Hello to all out there.My name is rikus veuger,original from holland but now living in bandung,indonesia.
I also want to build my own wooden boat and I am looking for many information by reading books and looking on the net.
But some questions I cant seem to get an answere for.So I try out here on this group.
It is maybe silly to ask but I am just curious to know why in a boat there is not a automatic gearbox.I ask this becouse I want to build a speedboat and I know that it take a lot of power to speed up the boat until it has
a surtain speed and start to get in plane.
Then you can lower the rpm of the engine but keep the speed.I thougt by using a gearbox the rpm can lower again,saving fuel and give more comfort.
My other question is about the angle of the shaft of the propellor.If the shaft and engine are on a angle it seems to me that, becouse of the direction of propellor power, the nose of the boat is lifted and the back is more down into the water.What is the use of that?
Is it not better to use a horizontal propellor,like a saildrive.It will give much more efficienty and it will be more pleasant to sit in when at lower speed becouse the boat stay horizontal.
I hope some one can give me some clear answere to one of my ,probebly silly,questions.
All the best
Rikus
ps.I already put this message in this group 2 months
ago,but in the Articles so got only one replay.Hopefully
this time more people will react.
By the way.I am a trader in East Indian Rosewood,so if anybody needs some timber I can help you to get this great wood,almost any size or quantity.
Rikus, I am carrying my answer over to the message forum so that everyone can easily see my response and hopefully correct and/or improve on it... We have many talented members in this group who could help answer your question. Rikus, I think that a gearbox on a 2-cycle engine would be rare to non-existant because these are designed to essentially be operated at full speed (I read that in a boating magazine somewhere , possibly 'Wooden Boat' or 'Good Ol' Boat') and rely on throttle control for speed. I don't see why any engine firing on 3 or more cylinders shouldn't be able to use a gearbox other than the fact that in rougher weather, when you need to really be on top of your game, that shifting an engine from gear to gear might be more of a hindrance when you should really be concentrating on the "tuning" of the boat and where the next wave is coming from. I would defer a more intelligent answer to one of the big-boat guys like Tom... As for the angle of the engine shaft... I believe that there may be a few reasons for setting an engine up and bedding it at an angle... Boats are designed to perform best at near-planing to planing of the hull. Think of a wedge of cheese with the point being the bow. As you move forward and the wedge is moving through the water, the water is thrust to the sides and beneath the hull. At a certain point along the hull the resistance or friction of the water against the hull lessons and a boat is said to reach "planing" speed. An engine and shaft set at an angle will dig deeper into the water at the stern of the boat and lift the bow, thus allowing the hull to reach planing speed quickly. Engines shafted on the level would tend to not lift the bow and thus make for harder work thrusting through the water and waves rather than lifting the hull up onto the water surface. This type of engine setup would require a hull which must do all of the work of lifting the hull through design of the hull... The designer's vision of the hull shape, creating one which inherantly lifts at a given speed. I believe that I read somewhere that some of these designed planing hulls have some other issues which are compromises in the performance of the hull but I am drawing a blank right now... Anyway, I hope this helps. I am sure that there are other members of this group who could give you a clearer answer... Best of luck, Andy
ReplyDeleteRikus, I am interested in talking to you about rosewood veneer strips to laminate boat hulls. You can contact me at thesawdustmaker@gmail.com David
ReplyDeleteHello David,I send you more then one month ago an email but no respons from you yet,so I try it this
ReplyDeleteway.
I dont make veneer at the moment, all sizes I make are made by cirkel or bandsaw.So if you need timber in
any size,I will do my best for you.
All the best
Rikus