- Water Channeling-
Water channeling is material added to or built into
the hull to disallow water from accumulating where you don’t want it, and
direct it to where you do want it. This is usually accomplished by adding in
material to fiber glass hulls or building it into the hull itself as is
commonly done in wooden hulls. The material in my opinion should be light
weight as to allow greater flexibility in placing weight more purposefully
while building the remainder of the ship. It also however needs to be durable
enough not to be crushed by batteries or damaged by stray BBs. Commonly foam, 2 part plastic, or balsa wood is used. Less durable
materials need to be coated by epoxy/fiberglass or some other protection. Some
captains prefer heavier/more denes material to affix to the bottom of the hull
to improve ship stability by keeping the center of gravity low. I have somewhat
commonly seen concrete crack filler used. I don’t like that approach because it
limits adjustability to weight redistribution with later refits and is very
difficult to remove. Essentially every ship should have some water channeling.
When done correctly, water channeling can significantly improve damage taking
capacity in terms of raw, heavy damage required to sink, but also can
significantly improve combat capacity and maneuverability while taking moderate
damage.
Central Water Channel
The most common and most useful application of water
channeling in larger ships is building up to form a sunken channel in the
central part of the ship running from bow to stern. The pump is placed within
this channel. The pictures below (Yamato, Florida) demonstrate this principal
both in wood and fiberglass ships. Generally speaking, I would recommend 2
inches wide running roughly underneath most of the turrets on a ship, obviously
turret location varies significantly by ship, most of the time this also
translates to the portion of the hull that visibly flatter on the bottom and
wide enough to accommodate a 2 inch channel.
Bow Water Channel
Water channeling should also be used in the extreme
bow of almost all ships regardless of size. This is usually a very narrow part
of the ship and in nearly all ships is continuous with the lowest section of
the hull. If water is allowed to settle forward, performance is negatively
impacted and you will settle by the bow when sinkin.
I advise building up water channeling all the way or nearly all the way (within
1/8 or 1/4 inch) to the bottom of the open “window.” The pictures below (wood Hyuga, fiberglass Littorio) show
the extreme bow sub division of the water channeling system. Both of these
ships also have a section that is not quite as low as the central water
channeling but not quite as high as the most forward water channeling. I will
often do this in longer ships where I want more but not too much water
channeling and need the space to put typically the RC equipment, potentially
the bottle, or potentially to leave room under the turrets for the actual
cannon(s) themselves.
Bulge Water Channel
Water channeling CAN also be used in the
bulges/width/beam of the ship but in some instances isn’t needed. Generally,
ships that have the most to gain are wider or have exaggerated torpedo bulges
(think refit Japanese Battleships or refit Queen Elizabeth). If water gathers
into the bulges it will frequently induce a list to
one side or another as it sinks. The clue that your ship needs more bulge water
diversion is if it is otherwise fairly stable (with non-shifting internal
components - I say this because shifting of the bottle or batteries for
instance can also induce a list) but unpredictable list (some
times port, some times starboard) occurs when
sinking. Adding water channeling to the bulges will force the water back
centrally as it takes on damage keeping it flat. A competing factor in bulge
water channeling can be having enough side to side
space for internal components. Another competing factor is ships will be more
stable if the internal components and internal weight is spaced to some degree
as wide as possible from side to side. Compromise can be required. The pictures
below (wood Yamato, fiberglass Tiger) show how up to 1 inch from the edge of
the hull but some times less is all that may be
required to divert water from the bulges back to the center of the ship.
Notably, the balsa wood as shown here is very easy to work with but requires
fiberglass protection to endure actual battle conditions. The picture on the right
was before the excess material in the barrier (grey plastic sheet) was trimmed
back.
Stern Water Channel
The hull shape of a ship will generally begin to slope
considerably in the stern and as such require much less attention to water
channeling because of the shape of the hull itself. It is harder to generalize
because of the variability however from ship to ship. The wood Yamato shows how
balsa was used to build the bottom of the hull itself in the stern. The Florida
shows how an area was raised by roughly 3/4 inch.
