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our week in aug managed to get some change from the deposit going to oulton broad & loddon back to potter , across to wroxham & back to stalham

one boat though was complaining of no warning re poss exceeding deposit & had gone 100.00 over on northern rivers to go with their blocked toilets . Not sure how they managed it but didn't think they'd get much joy from complaining..

one thing the old man agreed with from years ago the fuel used to get dipped b4 setting off to show was full but these days you just seem to have to trust it is. Which the complainer was alleging it might not have been

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:wave hi doc we did well too, we got some change back as well, & we went to ludham, from stalham, gt yarmouth, across to oulton broad, reedham, then back across again, then to wroxham, horning back to ludham then back to yard at stalham & all that in a week, not bad. :Stinky lori

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Hi Everyone,

Fuel consuption in my experience is not all about how far you travelled but more how fast did to get there? Evening Star is fitted with a BMC 1.5 and if we take a leisurely criuse from Potter Heigham to say Oulton Broad with revs averaging at around say 1400 - 1500 then the return journey can use a little as 20 Litres but if you run the same journey in the same tidal conditions at say 1900 - 2000 then the fuel consumption can be more than double, but the speed less than 1.5mph more! When we first had Evening Star, over three years ago there seemed much more urgency in our travels, nowadays we have calmed down and take things a lot more leisurely. We do notice a dramatic increase in fuel consumption in the colder weather though, running the diesel fired Webasto warm air heater. I'm sure it uses more fuel per hour than our old BMC !!

cheers!

Andy

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We've just got back from a great week on Broadland Saturn 3. Aware of the recent increases in fuel prices, and having been pre-warned by Richardsons that some people were finding that their fuel deposit was not covering the cots of a weeks cruising, we decided to try and be as economical as we could ....... and I was shocked when they came to fill up at the end of the week!

Broadland Saturn is a small boat, with a modern and economical (in our experience) Nanni engine. We were in no rush to get anywhere this week and had decided to stick to the northern rivers. We set ourselves a self imposed limit of 1600 revs ...... we seemed to end up going against the tide for most of the week and this often meant we were doing well below the speed limit ( 4.5 mph in a 6mph section for instance, or 4 mph in a 5mph zone). There were a couple of occasions when we had to up it to 1800 ..... travelling between Acle and Stokesby on Wednesday against the tide and similarly on the Bure between Thurne Mouth and the Ant Mouth yesterday morning when we were really battling to get above 3 mph.

Our GPS log records that we did just over 20 hours of cruising during the week, covering 82.6 miles with an average speed of 4mph. Maximum speed of the week was 6.4mph which shocked me as I don't recall getting above 5mph all week .... and then we sussed it was the bridge pilot at Wroxham who opened her up to power us through the bridge on Sunday! We had no need to use the heating, or run the engine at a mooring, so no extra fuel used there.

Day 1 - Stalham to Dilham

Day 2 - Dilham to Coltishall

Day 3 - Coltishall to Ranworth

Day 4 - Ranworth to South Walsham Broad and then on to Womack.

Day 5 - Womack to Potter Heigham, then to Stokesby and back to Acle.

Day 6 - Acle to South Walsham and then back to Womack again.

Day 7 - Womack to Stalham.

Total fuel used = £20.41 ..... yes £20.41 !!

I have to confess that I was expecting to have used more as we had travelled around a bit and was stunned when the guy filled us up when we got back to the yard. I'm not sure how much they charge per ltr, I am guessing somewhere around the £1.25 mark? It equates to having used roughly 16 litres of diesel which works out at around 0.8 ltres per hour of cruising .... wow!

Having witnessed how some people this week seemed to be in such a hurry to get everywhere I really can't say I'm surprised that a few hirers get a nasty shock when they get back to their boatyard! :o

I'm well chuffed at getting nearly £80 back .... it means I don't have to cook tonight and we can go off to our local for a meal! :dance

Carol

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It equates to having used roughly 16 litres of diesel which works out at around 0.8 ltres per hour of cruising .... wow!

That's even better that the 1.0lt/hr that I get on my 18' Mayland with a 1996 15hp Evinrude OB running at 4mph on the Thames with no tide or flow.

Well done girl :party2:

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Good point from Carol, if you can potter around at 3 – 4mph its amazing how far the fuel goes.

