Category Archives: mast

Radio mast bubbles

Before I set out on my Netherlands cruise I bought a main VHF radio for Tammy Norie. I got by all last year using a handheld Icom IC-M1Euro V (and very good it is) but I did notice the lack of range and the inability to talk to nearby boats, even though I was always able to get in touch with the coastguard. I was also thinking about AIS. When I want to sleep offshore I’d really like an alarm if a ship comes near. But I’m also reluctant to load Tammy Norie up with gadgets, in spite (or perhaps because of) my technical background.

AIS is also mentioned in Wild Song’s Final Reckoning as “possibly the greatest safety device of modern times”.

Then I found the Standard Horizon GX2200. This radio kills three birds with one stone. It’s a VHF, but it also contains an independent GPS, and it can receive and interpret AIS signals and warn of approaching shipping. Since it’s a DSC radio it can also buzz the radios of approaching ships even if they’re not listening on channel 16. This not only gives me a wake-up call if there’s a ship approaching, but a way of talking to them to make sure they’ve seen me. An extra GPS is welcome, of course.

I bought the unit not long before setting off for the Netherlands and tested it on board with the antenna in the cabin. I also thought about how to fit the antenna to the masthead and run the cable to the radio.

I noticed that the masthead had four tapped holes, but when I tried to fit screws into them I found that they were slightly smaller than 5mm and quite a bit larger than 4mm. Probably some imperial size. So my first step was to tap them to 5mm. I’d bought a small scrap of stainless steel strip from Percy M See in Fareham, and cut holes and sawed it into shape using the dock pilings at Rye as a workbench. This held the antenna nicely a little way from the forward side of the mast.

I could have just dangled the VHF cable down the inside of Tammy’s mast, it being a simple tube, but I realised that it would rattle around. Indeed, Marco on Stern was complaining about his cable doing exactly that. So I thought about ways to pad the cable. I also thought about buoyancy.

The top section of the mast weighs about 30kg. A quick calculation gave its interior volume as about 40 litres. If it were completely sealed, it would float! That was not likely to be possible, but I did think about packing it with closed cell foam, or air-filled bags. Then I realised I could use bubble wrap. It wouldn’t enclose the entire volume, but it would displace a lot of water, and delay water ingress, so that if I ever did drop the mast overboard I’d have a lot more time to deal with it. And if Tammy ever turned on her side or even turtle for any length of time it would help her to right herself.

I’d seen rolls of bubble wrap for sale at B&Q, but it turned out that Mum and Dad had a great big roll of it going unused in the attic. I’d stuffed it aboard Tammy Norie before leaving for the Netherlands.

The first step was to remove the mast.  I used the low tide and high wall in the harbour at Rye to lift the mast using (appropriately) the mast lift.  Soon it was lying on the grass next to the boules pitch.

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At this point a chap turned up and started asking questions about what I was doing and about Tammy Norie. He was Mike McCarthy, a local sailor with a wealth of experience and stories, who was maintaining his own boat not far away. He offered to help.

I visited Rye DIY, just along the street from Tammy’s berth, and bought two 3m lengths of domestic cable conduit. I joined them with duct tape. It was quite easy to arrange the bubble wrap around the conduit in a long helix and shove the whole thing up the mast.  The conduit helped keep the whole thing stiff.

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We then caught hold of the top end of the conduit through the hole at the top of the mast and threaded the VHF cable and a bit of mousing string through for good measure.  The mast went back down to the boat and we threaded the cable through the existing hole in the bottom section. I caught hold of it using a tool I’d made for fishing things out of CUYC Kestrel’s mast years earlier. I say “tool” but it was just a bit of bent coat hanger that I’d kept hold of.

By this time it was dark. Furthermore, a pair of enterprising gulls had broken into Mike’s shopping bag and eaten his dinner. We went and bought fish and chips and ate them aboard while swapping sailing stories. A great time was had by all!

The next day there was torrential rain and thunder as weather fronts passed overhead.

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This was a good thing, as it signalled the change in wind direction I’d need to depart for the Netherlands.  I used the opportunity to finish the interior wiring and install the radio. It worked well, and picked up AIS signals from ships out in the English Channel some way away.

Here’s a picture of the masthead with the antenna in place, taken later in the trip.

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Now, what I’m not telling you is some of the mistakes we made.  We had several attempts at threading mousing string through the mast.  My first string was some nylon orange stuff that had come with the boat, dangled through the mast while still attached using some washers. This got snagged and broke. I tried with it again but it got worse. Then I bought some smooth string from Rye DIY and threaded that. Initially we pushed the conduit over the string and spent ages shaking it through using a weight made of a piece of wire. After getting the conduit and bubble wrap into the mast another friendly local then pulled the mouse out of the conduit, thinking this was somehow helping. Poor guy — he was very embarrassed. But eventually I realised that it was easy to push the thick VHF cable through the conduit anyway, so the mouse wasn’t really needed. We optimistically shoved the bubble-wrapped conduit up the mast and found that we could retrieve the end through the hold and just push the cable through. All of this mucking about took several hours.

