Cedric Randolph (asker) Jul 4, 2009:

Shaft Lines vs shafts or shafting I believe through the whole context of the text that these two are what I was looking for, since in this case there is the possibility of this conventional power system and a more modern system with no shafts. Therefore, I thank you both, and absolve you of all further concern. I am happy with Maria Luisa's answer as hers came in first and fitted the bill. Thank you both for your attention and energy.

Maria Luisa Dell'Orto Jul 4, 2009:

That was my first thinking, i.e. propeller shafts. Let's wait for Cedric confirmation, then.
I think the lack of context is a little bit misleading.

Being Earnest Jul 4, 2009:

Hi - you are prefectly right but I think that what we have been asked is something which exists in a locker. Thus netiher my or your answer look right. Shaft lines are design issues and shafting is the shaft. It could well mean that there is a spare propeller shaft on board the vessel. I was in the RN for 10 years and ships do carry spare shafts. I might propose this as the answer

Maria Luisa Dell'Orto Jul 4, 2009:

Hi Being Ernest, in the internet I found examples motivating my terminology proposal, here is one:

http://www.reggianinautica.com/prodotti_cat01_05.html

Being Earnest Jul 4, 2009:

I beg to differ here but shaft lines are related to design of a propulsion system. From what I can see from the short extract given, this is something tangible and existent - hence the reason for shafting but I am not a Peer so it's up to you guys