The companionway ladder on Josephine 11 hugs the lagging and is locked on by a hook and eye.
The steepness of the ladder is compensated
for by the convex and concave arrangement of the steps which allow feet
to pass by unfumbled, although I feel that there may have been one more
step, perhaps closer to the gunwale, for optimum comfort. The best
place to put one of these structures in Ariadne would be just behind
the forward passenger seat where the curvature of the lagging allows a
little more room. This, unfortunately, is also the best place for the
portable refrigerator, whose power outlet has been positioned there in
anticipation. 
The challenge then is to combine the functions of both into an insulated and refrigerated stairway, which should revel under the title of the "cool step tansu". There is not enough spare room to be able to build a permanent structure here, as I am still keen for the forward seats to be on slides and swivels so that they can be turned around to face a table for meals. There is also the likelihood of the boat being boarded from the starboard on occasion, when it would be necessary to be able to move the ladder to that side. So the compromise will be a companionway which is able to straddle the fridge, rather than incorporate it. If such an arrangement makes access to the fridge too obstructed then the concept will not work. Nevertheless, it remains an intriguing design challenge.
The boat hook is stowed alongside the forward passenger.
The challenge then is to combine the functions of both into an insulated and refrigerated stairway, which should revel under the title of the "cool step tansu". There is not enough spare room to be able to build a permanent structure here, as I am still keen for the forward seats to be on slides and swivels so that they can be turned around to face a table for meals. There is also the likelihood of the boat being boarded from the starboard on occasion, when it would be necessary to be able to move the ladder to that side. So the compromise will be a companionway which is able to straddle the fridge, rather than incorporate it. If such an arrangement makes access to the fridge too obstructed then the concept will not work. Nevertheless, it remains an intriguing design challenge.
The next item is the boat hook. The only
evidence of one which I have seen on photos is shown here, suspended
next to the forward passenger seat along the cockpit lagging. The
curvature in the lagging which I was so keen to achieve is now going to
make this arrangement impractical, as the hook would bowstring away
from the lagging, right next to the seat where maximum room is needed.
The boat hook is stowed alongside the forward passenger.
So, instead, I have been thinking of
installing a tube into the under-seat locker and through to the rudder
compartment, which would have an opening in the front of the rear seat,
through which the hook could be retrieved. Again, it will depend on
curvature and distance to make the hook extractable, so more work has
to be done on the forward seating plans before this idea can come to
fruition.
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109. Forward
Seating
The traditional forward seating
was a pair of Lloyd Loom chairs, and there is something to be said for
their simplicity. However, the type of seats seen above in this new
Freebody designed boat is preferable to me for two reasons: they must
be more comfortable, but, equally importantly, they can house the
batteries which cannot fit in the motor compartment. These seats
feature the drop down Rolls Royce type trays, which I do not need, and
they are not fixed to the sole, so can be moved around. I want mine to
be fixed at their bases, so that the batteries will be concealed, but
mobile on top so that they can rotate. I imagine that the Freebody
seats are not often turned around for meals, and that the driver and
front seat passenger are more likely to take up positions on the dickey
seats on the sides, but being careful to avoid being stabbed in the
back by the drink holders. But Ariadne is not long enough for that
arrangement, and there will be no dickey seats.
It can also be seen that the
Freebody seats closely hug the contour of the cockpit lagging, leaving
a relatively wide gap between them where their sides are straight up.
I, however, want to be able to slide the seats backwards and forwards,
and to rotate them through 360°. That means that the side of the
seat will have to clear both the lagging and, in the case of the
driver's seat, the throttle lever and the steering wheel. Clearing the
wheel will be made easier by sliding the seat backwards before rotating
it, provided that the axis of rotation is not the same in both forward
and backward positions. In other words, the typical pedestal type of
seating will not work, because there the axis is fixed around the
pedestal. There have to be separate mechanisms for sliding and
rotating.
The one shown left is the simplest, with just
two sliding parallel rails running in tracks, and a detent lever on one
of them. It allows 160 mm. of slide. The platform supporting the swivel
would be mounted on this via the four mounting bolts on the rails. My
only concern about this type is that when the seat is fully retracted
and swivelled there is going to be a lot of leverage on the tracks,
which are attached by only four screws or bolts to the seat base. Some
reinforcement may be needed.
There are some rather more elegant looking ones, but they mostly allow only 110 mm. of slide, and are not going to be seen anyway, but the leverage forces would not appear to be as great with these models, because of their shorter excursion. I may be entirely wrong there, because it depends on the length of the track, which I do not know.
Two low level seat slide mechanisms showing similar properties.
In any case, the added 50 mm. of slide
available with the first type is the deciding factor, because the further back the seat is slid, the more room it has
to rotate, as
the cockpit narrows as it passes forwards. The tightest position will
be when the seat is at 45° to the midline of the boat, so the seat
back will have to be designed to allow clearance at that point. It may
well be that the U-shape of the old Lloyd Loom chairs might be the most
practical. In order to finalise the design
of the seats, the base must be set first. Its only non-negotiable
requirement is that it be wide and tall enough to house the batteries.
