I have read with some interest the comments on bilge keels on this web site, which seem to be a very British concept and not adopted in North America. For a better undestanding on this subject there is a very good direct comparison between a fin keel and bilge keel Hunter [Legend] 290 on the Legend web site. Apparently the vast majority of Hunters [Legends] sold in the UK are bilge keel models. One thing the article does not address is the vulnerability of the rudder and sail drive. However, in any marina you will see bilge keel boats so perhaps this is a non-issue. I suppose it could even be argued with twin keels there is greater rather than less protection.
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Don Alexander
Simon
Here is the (rather long) article which I did three years ago for the Legend Owners Newsletter - Wavelines. BILGE KEELS When it was first announced that Luhrs Marine in England would be building bilge keel yachts the American 'Hunterowners.com' website was suddenly humming with messages. Most were of the type "What the heck is a Bilge Keeler?" Surprisingly this keel arrangement seems to be little known on the other side of the 'long pond'. I say surprisingly because it has been recently reported that almost 70% of the water available for sailing in North America is between 3' and 4' deep. I think this must include the lakes. The American solution to this has normally been the 'shoal keel', which, as its name implies, is a single keel of shallow depth and mounted on the centre line of the hull. At the beginning of the century there were some beautiful large centreboarders built in America but this configuration ether means lots of hard work in raising and lowering a heavy ballasted board, or it means the inclusion of much of the ballast inside the hull. This high centre of gravity is not too good for the overall stability of the yacht and could constitute a nightmare situation should the yacht ever be rolled. However, in the very large sizes and in the smaller trailer sailor sizes these problems are much very reduced when the crew weight, judiciously placed, does much for the overall stability. To begin with it must be said that, from a performance standpoint and when hard on the wind, there is nothing to equal a deep draught keel. It puts the weight where it is most needed, allows a good aerofoil section and the profile can be long and narrow like a high aspect ratio aeroplane wing. This enables the bottom of the keel to operate in deep water untroubled by surface wave motion and clear of any turbulence caused by the hull. Furthermore the overall weight can be less for the same stability so this, in turn, means more boat speed. That said there are snags, as this writer can confirm, resulting mainly from occasional lapses in navigational accuracy!! Furthermore yachts do not spend all their time going to windward (heaven forbid) and the typical cruising sailor normally tries to arrange matters so that life consists mostly of fetching, reaching and running with only the occasional upwind slog. In times past, and before the advent of reliable auxiliary engines, windward ability was the most prized quality and we have all read those horrific accounts of windjammers being caught embayed and driven ashore. Thankfully, and with the exception of the 'blue water brigade', those times are long gone. However the true comparison should be between a shoal keel and twin bilge keels and, as the majority of the US Hunter boats sold world-wide are shoal draught, it is appropriate to look at these two forms. In the shoal keel all the weight is concentrated in a single lump at the bottom and when I stood directly in front of the shoal keel version of my 376 I was surprised to see just how big a dollop of lead was needed. The frontal area seemed very large for the sailplan to have to push through the water and the side area of the keel looked too small for efficient windward performance, particularly when moving slowly coming out of a tack. Winglets had been added to win back some of the lost performance and these also certainly assist in reducing pitching, though modern designs with a relatively flat run are quite good in this respect anyway. Of course everything on a yacht is a compromise and when this route is chosen for accessibility to harbours and creeks with only four or five feet of water it certainly justifies the shoal keel choice for those intending to do a little ditchcrawling. Turning to the ever popular bilge keel, this form has little difficulty in achieving the weight required for stability. Indeed my 1974 Westerly bilge keeler even had iron keels of which the after ends were hollow! Each keel can be splayed outwards such that the leeward one is running almost vertically thus improving its efficiency. They can also be 'toed in' like a car's front wheels and this means that the leeward keel provides more lift and so reduces leeway when beating. Again, on my old boat, we were once knocked down when spinnakering along in a club race and I happened to glance over the side. Imagine my dismay when I saw one of my keels flying along completely clear of the water. I don't think that designers Laurent Giles had intended this - but at least it was not causing any drag! Having two keels enables the designer to have all the lateral keel area he needs and there is plenty of scope to have small bulbs on the bottoms so that the weight is kept as low as possible. Winglets would be fussy and are not necessary anyway. So, in the bilge keeler, we achieve all the stability necessary, plenty of lateral area and an efficient aerofoil shape for each keel. The keels are also far enough apart so that one does not interfere with the other keel's water flow. Admittedly there is 10% to 15% more wetted surface area and this means a reduction in boatspeed when there is little power available from the wind, but this additional drag only has a noticeable effect in light weather when many would be motoring anyway. However bilge keelers do not have their deserved share of the popularity amongst sailors and I believe that this arises due to a combination of circumstances. Firstly, over the years, the various racing handicapping rules have not given much allowance for the second keel, which, despite its other virtues, is not as efficient as a deep fin when going to windward - a process much beloved of race