Forums > Sailing General

D.I.Y. Mast Down, New Rig, Mast Up.

Reply
Created by cisco > 9 months ago, 18 Dec 2017
cisco
QLD, 12364 posts
18 Dec 2017 10:05PM
Thumbs Up

It has been a long time making it happen as I have had to take care of business. Take care of the business and the business will take care of the boat.

The starting point was nearly a year ago when I hired a local crane mob to lift my mast off the boat.

Being charged for three hours crane hire for 3/4 of an hour's work got right up my nostril, especially when the crane driver was on the phone to his mates the whole time and I had to wait 20 minutes for him to get off the phone to hit me with his outrageous charge which I told him was a cash job anyway.

On top of that Wander66 and I had to do the hook up as the crane driver's monkey man was a monkey without a clue. Then when the mast finally reached the trestles, it had crane cable grease on it from the lift point up.

This is the start point with all running rigging disconnected from the boat and tied to the mast.

Finally the crane arrives late and we set up the lifting strop around the mast under the lowers so that it can slide up the mast.

That was mistake No.1 which did not prevent the lower but I will explain later.



The 3.7 m folding ladder is quite handy for a rig of my height which gets me to within boat hook reach of the spreaders. The lifting strop wrapped around the mast is not the way to go. Whether you are pulling up or down, it will tighten on the mast and become immoveable.

A lifting/lowering strop around the mast should only be a loose fitting single turn around the mast. A short piece of line of sufficient strength (10 mm double braid for a 100 kg mast is sufficient) with a loose fit around the mast tied with a reef knot or a bowline with another short bight bowline to attach to the lifting tackle on the standing part of the line.

You need to be able to get it on and off even if it means going up in a boson's chair before lowering and after raising.

So here we go lowering the mast to the ground and the crane wiping grease off it's cables all over the top half of my mast.



That is a nice motor boat there. The guy has spent about $70,000 on it.

cisco
QLD, 12364 posts
18 Dec 2017 10:56PM
Thumbs Up

So after being thoroughly ripped off by the crane guy I determined that I would make myself independant of him by building my own lowering/lifting rig as illustrated by a photo Ramona posted a couple of years ago.

This apparatus is demonstrated on Youtube. This method involves a lot less strain than using a spinnaker pole or boom as a "gin pole".



The "Gin pole" method is mostly only suitable for trailer sailers and is what I did many times on my Windrush Wildfire on my own but I had to use a sheet winch for mechanical advantage.



Those that regularly go in and out of the Swan River under the Freemantle Bridge will no doubt dispute that but there is no disputing the fact that lifting and lowering the weight of the mast only requires nowhere near the amount of grunt that levering a mast up or down does.

The "A Frame Method" naturally requires the lifting point is fixed and generally that it is at least AT or preferably ABOVE the point of balance (COG to be precice) of the mast. It fairly much requires two people, one on the lifting gear and the other to control the mast base. Also it may only be suitable for single spreader rigs.

It may vary from yacht to yacht and pre-measurements should be taken and some sort of calculations made before committing.

cisco
QLD, 12364 posts
19 Dec 2017 12:23AM
Thumbs Up

The Rig.

As we all know re-rigging is something we only want to do every 7 to 10 years and if we do it right and are lucky, should never need to use the boson's chair between times.

Get your mast head perfect. New sheaves, new mast head lights and new or repaired wind bird.

I have been up a few masts and working with split pins, pliers and trying to knock out seized pins with a punch is a mizerable exercise. So I asked the rigger if there was anything intrinsically wrong with using stainless bolts with nyloc nuts for sheave axles and attaching stays.

The answer was NO with the obvious proviso that the loads are taken on the shank of bolts and not on the threads. It is a lot easier to work with a couple of spanners up there than screwdrivers, pliers and multigrips.

Alloy sheaves replaced with self lubricating nylon, pins replaced with bolts.




As mentioned in a previous post, a Supernova anchor/tri light fitted with double insulated marine grade tinned copper twin flex going to it. It only needs twin flex as the light is supplied with a reversing polarity switch. LEDs are polarity sensitive. Polarity one way lights the anchor light, the other the tri light. You can't have both on at the same time. The stainless wind bird was repaired.










I went up in size from 7 to 8 mm wire and elected to have the open turnbuckles instead of closed rigging screws. The boat will probably break before the rig does.




There is a whole lot of other detailitus that I do not have pics of such as the new leather spreader end boots that I had to make and lace and repainting the mast base socket.







cisco
QLD, 12364 posts
19 Dec 2017 2:08AM
Thumbs Up

Raising the Rig.

The Youtube vid of the Cal 27 is educational but I just could bring myself to trust pine studs for my A frame legs.

I visited my favourite metal merchant and determined that 50 x 50 x 3 mm ally RHS would suit the job but 6.5 metres was not long enough and was a trifle too flexible. I bought two lengths, each cut in half. I then bought two 2 metre lengths of 40 x 40 x 3 mm steel duragal RHS as extension pieces, then a length of 100 x 6 mm ally plate for the top joiner.

This gave me a 2 mm per side clearance for easy insertion and when bolted each way would not be too flexible.


I drilled as accurarely as possible to make the joints interchangeable but still marked them to match.





The feet are bolted to the toe rail.




We did a trial a couple of weeks before the lift by raising the A frame, guying it fore and aft and then lifting an 85 kg friend off the deck and then bouncing him a bit to make sure the legs would not buckle under load.





This is where mistake No. 2 is. Unlike the Cal 27 set up, we had to raise the A fame from aft and the mast from forward due to the narrowing of the boat's beam towards the bow.

The forward guy lines need to be led inside the cap shrouds and over the spreaders. You will see why in following pics.

The A frame is erected with fore and aft guys and the 4:1 tackle attached.






The lifting tackle is attached to the mast and the tail end of the lifting tackle needs to go through a turning block and led to a securing point such as a rope clutch, self tailing winch or cleat near the hauling point.

Mistake No.3 is where we attached the lifting tackle to the mast. It should have been above the hounds and below the spreaders. When we got the mast up, the strop was jammed under the hounds and required a trip up in the boson's chair to free it.

That trip is required anyway both when raising or lowering the mast to take it off or put it on respectively.





I was wondering if the lifting line led straight down to the mast step would block slotting the mast in but it didn't.






The hoist was fairly easy with the haul on the line being only about 20 to 25 kg and winching not necessary.





A bit of juggling is needed to make sure the spreaders stay in front of the legs.


Wander66 is looking up there and thinking "I can' believe we just did that." while he is shouting "You idiot Cisco!! I told you we should have run the forward guys inside the cap shrouds."

And he is right. You can see it in the pic below.



A satisfying and successful operation overall and now that we have erected and lowered the A frame twice, we are confident we could lower or erect the mast in about an hour each way including assembly and disassembly of the A frame.

I hope this pictorial essay is of use to some other Seabreezers. Cheers Cisco.



Subscribe
Reply

Forums > Sailing General


"D.I.Y. Mast Down, New Rig, Mast Up." started by cisco