[Public-List] Hinged Mast Step
George Dinwiddie
gdinwiddie at alberg30.org
Thu Jan 18 08:01:14 PST 2018
Gerard,
When you're ready to document this more fully, I would be happy to help
turn it into a web page (or series of pages, like the mast stepping
pages) to add to the website for others.
- George
On 1/16/18 12:05 AM, Gerard Kuperus via Public-List wrote:
> Hello all,
>
>
> Thanks again for all the suggestions and warnings here and through email! They were very helpful in getting this all right. I did end up purchasing a hinged mast base from Ballenger. I actually was in Santa Cruz area around new years and talked with Buzz Ballenger. He is incredibly helpful and gave great advice. He also has a pdf on his website with all the details on what to do (and what not) in order to safely lower and raise the mast. They actually sell mast bases for masts up to 8" (the alberg 30 mast is 6" x 3.6"). It is a really sturdy base, 1/4 inch thick stainless steel. Drilling and countersinking it was actually the part of the installation process that required most elbow grease (if I had thought about bringing a template they would have done it for me at Ballenger).
>
>
> So, first of all I will start with the don't do this at home warning. Please remember that all of this is pretty dangerous if you don't know what you are doing. Even if you know what you are doing (or think you know what you are doing) a mast can fall and seriously injure or kill you or someone else. The fact that this works for me this time on a boat with new standing rigging and rated parts that can be trusted does not mean it will work for you (or for me in the future)! So, I am merely describing how I did it, I am not telling you to do it! If you have any doubts don't do it! If you don't understand ratings of materials, how to line things up correctly, tie the right knots, or if you are not sure how a halyard or other crucial part up the mast is attached, don't do it. It will only take one shackle to break to have your mast fall down.
>
>
> So, here is what I did:
>
>
> Installing the hinged mast basee
>
> I installed the mast base last week. I did it with the mast up (my boat is in the water - yes living in California has its advantages). I used a gin pole with block and tackle to raise the mast about 2 inches. I attached it to the mast with two straps and supported it fore and aft and both sides. I put the ginpole on a support to spread the weight on the deck. I loosened the stays and shrouds a bit at a time (and just took off the lowers), then raised the mast, loosened shrouds and stays again, raised the mast again, etc. In retrospect, I was a bit too conservative in keeping tension on the (upper) shrouds. When the mast was up about 2" I took the old mast base off. In order to get the bottom part attached to the deck I had to move the mast slightly aft, which meant I needed to loosen the straps around the ginpole a bit and I pulled the mast back with a line. I then rested the mast on a wooden block and tied it off, so that it didn't go anywhere while I moved around the boat. I took
> the old base off the mast, cut off the plug with an angle grinder, and attached it to the new top plate of the hinged mast base (sounds all simple, it was quite a bit of grinding with my small 4.5" grinder). I then attached the new bottom part of the plate to the aluminum deck plate (I drilled and tapped the holes then used flatheaded ss machine screws). Then it was time to realign the mast above its base plate (at this point I actually had to raise it slightly more, since the hinge was in the way) and lower it back (lower mast a bit, re-tighten shrouds, lower again, etc).
>
>
> Lowering (and raising) the mast
>
> Per the recommendation of Buzz Ballenger I used a ginpole. I got a 10' galvanized pipe (2"diameter) at the hardware store and attached that to a strap to tie it to the mast. I adjusting the height a few times to get a 90 degree angle, and ended up strapping it around 6" from the bottom of the mast. At the front I used the jib halyard and put a shackle around the forestay as well. The forestay did not carry the load, but at least it stayed where I wanted it to be.
>
> For the purchase I used two double blocks and tied the end of the line to the shackle where the tack of the jib normally goes. I also attached the bottom block to this shackle. I will do this different next time, probably use a block with a becket, since the blocks did not align correctly and thus did not run as smoothly as they should. Surprisingly this was especially a problem with lowering (the first 20 degrees or so took too much time). I ran the end of the line to the cockpit and used the winch on starboard side (instead of the one on the cabin top so that I did not need to work under the fall area of the mast). If I would have a windlass that would be even better. Yet for lowering I don't need a winch. It was nice to have it set up anyway, in case I needed to raise the mast if I ran into an issue halfway in the process.
>
> The hinged shroud is tricky. I used the uppers (Ballenger advises to use the lowers, but I was worried I would lack control and Gelinas also used the uppers ) I spent a lot of time thinking about this and sort of got it right. I used a piece of chain and some shackles and managed to line up a pivoting or turning point more or less in line with the hinge. I got lucky since the top of my turnbuckle is exactly the right height. So I used a shackle on the shroud, which sits against the top of the turnbuckle. The turning point needs to be slightly aft of the location of the chainplate. I initially put it one link too far aft, since the uppers were a bit on the loose side by the time the mast was down. I adjusted it and I think it is the best I can do. The lowers were completely off, but I attached them to the chain as well (loosely), so they stay nicely out of the way and I can easily keep an eye on everything.
>
> Lastly, the ginpole needs support. I tied a line from the top of the pole to the hinged point (on each side of course), although for some reason I tied it one link too low. They were really tight when the mast was up, but since it was rope it stretched and having it tight is not a bad thing. Nevertheless, next time I will tie them one link higher.