organisers. This has led naval architects to optimise their designs around 'the cruising man'. Accordingly the older yachts were less sleek and had more internal volume, i.e. living space. They were a little heavier and, of course, carried all the paraphernalia required for cruising. The designs do not make so much use of exotic materials such as carbon fibre and kevlar and - yes the racing fraternity used spent uranium in their keels years and years ago - until it was banned! Modern designs however are often the same as the fin keel version but with the added second keel; so there are not as many compromises to sailing performance. Then we come to the buyers. Bye and large these are emphatically not racing men. They are essentially families who are non competitive and who eschew the stresses, strains and expense of yacht racing. Consequently, and for most of the time, their boats are not being sailed to their maximum potential. There is nobody on the leeward genoa winch continuously trimming, no crewman dedicated to constant adjustment of the mainsheet and traveller, no one with the vang (kicking strap) in his hand; and so it is no wonder that the racing boats sail by. The owners of the slick racing yachts take a dim view of the performance of bilge keelers and are quite unaware that the bilge keel owner is fully contented with his way of life and, not surprisingly, even arrives in the pub only about a quarter of an hour after the hot shots. What the cruising man thinks of the race boat owner is not for printing here! Of course these opinions are not universally true - but I am sure you get my drift. So to summarise, in my humble opinion and for all the reasons stated above, modern bilge keelers are just about the best compromise for family cruising boats in our waters. But I have left the best bits to last:- Navigation. If other boats can go there so can you. It is possible to creep up an estuary, dodging amongst the moorings without fear of grounding. In itself grounding is not a problem anyway as the boat normally sits bolt upright, until either you can get her off the putty, or until the next tide up. Unlike fin keelers, if you touch bottom when heeled then just release the sheets to float free. Deep Water Moorings are like gold dust, but a bilge keeler can live on a drying mooring. Indeed a boat can be kept in a drying harbour where fin keels simply could not live. Scrubbing off is a doddle. I just used to motor gently on to the hard, late in the ebb, and keep the engine idling and in gear for a further five minutes. No piles, no fenders, no warps and no banging on the hard whilst waiting to take the ground. It was then a simple matter to hop over the side in waders and scrub off before the water went away. The space between the keels never sees any sunlight so there is hardly any weed growth here. Due to our shallow draught and late arrival we were always first away too, with no careering around the harbour at one o'clock in the morning. Winter lift out does not require a cradle nor is there any danger of the boat blowing over in the next gale. All that is required are four wooden blocks to stand her on and these will go into the boot of your car. The whole of the bottom is accessible without a step ladder and antifouling is not obstructed by props and shores or cradle legs, ........though rolling the paint between the keels can be a bit messy. And as for racing - one day I will show you the trophies we won in club events with my little 23' bilge keel Westerly Pageant. Don Alexander.
Here is the (rather long) article which I did three years ago for the Legend Owners Newsletter - Wavelines. BILGE KEELS When it was first announced that Luhrs Marine in England would be building bilge keel yachts the American 'Hunterowners.com' website was suddenly humming with messages. Most were of the type "What the heck is a Bilge Keeler?" Surprisingly this keel arrangement seems to be little known on the other side of the 'long pond'. I say surprisingly because it has been recently reported that almost 70% of the water available for sailing in North America is between 3' and 4' deep. I think this must include the lakes. The American solution to this has normally been the 'shoal keel', which, as its name implies, is a single keel of shallow depth and mounted on the centre line of the hull. At the beginning of the century there were some beautiful large centreboarders built in America but this configuration ether means lots of hard work in raising and lowering a heavy ballasted board, or it means the inclusion of much of the ballast inside the hull. This high centre of gravity is not too good for the overall stability of the yacht and could constitute a nightmare situation should the yacht ever be rolled. However, in the very large sizes and in the smaller trailer sailor sizes these problems are much very reduced when the crew weight, judiciously placed, does much for the overall stability. To begin with it must be said that, from a performance standpoint and when hard on the wind, there is nothing to equal a deep draught keel. It puts the weight where it is most needed, allows a good aerofoil section and the profile can be long and narrow like a high aspect ratio aeroplane wing. This enables the bottom of the keel to operate in deep water untroubled by surface wave motion and clear of any turbulence caused by the hull. Furthermore the overall weight can be less for the same stability so this, in turn, means more boat speed. That said there are snags, as this writer can confirm, resulting mainly from occasional lapses in navigational accuracy!! Furthermore yachts do not spend all their time going to windward (heaven forbid) and the typical cruising sailor normally tries to arrange matters so that life consists mostly of fetching, reaching and running with only the occasional upwind slog. In times past, and before the advent of reliable auxiliary engines, windward ability was the most prized quality and we have all read those horrific accounts of windjammers being caught embayed and driven ashore. Thankfully, and with the exception of the 'blue water brigade', those times are long gone. However the true comparison should be between a shoal keel and twin bilge keels and, as the majority of the US Hunter boats sold world-wide are shoal draught, it is appropriate to look at these two forms. In the shoal keel all