Beta Marine Beta 10 Operator's Maintenance Manual page 22

CANAL BOATS WITH KEEL COOLERS
Most narrowboats on English canals have keel cooling,
and this is standard for our 'Green Line' Narrowboats'
and 'Wide Beamers' (heat exchanger cooling is available
as an option if required).
The Beta 10 to Beta 25 propulsion engines are available
with keel cooling if required. The keel cooling supply
and return pipes are 22mm diameter; requiring flexible
rubber hoses with a 22mm bore. These rubber hoses
should be designed and manufactured as hot water
heater hoses suitable for operation up to 100°C.
30 Ideal Keel Cooling Tank
The keel cooling tank size should have a
surface area exposed to the canal or sea water of:
0.25 x the bhp of the engine = the square feet
of cooling area required (for steel hulls)
NOTE: If you boat has a hydraulic drive, you will need to increase the surface area by approximately 30% percent.
Keel cooling pipes under the hull of yachts or work boats, that achieve the same surface area can also be used. If you
have any questions about keel cooling please refer to our design guidelines detailed on our website, or ask us.
Narrowboats: With keel cooling the coolant (same fresh
water / antifreeze solution as heat exchanger cooling)
flows around the engine and also the keel cooling tanks,
before returning to the engine.
These keel cooling tanks are normally welded into the
'swim' of the narrowboat, using the 8mm steel plate hull
as one side of the tank to transfer the engine heat to the
canal water. The required surface area for keel cooling
our engines in narrowboats is as detailed.
Bleed Screw
Baffle Gap
Min. ø D x1.5
Max. ø D x 3.0
20
A B = SURFACE AREA
X
(MUST BE BELOW WATER LEVEL)
A
Baffle
Hot
Water In
ø D
Cold
Water Out
B
H