Lowering Grand Banks Mast

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NightCrawler

Senior Member
Joined
Feb 17, 2016
Messages
211
Location
USA
Vessel Name
Previous owner GB 42 Classic
Vessel Make
Currently running a 23' CC
We are looking at some trips north this upcoming '17 season. That will require lowering our mast. I've searched here and the Grand Banks forums and have not found any information on the process. Can anyone point me in the direction of information on this topic? We're a bit nervous about the process after hearing the crew who replaced our radar had a tough time with the mast.

Thank you. . .
 
Does the mast pivot forward or back?
 
There are so many variables, as not all GB masts are the same.
some are made of wood, some of steel, some stand on the upper deck, some on the back cabin top, some have attachment points for a block and tackle, some only for stays, some have already been replaced in order to better manage lowering, so are better designed.

Some detail of yours is required before a lot of posts are wasted in idle speculation.

That said, since you are having trouble, my guess is that you have a steel mast that pivots on the lower deck step, but the mast step provides no side support whatsoever (common for GBs) I have seen this solved, but only at great expense. (on a GB 36 that had a substantial roof structure over the flybridge, which was used to provide support to the lowering mechanism). I don't recommend that approach.

My choice, many years ago, was to lighten the whole affair, so that it would stand on its own (no stays) and could be lowered by one person using a single part line. Mine is made of Aluminum pipe, is supported on a mast step on the lower deck, that has approx 10" tall side supports, so the mast doesn't get to fall sideways on its way down, and in the upright position is supported by a bracket attached to the original base position on the upper deck, this 3 steps up from its new base. This mast is taller than the original, carries all the lights and lines of the original, plus a Radar Dome. The hoisting/lowering is done from above, with a single line to the base of the radar mount, and it has a stand that is pinned to the back side of the mast, that, when lowered, stands it just above walking height over the back deck. I have been quite happy with this arrangement, as I need to raise and lower every time I go out and back in, to my shelter. OK, I admit that is occurring less frequently since I have moved to summers in outside moorage.
 
Great points. Thank you Keith. This is the original aluminum mast with 4 guy wires and a pivoting base that folds to the stern. It's mounted at the rear of the fly bridge.
 
I've never found it to be particularly difficult if you're careful.

Once the mast is freed up to drop, have one person hold on to the stays, guide and start lowering the mast while one or more people take the weight and then walk the mast down into a crutch or all the way down onto a make shift pad on the top of the aft cabin roof.

I've done it with just two people many times.
 
Not familiar with the GB set-up but it sounds very similar to that on our Selene, except that had 2 side guy wires and a forward guy. In that situation we simply loosened and disconnected the forward guy while somebody supported the mast in the upright position. Supporting was easy because all load was still on the deck plate. Next step was to lower the hinged mast onto a support (stool or 2x4, etc) so that it did not hit anything else on the deck (eg dinghy). This was the harder part because the mast with dinghy hoists, radar etc was pretty heavy. It was a 2-(strong)man job at least. The two side guys were left in place.
With the GB set-up, I would guess that you would need to release the two forward guys to accomplish the same, and may be able to leave the two rear guys in place , though they may get in the way underway.
By the way the reverse process also needed a couple of strong men to lift the mast vertical. Perhaps your mast is lighter.
 
I think that's the best advice. Have a strong team there the first time. We have the original 4x4 deck cradle that sits on the weather deck and that will park it just above the salon roof. We're considering doing the Loop so this could end up being a yo-yo job, up and down from what we're learning. :(
 
We have a GB36CL with similar aluminum mast though rumored to have been upgraded. In order to easily raise and lower mast on the fly with 2 people, we did the following:

1) install s/eye boltas high as possible on flybridge enterdash with large backing washers/plates
2) install a s/s shackle on the forward aspect of radar platform
3) replace the forward shroud shackles with strong quick release "gate shackles? that can be released and fastened under slight tension. The aft shrouds don't need to be released to raise or lower the mast
4) block and tackle with double sheaves and a cam lock at forward end with appropriately sized snap hooksfor easy attachment to eye and radar shackle respectively.
5) I can easily raise and lower the mast from the mast crutch. Wife pulls on the block and tackle I lift the end of the mast the first few feet, as the mast come up the angle for the block and tackle becomes so efficient that wife can raise it easily.

The only catch is that on my boat a straight line from forward eye to the radar shackle is obstructed by the Bimini when the mast is all the way up. I just haul the mast up with the block & tackle until the line touches the bimini & marked that place on the rope for future mast lowering. From that point I manually pull the mast erect (1 handed task as it's nearly straight up). thread on and tighten wing nuts on base, Connec the quick release forward shackles, stow the block and tackle and I'm done. Takes 5mi utes up or down, most of which is retrieving/stowing the block and tackle and the mast and boom crutches
 
We built a simple system whose idea actually came from a GB owner.
I installed a pad eye on the back of one our back to back flybridge seats.
Bought a 3 and 4 pulley block and tackle from ebay for $10.
Screwed a pad eye onto the mast up only as high as I could easily reach.
Short line with a clip on one end for the mast, and a thimble on the other end for the block & tackle.
My wife can easily lower or raise the mast until about 45 degrees, then if we are lowering all the way I take the weight and ease it onto the crutch.
If lowering to "half mast" to get under 19 feet, I built "extension" cables out of wire and clamps from True Value. and those take the weight.
I only have half mast pictures. In the second one you can see the mast attachment point and short line.
Hope this helps.
 

