Dutchman Mainsail Flaking System

The Dutchman System is one of the best ways to handle your mainsail while hoisting or lowering. In most conditions it self tends, allowing you do to complete maneuvers without an out of control sail. To drop the main feather the mainsail or go head to wind and ease the main halyard reasonably fast. If you are navigating a crowded harbor, you can let the halyard run and leave clean up until later.

This article describes the function of the Dutchman main sail flaking system. We look at the important set up features that will ensure proper operation, plus potential hazards to function.

Introductory Video

sailing channel

 

Article Index & Quick links
	General description
	Dutchman System how it works
	Parts of the system
	Installation
	Operation
	Maintenance & storage
	Conclusion

 

General description

The Dutchman system invented by Martin van Breems is a main sail flaking system that works like a blind. You know the blinds in your windows, that weave in and out of the vertical line.

When you pull up the blind the pleats neatly stack flat. Martin must have seen a resemblance here and applied the same principle to a mainsail. When a main is flaked properly

Take a look at your main when it is properly flaked on the boom. Now imagine 2 control lines (3 for larger boats) leading from the boom and going through the main up to a topping lift. These lines control the main sail during hoisting and lowering.

The system is quite simple in its design but does require proper installation and setup.

Dutchman System (how it works)

The major components of the Dutchman system, consist of a topping lift and vertical control lines weaved in and out of the main sail.

When the main sail is lowered, the boom drops until the topping lift takes up the weight.

When this happens the vertical Dutchman filament lines should also become tight, if not adjust them ( see installation).

When the main is raised or hoisted, the boom rises (see checked line in diagram) and hence the topping lift and the Dutchman lines go slack. Therefore the lines do not interfere with the set of the sail as it fills with wind.

Parts of the Dutchman system

There are 3 options to the Dutchman system and the best is the A system.

The Dutchman works best with a good smooth running mast track and slide system.

Here are the components of the system.

Dutchman Kit	kit contains, discs, mono clamp, Donut clamp, control lines
Topping lift	You have dedicated halyard for a topping lift or you can add a static one	see installation below
Track	Tides strong Marine track	Not a requirement but this simple track to add to your mast, makes the sail slides move easily.
Mainsail Slides	Ronstan Ball Slider	This ball slider works with a standard bolt rope mast track
Discs	Special chafe guards are added to the sail where the filament control line goes through the sail.	see installation below
Sailmaker	Sailmakers who can Install Dutchman	Discs and pockets need to be added to your sail
Battens	Do you have full battens	Full battens work best
Pockets	See  setup below

Owners Manual Dutchman A system

You can make an A system without a dedicated sheave, but will need a bosuns chair to go up and fix a topping lift permanently to the mast head crane. I have done this many times so it works fine. For this system it is best to have the bottom of the topping lift adjustable.

The other problem with this is that you many have to go aloft to adjust the position of the  clamps, see diagram left. The vertical lines need to be vertical if the are not you will have to adjust the clamps on the topping lift

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Installation

There are 3 stages in installation;

• Adding the discs and foot pockets.

• making and installing topping lift

• Set up of your system.

mainsail modification

Getting a main sail ready for a Dutchman system involves adding the discs that the vertical lines pass through, then adding the pockets at the bottom (foot) of the sail. You can add these pockets to a main with a bolt rope foot, or a loose footed sail. A Bolt rope is better, but not a huge difference. If you have a footless bolt rope then you will need a fairly tight outhaul as the foot of the sail may get pulled up during hoisting.

You will need a sailmaker to add the grommets into the sail. Its important to have them in exactly the right place so the sail folds flakes properly. If you have sail slides and full length battens will effect the layout and where the grommets should go.

Consult a sailmaker that has good experience with the Dutchman system and ask to see if they have one they can show you. Incorrect layouts will hinder performance

Sailmakers who can Install Dutchman

If the sail is laid out correctly and installed correctly you will have a wonderful system.

I say you need a sailmaker, but there are plenty of sailors out there that can do it them selves, with the right equipment. I am just saying I would get a sailmaker.

Topping lift & Clamps

The A system can be worked with a dedicated topping lift halyard or a topping lift which can be added. The diagram to the left shows a dedicated topping lift halyard, which is shackled to the end of the boom and boom height can be controlled with the halyard.

If you decide on adding a topping lift, but do not have a spare sheave, you can attach a static topping lift to the masthead crane and then have a adjusting system at the boom end to control boom height.

Clamps

Once you have decided on the topping lift the next stage is to install the clamps. The clamps hold the filament lines to the topping lift.

The bottom clamp shown here is to keep the filament clamp at the right height.

Setup

One of the most important details is to make sure the topping lift and vertical Dutchman filament lines become taught at the same time. Without this the sail will not flake properly. There are adjustable pockets on the bottom of the main sail that allow you to alter the vertical lines.

First set the topping lift. The boom when lowered should be held up by the Topping Lift.

next set the vertical lines so they are taught but not too tight they loosen the topping lift.

Operation

The first few weeks or longer you will have to help the mainsail drop and flake. The reason is a new sail, at least new to the Dutchman system will not know where to fold / flake. If you make sure its well flaked when you leave the boat it will develop creases and a memory. One the main has developed this memory you should be in good shape.

Go head to wind and let the sail down reasonably fast. My experience and that of others, is that if you let the sail down too slowly there is more of a chance the boat moves around destroying the flaking process.

With a smooth running mast track, I have found let it rip and you will have a good flake.

Maintenance and winter storage

There are two ways to remove the Main sail for storage.

The easiest way is with a dedicated topping lift halyard. Drop the halyard unshackle it and place the Dutchman lines on top of the flaked sail. The Dutchman lines can stay with the sail, as you pull it off the boom.

Re installing the sail requires threading the filament lines back through the sail. Its a good idea to mark the discs "UP" on the top side of the disc so when you are rethreading the line you have it going back the same way as before.

Conclusion

why choose a Dutchman over lazy jacks.

Positives are:

Ease of hoisting and dropping sail. In emergency situations you can almost "drop it and forget it". If you do not have experienced crew this is a blessing. Lazy jacks can do the same but not as neatly or quickly. The main can get caught up in the lazy jack lines requiring some manual setting.

Negatives are:

More costly than lazy jacks, fiddly to install and maybe tough on the sail in extreme conditions. Also the main cover needs modifying unless you have a dedicated topping lift and can lower the lines.