Princess 415: Performance

[NigelChattin]

Hi,

I've trialed a Princess 415 today fitted with TAMD61A engines. We were impressed with the boat but concerned about the performance. Flat out she only achieved 2500rpm and about 22knots. Is this realistic or should she be capable of more?

The sea wasn't flat but nothing too bad (F2-F3), she had approx 3/4 fuel and water, & 7 people on board.

Can anyone tell me if I should be expecting better performance than this or am I worrying over nothing?

Thanks,
Nigel

 

[Bandit]

Correctly propped they should rev to 2800.

How clean was the bottom and the props?

 

[NigelChattin]

I think the props are correct because at 22rpm she was making 17/18knots so I don't think she's over propped. She does have rope cutters though and I'm not sure what difference they make.

As for the bottom, she was out last Autumn but not used much since then so will have some weed but we were out for 30-40 minutes so I imagine we cleared most of that - what do you think?

 

[rickp]

[ QUOTE ]
As for the bottom, she was out last Autumn but not used much since then so will have some weed but we were out for 30-40 minutes so I imagine we cleared most of that - what do you think?

[/ QUOTE ]

If only it were so easy! It takes more than a quick blast to shift weed and barnacles....

Rick

 

[Bandit]

If she has not been out since autumn she definitely has a s###ty bottom for sure and will be loosing a couple of knots on cruising and probaly three on top end. Even a slime will slow you down considerably.

If you are seriously thinking about buying put in an offer for purchase subject to survey and subjest to satisfactory sea trial with the surveyor at whatever the owner says it will cruise at. A pressure wash at about £60 will tell you if she will or wont hit the speed.

However I have a sedan 36 with 2 x 370 hp which incidentally is for sale and although she has a shorter waterline length and more horse power cruises at 23 to 25.

I would have thought the 415 should cruise at 2500 at 19 to 20 knots and top at 24 to 25 on a clean hull.

If corectly propped and the engine in good order she should top at 2800 rpm.

 

[Garryt]

I have rope cutters / strippers on my shafts and you can expect to loose about 1knt on your top speed!

 

[DoubleVision]

I had a Fairline Phantom 38 which in reality was 42 ft long with 61a`s. probably a bit lighter than the 415 but with the cleanest bottem I never saw more than 25 knots at 2800 rpm. She would cruise at 20 knots at 2500 but prefered 18 at 2350. It sounds like your boat needs a haul out and blast off and as previouse poster says take your surveyer with you on the sea trial and look for 23-24 knots @ 2800 rpm. Good luck!

 

[Deleted User YDKXO]

Very valid comments from other posters. The other thing to consider is that the engines are 20yrs old and therefore unlikely to be developing the same maximum power as they did when they were new even if you could get them to rev to 2800rpm. Certainly you will also lose 1-2 knots with rope cutters as well
On a more general point it does amaze me that owners of boats for sale do not bother to lift their boats for a scrub before a sea trial in order to show them off to their best advantage
IMHO, you should definitely insist that the boat is cleaned and re-trial the boat to satisfy yourself that the engines can reach close to their max rpm, if you want to pursue this further
What happened to the boat with TAMD70E engines?

 

[longjohnsilver]

[ QUOTE ]
we were out for 30-40 minutes so I imagine we cleared most of that - what do you think?

[/ QUOTE ]

It would be good if that were so but unfortunately it aint!! Suspect that's where you're losing your revs and speed. She will need a good clean, paying particular attention to the sterngear and I bet she'll then feel like a different boat!

Mine has been in all winter and I dived under her a few weeks ago and cleared something like an inch of white worm type casts as well as barnacles which were growing over most of the hull and sterngear. I thought she felt a little sluggish when I used her the week before!

It makes a huge difference.