As before, I both agree and disagree (again there are many different ways to turn one’s crank – not necessarily wrong, just different)
On my last five boats I have used a rigid vang and didn’t use a topping lift (although on a couple I actually had the gear already on the boat, but didn’t use it). I agree the primary function of any vang is to keep the boom from lifting when sailing down wind -- the sheeting angle of the main sheet exerts less downward pressure because of the oblique angle when the boom is out from center. A rigid vang has an addition job however and that is to support, and even lift, the boom (or why else go to a rigid vang anyway as they are pricey). Most rigid vangs will lift the boom some, I suppose all will if installed properly.
That brings up another point, most rigid vangs aren’t just a rigid piece of tubing. They have some spring in them. Some have a pneumatic cylinder and some actual springs (or the one I use is just fiberglass tubes that are bent under pressure). Thus, when buying a rigid vang it is necessary to calculate the amount of upward tension needed along with the size of the device. Many vangs allow different spring tensions to be installed in the same size unit.
When my main is down I do attach my halyard to the boom’s end and put some upward lift to it. Not much, just some. Not that I have to, but why not since the halyard is just hanging around not doing much anyway. While this is not a topping lift by definition, in this instance it is doing what a topping lift would be doing at anchor. By the way, on many of the big boats I’ve raced on, or used to race on, we’d often take the topping lift totally off even if we didn’t have a rigid vang or before they existed (the rigid vang is a rather new invention in the history of sail).
There is no reason not to have a topping lift with a rigid vang other than the thing flapping around and slapping on the sail. When one has full battens and an extended roach it can get rather annoying. As was said, you don’t want tension on the topping lift since the sail holds the boom up, while the sheet and vang hold the boom down – thus allowing proper sail shape to be accomplished.
As with many things in sailing there are many ways to accomplish the same thing and none are inherently wrong. The best example I can think of is just to walk down a dock and marvel at all the different types of anchor and anchor gear – all to accomplish the same basic thing.
From:
AlbinVega@yahoogroups.com [mailto:
AlbinVega@yahoogroups.com] On Behalf Of Bob Carlisle
Sent: Sunday, October 26, 2008 1:05 PM
To:
AlbinVega@yahoogroups.com
Subject: Re: [AlbinVega] Topping Lift -vs- Ridgid Vang
Does a "Ridgid Boom Vang" replace a topping lift? No.
Is the topping lift used when sailing No.
or just to support the boom while at rest? Yes
In other words does the main halyard serve as the topping lift at the dock, and then get moved forward to hoist the mainsail No, they\'re seperate pieces of string; the main halyard is connected to the head of the sail and pulled tight, so raising the mainsail, at which point the topping lift is slackened off and left loose whilst sailing.
and does the leech tension of the mainsail support the aft end of the boom
exclusively while the main is up Yes
or is the topping lift still in use? No left loose (see above)
Whilst either a vang or a topping lift will both hold up the boom, when the mainsail\'s not raised, they do very different jobs once it is. At this point the topping lift should be loosened off as described above and doesn\'t generally do anything at all (other than make an irritating slap-slap-slap noise against the sail in certain wind conditions) until you re-tension it prior to dropping the sail once again. The vang meanwhile now commences doing its primary function, which is to hold the boom DOWN; without it or the more usual/standard kicking strap fitted, the boom will have a tendency to lift when the wind\'s blowing from abaft the beam, thereby scandalising (a fancy name for making baggy) the main sail and so losing power.
Hope this helps
Bob Carlisle
Spring Fever 1776.
