HOME

Mac Weak Points

     
       
 

The Mac is a very safe boat. However there are a few points that come to mind as absolute essentials if one wishes to avoid some potential catastrophic failures, which in turn could prove to be fatal.

Following is a list that I would recommend all MacOwners to bear in mind.

     
FORESTAY      
  When the mast is raised and lowered, it is not unusual to put a nasty kink in the forestay at the mast hound end of the wire. While the tensile stress of this bit of wire is immensley strong, repeated bending causes the strands to break. I've experienced it personally on Restless, witnessed a forestay fail on an M (below), seen another X with a frayed swage and read a few accounts of the same. If a strand is broken, the loading strength of the stay reduces by some unbelieveble degree, maybe 70%. Yacht surveyers will mmediately condemn all rigging if one strand is broken. How fatigued are the remaining?? Think about it. with the shrouds and the mast hinge without a forestay there is only one place a mast will fall... straight into the cockpit. Makes my blood run cold...      
       
  Thanks to a following wind, the main kept the mast up as the crew rushed to get another halyard tied to the pulpit. Their stay broke atypically through the top of the loop... another reason for getting an eye put on.. the top of the foil will also ride up to the top so it is easier to lift the furler and get to the turnbuckle. Below is my old stay. Didn't even know about the breaking up of the strands a foot down the wire till I took it out.      
         
       
 


Remedy:

Check your wire for any sign of fraying! If found, replace immediately! You can upgrade the 3mm wire up to 4mm and I would go for an eye swedged on with the longer neck.. about 2". Standard kit at any riggers. Simply unscrew the wire from the turnbuckle in the furler and it'll come straight out through the foil. make sure you take the complete assembly (inc furler drum, don't need the foil) to the rigger as you'll need a slightly larger turnbuckle for the heavier guage wire.

When stepping the mast, I set up the furler line as in the photo below. As the mast comes down, I simply let out the tension on the furler line so it remains taught. It'll also stop that annoying bouncing around of the furler drum on your foredeck! I leave it in place as when the mast goes up it works just as well.

     
       
         
  When you move the mast forward for trailering, maintain the taughtness by pulling them together. As soon as is possible I then unclip the forestay from the hound and release the stress. The number of times I've seen the wire bent at 90deg out of the top of the foil is simply scary. A bit of a fiddle, but one I'll not avoid. I find it easier to stow the foresail along the deck.

     
  BALLAST      
 

 

We all have heard of this. Just remember that half ballast is far far worse than none at all. It's what makes car ferries turn turtle. I've had a couple of shocks when Mrs checks the level and finds it low... once after beaching (it half drained while out on the dry.. (earlier macs with the under step valve are really prone to this) and once when I forgot to close the transom valve. Not a problem unless your on a long tack with the valve above water level! I've built myself a level alarm to give me an extra catchnet.

     
         
  TRAILERING      
 


A sticky brake cable will cause the shoes to slighty bind which will generate enough heat to melt the seals on your bearings and lose their grease as well as overheating your tyre putting it in the danger zone of bursting. Get stainless cables and check them! I've read countless tales of tyres/bearings failing and have experienced losing a wheel by this process. It can ruin your planned break, and in some cases has caused total destruction of the boat. Every time you have a stop, put your hand on the tyre, then the wheel to check that they're not cooking.

Remedy:
Tandem axles and stainless cables. Otherwise check regularly, and never ever leave your trailer parked with the handbrake on! They'll seize in no time and cause friction hence heat when rolling.

     
         
  LEAKING      
 


Macs are notorious for letting in rain water at the chainplates. Other deck fittings can also leak, and don't forget the rubbing strake.. go over all of it with some marine bonder every other year or so and avoid coming into a damp dark mouldy stinky boat.

     
         
  HANDY MAC TIPS      
  Center Board
Get a marker pen and mark your dagger/centre board rope. You can check depth in shallow water with a boathook. This comes in very handy next season when you can't remember what's what. Even when recovering the boat, I'll still have a foot or so of board down to help with the steering. It just rolls out of the way when going on the trailer.

     
         
 

Emergency Steering
If you have something awful go wrong with your rudders, like something jamming or breaking, bear in mind you can transfer the steering cable directly to the engine. Check you can do this and that you've got the tools onboard if you need them. Saved me from calling for assistance!

If the steering fails at the helm (common problem) then one option is to raise a rudder and lash an oar or boathook and there you have a basic tiller. Some folk make a tiller that fits onto the engine. Not a bad plan either. Again it is good to run through the drill of dissassembling the steering components while on the trailer.