Some of the stories that Mike and I swapped that evening involved people not telling the whole truth about how difficult jobs are on boats, but instead presenting a fait accomplis as if it were all easy and they knew what they were doing all along. It’s rarely so! Mike told me about a magazine article that described several weeks of faff and mistakes as an easy weekend job. I won’t name any names, but just be sure to take those articles with a pinch of salt. Sailors have plenty of salt available, after all.

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Filed under antenna, instruments, mast, radio, Repairs and Modifications

Your bridges cannot stop me

At Lowestoft I got to drop the mast for a good reason for the first time. I wanted to leave Tammy Norie at the Lowestoft Cruising Club beyond the lifting bridge and then catch a train home to Cambridge, but the bridge wasn’t due to lift for a couple of hours. Not a problem!

Very satisfying after all the work I put in to the mast hinge.

My friend Greg responded:

Dare you to shoot a bridge (sail at it, drop mast and sails, rehoist all without stopping).

Hmm… maybe, with the mast lift on a block and no mast gallows. I’ll have to practise!

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2014-08-05 · 08:32

Mast raising demonstration

Raising the mast and sail now that the hinge has been reinforced.

This is an easy one-person job now, though I have yet to try it in the water. It would be much quicker than shown in the video if I wasn’t fiddling with the sail cover, too.

This video shows an experimental mast gallows made by crossing the oars with a bungie cord. It seems like a good way to keep the mast out of the way while travelling with it down.

30kg force is required to lift the mast when standing on the sliding hatch. I measured this with a 100kg spring balance I found in a hardware shop for £3 — very handy!

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2014-06-21 · 23:42

Making the mast hinge: blood, sweat, and Duralac

I made the mast hinge improvement this past weekend and it was a complete success!

Firstly, we paid a surprise visit to MG Metals who had a very fine piece of aluminium alloy bar. I think they were a bit puzzled by me and Dad just turning up, but were very helpful and sorted us out in five minutes. It wasn’t so easy to buy stainless-steel machine screws. Screwfix seem to have given up selling screws. Fortunately, B&Q had a few. We ended up with 5mm pan-head screws and a few countersunk screws for fixing through the hinge outer.

The first step was to work out an appropriate length for the flanges. We settled on 200mm. Dad suggested we put as six screws through the mast in each flange, and stagger them for strength. I cut a single 200mm flange and we drilled a centred 12mm hole at the top for fitting. Here it is hanging into the mast stub on the hinge pin I’d already had made, with the mast folded down and resting on the back of the boat.

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I found positions for the six screws and drilled 5mm holes in the flange. Then came the nerve-wracking stage of drilling holes in the mast. A committing move. I did this by hanging the flange from the pin on the outside of the mast, aligning it carefully, then duct-taping it into position. I was then able to drill through the screw holes and through the mast. After that, I put the screws through and nuts on the back to test the fit. It took a bit of wiggling and everything was very tight, but I was able to get the pin into position. Here’s the result. 

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At this point I made a second flange, using the first as a template, and repeated the procedure. I also made some thin spacers from plywood so that the flanges didn’t press directly onto the mast. I shaped these with a surform so that their curve fits the mast pretty well, with a flat face against the flange. This gives the flanges a tiny bit of movement but will avoid their edges cutting into the mast when the whole thing flexes. The movement helps with aligning the hinge pin.

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This all took up most of Friday, but we were able to raise the mast on Saturday morning in time for my brother’s family to visit. We did this with guy ropes either side, but it already felt pretty steady, and there was no way that the pin was going to escape.

However, we were unable to drop the tight-fitting mast sleeve over the hinge. My screws had spread the hinge outer a little, and it was already an almost perfect fit. We cured this by drilling the holes for the top four screws to 5.5mm, allowing the hinge outer back to its original position.

My niece was particularly keen on the boat and set to work scrubbing the decks, though I think mostly she liked throwing water around and playing with the pumps.

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On Sunday I made the two upper flanges and spacers, again using the first flange as a template. By this stage I was getting pretty quick, and drilled the mast with confidence. Because there’s a ring here to support the mast sleeve, there was only room for four screws. Also, with the flanges so close together, it became impossible to put nuts on the back of the screws! At this stage, Dad suggested capturing the nuts within the flanges. I drilled 8.5mm recesses into the flanges and (gently) hammered in nyloc nuts, with Duralac to prevent electrolytic corrosion between the stainless steel and aluminium.

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This made assembling the whole thing much easier: I simply had to screw in the machine screws from outside. I also ended up drilling out all the holes to 5.5mm to allow the flanges to move around a bit more and let the pin through without enlarging the 12mm holes at all.

