Narrowboat domestic water
systems
There
are several major components to the water system on your boat which must
be in place to supply water to the taps and showers around the boat. The
tank, pipes, pump and heating system. You will also need to make decisions
about what kind of toilet system you will be requiring, but that is covered
in a separate section of this site.
Firstly, the Tank. Storage tanks come in various forms,
either built into the hull of the boat, or a separate structure altogether.
Built in tanks have the advantage of being able to be designed to fill all
wasted space in the bow of the boat, even replacing the bow locker in some
cases. Most narrow bat builders will include the cost of the tank in the
shell price, although some may include it as a small extra.
Tanks
can be built from Steel, Stainless steal, plastic or rubber, each with their
own relative advantages and disadvantages.Steel is cheap
and is often used by boat builders. Unfortunately it rusts, and must therefore
be painted inside to prevent this. It is important to use the correct paint
(often bitchumin based, similar to that used for blacking the hull of boats)
to ensure there is no polluting of the water system by paint dissolving
off. In addition to this a hatch must be built into the top of the tank
to allow regular re-painting every few years.
Stainless steel may be used as an alternative, which will
not rust, but is much more expensive and must be built as a separate compartment.
Also many boat builders may not have the technology to weld Stainless steel
plates.
Plastic has more recently become an option for water tanks,
and these can either be built square or fashioned to the same shape as the
spare bow space available. One "Clear" advantage is the ability
to make the tank translucent, so that the level of water is easily visible.
Rubber or Neoprene can be used to produce a flexible tank,
which has the obvious advantage of being able to form itself into any space
it is put in - useful on small barges or cruisers where the tank can be
installed under bunks or cupboards.
The Piping you use on your boat comes in two different types
- the standard copper piping you would have at home, and semi-rigid plastic
tubing. The later is now more commonly used by professional boat builders
as it has many distinct advantages. Its flexibility means it is less prone
to breaking if the water system should freeze, and the joints are able to
flex which reduces cracks in more stressfully areas. It also reduces the
amount hot water cools by between the heater and the taps as it is less
thermally conductive.
The Pump which powers your water system (vital as the tank
is at best level with most of the taps on board, and thus gravity is not
as much use as it is with the tank in the roof of your house) is run from
the 12 Volt power supply onboard. It is operated by a simple pressure switch
which is activated when you turn on a tap, and deactivated as pressure builds
up once the tap is closed. This can be unreliable, so many hire boat operators
and people living on board for long periods of time will often fit two pumps
in series or parallel to counteract this problem. This technique also solves
the problem of a drop in pressure when more than 2 or three taps are operated
at once, or if someone is using the shower. By using the dual pumps are
greater amount of pressure is produced, resolving the need for a larger
pump.
Another
annoyance with water pumps is when you have a tap which is half open for
a low flow rate. The pressure tap may constantly switch on and off causing
often violent surges of water. By installing an accumulator tank on the pump, these surges can be smoothed out by air in the tank expanding
and contracting.
Water heating is vital onboard for washing and showers,
and is again achievable in a variety of ways, with no real right or wrong
answers. The simplest option is to use a Calorifier which uses the waste
heat from the diesel engine cooling circuit to heat a tank of water. These
are not always a reliable hot water source, as the rely on the engine having
been run for at least half an hour before hand, and the temperature of water
drops off quickly as you run it, as used hot water is replaced by cold.
Newer units are starting to make use of modern advances such as heat blocks
and an integral Immersion heater element included in the package. These
options should be investigated thoroughly before making a rushed decision
about what to use.
You may also want to consider the use of Filter systems as the sources of
water by the canal side may be extremely dubious. There are a wide range
of options on the market suitable for canal use, so look into these if you
decide this is important for you.
Narrowboat and canal boat domestic Water Systems