Perhaps one of the technical experts could help here but I have feeling that if you increase speed by only a small amount you can use twice as much fuel – in other words speed and consumption are not linear. Its amazing the number of people you see blasting around, I’m sure they haven’t a clue how much they are using. :Stinky

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This gives a good indication of what fuel consumption is like on a naturally-aspirated diesel lump

http://www.perkins-sabre.com/Engines/M9 ... rmance.cfm

Scroll down to the bottom graph and you can see that at 1800rpm it's not too bad but in Full Throttle Freddy mode it's a very different story!

Obviously these specs are for an 85hp Perkins engine, but the curve isn't that different on the ubiquitous 42hp Nanni.

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Thanks Jonzo that is exactly what I was looking for.

So at Carol’s 1,500 revs (which is about what I tend to stick at too) consumption is 5 litres per hour. Go up to 2,000 revs and its 10. Go up to 2,300 revs and its 15. I suspect most Broads boats will not go above that and it’s probably the limit of displacement speed anyway. But the point is you can use THREE TIMES as much fuel going flat out as pottering along. You’re on holiday, what’s the rush.

The consumption will be less for the Nanni but the curve will be the same.

But as Setfair says do they care? Probably not!!!

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Hi all, just been reading this post and ive got to admit to being a bit miffd, We have just got back from our week we hired northan light from woods, We went to Acle to Beccels to Lodon to Norwich to Reedham to Acle a little stop at Ranworth and then last night at Luddon. Now I kept under the speed limit and abt 1300 to 1400 revs most or the time and my fule bill was £150.80, now I was expecting to pay a bit extra but was not expecting that. Now im not saying anything about the boat yard but didnt get the fuel dipped b4 we left so cant argue, has anyone else had a bill of that size, I know we done some miles and we didnt have the best of tides with us but £150 did shock us a bit. Still had a good week and our Daughters loved it and want to go back, We have our own Norman 18 as well now so us 2 hope to get her up on the rivers some time next year and an 9.5 hp outboard should be a lot cheeper to run lol.

P & S

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Hi Highside :wave

I've just done a quick calculation based on your craft burning 4lt/hour.

Assuming they charge out the fuel at £1.10/lt (?), your £151 would have given you around 34 hours cruising, so around 5.6 hours a day, excluding heating and perhaps running the engine for hot water. At £1.20/lt, this brings your total hours down to 31.5

Any idea how many hours you actually did in the week?

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As boat speed increases so to does resistance, by how much will depend on hull type but this is where the fuel goes.

At 3 mph there is very little resistance from the water but at 5 there could be three times as much, hence 3 times as much power needed and consequently 3 times as much fuel to cover the same distance.

longer hull will allow a higher top speed in displacement mode but you still increase the resistance by the same amount per ever 1 mph.

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Hi all, It looks like we done about 26hrs crusing and the heating was on for about 20hrs in total. I think the fuel charge was around £1.30 pl , have shreded the number of lts info but it was around that mark.

Paul & Sue

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nice to hear the fuel returns we do a week on a Judith from Martham which includes 114 litres of fuel a typical week is martham to coltishall then to wroxham to stalham or neatishead from there to loddon from there to norwich back to loddon from loddon back to ranworth or wroxham(Roys of course lol) back to potters under the bridge and at least one night top side up to the pleasure boat inn for a meal then up to the end of the Thurn for an overnight to get back for sat 9 am to Martham plus we sometimes use the warm air heating as it can be a bit fresh in May as like this year was lovely sunny days but cool nights and we have never had to add any fuel this year we checked and there was a good 20 litres left in the tank :Stinky:trophy

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Hi all, It looks like we done about 26hrs crusing and the heating was on for about 20hrs in total. I think the fuel charge was around £1.30 pl , have shreded the number of lts info but it was around that mark.

Paul & Sue

So based on 4lt/hr (less than a gallon per hour) which I reckon is about right for say a 50-70hp Broads engine, so thats 4 x 26 hrs = 104lt.

IMO, most diesel fired boat heaters use 0.5-0.8 lt/hr so at the worst that would be another 16lt.

120lt x £1.30 = £156 :wave

FWIW, I posted this elsewhere on the net re. Swan Rhapsody, a 33' aft cabin boat - "I worked out that the average consumption for the week was around 3.6lt/hr with the engine running at 1800-2000rpm all week (we did 40 hours cruising) and using the genny for 1 hour and the heating for around 6 hours a day. Power comes from a 43hp Beta engine, encapsulted in a sound proof box whick makes for very quiet cruising. All in all, a great boat and would certainly hire again."

HTH.

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