On top of the base there will be the forward/aft slide, surmounted by
its
platform. On top of the platform there will be a swivel, attached to
the seat above. (Alternatively, the swivel might bolt directly to the
slide). These swivels can be found either as locking versions, or
freely rotating on a friction base. To rotate the seats to face aft
they should be slid
back as far as possible, so that they clear the narrowest part of the
cockpit. The angle of inclination of the seat backs should enable the
driver's seat on rotation to clear the steering wheel, or else it
should be adjustable such that it can be tilted to a more upright
position if necessary.
The height of the seat will be dictated by function and comfort, as will the inclination of both seat and seat back. They will not, for example, be as laid back as the rear seat, which only has to indulge the baggage, human and otherwise.
Experimentation with an adjustable desk chair has given me a working height of 420 mm. for the top of the seat cushion. This is a comfortable driving height. The depth of the seat is 430 mm., which makes the front surface of the back of the chair 960 mm. aft of the dash bulkhead. In this position there is just enough room to swivel the chair on its pedestal, but the back does hit the steering wheel when I sit on it and lean back. The back of this chair is also quite narrow, so there needs to be more clearance than this for the actual seats. Nevertheless, a slide back of 160 mm. will give me plenty of room.
Determining seat positions and dimensions.
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It can also be seen that the
Freebody seats closely hug the contour of the cockpit lagging, leaving
a relatively wide gap between them where their sides are straight up.
I, however, want to be able to slide the seats backwards and forwards,
and to rotate them through 360°. That means that the side of the
seat will have to clear both the lagging and, in the case of the
driver's seat, the throttle lever and the steering wheel. Clearing the
wheel will be made easier by sliding the seat backwards before rotating
it, provided that the axis of rotation is not the same in both forward
and backward positions. In other words, the typical pedestal type of
seating will not work, because there the axis is fixed around the
pedestal. There have to be separate mechanisms for sliding and
rotating. The one shown left is the simplest, with just
two sliding parallel rails running in tracks, and a detent lever on one
of them. It allows 160 mm. of slide. The platform supporting the swivel
would be mounted on this via the four mounting bolts on the rails. My
only concern about this type is that when the seat is fully retracted
and swivelled there is going to be a lot of leverage on the tracks,
which are attached by only four screws or bolts to the seat base. Some
reinforcement may be needed.There are some rather more elegant looking ones, but they mostly allow only 110 mm. of slide, and are not going to be seen anyway, but the leverage forces would not appear to be as great with these models, because of their shorter excursion. I may be entirely wrong there, because it depends on the length of the track, which I do not know.
Two low level seat slide mechanisms showing similar properties.
A standard lockable
seat swivel.
The height of the seat will be dictated by function and comfort, as will the inclination of both seat and seat back. They will not, for example, be as laid back as the rear seat, which only has to indulge the baggage, human and otherwise.
Experimentation with an adjustable desk chair has given me a working height of 420 mm. for the top of the seat cushion. This is a comfortable driving height. The depth of the seat is 430 mm., which makes the front surface of the back of the chair 960 mm. aft of the dash bulkhead. In this position there is just enough room to swivel the chair on its pedestal, but the back does hit the steering wheel when I sit on it and lean back. The back of this chair is also quite narrow, so there needs to be more clearance than this for the actual seats. Nevertheless, a slide back of 160 mm. will give me plenty of room.
Determining seat positions and dimensions.
More gratifying than
that however, is the fact that the chair was able to clear the side
lagging during rotation. There was some problem with the arm rests
engaging the steering wheel, but they will not be found on the eventual
seats. Also, this chair was too far across the midline of the boat, so
the seat will need to be narrower, which will allow even more
comfortable side clearance.
The battery cable outlets in the lagging coincide with the pedestal position, which should be about the middle of the base of the seating, and there is plenty of room for the speakers to produce their sound without muffling by the seat base side. There is some considerable height discrepancy between the forward and aft seating at the moment, but, once a 100 mm. cushion has been put on the rear seat, this will be a lot less.
The battery cable outlets in the lagging coincide with the pedestal position, which should be about the middle of the base of the seating, and there is plenty of room for the speakers to produce their sound without muffling by the seat base side. There is some considerable height discrepancy between the forward and aft seating at the moment, but, once a 100 mm. cushion has been put on the rear seat, this will be a lot less.
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110. Battery Configuration
Forward to October
'08Until now I have delayed making
a final decision about the size of the drive system. I have vacillated
between 24, 36 and 48 volts. It is time to commit, and I have decided
to go with 48 volts. With 48
volts I could have two banks of 4 batteries giving 800 amp hours. If
battery discharge is limited to 50% and the full 80 amps current to the
motor is used, that will allow about 5 hours of cruising time. However,
with AGM batteries it is safe to discharge them down to 80% provided
they are recharged without delay, and much more time can be gained by
cruising below top speed, so effectively I could easily get 8 hours if
needed.
