Another Boat manoeuvring in windy conditions thread

[Paulfireblade]

Interesting thread, especially as I have recently returned from the Canals in South Netherlands.

Does individual boat shape effect the way a boat responds to using a stern or bow spring? With my boat using a stern spring I can get it almost 90 degrees to the dock if needed so is my go to especially sailing single handed but when I tried a bow spring was it was next to useless.

 

[srm]

Does individual boat shape effect the way a boat responds to using a stern or bow spring?

The simple answer is yes.
With a stern spring it is the lever between the prop and cleat. With a bow spring its more a case of using prop/rudder thrust to push the stern out. Size and deployment of fenders plus location of the cleat and hull shape all have effects on how far, or little, the end of the boat can move away from the pier. I also think there is a difference between using a bow spring against a pontoon and a solid pier as the thrust can dissipate under a pontoon but build up water pressure between boat and a solid wall.

 

[Paulfireblade]

I also think there is a difference between using a bow spring against a pontoon and a solid pier as the thrust can dissipate under a pontoon but build up water pressure between boat and a solid wall.

Thank you, and the one time I tried the bow spring I was alongside a pontoon so prop wash over the rudder would have been dissipated so had not thought of that.

 

[srm]

If the wind channels up & down the canal- which I suspect is likely - then sailing against it would be a no no.

Sailing goose winged in light wind along Loch Ness heading south west. Boat in the distance ahead also goose winged. Distance between us closing far to rapidly for us to be catching up. As distance reduced realised other boat on a reciprocal heading, also in light winds. Just before we passed we were headed, he was riding the front of a SWly wind that slowly increased.
A boat I once owned experienced a 90 degree knock down in Loch Ness with its previous owner. They were sailing close hauled in light winds and hit by a katabatic wind on the beam. Genoa sheet winch submerged.

 

[B27]

Interesting thread, especially as I have recently returned from the Canals in South Netherlands.

Does individual boat shape effect the way a boat responds to using a stern or bow spring? With my boat using a stern spring I can get it almost 90 degrees to the dock if needed so is my go to especially sailing single handed but when I tried a bow spring was it was next to useless.

FTAOD. bow spring from the bow of the boat, back to the shore near the stern of the boat?
I find this always works, because pointy end is narrower and the bow comes in easily, resulting in the spring having a good turning moment relative to where the prop is pushing. Also, the rudder helps increase the turning moment.
Stern spring, the prop force has a shorter lever, because the pivot point of the hull on the wall is closer to the prop, and your rudder won't do much.

Stern spring is good if there is current and what you mainly need to do is get the bow out so the current is on the shore side of the keel.

A boat that's slim at the stern with a smaller transom will stern spring better, it pivots further forwards.

Depending on the relationship between prop and hull, boats have more or less 'prop walk' which can help or hinder.

Before engines, ports had capstans to wind boats around, and boats were built with actual rubbing strakes to work against the piles on the dockside.

 

[Momac]

Yes the No 1 thing I learned was tie up on the windward side of the lock. In this case we were sharing the locking with a big steel barge, already on the windward side. And from the canal at the lower side of the lock, the wind was not so obvious. But the lesson learned is demand the windward side of the lock, and in this case that would have meant let the barge go on his own and wait for the next locking.

In some locks the wind can bounce off the wall. So the boat inside the lock is pushed in the opposite direction to the wind direction outside of the lock.
I don't think you should ''demand'' one particular side of a lock but you can of course request it.

 

[RupertW]

Stern spring or bow spring which ever works better. In our case we almost always stern spring as there is a reasonable curve from midships to stern, it’s easy to fender the stern and the boat gets into a straight line if we end up going from astern to ahead at the end of the manoeuvre than the other way round.
The brilliance of springing is that you put up the throttle slowing until it works and if it doesn’t then don’t untie and you are just left gently resting against the wall/quay/pontoon as before. Even at its worst we were on hard astern with not enough of an angle for nearly a minute, there was a momentary lull and we swung way out, and got going.

 

[RunAgroundHard]

Hullk shape, within reason doesn't really impact how the boat will move using a spring around a pivot. The position of the pivot point, rudder and propellor wash over the rudder, or just thrust, are all that really matters.

Previously I mentioned the mid ship spring, but I now think that a stern line on the outboard cleat to somewhere aft on the opposite side of the canal lock wall would be a better solution. By driving forward the boat has to pivot around the point on the opposite wall. It would be easier to control boat position with rudder and engine, as the cleat on the boat will be aft of the propellor and rudder force.

 

[Chiara’s slave]

Hullk shape, within reason doesn't really impact how the boat will move using a spring around a pivot. The position of the pivot point, rudder and propellor wash over the rudder, or just thrust, are all that really matters.

Previously I mentioned the mid ship spring, but I now think that a stern line on the outboard cleat to somewhere aft on the opposite side of the canal lock wall would be a better solution. By driving forward the boat has to pivot around the point on the opposite wall. It would be easier to control boat position with rudder and engine, as the cleat on the boat will be aft of the propellor and rudder force.

