What It's All About?
Excerpted from Ocean
Spirit Magazine
Probably no craft suffers from
greater misrepresentation or is surrounded by more myths
and fallacies than the trailer-sailer. Purist yachtsmen
scorn it as a half-breed design while the uninitiated,
having picked up all kinds of unfounded information from
all kinds of sources, often regard it as the fastest form'
of maritime suicide. |
Neither of these theories is accurate nor, for
that matter, are ninety per cent of other stories that discolour
the true picture of what the trailer-sailer is and what it is
intended to do.
The
only way to really understand what the T-S is all about is to
look at it closely in relation to basic yacht design, sailing
theory and the adaptation of both which has created this hybrid
boat.
The whole trailer- sailer argument centres around
the keel, so let's look briefly at the keel and see how it works
and why there should be problems with this type of craft.
The Theory
The theory of sailing revolves around two centres
of pressure-the pressure of the wind on the sails and the pressure
of the water on the keel. Neither can work without the other.
If there were no pressure in the sails the boat would not move,
and if there were no countering pressure on the keel, the boat
would be pushed sideways through the water.
The
theoretical point at which the wind pressure operates on the
sails is termed the centre of effort, and where the pressure
of water acts on the keel is the centre of lateral resistance.
It is the balance between the centres of effort and lateral
resistance that determines, to a great extent, the boat's performance.
Particularly this is the case when the boat is going to windward,
for when running before the wind, no lateral resistance is required,
and thus the keel is non-effective. This indicates the reasoning
behind the shape of the keel, which offers its greatest area,
and thus its greatest lateral resistance, when the sideways
pressure in the sails is greatest- i.e., when close-hauled.
So it follows that the bigger the keel area and
the deeper the keel, the better resistance it offers to the
water. Obviously, there comes a point at which the size, weight
and friction of a huge keel would create more problems than
it would cure, but in theory at any rate, a deep keel is the
ideal means of reducing sideways drift or 'leeway' as it is
termed.
That's fine for sailing performance. But when
the yacht has to be pulled out of the water, the keel becomes
one great clumsy nuisance. Bad enough when you just want to
run onto a beach, but quite impossible when you want to put
the boat on a trailer and take it home. Here exactly the opposite
applies, and the ultimate keel for trailering is no keel at
all, or at best just a shallow stiffener on which the boat can
be landed.
The Practice
A large centre plate which can be raised for
trailering and lowered for sailing resolves both problems, and
in small sailing dinghies this is the practice used. However,
there is another factor involved, for the deep keel of a yacht
serves another purpose-that of counteracting the heel of the
boat and preventing her from capsizing. Such keels are heavily
ballasted with weights of something like 40 or 50 per cent of
the total weight of the boat and provide a very strong righting
lever when the boat is heeled.
However, it is almost impossible to get anything
like good weight into a centreplate. Heavy iron plates are often
used, but because of their relatively thin gauge they are never
heavy enough. Heavy ballast cannot be secured to these plates
or they would not be retractable. Thus the essential righting
lever is lost. While some trailer-sailers compromise by having
weight low down in the hull, this is still not completely successful
as it does not act low enough to create the required righting
lever. Which means that given a strong gust of wind, the boat
can be capsized, or at least heeled excessively to a point where
she will swamp.
The Problem
And this is where the hoodoo of the trailer-sailer
lies. Early models would almost certainly capsize if not handled
properly, just as a centreboard dinghy will capsize in the same
circumstances. Developments in the design of trailer-sailers
in recent years have reduced this tendency, however, and it
is not common (although still not unheard of) for a T-S to completely
capsize and finish upside down. The problem that has not been
eliminated, although again it has been greatly reduced, is the
tendency for the T-S with its lack of righting lever, to heel
excessively, and thus risk swamping.
The Answers
Some of the design methods used to reduce this
risk is simply the addition of further ballast in parts of the
hull, or by means of bilge keels or patent swing keels which
lower a ballast section when the boat is in the water. But even
allowing for the possibility of overcoming the lack of ballast
to a certain extent, these methods often increase trailering
problems because of the added weight or depth of the ballast
section.
