Plan mince

00:10 Dec 31, 2015 

Chris,

Extra context is always helpful. The "steerable pod" info is a key piece of info. I suppose you are not able to give much away but without more info, it's tough to see what part is being referred to.

Here's one source with "plan mince" and "steerable pod". Not wild about the solution of "thin plane" though : http://www.google.com/patents/EP1826117A1?cl=en

Here's another source from the Ecole Centrale, where "plan mince" is in fact "plan mince de dérive" : http://website.ec-nantes.fr/ingenieurs/breveMetierdelaMer6.p...

And another which confirms that "plan anti-dérive" includes both keel and rudder : http://www.jph-lamotte.fr/files/tech_safran.htm#n03
See the part of "la fonction anti-dérive".

Note also that "dérive" is in fact a short-form of "plan anti-dérive". "Dérive" and "safran", keels (fixed or not) and rudders are collectively described as "appendages".

Without more context, this could be:
- plan mince anti-dérive
- plan mince de quille
- plan mince de safran (probably unlikely now you say it has steerable pods).

Can you not ask the client what the "plan mince" is actually referring to?
If it is the keel, then "thin keel" alone is meaningless.

08:41 Dec 30, 2015 

The ship concerned is a very modern, specialised vessel of several thousand tonnes. I'm inclined more and more to think that this is just a rudder, though given that propulsion is by steerable pods, this would make a rudder redundant! A picture would be worth a thousand words, but I don't have one...

19:40 Dec 29, 2015 

I agree with you too.
Your definition of "plan mince" likely matches the "name" I have found, and also Chris' earlier hunch (the fixed part of the hull which precedes the rudder).
As to what it's called I haven't got a clue!

19:13 Dec 29, 2015 

"Le plan mince d'un navire est la partie plane arrière de la coque servant de plan anti-dérive à la carène. Dans certains cas il renferme le tube d'étambot".
http://www.crdp-montpellier.fr/ressources/examens/sujets/06/... (p. 3)

Unless I've misunderstood this it's referring to the transom. And it's clearly a name, not a description. However, I wouldn't say that settles it. I agree with you, Philippe; it could be a number of things.

19:01 Dec 29, 2015 

As Phil mentioned earlier.
From what I found, all protruding, flat, low-drag bits below the waterline are descriptively deemed "plan mince": rudders, rolling chocks, bilge keels, stabilizing fins. The only occurrence I found where a "plan mince" is actually something is here: http://www.calcoque.fr/model.html
From the sound of "plan mince", there could be a hydrodynamic definition attached to it (reminds me of "couche mince"), and anything within the scope of the definition is a "plan mince". But by extension, it could also mean something specific in FR.

18:39 Dec 29, 2015 

I looked at this question when it was posted some hours ago, but was led astray by misunderstanding your question to mean that the "plan mince" in question was one of the sacrificial anodes, rather than one of the parts of the boat to which the sacrificial anodes were fixed. I feel the weight of evidence from usage points quite strongly to the rudder blade, though as Philippe has shown the expression can be found referring to other parts. After all, it really just means "thin plane". In other words, more often than not it seems to be a synonym for safran.

Apart from the Wikipedia page Daryo has quoted, which includes "un ou plusieurs safran(s), plan mince à l'arrière de la coque déviant l'eau du côté désiré", there are other references like this:

"Le système de gouvernail est composé de :
- safran: plan mince et profilé"
http://dept.navigation.enmm.free.fr/giration.swf (slide 2)

And quite a lot more.

Here's a nice picture of a sacrificial anode on a rudder blade:
https://www.boats.com/how-to/protecting-metal-rudders-with-s...

17:48 Dec 29, 2015 

Could you indicate what type of craft is concerned? Indications of the term preceding and following this one in your list may help too.
It is highly likely to be referring to the rudder blade.

17:27 Dec 29, 2015 

The context is pretty much as I described it, being a list of the submerged parts of a steel hull where one might want to bolt on a sacrificial anode. Yet more research suggests that this may simply be a naval architect's synonym for "rudder", though other refs suggest it may be that fixed (and thin) part of the hull which precedes the rudder. These are particularly prominent on racing rowing shells, where the rudders themselves seem impossibly small, only a few tens of square cm. in many cases.

14:57 Dec 29, 2015 

I'm no expert either, but it sounds like it may be a description of a part, rather than its name. Could we have the French context, please.