Loading on Pole Topping Lift

[Channel Sailor]

I have been looking more closely at my pole topping lift line which is looking rather worn. It looks to be a little spindly (8mm) considering the load sometimes on it. It is a 43squ m area downwind type spinnaker, Fractional When well downwind I have the pole usually at 90 degrees to the mast so load on the topping lift appears OK. The theory I have read is to try and keep the pole level with the sea/horizon, which I get for well downwind. But for a Reach should something different apply?

But for a Reach I usually lower the pole outboard end to create a straighter luff, but keep the inboard end high enough to keep the tack very close to the forestay. This means the pole is certainly not level with the sea/horizon. Also the topping lift load seems quite high. My questions are, when on a Reach and the wind increases to say upper F2 or more if still OK:-
should I level the pole (in a low position both ends)? This reduces the load on the topping lift. Or for Reaching should I up the strength of the pole topping lift? I do have a strong 2:1 pole downhaul on a bridle.
Is there a technique to ease the compression load on a spinnaker pole so the deck crew can move it safely without it being either stuck, or risk of it quickly slipping uncontrolled up or down the mast track.? Is it simply a big ease on the sheet and a lot of flapping for a few seconds, which is tricky if Solo.
should the backstay always be on hard when Reaching with spinnaker? This to help protect the mast from bending aft in the middle.

 

[Laser310]

I'm not sure why your topping lift load is so high...

how about just easing it?

the pole will not fall to the deck when the spinnaker is up and drawing - the loads are compression, as you note, and upwards.., not so much downwards. the foreguy should be much more highly loaded than the topping lift.

maybe having it angled down does increase the downward load - so level it at least part way.

the tack does not need to be close to the forestay, and indeed while reaching it is probably better to have it a bit forward - the further forward it is the more it can counter the tendency to spin out on a powered-up reach.

if you are reaching - pole to the headstay.., the compressive loads will be large - not much you can do about it.

why do you need to remove the pole when you are reaching with pole to headstay? - you are always going to do a leeward douse in that situation.., just leave the pole on and get rid of the chute, then remove the pole.

 

[Channel Sailor]

I will try easing the load off the topping lift to see what happens. I should clarify, I should have said “adjust” rather than “move” the pole on the track.

 

[TernVI]

The kite is pulling up, so the load on the pole up is from the guy and foreguy or pole downhaul.
If the guy is not far enough forward on the toe rail on a reach, there will be a lot of tension in it, and a lot of compression in the pole and possibly high loads on everything else.
Except in light weatheryou shouldn't need to have the pole sloping down from the mast, even then it's better to lower the heel of the pole as well, to get the tack of the kite further from the mast.

 

[flaming]

8mm on a pole up seems absolutely fine. Ours, on a kite very nearly twice the size of yours, doesn't even go to a clutch but to a swivel jammer so the crew can reach it from the rail. So never more load than a person can comfortably hold. If you've loaded up the pole up much beyond the weight of the pole than you've got something badly wrong. I expect it's your habit of having the pole sloping down on a reach to keep the tack near the forestay. I can see how that might load the pole up if the pole is trying to swing down under compression.
But, as others have said, this is very much the wrong approach. When reaching you definitely do not want the tack of the kite close to the forestay, but project it as far as possible forwards.

 

[Laser310]

How is your foreguy rigged?

to be clear - i am not asking about the afterguys, but rather the pole-down line.

on some smaller boats, the foreguy leads from a bridle on the pole to the deck near the mast

this can cause compression on the pole- it's okay on smaller boats and makes gybing easier

a bigger boat needs a foreguy that leads from the pole end down to a fitting near the bow

 

[Channel Sailor]

Ah, it seems my angling down of the pole end is not right thing to do. I read it somewhere on the web and did not question it at the time. Also I tend to have the tack ending up close to the forestay, not well forward. Instead I can lower both the mast and outboard end of the pole which will position the tack further fwd and the downhaul can be used to help straighten the luff.

Yes, I have a pole down line (foreguy? Downhaul?) on a 2:1 connected to the centre of a pole bridle. The pole down line is connected at the mast base. Which at present does not seem to do much that I have noticed, though I always set it up with the intention that it stop the pole skying. I could reposition the pole down line (foreguy?) from in front of the mast to a fitting nearer the bow, but would need to why this is worth doing as it makes gybing more complicated (Solo).

The Topping lift is also on a bridle. Gybing method is end to end, not dip pole.