Time for final assembly. I dismantled the whole thing, treated the wooden spacers with three coats of exterior wood preserver, painted Duralac into all the holes, and screwed everything together. Finally, the pin went into place with a few gentle blows from a mallet — just right. Here’s the result.

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The red stuff is my blood. And with the temperature at over 25°C there was quite a lot of sweat involved too.

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And here you can see the screws in place painted with Duralac. Blood, sweat, and Duralac pretty much sums it up.

But what fantastic results! We raised the mast, again with guy ropes just in case. It felt rock solid. Once we had it vertical I asked Mum and Dad to be ready on the guys and tried to push the mast from side to side. Nothing. In fact, I was unable to get it to wobble at all in any direction, except backwards in order to fold it away. Here’s a picture of the hinge with the mast raised.

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The mast sleeve slid neatly into place over the whole thing, making everything even more rigid. You can see the sleeve covering the hinge in this picture of the rig reefed down to three panels.


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During that afternoon I had to make several changes to fittings at the top of the mast. No problem: down with the sail, up with the sleeve, and just fold the mast down. No need for help. It feel like about 15-20kg of force: no problem at all. And I’m pretty sure it’ll work just as well on a canal or river.

So now Tammy Norie can duck under bridges with ease, opening up a lot of opportunities for inshore exploration.

Many thanks to everyone who suggested solutions, but especially to Dad who gave me advice at every step of the way and taught me to use his tools. Hurrah for engineering!

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Filed under mast, Repairs and Modifications

Mast hinge design

I’ve had some useful discussions about Tammy Norie’s dodgy mast hinge with members of both the Junk Rig Association and the Cambridge University Yacht Club and have come up with a winning design.

Many people’s first suggestion was to somehow prevent the pin from popping out by using countersunk screws.  The problem with this is that the mast sleeve is only about 3mm thick and doesn’t have a lot of depth for countersinking.  I’m also reluctant to weaken it any further.  It already seems like not enough material to support a wobbling mast.

Another common suggestion was to make the pin longer and somehow shorten or remove it just before dropping the mast sleeve. Various ideas involving springs, bolts, and slots in the sleeve were suggested. The problem there is that if I’m single-handed on the boat on the water then I won’t be able to let go of the mast, remove or adjust the pin, and drop the sleeve in a safe way.  At some point the mast will be insecure.

The best suggestion came from Igor Gotlibovych of CUYC. (Igor is, with two friends, fixing up their yacht Auriga for an imminent circuit of the South Atlantic.) He sent this picture, saying “you could add two of these, riveted to the inside of the lower section of the mast, to provide extra support.”

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In fact, it’s even simpler than that, because the flanges don’t even have to be bent. Here’s the sketch for reinforcing the lower part.

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In fact, since I’m at it, I’ll probably reinforce the hinge connection to the upper part as well, like this.

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A good thing about this design is that the exact dimensions of the flanges aren’t critical. The plan is to visit a nearby metal merchant and see what pieces of aluminium alloy he has available. It won’t be hard to cut them to shape. I’ll space them out from the curved inside of the mast using wooden padding, which will also provide a bit of compliance while preventing the flanges from grinding away at the mast.

Watch this space for the results.

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Filed under mast, Repairs and Modifications

Launch weekend part 2: Breaking the boat

[Follows on from Launch weekend part 1: Keyhaven to Yarmouth.]

This is the day that I broke the boat.

We had a leisurely breakfast in Yarmouth and set out in glorious sunshine to sail to Newtown Creek.  We had no real purpose in going there other than to sail Tammy Norie.  Our destination for the day was the Junk Rig Association AGM at the Royal Lymington Yacht Club that afternoon.

This is the first day we could really sail and try out the rig.  The wind was a southerly breeze, making a pleasant reach for Newtown Creek.  We just sailed along and tried stuff out.

As we were sailing along I noticed the mast wobbling a little bit. I remembered the surveyor’s advice about the mast partners and thought I should have a look.  The survey mentioned that the mast needed wedges, and the boat had come with a bag of them, so I thought I could slip them in.

Tammy Norie’s mast is unstayed and sits on a substantial step at the bottom of the hull.  I won’t say “keel stepped” because she has twin keels and in any case the step would be well forward of any fin. The mast passes up through a stainless-steel disc about 25cm across and bolted to the coachroof ceiling, then through a cone moulded into the coach roof.

I undid the bolts holding this disc up in order to have a look at how the mast was resting on this cone.

Only it wasn’t.

As soon as I removed the disc the mast started pressing against the top of the cone.  The wedges I had were quite small and I imagined they were meant to go in the thin gap between the cone and the mast.  I pressed a couple in.  Almost immediately, the fibreglass cracked.  Fortunately, the wind was light and the main movement of the mast was from the chop and wakes in the Solent.  However, those caused the mast to wobble around and bash against the other side of the cone, creating more cracks.