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Jay, thanks for the pics. I believe this is almost exactly what we would need to do. There are already beefy attachment points on the helm and mast for the block and tackle (?) Wondering about the weight making that last 45 degrees of drop to horizontal. You are able to get a hold of the mast somehow and drop it that last half of the trip down? Weight an issue?
Again, thank you.
 
On my MT34 it's a one man job but a character builder. The solid teak mast is stepped on the aft cabin top and has fore and aft side stays as well as a fore stay. I loosen all the stays, disconnect the fore stay (it's not really needed) and place a "crutch" to hold the mast when it's horizontal back at the end of the aft cabin.

I temporarily tie the mast to the fly bridge handrail in it's vertical position and release the two forward side stays. I stand on the aft cabin top behind the mast, release the mast from the handrail and begin letting it down. At first it doesn't weigh anything, then it weights a bit but by then I've stepped back several foot and leverage makes it easy to plop into it's crutch. If I'm removing the mast entirely, I remove the aft side stays and release it from the mast step.

Then I have a beer.

I think the mast weighs about 150 lbs and is about 15 or 16 foot long. It's more obnoxious than heavy to carry around or put into the cabin when the boat is shrink wrapped.

Once I brought it home sticking out of a convertible. Everyone thought I was making a religious statement.
 
Jay, thanks for the pics. I believe this is almost exactly what we would need to do. There are already beefy attachment points on the helm and mast for the block and tackle (?) Wondering about the weight making that last 45 degrees of drop to horizontal. You are able to get a hold of the mast somehow and drop it that last half of the trip down? Weight an issue?
Again, thank you.

The mast is hollow to some degree and the radar antenna is only 7 lbs, so the weight is no problem on the lower end, plus there is still "some" supported by the block & tackle.
When we bought the boat, the radar was higher and it weighed 42 lbs, and we could not even come close to lowering ourselves.


Once I brought it home sticking out of a convertible. Everyone thought I was making a religious statement
LOL
 
Great info all. And I somehow picture those spots along those two lane roads across the mid south with the three crosses. . . .

Feeling less anxiety over this now. (deciding to do the Loop knowing we had to do this mast thing had me rethinking the trip) I'll get a block and tackle set on the way and round up a case of beer when we get close to 'practicing.'
Again, as usual - great feedback. Appreciate it very much.
 
:) That was the Admiral's suggestion as well. She REALLY wants to do this trip.
 
By using the boom or other pole and the attached stays, it is a simple one man job with no physical effort.

Used to single handed lower the mast on my 23 foot sailboat the same way.

The pic gives the idea, you hust have to work out the lunes, stays and attachment points.

I lower mine all the time for some ICW bridges single handed, underway.
 

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I'm getting dizzy just thinking about rigging that up. . .
 
That is why I originally asked if it laid forward or aft...mine goes forward so nothing to rig....

But if weight is a concern, some pole like the boom makes the action much easier.
 
JL, should not your tag line be 'Altitude Adjustment'?
 
With the right rigging and planning it's a one person job - I do it regularly alone on my 46' GB Classic.
For a first timer best bet is to have some extra hands available and plenty of time!
 
Mast

That is why I originally asked if it laid forward or aft...mine goes forward so nothing to rig....

But if weight is a concern, some pole like the boom makes the action much easier.

Does anyone know what size are the nuts that hold the mast up she folds foward 1972 36 GB thanks
 
Plan B could be to get a flag pole base as used in Skool yards .


They are aluminum with a geared 1/4 of a circle ring that can simply be cranked up and down.
 
Wondering if anyone has a still better approach to lowering their mast?
 
Wondering if anyone has a still better approach to lowering their mast?

There are a lot of variables depending on how your mast is set up.

It then depends on which way you want it to lower, I chose forward but it did make the flybridge almost unusable while down unless I stripped the rigging.
 
Wondering if anyone has a still better approach to lowering their mast?

Better than what?
We lower it once a year. A person on each upper shroud. They lower the mast down to me as I am standing on the aft cabin. I lower the mast into the crutch. If lowering the mast more frequently I would rig a block and tackle. One end connected over the mast spreaders and the other running forward to a connection point at center of flybridge helm station. Would then be an easy 1 or 2 person job.
 
Exactly. My wife and I could lower ours in about 3 minutes to either “half mast” or all the way.
Then I’d take a few minutes securing things while she continued running the boat.
We would raise it during spring commissioning usually in LI sound after we cleared the RR bridge and raise it for storage on our way back up the CT river.
Then probably 2 times during the summer to half mast when we anchored in Sag Harbor cove.
We also ran the NY canals at half mast for the entire trip.
All my hardware and rigging fit in a small plastic bin under the helm seat. I think I had about $30 invested in rigging.
 
Jay did you use a pully up high on a pole/2x4 to get a better angle? Then it seems it would be a one person job.
I was thinking of using the boom set into a wood block. There is already a pully on the aft end of the boom.
 
Similarly, what are thoughts about the attachment point(s) on the fly ridge? For me the current radar unit is older (heavier) and there’s more weight on the mast that others might have.
 
Similarly, what are thoughts about the attachment point(s) on the fly ridge? For me the current radar unit is older (heavier) and there’s more weight on the mast that others might have.

Check your seats to see how they are attached to the deck. If those attachment points are robust enough, a pad eye on the side of the seats will suffice. If you don't like that, a well secured pad eye on the floor should suffice.

Remember, your seats have to stay in place with the weight of people crashing against them when you are in a seaway. That can be a lot of force.
 

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