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diesel-electric propulsion

Where can I find out about diesel-electric propulsion? I am contemplating a newbuild narrowboat and wonder if the diesel engine could be in the bow so there is little sound in the stern with an electric drive.

Asked by: A. J. Curtis  | 4.07pm, Friday 19 March

WW says:

Some companies specialise in diesel-electric propulsion, but you might find that hydraulic drive (with the engine snuggly fitted in the bow) more cost effective (and proven).
The engine runs a pump, which transmits it energy through rubber (or steel) pipes to another pump on the prop shaft, and the returning fluid is cooled and returned to the engine.
It is possibly more efficient than using the engine as a generator, and the hydraulic fluid can also be used to drive a bow thruster, if you feel the need for one, and a generator as well (for 230V power).
Many cruisers on the Broads and Thames (especially hire cruisers) use this technology- and so has a good pedigree.

Mark Langley  | 4.32PM, Friday 19 March

Well, electrical power is more economical in some respects, although the intial outlay could be quite high. You would also have to take into account the cables... if the motor is 36 or 72V, the cabling costs would be a nightmare. The components for a hydraulic system are "off the shelf", including bow thrusters...
Most electrical propulsion power systems in narrowboats use the generator close to the prop shaft, so if the engine is running, it isn't that quiet!
In my experience, a well-insulated hydraulic system is quieter at the tiller, than an electrical system. With both systems you do not usually need a gearbox.
Hydraulic systems are alos more "narrowboat friendly", in so much that they are less effected by water, than a motor (and associated cabling)- it is very rare to find a space around a prop shaft that will always be nice and dry...!
Whatever you choose, also consider how this will effect the future resale value of the boat... alas, the market often doesn't like "different" propulsion systems to the considered norm... even though other systems might be far superior!

Mark Langley  | 5.05PM, Friday 19 March

Readers say:

Many thanks for your prompt reply Mark, but I have heard that electric is more effective/economic than hydraulic. Is this so, or is the difference nominal? Also do you need a gearbox with either?

A. J. Curtis  | 4.56PM, Friday 19 March

Thanks for your help Mark.

A. J. Curtis  | 5.15PM, Friday 19 March

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