Here’s the cone damage, photographed later with the mast boot off. Note the bolt head bottom right.

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At this point I realised that these wedges couldn’t possibly be for this purpose (I still don’t know what they’re for.) The mast should be braced against the deck at deck level.  I called to Dad to heave-to to reduce wind pressure on the mast.  Then I grabbed a towel that was nearby and stuffed it tightly into the cone, hoping to press it firmly with the disc and brace the mast. I tried to get the disc back onto the bolts.  There was no chance of that.  The mast was no longer quite vertical and wouldn’t line up.

I asked Mum to keep trying while I went outside and hauled on the various lines we had rigged to the masthead.  Nearly.  Then I threaded a spare halyard through the anchor roller and started sweating it.  Success!  The disc went on to the bolt.

Then there was a horrible splitting noise as the anchor fitting lifted, levering up a small section of deck.  I’d broken Tammy Norie’s nose!

Here’s a photo of the damage when back ashore, with me pressing upwards on the anchor fitting.  That part of the deck isn’t fixed to the hull, and was only held down by the general stiffness of the deck and some sealant.  The repair, when I do it, will be bulletproof!

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This was more inexperience on my part. Firstly, I’m used to larger boats and don’t expect to be able to break things with my bare hands. Secondly, I’m used to bermudan rigs where a line from the masthead to the bow (the forestay) can certainly take a great deal of load. But Tammy Norie’s bow fitting wasn’t designed for upward forces. It’s just an anchor roller on a plate bolted to the deck.

At least we were able to tighten the disc towards the coachroof ceiling, squashing the towel into a pretty firm but compliant bundle that held the mast tightly. No more wobble, no more creaking. No more cracks.

It’s a good job I knew where my towel was.

This is why we try out a boat in the Solent in good conditions. I’m very glad I didn’t try to sail Tammy Norie back from Inverness when I first bought her.

So, what I discovered was that the mast was resting on the disc, and that the forces on the mast were being transferred through those bolts to the deck.  Two 8mm stainless bolts, passing through simple holes in the deck without even a washer, their heads pressing straight onto the external gelcoat.  Unacceptable! You can read about the cone repair elsewhere in this blog.

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After that we had a very nice but brief stop in Newtown Creek and a fairly fast broad reach to Lymington, where we arrived only 10 minutes late for the AGM. The committee were very nice about it, saying that anyone who arrived by sea had a dispensation to be late.

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After lurking in the JRA for such a long time it was good to meet some members, and the next day we had a lovely junket and an amazing chance meeting. I’ll write about that later!

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Filed under anchor-fitting, Logs, mast

The mast hinge saga

Tammy Norie came with a hinged mast of dubious origin with a pin that has been lost.  The hinge is about 1m above the deck. Once the mast is upright on the pin, an outer sleeve about 1.5m long slides snugly over the join. In theory.

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The papers I received with the boat don’t actually match the mast I have. The one that looks plausible says it’s “the Unique Sunbird hinged mast”, but when I asked Robin Blain of Sunbird Marine about it he said it wasn’t one of his. It has a small label saying “Proctor Masts”, but they don’t seem to exist any more. Proctor Masts USA has a link for Proctor UK that goes to Selden. I wrote to them both, but no reply.

One of the first things I did was cut away the badly corroded supporting tube and have a new tube and pin made for me (at very reasonable cost) in stainless steel by the excellent Mackay engineering in Cambridge.

The main problem is that the pin must fit within the sleeve, and so it can’t protrude beyond the holes in the lower section of the mast. This means it only has about 3mm of purchase on each side. We found that if you don’t handle the mast very carefully the pin pops out of the holes and the mast basically falls off.  This is very hazardous to anyone or anything nearby, and could potentially do serious damage to the boat and mast as well.

While Tammy Norie was in the driveway we rigged up a guying system using a ladder.

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We later found that we could support the mast well enough with a person on each side of the boat, but I’m not happy with the hinge at all. I certainly wouldn’t attempt to raise or lower the mast alone while afloat. That’s a great shame, since there’s an obvious advantage to enabling her to duck under bridges.

So although we can get by for now, we are thinking about how to fabricate a better hinge. It must allow for single-handed raising and lowering of the mast on the water (on rivers etc.) and be stronger than the current arrangement.

The best hinge I’ve seen is one used on Marshall Marine’s catboats.

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I wrote to Marshall but they only make the hinge to fit their own smaller masts, and as you can see it doesn’t allow for any cabling in the mast.

So I need to come up with a design that will fit snugly inside the current mast tube and provide extra purchases on the pin. And I probably need to machine it out of aluminium alloy to match the mast.

I’d welcome any suggestions!

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Filed under mast, Repairs and Modifications