Increasing the beam of the boat makes her more
stable and many trailer-sailer designers have adopted this method
either on its own or in conjunction with increased ballast.
And there are other systems which rely on the boat rounding
up in a squall (not a good practice!) or the use of fancy release
gear to free the mainsheet under pressure. But as long as the
righting lever is reduced or lacking, there is no way that a
boat under sail can be made completely stable, and thus the
trailer-sailer buyer must live with the fact that his boat can
and will heel to a greater degree than a ballast keel yacht.
However, accepting that fact is perhaps the most important aspect
of trailer-sailing, for having once accepted it you will take
steps to allow for it, realising that like all boats, trailer-sailers
have their limitations.
A pilot flying an aircraft with four engines
has little fear of engine failure since he has four chances
of survival should such a happening occur. The pilot of a single-engined
plane, by contrast, knows that if his engine fails, he must
put his aircraft-down quickly before she runs out of gliding
space. He is therefore aware of this throughout his flying time,
and keeps a constant eye out for likely landing places in the
event of having to make a forced landing.
So with the trailer-sailer skipper. He knows
that his craft may be endangered by a sudden squall unless he
is ready for it, and thus sails all the time with this in mind
and his eye alert for any such problem. Single-engined aircraft
fly hundreds of thousands of kilometres safely, and there is
no reason why trailer sailers cannot sail a comparable distance
with equal safety provided the person in command knows what
he is doing. Most of the rumor and fantasy that has built up
around trailer-sailers has been the result of accidents due
to 'pilot error', rather than any defect in design or construction
of the craft.
The Advantages And Disadvantages
It
would be safe to say that the main feature of trailer-sailer
design is compromise. Basically, this boat is a compromise between
a centre-board dinghy and a keel yacht. As such it inherits
many of the advantages of both while also inheriting a few of
their disadvantages. And in addition, it has some of its own
unique features.
One of the hardest things about the trailer-sailer
is to put it in a specific category. That is because some trailer-sailers
are in fact big centre boarders, some are small keelers, and
some, such as swing keelers, have no comparable design in either
the larger or smaller boats. Perhaps the only feature which
can in any way categorize the design is the term 'trailer',
indicating that this type of craft is portable. The means of
trailering it, however, can be wide and varied, hence the different
designs used in relation to the keel.
The compromise between keel yacht and centre
board dinghy has come about as a result of the demand for sailing
craft which can be taken from waterway to waterway without the
problem of hazardous passages in open water, and which can be
taken to waterways which are completely landlocked or inaccessible
from seaward. Initially this demand was relatively small but
the advantages of this type of craft have caught the imagination
of the public and nowadays it is the most up and coming type
of yacht design in Australia and New Zealand. Its popularity
has been increased by some of the spin-off advantages, not least
of which is the saving in mooring and maintenance costs as a
result of keeping the boat out of the water. Mooring, slipping
and anti-fouling expenses are eliminated, and the boat can be
protected from the ravages of the weather in the garage, or
under tarpaulins in the back yard. It can also, of course, be
protected from light fingered gentry and others of the waterfront
who do not have boating in mind when they creep aboard.
Of course, like any other compromise, there are
some disadvantages in the T-S design. It would be a remarkable
achievement if any craft were designed without some problems
somewhere, and particularly so when the design is intended to
cover a range of boating activities or satisfy a great number
of different needs.
Probably the best way of looking at this type
of boat is to compare the various advantages and disadvantages
of the trailer- sailer design with those of a keel yacht of
comparable size.
Advantages.
Price:
The
saving in cost initially is not very great. Although generally
speaking, trailer-sailers are somewhat cheaper than comparable
keel yachts, that is not always the case, and there is the additional
cost of a trailer, which often brings the total outlay up to
that of a comparable keel yacht.
Maintenance:
This is one area where saving in cost can be
considerable. The T-S can be kept under wraps or in a garage,
thus reducing the need for maintenance work, particularly where
varnish or painting is required. It is more convenient, also,
and one is more likely to spend an hour polishing and cleaning
if the boat is at home, than when such a job involves getting
a dinghy down to the beach and rowing out to the mooring.