>
> I made two small mistakes: 1) I have a little flagline that was attached to the lifelines. It was really tight by the time the mast was all the way down and pulled the mast out of line. I had taken care of all other lines, but this one is so small I just did not see it (I guess). 2. There is a block just below the gooseneck that can be used to lead the outhaul (or a reef) down to the deck (to lead it back to the cockpit). I had measured the height for a mast support correctly (to support the mast on the stern when it is lowered), but the block got in between the deck and the mast. I could not figure out why the mast was not coming down further until I saw the block (and the dent it made in the deck).
>
> One last thing: I used a long bungy cord to pull the backstay forwards (I attached it to the pullpit) so it does not drop in the water or gets tangled up somewhere.
>
>
> I had set up things a few days ago, checked everything several times, waited for a calm day and this afternoon I took the mast down. Besides the small mistakes just mentioned, it was an easy process. I had seen some videos with noises indicating high tension loads, shrieking sounds and loud bangs, and I saw some videos with really smooth operation. Mine was very smooth. There were a few people working on their boats and I had assumed they would come check out what I was doing or give me some warnings, but they they did not even seem to notice. Although I was a bit nervous doing this for the first time I am very happy with how it worked out. It is great to know I can lower the mast as often as I want to. It is incredibly easy to inspect everything that way. I had an issue with the main halyard which I fixed today (there are two plates screwed on the fore and aft side to prevent the halyard from jumping the sheave, they were both a bit too close to the halyard). All the standing riggi
> ng (which I replaced last year) looks great (as expected, but still nice to confirm!). Raising the mast was a bit of work in terms of working the winch, but compared to an afternoon of racing in 12 knots of breeze it was easy. I did not break a sweat. Obviously, the higher the mast the lower the load.
>
> I did the whole process by myself. A few folks had offered to help, and I probably would have avoided a few mistake if I had a second set of eyes, but I also wanted as little movement on the boat as possible. The bottom-line is I can do this solo. Next time, my guess it will take about 45 minutes of preparation, 10 minutes to lower, 10 minutes to raise and about 30 minutes to clean up. This first time prep took a lot longer, obviously. The rest is what it took today. But then again, on a boat everything takes 3 times as long as you think it will take.
>
>
> I have made a few photo's which I am happy to share, but I don't think I can attach them here. None of the pics are too great (I was focusing on the task, next time I will ask someone to document it). Once I have done this a second or third time and fine-tuned it I am happy to rewrite this as a little description (with the appropriate disclaimers) similar to the A-frame description and hopefully add some helpful pictures.
>
>
> Cheers,
>
>
> Gerard
>
> Skye Mist
>
>
> ________________________________
> From: Gerard Kuperus <gkuperus at hotmail.com>
> Sent: Wednesday, December 27, 2017 8:37 PM
> To: Public-List at lists.alberg30.org
> Subject: Hinged Mast Step
>
>
> Hello all,
>
>
> Inspired by Yves Gelinas (as well as by my fear of heights) I am thinking about installing a hinged mast base. It would allow me to inspect once in a while and to do maintenance or solve problems up there. I would use an A-Frame (two 10' galvanized pipes bolted together) attached to the forestay or jib halyard, take the front lowers off, and ease some tension on the uppers (I guess) and slowly lower with a block and tackle (possibly the mainsheet). I am sure some of you have a system set up, so here are my questions:
>
> - the existing baseplate (the aluminum piece on which the mast sits) is rather large. I found Ballenger makes hinged mast steps, with a topplate that is 8" x 5.5" (see http://ballengerspars.com/) .This looks like a sturdy unity with the top and base plates on top of one another, but how do I attach the alluminum base to this (mine is the standard one with 4 big bolts). Having the nuts under the topplate would make it non-functional.
>
> - If I could somehow figure out how to attach these (or get another mast base that can be screwed on) it seems that the hinge should be as close to the mast as possible. If the pivot point is far aft the shrouds would need to be loosened quite a bit (since the mast would first go up). Or do I not get that right?
>
> - So, it seems I need a smaller mast base. Ballenger does have a smaller hinged mast step. Not sure where I can find a mast base for a 6 x 3.6 extrusion, but I am sure it is out there.
>
> - Another option is the hinge made by Dwyer (see for example here: http://www.downwindmarine.com/Dwyer-Hinged-Mast-Plates-Stainless-Steel-p-90890668.html). Now the biggest one is 6.5. The Alberg 30 mast would just fit on that.
>
> - A custom option is possible, but I think Ballenger makes a pretty solid product.
>
>
> Any thoughts on my thoughts? Would I be right in getting a smaller mast base and then go for a hinged mast step that is about 6.5 x 4?
>
>
> Thanks,
>
>
> Gerard
>
> Skye Mist
>
> San Francisco Bay Area
>
>
>
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--
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When I remember bygone days George Dinwiddie
I think how evening follows morn; gdinwiddie at alberg30.org
So many I loved were not yet dead, http://www.Alberg30.org
So many I love were not yet born. also see:
'The Middle' by Ogden Nash http://idiacomputing.com
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