People often ask "Why electric?", but some nod sagely and give me the warm, fuzzy look of one who is a member of the quietly concerned green alliance. To the latter I should point out that these batteries will be recharged via the mains, which is powered by coal here in Sydney. Furthermore, in order to be able to transport the boat, I purchased a four wheel drive car, which I use every day, boat or not. To the former, the answer is "Quiet". The relative silence of electric motors makes cruising a pleasurable experience, rather than a hectic lung buster, and that is the main reason. There are others: lack of diesel fumes and space savings (no fuel tank) chief amongst them. But anyone who thinks that my little electric boat is going to start a green conversion of the rev heads, and save the rivers, needs rewiring.
So, why 48 volts? The original intention was to go with 24 volts, but the lightness of construction needed to make 24 volts a viable proposition results in a vessel which can be tossed about on the waters like a plastic dinghy. The same rev heads who will be impervious to the green arguments, also love to buzz past other boaters at high speed and testosterone wash. A light weight boat can become very uncomfortable in those conditions, so I have built for comfort rather than speed. Hence the higher power.
Having decided that 8 main batteries will be needed, the question of their distribution comes up. To start with, I am going to put 6 of them in the motor compartment, 2 under the forward passenger seat and put the 12 volt house battery under the driver's seat. If the weight distribution is not satisfactory I can move them, but four of them will be just on the motor side of the dash bulkhead, which is very close to the centre of buoyancy. The two nearer the front of the motor compartment will be balanced out by the two under the seat.
Considerable cost savings can be made by using 6 volt batteries instead of 12 volt ones. These are mass produced for golf carts, and you get a lot more power for your dollar. 200 amp hour 6 volt batteries are about the same size and weight as 100 amp hour 12 volt ones, but the wiring needs to be different. Instead of two banks of 12 volt batteries providing 48 volts each there would be only one bank of 6 volt ones, all connected in series. The question of charging arises with two banks too, necessitating in some cases two chargers, but I have installed a battery switch capable of supplying power from either one, or both, banks, and there seems to be no reason why the charger could not operate via that switch in the "Both" position to charge two banks simultaneously.
There is the concept of having an emergency bank of batteries in case of unforeseen problems, and, therefore, running the boat on only one bank, which would not be possible with 6 volts, but there is a problem then with having two sets discharged to different levels, and the complications of recharging those. I have already decided to run on both if I have two banks. With the battery condition monitor I have installed there should be no unforeseen problems, and the boat is only going to be used in closed waters, not out to sea. So, there is really nothing to choose between the two systems except the cost. But there does not have to be a final decision on this question until later. The accommodation and wiring needs are already catered for, no matter which system is used.
People often ask "Why electric?", but some nod sagely and give me the warm, fuzzy look of one who is a member of the quietly concerned green alliance. To the latter I should point out that these batteries will be recharged via the mains, which is powered by coal here in Sydney. Furthermore, in order to be able to transport the boat, I purchased a four wheel drive car, which I use every day, boat or not. To the former, the answer is "Quiet". The relative silence of electric motors makes cruising a pleasurable experience, rather than a hectic lung buster, and that is the main reason. There are others: lack of diesel fumes and space savings (no fuel tank) chief amongst them. But anyone who thinks that my little electric boat is going to start a green conversion of the rev heads, and save the rivers, needs rewiring.
So, why 48 volts? The original intention was to go with 24 volts, but the lightness of construction needed to make 24 volts a viable proposition results in a vessel which can be tossed about on the waters like a plastic dinghy. The same rev heads who will be impervious to the green arguments, also love to buzz past other boaters at high speed and testosterone wash. A light weight boat can become very uncomfortable in those conditions, so I have built for comfort rather than speed. Hence the higher power.
Having decided that 8 main batteries will be needed, the question of their distribution comes up. To start with, I am going to put 6 of them in the motor compartment, 2 under the forward passenger seat and put the 12 volt house battery under the driver's seat. If the weight distribution is not satisfactory I can move them, but four of them will be just on the motor side of the dash bulkhead, which is very close to the centre of buoyancy. The two nearer the front of the motor compartment will be balanced out by the two under the seat.
Considerable cost savings can be made by using 6 volt batteries instead of 12 volt ones. These are mass produced for golf carts, and you get a lot more power for your dollar. 200 amp hour 6 volt batteries are about the same size and weight as 100 amp hour 12 volt ones, but the wiring needs to be different. Instead of two banks of 12 volt batteries providing 48 volts each there would be only one bank of 6 volt ones, all connected in series. The question of charging arises with two banks too, necessitating in some cases two chargers, but I have installed a battery switch capable of supplying power from either one, or both, banks, and there seems to be no reason why the charger could not operate via that switch in the "Both" position to charge two banks simultaneously.
There is the concept of having an emergency bank of batteries in case of unforeseen problems, and, therefore, running the boat on only one bank, which would not be possible with 6 volts, but there is a problem then with having two sets discharged to different levels, and the complications of recharging those. I have already decided to run on both if I have two banks. With the battery condition monitor I have installed there should be no unforeseen problems, and the boat is only going to be used in closed waters, not out to sea. So, there is really nothing to choose between the two systems except the cost. But there does not have to be a final decision on this question until later. The accommodation and wiring needs are already catered for, no matter which system is used.
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Problems shows higher resolution shots as well.