Our amas are as flat as can be, they’re only 60cm or so beam, so can only taper a limited amount. You must be right as springing still works for us, usually we’d use a bow spring, kicking the stern out is far easier, especially with our steerable outboard. The bow windage is noticeably greater too, the boat will naturally pivot to bows downwind if left to it’s own devices. Being windbound against static objects is a daily hazard for us, it doesn’t take much. We have lots of practice, our mooring is side on to the SW., pontoon to NE.

 

[ctva]

Yes park on upwind side is #1 tip to learn from this, discuss with lock keeper before entering. Before this happened it was not something I expected to be an issue.

No we are back home now. It was a little outing to "do" the canal with SWMBO. We had 7 days on the canal made it to Banavie and back, got to sail on Loch Ness and Loch Lochy but not enough time to go out to sea at the western end. SWMBO is still working, probably retiring next year so we will then be free of such 4 letter words like "work"

The Caledonian Canal is a great holiday in itself.

‘work’, what’s that? We chucked it last month and are now bobbing about in Orkney, wondering where next! It’s great.

 

[srm]

‘work’, what’s that? We chucked it last month and are now bobbing about in Orkney, wondering where next! It’s great.

Congratulations.
I would suggest Fair Isle, then Shetland, all doable with day sails but beware the tides. Then an overnight passage from Lerwick (stock up on duty free) to Norway. Enter Norway at Korsfjorden, north of the Marstein light, good anchorage on the north shore to recover. Then pleasant day sail in the inner leads up to Bergen.
Another entrance to the inner sounds about 20 miles N of Bergen, again with a landfall light and pleasant anchorages just inside the islands to recover. Two options give a bit of flexibility depending on the wind.
Alternative head slightly more north for Alesund.
If you need somewhere to leave the boat Stromness is a good place, was my home port for a number of years and have kept boats afloat all year round in the marina.
As you may guess, my old cruising grounds.

 

[ctva]

Shetland and Fair Isle are on the list. No passports so no further this time.

Was in Stromness yesterday and looks the same as it was when we were last there 15 years ago but could not see the Chippy where we had the best fish supper ever.

It is lovely here, apart from the lightening just now!!

 

[RupertW]

Hullk shape, within reason doesn't really impact how the boat will move using a spring around a pivot. The position of the pivot point, rudder and propellor wash over the rudder, or just thrust, are all that really matters.

Previously I mentioned the mid ship spring, but I now think that a stern line on the outboard cleat to somewhere aft on the opposite side of the canal lock wall would be a better solution. By driving forward the boat has to pivot around the point on the opposite wall. It would be easier to control boat position with rudder and engine, as the cleat on the boat will be aft of the propellor and rudder force.

It really does matter, in my experience. Trying to pivot a slab sided boat is very hard compared to a curvy one where the angle gives you the first 15-20 degrees for free and that starts getting wind/current to work for you a bit.

 

[RunAgroundHard]

It really does matter, in my experience. Trying to pivot a slab sided boat is very hard compared to a curvy one where the angle gives you the first 15-20 degrees for free and that starts getting wind/current to work for you a bit.

Everything has it's limits, of course, but thrust position, rudder wash, thrust power relative to pivot points can all be used to advantage on "slab sided" boats, just like other hull shapes. My personal experience, is that hull shape in reasonable wind strengths is less important than orientation of pivot point to thrust position.

 

[srm]

I have found curvy boats will spring out easily up to a point then part of the curve lies against the wall/pontoon and prevents further movement as cleat/fairlead is usually some way in from the end of the boat. With a slab sided boat you have to set up the pivot point at the end of the hull so can then spring out much further. Of course, a cleat/fairlead right at the end of a curved hull will have the same effect.

As an aside I was skippering/coaching candidates doing sea miles for the German yacht master. Leaving a hammerhead they were about to set up a spring. I stopped them and asked "what would happen if you just let the ropes go?" After a bit of thought the acting skipper said "the wind would blow us off?". "So why use a spring?"

 

[Chiara’s slave]

It really does matter, in my experience. Trying to pivot a slab sided boat is very hard compared to a curvy one where the angle gives you the first 15-20 degrees for free and that starts getting wind/current to work for you a bit.

You might be right about the first 15-20 degrees, but sooner or later you come to the harder part. We have that from the outset, it gets easier, not harder, as we pivot out. We’re almost immediately pivoting around the outrigger bow, against the strategically placed dock fender, if it’s our own berth.

 

[B27]

A Trimerangue has a good lever for springing, because the prop is a long way from the wall or pontoon.

I think it's worth experimenting with whatever boat you're on.
Ideally in different circumstances.

If you are two up (or more) the key to it working well is you all know what the plan is, and you've done it before, so you know what will happen and you're confident it will work.

Having done a YM prep week where there was a lot of time spent 'pontoon bashing', I'm a fan of 'trying stuff' and then thinking about what worked better or worse, so long as you can do that with no risk of damage. It's better than analysing what you think should work.

Also having at least one fender that looks like it belongs on a bigger boat is a plus!