
3/ Sailing Magazine RSA
4/ Recommended by Practical Sailor July 2017

In the US Contact us or order here.
For non US orders please order via our eBay store orContact us directly.

Boom safety concerns (http://en.wikipedia.org/wiki/Boom_%28sailing%29 )

Boom strikes are the most common cause of serious sailing injuries overall and a leading cause of death on sailboats.. (This is backed up by research from Andrew Nathanson, MD, an emergency physician who is conducting a worldwide study on sailing injuries) Booms can cause injuries directly, sweep people overboard, and their associated hardware and lines represent tripping hazards. On larger boats, sailors tend to stand on the boom to perform sail maintenance and install or take off sail covers. Falls from the boom onto the deck below occur. Even when stationary, booms represent a hazard since on most boats there is insufficient headroom to walk below them without ducking.

When boom injuries occur far from shore they can require expensive rescues. In 2010 the US Coast Guard and Air National Guard utilized a Lockheed C-130 Hercules aircraft to rescue a man from 1400 miles off the Mexican coast. Deaths and injuries can occur on boats operating upon lakes and coastal waters. Boom related accidents can also imperil the remainder of the passengers and crew aboard when a key member is lost.

As a precaution, any sailboat with a low boom should mandate use of life jackets, and ensure others know how to obtain assistance and operate the craft. In Boston a sailor knocked overboard by the boom died in full sight of the land and other boats and the person left aboard didn't know how to use the radio.

Boom accidents happen to the best sailors too, a quick Google and YouTube search will confirm this.
Examples:
http://www.sail-world.com/Australia/Platino-rescue---Top-boatbuilder-named-as-dead-crew-member/145551
http://www.nytimes.com/1998/06/16/sports/eric-tabarly-66-ocean-sailor-known-for-his-solo-exploits.html?_r=0

Videos on boom brake installation:

https://www.youtube.com/watch?v=-5TNkdoV6hE&feature=youtu.be

https://youtu.be/YOgubkfWhYk

Review by Ed Martin

As an avid Chesapeake Bay and offshore sailor, safety has always been my highest priority. We have flares, life jackets, EPIRB's, life rafts, etc. but why not a boom brake? Studies indicate that boom strikes were the most common cause of sailing injury overall and probably after drowning, the second leading cause of death.

There are a good selection of boom brakes to choose from that span most cruisers budget. These include The Automatic Safety Brake, The Walder Boom Brake, The Dutchman, The Wichard Gyb’Easy and a climbers 8 for smaller boats.

Capt. Don, asked me to do a review of his new Boom Brake. Admittedly I have not used one before on my Bristol 32 but I knew I really wanted one as I sail a lot single handed and using a preventer is extra work. I square lashed the boom brake aft of the vang and ran the friction line (New England Rope 3/8”Sta-Set Polyester Double Braid works well, although VPC, spectra SK-75 and many other high tech lines probably will work fine) through the Brake to a Ronstan 2 11/16” S-Bail Snap Shackle to the Port lower aft stay turnbuckle. In order to adjust the tension of the friction line the other end was attached to a block and tackle between the brake and the Starboard lower aft stay. I used a Ronstan, Series 40, Fiddle block which has a cam so I did not have to have a line running back to the cockpit. This proved easy to adjust and forget. Here is a video of my setup. http://youtu.be/yCkFUGl12xw

The Capt. Don boom brake is inexpensive, made from polished ½ in 316L stainless steel, not aluminum. It is also about 20 % bigger than a Climbers 8 being 6 ¾” long and 3 3/4” wide with a center pin for increased friction if required.

I am very pleased with my installation and ease of use. I recommend you consider installing a boom brake. You will wonder why you sailed without it.

Ed Martin

Retired Cartographer and current member USCG Auxiliary

Note: Breaking Strength of 3/8" Sta-Set, 5100lb., 1/2" Sta-Set, 9200lb. 3/8" Amsteel 17600 lb
Boom Brake over 9000 lb calculated.
Is the Capt. Don boom brake big enough to handle your sail loads? Well how big is the shackle on your vang and traveler? Typically those shackle bolts are smaller than 1/2" diameter and see more loading than the boom brake. If you trust them, you can trust our brake. Please note that a boom brake is not intended to replace a preventer and it is advised to rig it with only enough tension on the friction line to slow the boom travel.

Here is an online calculator that reveals sail loading:
http://www.harken.com/MainsheetLoading/

Installed on a Bristol 32. See the video at: http://youtu.be/yCkFUGl12xw

Remember that the mast and boom absorb most of the sail loading so this boom brake can be used on a sail with a loading far in excess of the 9800 pounds yield strength of the boom brake. Complete parts list and larger images of the above Bristol 32 installation.

The brake can be attached directly to the end of the Vang at the boom or to a bail in the boom track just behind the Vang or to a line wrapped around the boom but the best is to rig the way that serious racers attach boom preventers, by running a line (bridle) under the boom or on the side of the boom between both ends and attaching the boom brake to that. This eliminates any boom point loading and keeps the boom under compression. See images of a Catalina 27 below rigged this way. Another option is to attach it to the center of a line that is attached to the boom in 2 places preferably spaced apart at least 1/3 as long as the boom. In other words the load is spread across 2 attach points to the boom and not a single point.

