Mainsail Handling Systems; Which is Best for Your Boat?

March 12, 2021

Barry Hayes from UK Sailmakers Ireland explains which system is best for various situations

There are times in your boat-owning life when you need to step back and evaluate your vessel’s set-up. With an eye towards optimising the boat for the way you sail it, you can opt for different sails, winches, running rigging, nav systems, and even headstay options. Finding the right combinations of these options can be a daunting task, and it helps to do your homework before putting a credit card on the counter of the nearest marine supplier.

In recent articles here, I’ve covered a number of boat set-up options ranging from sail selection to headstay set-ups and roller furlers. This article address what may be a simple but critical matter – the best way to attach the luff of the mainsail to the mast. Here’s a look at the primary mainsail attachment/handling systems with some perspective on each. I hope this helps you to set-up your boat to meet your needs.

Let me start by describing the three basic methods or systems to attach the luff of a mainsail to a mast. The first is external luff cars that slide on a track attached to the aft side of the mast. The second uses slides, or slugs, attached to the luff that slides up and down in an internal track on the back of the mast. The final one is inserting into the mast groove a bolt rope sewn onto the luff of the sail. Each has its pros and cons, as you’ll read.

Overview of decision-making criteria

There are five basic factors to consider when selecting a mainsail handling system:

  1. Cost – this is always a factor.
  2. Control of the sail as it is raised and lowered – is the luff “captured” or not. Non-captured systems require more hands to raise and lower to prevent the sail from ripping or blowing away – it’s the same differences with raising and lowering a headsail that has hanks vs one that fits into a luff foil.
  3. Ease of raising and lowering the sail.
  4. For captured systems, the height of the stack when it is lowered. This can be a factor when it comes to attaching/removing the halyard and putting on the sail cover.
  5. How critical is the aerodynamic factor?
XD main carbon racing mainsail with luff slides

Luff Cars

Luff cars are one of the two methods of “captured” luff attachment, and luff cars are the preferred systems for offshore cruising and doublehanded sailing. In all these systems, cars are permanently attached to the luff of the mainsail, and they get mounted onto a track, which is attached to the aft side of the mast. These cars can be either simple slides or with captured ball bearings, and the configuration of the actual slides will vary if your sail has any full-length battens. The cars for the forward end of full-length battens are heavier and, in some cases, incorporate internal batten tension systems.

Harken, Antal, and Ronstan all make quality car systems that all do the same job but in different ways. Each has a track mounted to the exterior face of the mast. Harken and Antal produce a combo racing track that takes slides and luff tape. These are the preferred option for boats racing inshore and offshore. Most boats go with Antal slide as it’s the less expensive and easier option (no ball bearings).

Antal uses metal and Teflon slides put on a track making it hard to lose them. With Antal, the stack height on the mast is low. For Ronstan and Harken, the cars use ball bearing, which, at times, can be problematic. If one of the cars breaks, you can lose the bearings. Harken now has captive ball bearing cars which are easy to take off the mast. Both have relatively higher stack heights.

Most sailmakers prefer not to use headboard and carriages as they add weight and drag aloft. Headboards and carriages reduce the sail area while increasing the stack height. We normally now just web the sail onto the head car to make it easier and simpler while reducing the stack height considerably. All these systems need their own track to be fitted to the mast.

Ocean runner 111-ft maxi with Harken 32mm split-track system to lower the stack height on the 307 sq metre Dacron mainsail.

Another interesting luff car system is the Strong Track manufactured by Tides Marine. Rather than having to screw/bolt an external track onto the mast, the forward side of the Strong Track is a continuous protrusion that you can slide into the luff groove in the back of your mast and sets there permanently. The track itself is a one-piece UKMW insert with matching slides and batten receptacles designed for smooth, long-lasting operation. These cars slide up and down so smoothly.

The advantages of luff car systems are that they capture and control the sail, and they make it simple to hoist and drop the sail. Theoretically, both evolutions can be done from the cockpit with no one forward. Also, when reefing, you never lose the luff out of the mast. The disadvantages are that it takes more time to install/take off the main; every slide must be taken off individually.

PRO TIP: When lowering a mainsail with cars, have someone at the mast alternating the luff folds of the luff port and starboard. This will make flaking the sail much easier, will lower the stack height, and will make putting on the cover easier. For larger boats, it can be easier and faster if a crew member uses a climbing harness to flake the sail from a higher position as it is lowered.

Skywalker is a Jeanneau 42 with XD Carbon sails and racing lazy cradle with Rutgerson 1525-11 and plastic A014 slides

Here, I’m talking about plastic slides attached to the luff that are inserted into the slot on the back of the mast. These are a good option for coastal cruisers and one-designs. They’re also the most common system used and are very cost-effective. When using slides, you don’t need to add an external track, they are light, and the stack height is really low.

There have been some cool developments with plastic slides over the years, including All slip low friction slides and, perhaps the best option, Rutgerson slides. The Rutgerson slides actually have wheels on them, making them the slide with the least friction – a good thing when raising and lowering sails. They do increase the stack height a bit, but they are worth the price for their ease of use. Both the All slip and Rutgerson slides can be added to an existing system. This is relatively affordable to do and will make your cruising life a lot easier.

There is also an internal slide wheel car system from Selden, but you may need to change the mast making that car system expensive.

The advantages of luff slides are that they are quick and simple to install and replace; they are the most cost-effective mast attachment system. The disadvantages are that they can break under load and can stick inside the mast when hoisting and dropping the sail if they are too loose inside the groove.

PRO TIP: Always have a bunch of spare luff slides on-hand to replace one should it break.

Luff tapes

in this video from onboard Jelik in Samui, Thailand, you can see how hard it is for a Maxi to hoist a luff tape mainsail. They need to get the mainsail into a halyard lock, with eight grinders hoisting the 160 sqm Uni Titanium mainsail.

Most racing boats use a system where a luff tape/bolt rope, ranging from 7 – 12 mm, is inserted into the groove on the mast. It’s the most common system used currently. Due to the elimination of the gap between the mast and the luff of the sail itself, aerodynamically, this is the best set- up. In IRC, you lose nothing on the foot length of the sail as you do with mainsail cars. That said, this is the most difficult way to hoist and drop a sail as 1) you have to hoist the whole sail into to a tight groove in the mast, usually requiring someone to feed the sail into the mast and another on the halyard, and 2) when you lower it, you need someone to control the sail, so it doesn’t get blown over the side (the opposite of a captured system).

You also can have an external slot/track on the mast to accommodate bolt rope. Harken and Antal tracks mounted on the back of the mast work best, making it easier to hoist and drop the sail. But they add weight to the mast.

The advantages if this non-slide system is that its lightweight, very cost-effective, and it’s the best aerodynamical set-up. The disadvantages are that it’s easy to tear the luff rope.

It is clear to see how smooth the luff is on this luff tape J 109 uni Titanium carbon mainsail.

Hoisting, you need to control the loose sail as it’s lowered, and there is the possibility that the luff tape can pull out of the groove easily if it’s not the correct size.

Talk to us about which system is best for your boat. Just because you have one set-up currently installed, it may not be the best option for you and changing systems is done routinely. Regardless, sail safely and sail with confidence.

You May Also Like…

J109 Class FSI development

J109 Class FSI development

In grand prix classes throughout the sport it is well known that sheeting angles are becoming tighter and tighter –...