LM27 rolling like a pig

[oldmanofthehills]

Having started exploring the Cornish coast with our new LM27 we had an unpleasant passage against dead on 16kt headwind with fairly moderate seas, perhaps 0.75m to 1m waves. This got fairly tiring until after 9 miles I put our makeshift mainsail up to dampen the motion. (There's another story about how a 36 year old Green's mainsail could not cope with strong gust while racing).  She certainly is more tippy than I am used too. 

Having sailed smallish bilge keelers and bulb fin keels I wondered if this rolling was a function of the long keel?

[Sula]

Tendency to roll (or not) is a complex function of the combination of a whole range of things, principally hull shape, weight distribution, and both area and depth of keel.

A long keel does not of itself mean a tendency to roll, and in fact the greater area of a long keel should, in principle, be better than a fin or bilge keel of the same depth, all other things being equal (which they never are!).

In my estimation it is the shallow depth of the LM24 & LM27 keel that is more influential for tendency to roll, rather than the fact it is a long keel, along with their rounded lateral hull shape.

The LM24/27 is reportedly derived from traditional Baltic sailing boats. I've never sailed in the Baltic (yet!), but imagine that it doesn't get the big swells you often find off Cornwall.

The LM27 can roll quite badly in certain circumstances, in my limited experience, but I suspect that it seems worse than it is if you are sitting forward facing at the wheel, where the outlook is framed by the wheelhouse windows, and the rolling is trying to tip you off the seat. In my previous boat I would usually be sitting sideways on in the cockpit, feet braced against the other side, or standing facing forward, tiller between my legs, and accommodating the rolling of the boat by bending one leg after the other so my torso remained fairly upright.

The other crucial factor in tendency to roll is the frequency of the waves compared to the boat's natural tendency to roll at a certain frequency. If they coincide they will tend to reinforce one another, and that's when rolling gets bad. If they are out of phase they will tend to cancel one another out to some extent. So if you find yourself rolling it may well be worth trying to change your angle to the waves to see if that makes a difference (as that will affect the frequency (as well as angle) at which the waves pass your boat).

I encountered some steadily building seas, beam on and causing quite a bit of rolling, on my way to France recently. Not being that familiar with the boat I was a little anxious about her ability to cope as conditions got worse , but I soon found that despite looking straight out of the side wheelhouse window at the face of approaching waves almost the height of the wheelhouse, the LM27 slid over the top of each of them without fuss, and I could look out the other side window at the same wave's back face retreating. I now feel a lot more confident in the boat.

Unlike you I do not find the LM27 to be 'tippy' (tender). Unlike my previous boats (all smaller), she moves little as me or the crew move about the deck, and does not heel as much as them under a good press of sail.

Hopefully others will be along soon give you their take on the LM27's rolling and stiffness.

[oldmanofthehills]

I noticed that she moved/rolled more than my other boat the moment I stepped from the pontoon on viewing her. Her rolling action at sea is not seasick inducing but is tiring as one autocompensates. My question arises because we intend to use her for middle distance cruising Plymouth-Scilly, Scilly-Ushant, Scilly-Bristol, and Bristol-Dublin, and these involve non-coastal legs of 80 to 120 miles. There are big seas out beyond Landsend and it blows up nasty in the Irish sea and I expect to be able to manage F7 if not exactly enjoy it. The problem is that if rolling can only be eased by having sails up as a damper then the moment I reef for a blow the rolling will get worse. I have heard of LM27 with extra ballast ingots but unless these are secure and they are a liability and in anycase would be almost impossible to mount low enough to be effective.

[oceandancer]

Hi,
The LM27 ballast ratio is 45%, 1.8tonnes of ballast compared to 4tonnes gross which is considered to be on the "stiff" side for a cruising yacht. The boat is quite happy with full sail up to 18knts of apparent wind. I agree with Sula regarding the shallow draft which can induce a roll frequency which seems to match shorter seas. Just a small amount of sail even a reefed mainsail sheeted in tight, however, should dampen the roll significantly.
Horses for courses the LM27 can hardly be considered to be a blue water cruiser but most owners are content with her qualities as an inshore, occasionally offshore "sunshine superboat" to quote an early review.

