Montemar
Well-Known Member
When cruising a river in UK would one run on one engine to save fuel and minimise noise? If so which one?
River cruising with two engines
- Thread starter Montemar
- Start date
Megs20Burt!
Well-Known Member
Montemar,
We cruise on the river Trent with a twin diesel boat.
Generally, we are at around 1,300rpm on the speed restricted stretches. Personally, I would prefer both engines in use for manoeuvrability & safety. When we did our RYA training, our instructor showed us the power of the Trent and the effects of the flow on the boat in what can be narrow channels, he used the term ‘collapsing timeframe’ and boy did we see how quickly things can change. I would not want to be without both engines at any time. We use the boat regularly and apart from exercising the turbos on the non-restricted stretches, use little fuel through a season.
We cruise on the river Trent with a twin diesel boat.
Generally, we are at around 1,300rpm on the speed restricted stretches. Personally, I would prefer both engines in use for manoeuvrability & safety. When we did our RYA training, our instructor showed us the power of the Trent and the effects of the flow on the boat in what can be narrow channels, he used the term ‘collapsing timeframe’ and boy did we see how quickly things can change. I would not want to be without both engines at any time. We use the boat regularly and apart from exercising the turbos on the non-restricted stretches, use little fuel through a season.
kashurst
Well-Known Member
unless you are on outdrives with power steering, it doesn't really matter which engine you use. When we were on rivers I would alternate engines every hour or so.
Running on one engine doesn't really save any fuel but I think it is better for the engine as it is under load and heats up properly minimising the risks of condensation build up in the engine.
But as Megs20Burt explained if things could get tricky have them both running.
Running on one engine doesn't really save any fuel but I think it is better for the engine as it is under load and heats up properly minimising the risks of condensation build up in the engine.
But as Megs20Burt explained if things could get tricky have them both running.
Bouba
Well-Known Member
If you have to run close to the side of the river, there will be obstacles that could damage a spinning prop. So I would only use the outside engine in those circumstances
Greg2
Well-Known Member
Before running on one engine check that your gearboxes are designed to be sufficiently lubricated when the shaft is freewheeling and the same for your shaft seals. The design of your hull will also be a factor - our Hardy has a keel so tracks well with a bit of counter helm to keep her straight. Friends who had a planing hull went round in circles with one engine and couldn’t run on one.
Montemar
Well-Known Member
Thanks for all your replies which make excellent sense.
Also we have a small keel and the PRM gearbox can be freewheeled.
Also we have a small keel and the PRM gearbox can be freewheeled.
Momac
Well-Known Member
So do we
Like you I find at slow speed the fuel use when using both engines is modest .
oldgit
Well-Known Member
30 years cruising inland waterways.
3 boats all with diesels, both O/Ds and shafts.
Always used both engines.
Both engines gave about 4 knots on tickover and around 1000rpm gave 6 knots all under the 8kph on most inland water ways.
Am very dubious about any noticeable saving on fuel with drag created by unused prop.
And as for constantly compensating with the helm and the lack of response due to one rudder doing nothing ?
Add all that extra wear and tear on starting up the dead motor to enter and exit locks ?
3 boats all with diesels, both O/Ds and shafts.
Always used both engines.
Both engines gave about 4 knots on tickover and around 1000rpm gave 6 knots all under the 8kph on most inland water ways.
Am very dubious about any noticeable saving on fuel with drag created by unused prop.
And as for constantly compensating with the helm and the lack of response due to one rudder doing nothing ?
Add all that extra wear and tear on starting up the dead motor to enter and exit locks ?
Montemar
Well-Known Member
Thanks for replies. It was an academic question as we are miles from any canals or rivers but previous owner was on the Thames. I wondered about the affect on the boat.
Momac
Well-Known Member
An advantage is relatively little corrosion on fresh water .
Extended low speed running not necessarily a good thing if engines are turbocharged but seems okay if the opportunity is taken for an occasional high speed run .
Extended low speed running not necessarily a good thing if engines are turbocharged but seems okay if the opportunity is taken for an occasional high speed run .
oldgit
Well-Known Member
Casual observation suggest that most/many boaters on the Thames use both the engines as a matter of course, when the next lock could be only be 10 mins away from the one you have just left ie. Harleyford, , hardly worth turning an engine off, only to restart 5 mins later.
Most boats with twins being a pig to manoeuvre esp. when going astern
