Lowers - how to rig

[intheboatshed]

Hi,
I've just acquired this rather tied Baggy and have no idea how the lowers might have been rigged. I've just been left with 2 wire strops hanging from an eyelet on the mast. The shrouds are run through a PTFE tube in the side deck (something that I think will need changing at some point before the shrouds saw their way through the side deck - although there seems remarkably little wear for a boat that's over 20 years old). 

Do I need to run another line through the tube, and use a pulley system from there to the foot of the mast?

Can anyone shed any light - or give me some suggestions. I've never had a dinghy with lowers before, so don't really know the best way of setting them up. Although I want to keep it a simple as possible!

Thanks

Tim

[David (Guest)]

Not any Baggy, but either Baggy Trousers or Token Gesture.
Even though there appear to be various strops around the gooseneck I would be inclined to strip them off and start again.  One of the best mast attachments is to loop some spectra or dynema rope around the front of the mast and loop around the gooseneck, this ensures that you are pulling back at a decent angle.  You then need to consider how to set up a cascade block system pulling from around the shroud position, you could have a 2:1 above the deck, 8:1 between the mastfoot and deck going onto a 2:1 or 3:1 going down the side of the centreboard case.  This last set of purchases should combine the port and starboard purchases, so that the two sides balance and you pull one string.
A word of caution, despite having a spave frame this set up could develop a lot of compression which was never intended when these boats were built ...

[Alex D]

Here is a photo.

[intheboatshed]

Thanks for the input, and the photo, thanks Alex, your assistance is much appreciated.

The boat is Token Gesture - well spotted. Looking a bit sad for herself at the moment, but I'll try and get her back into shape.

I'm not going to go mad with the purchase on the lowers, but thanks for the tip. I just sense the mast needs something to help control the prebend a bit. I had almost considered just putting something around the front of the mast at the level of the space frame, but she'd obviously had lowers at some point, so I thought I ask. 

Did any other boats use PTFE tubes through the deck for the shrouds? If yes, have they now replaced them with through deck sheaves?

Tim

[Lukepiewalker]

I think mine (similar spaceframe arrangement) went to turning blocks on the spaceframe by the shrouds and then down to the floor. I did have a mast ram and a mast puller at 'deck' level too.

[Steve (Guest)]

Tim,
From the photo it's not absolutely clear, but if your set up is the same as I had on the Baggy 2, at the end of the spaceframe, where it attaches under the deck, there will be a stainless steel insert with a flat plate that the PTFE (or nylon or similar) bush passes through. This effectively transfers any shroud loads to the spaceframe rather than the deck and judging by the state of the decks this is probably just as well for Token Gesture. If it had deck sheeves just fitted in the deck and not connected to the spaceframe the loads may have pulled them out by now. I would hold fire on getting rid of the bushes if I were you. I had no problems with wear of the bushes, the only problem in that area was a bit of corrosion of the end of the aluminium tube. The stainless fitting resulted in a bit of electrolytic action with the aluminium. I replaced the ends of the tube and used zinc chromate paste to reduce the risk of future corrosion and that seemed to sort it.
 
The route the lowers took was from a fitting on the front of the mast near the gooseneck, round turning blocks on the spaceframe near the outboard ends, down to the mast foot and round turning blocks. The lowers were tensioned with an 8:1 lever with about 4:1 multi-block purchase system on the end. I know others who set them up with fixed lengths and used mast rake to do all the control. Not sure how that worked if you wanted to pre-bend the mast in light airs, but didn't want to rake the mast. There may have been some kind of bottlescrew adjuster to alter the lowers tension.

Regards,
Steve

[intheboatshed]

Thanks Steve, for you experience and advice.

Sounds like I had better take a closer look under the side decks. Ignorance is bliss!

The way you describe the lowers was the way I had thought I would re install them - in the absence of any other information. However, there doesn't appear to be an obvious place to attach a turning block. The only fitting at the outer end of the tube is a plastic eyelet which already keeps the bracing wire (from the mast step) outboard.


Tim

[intheboatshed]

Steve,

I checked Token Gesture last night, and you are absolutely right about how the PTFE Tubes/bushes are connected to the space frame. Think I'll leave well alone for the moment and take a look at how much corrosion there is next winter - when I plan to do some more serious maintenance.

Thanks again for your help.

Tim

[Michael]

Hi,  Just about to put my lowers on.  Had envisaged one line running through the 2 blocks on the mast fitting to each gunwale.  Below the mast fitting in front of the mast there would be a single block through which this line runs.  This will then be connected to an 8:1.  So when tension is applied it is equally distributed to both lowers as they are one line running from gunwale to gunwale.  This is fine for restricting forward movement but will do nothing sideways.  The alternative would be to have one line from each side of exactly the same length linked straight to the purchase.  This way the load will be taken by the two lines unequally, with the shortest line taking more.  This will be more direct and deal with sideways bend to some degree.
Have i answered my own question?  I think the second solution is best!

[Antony (Guest)]

Martin,
You are right, the second will do what you want the lowers to do....  the first will only partially fill the role of normal lowers.
Antony

[Overomtimistix]

I was just looking at this example on a British Moth with a single line using a knotted eye around a single block to do what you suggest.
http://bmba.proboards.com/index.cgi?board=tobuy&action=display&thread=216
 

[Michael]

yes can see the knot, but that surely renders the block useless!

[tom lee]

The tension on each side is not going to be the same anyway, the boom applies tension to the leward lower because of the kiker tension so in reality the winward lower doesn't  do a lot (especially on a reach).
I've rigged my lowers using the second sytem michael describes because it is relativelly simple to fit. the only trouble with it is it adds a lot of compression in the mast which is why a lot of boats have the turning blocks in the side decks and the fixed end on the mast.

[Overomtimistix]

Michael, you're right - the block doesn't really do anything you could just tie the downhaul onto the becket. if you prefer.
It may help to relieve the stress in the rope a bit ...
 
dan

[Michael]

Yep have put it all tpogether with an 8:1 led back to the thwart and it looks like it works pretty well.  Thanks for helping.