Regards

Mick

[Sula]

When Scanyacht started building LM27s (calling them Scanyacht 290s) after LM ceased production, they offered various options including lead ballast (I can't remember if that was fitted to all Scanyachts) to balance a larger rig (this would have slowed, rather than reduced rolling, I would think), but also produced a deeper draft version.  The deeper draft would almost certainly reduce rolling to some extent. 

It would be impractical to change to lead ballast in an existing boat, but perhaps not a huge job to add a couple of inches to the keel.  (A previous boat of mine had a solid GRP 'shoe' added, wrapping round the base of the keel,  adding perhaps an inch in depth.) Whether, or how much, you'd notice any difference, I wouldn't know.  Any greater depth, and certainly adding any significant weight under the original keel, would be more challenging engineering and cost-wise.

In real life, I think you probably need to take a little time to decide whether the LM27 as she is will suit you, and the sort of sailing you want to do.

[stevespring]

Motoring directly into the wind can be a tiresome affair, and I generally find that if there is a choppy sea, I am better off either a) sailing or b) motor-sailing. Now the LM27 isn't a fantastic boat sailing hard on the wind, it has to be said. She makes a fair bit of leeway due to the shallow draught, and also suffers from an outboard sheeting position for the genoa. You can however get harder on to the wind when motor-sailing, and just by moving the angle of attack to the waves, you will find the motion much improved.

I can't say that I recognise the comments regarding the 27 being a tippy boat. I hold that accolade for boats that like to bury the lee rail into the water easily, and you really have to TRY to do that on a 27.

The other point of sail that I have encountered rolling is when sailing with a sea running at a particular angle from astern, and I sometimes need to change course a bit to find the sweet spot, and then gybe round at some stage.

I sail mine mainly in the Firth of Clyde, which can be choppy, and have ventured into the Irish Sea this year also, and she coped very well. Of course, every boat has some sort of compromise to be dealt with.

[oceandancer]

Hi All,
I seem to remember than Jan has a friend with an LM27 and he has attached large baulks of timber to increase the draft and keel profile. I don't know how that was achieved or if it worked. Perhaps Jan may be able to tell us ?
In any case I would be very wary of drilling into the keel from below to attached anything in view of the danger of water ingress into the ballast.

Mick

[oldmanofthehills]

Oct 5, 2018 9:55:58 GMT oceandancer said:

Hi All,
I seem to remember than Jan has a friend with an LM27 and he has attached large baulks of timber to increase the draft and keel profile. I don't know how that was achieved or if it worked. Perhaps Jan may be able to tell us ?
In any case I would be very wary of drilling into the keel from below to attached anything in view of the danger of water ingress into the ballast.

Mick

Heavens above that is a drastic and risky solution and would conflict with trying to get into shallow drying harbours with the appropriate quayside arrangements.


Perhaps when I said tippy I didnt make myself clear as I dont mean tender. When I step on the side of my Westerly the rail drops maybe less than half an inch, when I step on our LM27 it drops maybe an inch. She carries her canvas well, so I will take note and keep mainsail up if motorsailing.

[Charles]

Oct 5, 2018 6:53:39 GMT stevespring said:

Motoring directly into the wind can be a tiresome affair, and I generally find that if there is a choppy sea, I am better off either a) sailing or b) motor-sailing. Now the LM27 isn't a fantastic boat sailing hard on the wind, it has to be said. She makes a fair bit of leeway due to the shallow draught, and also suffers from an outboard sheeting position for the genoa. You can however get harder on to the wind when motor-sailing, and just by moving the angle of attack to the waves, you will find the motion much improved.

I can't say that I recognise the comments regarding the 27 being a tippy boat. I hold that accolade for boats that like to bury the lee rail into the water easily, and you really have to TRY to do that on a 27.

The other point of sail that I have encountered rolling is when sailing with a sea running at a particular angle from astern, and I sometimes need to change course a bit to find the sweet spot, and then gybe round at some stage.

I sail mine mainly in the Firth of Clyde, which can be choppy, and have ventured into the Irish Sea this year also, and she coped very well. Of course, every boat has some sort of compromise to be dealt with.

My experience of the North Sea agrees completely with Steve's. To cover ground to windward, particularly in a choppy sea, I find it best to stow the genoa and motor sail as close hauled as possible keeping the main still drawing. It reduces the rolling and adds a couple of knots to the speed through the water. If that requires a tack from time to time to maintain direction, so be it.
Charles