The Guy (combined with Sheet in my case) has an aft turning block but it also has a Tweaker (Twings in the USA maybe) at the widest point on the beam. When used at a Guy the Tweaker pulls the Guy down to the rail midships. I was wondering if the Tweakers should ne mounted further forward than midships, but it seemed to be OK because the strain of the Guy on the stanchions looks bearable.


Photo attached is what makes spinnakers all worthwhile for cruising. Daybreak from Poole to Near Cowes, 3 hours or so downwind on spinnaker in around 5kts increasing to around 8kts for a long while, finally around 12 kts of wind when I doused it because it tiller pilot was not coping so well. As I passed through Hurst the true and apparent wind changed around a lot so sometimes I was on a Reach then back to well downwind.

 

[Laser310]

how big is this boat?
fractional spinnaker?

anyway - if you are gybing end for end, it's probably okay to have the foreguy led to the base of the mast - especially in light air, and if you are mostly using tweakers. when i have tweakers i disconnect the fore guy in most conditions

it is possible to do end for end gybes with separate sheets and afterguys - some people think that's easier as the new afterguy has no load (and neither does the pole) until the pole is on the mast and the guy gets trimmed to take the load off the old sheet. this techniques is common on boats that are near the size limit of practical end for end gybing, but don't want to go to dip pole. These boats will often have a foreguy that leads straight down from the pole end rather than from a bridle to the mast base

 

[flaming]

how big is this boat?
fractional spinnaker?

anyway - if you are gybing end for end, it's probably okay to have the foreguy led to the base of the mast - especially in light air, and if you are mostly using tweakers. when i have tweakers i disconnect the fore guy in most conditions

it is possible to do end for end gybes with separate sheets and afterguys - some people think that's easier as the new afterguy has no load (and neither does the pole) until the pole is on the mast and the guy gets trimmed to take the load off the old sheet. this techniques is common on boats that are near the size limit of practical end for end gybing, but don't want to go to dip pole. These boats will often have a foreguy that leads straight down from the pole end rather than from a bridle to the mast base

Close to what we do. 32 foot, 90ish sqm kite, separate sheets and guys unless it's very light. Pole down is on a bridle and goes to the middle of the foredeck. Doesn't make gybing any harder, and does allow the pole down to be used to pull the pole forward when required.

For the OP's setup, the tweakers are good, and I wouldn't change anything there, just move the pole down to the middle of the foredeck so it will also give a forwards element. This helps keep the pole absolutely locked in space, and doesn't waste any of the kite's energy moving the pole back and forward rather than the boat.

 

[Channel Sailor]

Thank you all. I'll also look into moving the Pole Down to the centre of the foredeck. I happen to have a Selden D ring rated at 1100kgs located there already. I'll need to work out how to get the line back to cockpit jammer.

 

[RJJ]

Pole should always be perpendicular to mast in the vertical plane; if you raise the outboard end, raise the inboard end. Of course if the outboard end is too high, it will be hard to pull it down - you'll be pulling against the compression of the downhaul aka. foreguy and afterguy. You can make it easier by investing in a ball bearing car, but that may be a bit much £££ for cruising purposes.

That's the same as saying "project the tack as far from the mast as possible". Which is of course the elementary function of a spinnaker pole.

Forget the adage that the clews should be the same height. Quite often, they should not be.

Pole height starting point is for the luff to curl evenly around the mid point. If the top curls, pole should be higher. If the bottom curls, pole comes down. That's the same as saying, on a jib, that you adjust the car so that all the tell tales break evenly.

When does that change?

In very light winds the spinnaker struggles to hold its own weight so we drop the pole as it droops. Sail up to a reach to build apparent wind and bear away gently; as the spinnaker goes too light, point up again.

On a beam reach, dropping the pole (at both ends) has the effect similar to pulling on the Cunningham on the mainsail. It pulls the cloth forwards and therefore helps open the leech, spilling power and reducing heeling moment so you can stay under control.

On a windy run, dropping the pole (at both ends) stabilises the sail and helps stop the pendulum effect (good) but also opens the leech which pushes the mast to windward (bad in any seaway). Complementing a low pole with a low sheeting angle -using tweakers or even just trimming with the guy - significantly stabilises the sail and the yacht.

Well I have banged on a bit. Agree that uphaul shouldn't be loaded, especially on a reach. Adjusting the pole inboard end may be tricky if there is load on the fore and afterguys. To adjust it, ease one of them.