the weight is concentrated in a single lump at the bottom and when I stood directly in front of the shoal keel version of my 376 I was surprised to see just how big a dollop of lead was needed. The frontal area seemed very large for the sailplan to have to push through the water and the side area of the keel looked too small for efficient windward performance, particularly when moving slowly coming out of a tack. Winglets had been added to win back some of the lost performance and these also certainly assist in reducing pitching, though modern designs with a relatively flat run are quite good in this respect anyway. Of course everything on a yacht is a compromise and when this route is chosen for accessibility to harbours and creeks with only four or five feet of water it certainly justifies the shoal keel choice for those intending to do a little ditchcrawling. Turning to the ever popular bilge keel, this form has little difficulty in achieving the weight required for stability. Indeed my 1974 Westerly bilge keeler even had iron keels of which the after ends were hollow! Each keel can be splayed outwards such that the leeward one is running almost vertically thus improving its efficiency. They can also be 'toed in' like a car's front wheels and this means that the leeward keel provides more lift and so reduces leeway when beating. Again, on my old boat, we were once knocked down when spinnakering along in a club race and I happened to glance over the side. Imagine my dismay when I saw one of my keels flying along completely clear of the water. I don't think that designers Laurent Giles had intended this - but at least it was not causing any drag! Having two keels enables the designer to have all the lateral keel area he needs and there is plenty of scope to have small bulbs on the bottoms so that the weight is kept as low as possible. Winglets would be fussy and are not necessary anyway. So, in the bilge keeler, we achieve all the stability necessary, plenty of lateral area and an efficient aerofoil shape for each keel. The keels are also far enough apart so that one does not interfere with the other keel's water flow. Admittedly there is 10% to 15% more wetted surface area and this means a reduction in boatspeed when there is little power available from the wind, but this additional drag only has a noticeable effect in light weather when many would be motoring anyway. However bilge keelers do not have their deserved share of the popularity amongst sailors and I believe that this arises due to a combination of circumstances. Firstly, over the years, the various racing handicapping rules have not given much allowance for the second keel, which, despite its other virtues, is not as efficient as a deep fin when going to windward - a process much beloved of race organisers. This has led naval architects to optimise their designs around 'the cruising man'. Accordingly the older yachts were less sleek and had more internal volume, i.e. living space. They were a little heavier and, of course, carried all the paraphernalia required for cruising. The designs do not make so much use of exotic materials such as carbon fibre and kevlar and - yes the racing fraternity used spent uranium in their keels years and years ago - until it was banned! Modern designs however are often the same as the fin keel version but with the added second keel; so there are not as many compromises to sailing performance. Then we come to the buyers. Bye and large these are emphatically not racing men. They are essentially families who are non competitive and who eschew the stresses, strains and expense of yacht racing. Consequently, and for most of the time, their boats are not being sailed to their maximum potential. There is nobody on the leeward genoa winch continuously trimming, no crewman dedicated to constant adjustment of the mainsheet and traveller, no one with the vang (kicking strap) in his hand; and so it is no wonder that the racing boats sail by. The owners of the slick racing yachts take a dim view of the performance of bilge keelers and are quite unaware that the bilge keel owner is fully contented with his way of life and, not surprisingly, even arrives in the pub only about a quarter of an hour after the hot shots. What the cruising man thinks of the race boat owner is not for printing here! Of course these opinions are not universally true - but I am sure you get my drift. So to summarise, in my humble opinion and for all the reasons stated above, modern bilge keelers are just about the best compromise for family cruising boats in our waters. But I have left the best bits to last:- Navigation. If other boats can go there so can you. It is possible to creep up an estuary, dodging amongst the moorings without fear of grounding. In itself grounding is not a problem anyway as the boat normally sits bolt upright, until either you can get her off the putty, or until the next tide up. Unlike fin keelers, if you touch bottom when heeled then just release the sheets to float free. Deep Water Moorings are like gold dust, but a bilge keeler can live on a drying mooring. Indeed a boat can be kept in a drying harbour where fin keels simply could not live. Scrubbing off is a doddle. I just used to motor gently on to the hard, late in the ebb, and keep the engine idling and in gear for a further five minutes. No piles, no fenders, no warps and no banging on the hard whilst waiting to take the ground. It was then a simple matter to hop over the side in waders and scrub off before the water went away. The space between the keels never sees any sunlight so there is hardly any weed growth here. Due to our shallow draught and late arrival we were always first away too, with no careering around the harbour at one o'clock in the morning. Winter lift out does not require a cradle nor is there any danger of the boat blowing over in the next gale. All that is required are four wooden blocks to stand her on and these will go into the boot of your car. The whole of the bottom is accessible without a step ladder and antifouling is not obstructed by props and shores or cradle legs, ........though rolling the paint between the keels can be a bit messy. And as for racing - one day I will show you the trophies we won in club events with my little 23' bilge keel Westerly Pageant. Don Alexander.
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