Mooring:
Kept on the trailer at home, the T-S costs nothing,
unlike the keel boat which is eating its head off on a mooring
while it is not in use. This is probably the biggest Cost advantage
of this type of boat as mooring fees are not inconsiderable.
Anti-fouling:
Another good cost saving for the trailer-sailer.
A boat kept out of water does not require anti-fouling, and
like moorings, anti-fouling composition is not cheap.
Portability:
The greatest physical advantage of the T-S design,
it enables you to take your yacht with you on holiday no matter
where you go, provided there is water and access. Always check
the latter, as even waterways with boat ramps often have difficult
car access or ramps that are too shallow for trailer-sailer
launching.
Accommodation:
Apart from the immediate offering of lots of
stowage room for holiday gear in the boat, if need be she can
be utilized as temporary accommodation both on the trailer and
in the water. This is a common practice in Europe where T-S's
vie for space in caravan parks.
Beaching:
Another good physical advantage of the shallow
draft design. You can run your boat up on a beach without risk
of damage to the keel and thus eliminate the keel boat hassle
of having to tow a dinghy everywhere if you want to get ashore.
Indeed, while requiring the added expense of a trailer, at least
the T-S eliminates the cost of a dinghy!
Disadvantages:
Stability:
This
is without doubt the principal disadvantage in the trailer-sailer
design. Although different types of craft may approach the problem
differently, the fact remains that without the deep keel, a
T-S can never be as stable as a keel yacht. To what degree this
instability affects the boat and her sailing ability varies
from model to model.
Convenience:
Not a very great disadvantage, but there is no
denying that getting sailing on a T-S involves more hassle than
on a keel boat. Where in the latter case you just slip the mooring
and go, with the trailer-sailer there are all the problems of
trailering, launching, rigging the mast, parking the trailer
and so on. Of course, these have to be weighed against the saving
in the cost of moorings, and the ability to launch and sail
where you wish.
Accommodation:
As a general rule, interior accommodation is
usually more limited in trailer-sailers than in keel yachts,
due mainly to their design needs for trailering, and intrusion
of the centreplate housing.
Summary:
The question that arises out of all this, of
course, is whether the advantages outweigh the disadvantages.
And the answer, obviously, depends on the individual boat and
the individual buyer, and also on the sort of work he intends
the boat to do. If your plans involve only quiet water sailing
in sheltered areas then the disadvantages virtually do not apply,
and the advantages of the design are considerable. By contrast,
if you aim to sail offshore or in any sort of open sea areas,
then the lack of stability overrides most of the advantages.
For the most part it is probably safe to say that the average
trailer-sailer man has family holidays in mind with perhaps
the odd bit of club racing. In this case there is much to be
said for the design provided, of course, its limitations are
kept in mind. This sort of sailing usually involves both sheltered
and open waters, although not usually open sea. So both the
advantages and the disadvantages have a place, but without doubt
the advantages have the edge.
Naturally, it is not easy to make comparisons
when there are so many different styles of trailer-sailers.
Where a centre-boarder may offer decided advantages, a swing
or bilge keeler may not be suitable. However, in order to offer
some guidance to the would-be T-S buyer, some standard must
be set. For the following guide to the features of keel and
T-S boats an average comparable craft of each design is used.
This means that the descriptions are broad and some variation
may occur in special cases or with special craft. But as a general
all-round comparison, the table will give some indication of
the advantages and disadvantages of trailerable as opposed to
keel yachts.
Location: |
Trailer
Sailer |
Keel Yacht |
Shallow Lake |
Good |
Poor |
Deep Lake |
Good |
Good |
River |
Good |
Limited |
Harbour |
Good |
Good |
Offshore |
Limited |
Good |
Wind Strenghts |
|
|
Light |
Excellent |
Good |
Moderate |
Good |
Excellent |
Strong |
Limited |
Good |
Gale Force |
Poor |
Limited |
Uses |
|
|
Performance Racing |
Poor |
Good |
Club Racing |
Good |
Good |
Day sailing |
Excellent |
Excellent |
Family Holiday |
Excellent |
Limited |
Extended Cruising |
Limited |
Good |
|
|
|