Wood Hull Approach
As I have alluded to, the process is slightly
different in wood vs fiberglass ships. My approach with a wood hull is fairly
straight forward in theory but to build a wood hull in general does require
certain tools and aptitudes. It is easiest to build the ship with the water
channeling in mind from the onset of the project. The disadvantage is that
sometimes more is needed and some times less is
needed and the ship gets cut apart or Frankensteined
together. The baseboard construction technique shown in this article makes it
easy for a 2 inch wide slot to be cut into the 1/4
inch base board basically wherever there is enough width for it to fit. The bow
and stern and bulges are just built directly from balsa thereafter. Since BBs
will hit the sides and top of the balsa, it must be coated with epoxy and
fiberglass cloth.
Fiberglass Hull Approach
My approach with prefabricated fiberglass hulls is
generally to make appropriate height barriers from plastic and first super glue
then epoxy them into the bottom of the hull, subsequently filling in the places
I want to be bult up. The next several pictures show how I completed the
process for the RM Littorio. I have added water
channeling to a fiberglass hull both before and after placing the deck/subdeck.
Before the deck/subdeck is inserted is ideal in that it is easier to actually
work inside the ship but harder because without actually setting the locations
of the pump, motors, shafts, rudder, etc; it can be a
setup for grinding out material later. To combat that problem for this instance
I opted to do just the more forward part of the ship with the upper portions
off and will do the stern portion with the decks in place. This ship will
likely require work in the stern as well. Before any of this is done the entire
inside of the hull should be sanded as to accept/bond the new material. The
barriers are made from 1/16 ABS plastic initially superglued and subsequently
epoxied in place to seal the bottom edges.
The next step is to cut and glue in foam. As mentioned
earlier in this article, one could use some form of liquid or expandable foam,
any 2 part pourable plastic, or concrete crack filler.
Since my goal is both light weight and durable, I use a 2
part plastic that is a little less dense/heavy than epoxy along with a
fairly generous amount of micro-balloons. To keep it even lighter I cut out
closed cell foam to take up most of the volume, glue it in, then pour the 2 part plastic over the top. Closed cell foam as opposed to
open cell foam is not porous in that the small pockets of trapped air are each
sealed individually and non-communicating with each other. You can test a small
amount of material before committing to the entire ship if you are not sure if it
is open cell foam or closed cell, a quick test also is to put some water on it
and see if it settles into the foam or not.
The last part is to pour the 2 part
liquid plastic + micro balloons which turns solid. The product I use does
expand slightly but is easy to sand back to flat.
Pitfalls
Water channeling can go wrong in a few ways.
1. The
bulges near the bow (under the forward turrets) in most ships where the is
beginning to widen out significantly doesn’t have enough material built up.
This will cause the ship to settle forward/bow heavy as it sinks despite
adequate far bow water channeling.
2. The
bulges were left too open in order to accommodate
batteries/etc. This usually causes an inconsistent list that looks different
every sink.
3. The
central channel is left too narrow. I use 2 inches of width whenever I can.
Internal components can block the flow of water creating a bulk head like
situation which can cause inconsistent damage taking. This is becoming less
common as water tight radio boxes are becoming less common and batteries are
becoming much smaller. Smaller ships can probably afford narrower than 2 inch central channel. Some smaller ships might use a
tapered water channel that widens as it approaches the pump.
4. Too
much water channeling material is used, especially when creating the central
channel component. Close to 1/4 inch is generally plenty deep, up to 3/8 inch
is OK, but much more than that can lead to instability by raising the center of
mass/gravity.
5. The
ship is too small to benefit from much water channeling and adding it makes the
ship inherently unstable. For instance, cruisers and destroyers generally only
require bow and stern water channeling without much attention to the central
channel or bulge portions.
-Tyler
Helland, 6/29/2024
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