A new prototype software to optimize position on boom etc. Try it and let me know your thoughts.

All you need to input is the dimensions of the following in inches:

Height of boom above anchor points
Horizontal Length between anchor points
Distance of anchor points aft of gooseneck (stretch a thin line or nylon fishing line between the anchor points. Measure from that to the aft edge of the mast). Length from attach point of vang to boom to the gooseneck

It is often easier to attach the friction line to the top of the shroud turn buckles. see image above. This is not recommended as turnbuckles are designed to carry loads under tension, even though this provides the clearance to prevent the friction line rubbing on the coach roof which can cause changes in line length thus changes in tension and friction. Also testing has shown that it is not advisable to run one side of the friction line back to a cockpit winch for tension adjustment as the difference in line length between the sides causes trouble adjusting for the same friction when the boom travels in opposite directions due to uneven stretch.  
It is better that a set of blocks with a cleat be attached between the anchor point and boom brake at the lower end of the friction line, see image above to provide tension adjustment without cluttering the deck. Once set it should require little adjustment for changes in wind strength. It is important to not over tension the friction line as damage to a boom can occur in a gybe if the boom suddenly stops part way in its travel. Again consider the brake as a device to only slow the boom travel to a safe speed. Do not think it can be used as a preventer. Use both if necessary.

Catalina 27 See video: http://youtu.be/GGWI9OqsDFk

A boom brake can be used in conjunction with a preventer since a preventer has to be released to swing the boom and thus the brake will take over until the preventer is again set on the opposite side.

Remember:
1/ You do not need to use the winch to tighten the friction line, hand tighten is often enough.

2/ A change of only an inch in the friction line tension makes a big difference. As the boom swings the friction line length required will change as the brake does not travel in a perfect arc relative to the anchor points and thus the location of the boom brake is important to minimize this change. If in doubt about position please do not hesitate to contact me and I can do some calculations in the spreadsheet to show what impact your vang, shroud, boom arc and boom brake locations will have.

3/ If you find that you have a nice moving boom swing in one direction but not the other then try tying both ends off at the anchor points or put a cam cleat on both sides so the set up is the same on both sides. It seems some folk have a line with too much stretch and when the one side leads back to the cockpit via a block more stretch occurs on this side causing this problem. This problem has also occurred when the boom brake was placed too far aft on the boom, typically attaching about one third aft the length of the boom is good but this is highly dependent on the location of the friction line anchor points. Use the spreadsheet to minimize potential line length change requirements during the boom swing.

4/  If the brake jams, you might have too many friction line loops in the brake, change to match the images above, the geometry needs to be adjusted or your friction line is too thick. Start with a friction line that is approximately 3/8" diameter. It is always best to begin with a low friction setup and if it works but is loose try a slight change in tension before changing to a thicker line. Also make sure the friction line does not rub the coach roof or even a life boat as it can cause problems. Yes, seen them both.

Hope this helps.

Capt. Don

Comments:
Joe Anshien 2014-05-01 : Used the boom break on delivery from Martinique to Annapolis. Worked well.

Rodney Wood 2014-8-20 : I have an old IOR 1 ton warhorse with a fractional rig (rather long boom).   
The Boom Brake worked great during the Summer Social buoy races with novice/passengers on board on the down wind legs.

Peter Puky : Don, suspending your brake from the boom ends turns the entire boom into a "compression post"! This makes the boom bullet proof! A very strong method of diverting the energy. As a rigger (historic = 25 years ago) I love it!! I purchased 3, one for me and the others for members of the WORLD CRUISING CLUB team.

Steve Kratchman: I only went out the day before pulling for winter but come spring I will experiment with my line sizes, however, I do have a 3/8 line now and that did work well enough. The mainsheet went over quickly but did not bang against the stops as it would have normally. So I am very pleased with my setup although now I have it tied off at the strbrd inboard shroud turnbuckle and am using the cam cleat block at the port inboard turnbuckle. It does make it quicker for testing tensions. 

Ed Martin: After some initial difficulty and testing I followed Don's calculations and rigged the boom brake 48 inches aft of the Gooseneck on my Bristol 32 and it works great with the same friction when the boom swings  both sides, slowing it down nicely to a comfortable speed where no one is going to get hurt but not too tight so avoiding any excess load on the boom.

See images of Open 50 and 60 boats including from the Vendee Around the World boats rigged with a line between ends of the boom on which a preventer or boom brake is attached.

  Contact us to reserve or order a boom brake.

The first image above is the typical setup that the vast majority of over 2000 users of our boom brake use.

© Don Green 2013

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Welcome to MeriMarine custom boat parts including the Capt. Don Boom Brakes, Dolphin Cleats, custom made sheaves and anchor rollers, custom cut fiberglass sheet and other items since 2012.

Contact us to order.

Thank you
Capt. Don & Sharon

Follow the links below for more information.