Friday, March 9, 2007

Message board

To make communication with designers and other stakeholders easier, I've created a bulletin board in which we discuss specific topics. Registration is required.

Message Board

Thursday, March 8, 2007

Tender design & engine

views of our tender to take (diving) guests around We like diving and as a true expedition vessel, we'll be set up for serious diving. We'll also go with aluminium tenders. They simply last longer, give us more design choices and are more affordable then fancy looking RIBS.

This is our aluminium dive tender, a Van Vossen Engineering design. Rugged, built-to-last and with some very unique extras to make boarding a piece of cake.

We plan a 235 HP Yanmar engine with a stern drive. While doing our reseach we ran into some folks in Auckland, New Zealand, a company called Q-SPD International. It's a so-called surface drive.
getting in and out of our tenders will be very easy for divers
Supposedly it would bring less maintainance than a stern drive, more speed, less vibration thanks to its Python drive (another Dutch design).

More information on surface drives can be found at this site, also from New Zealand. How come those Kiwi's are so into surface drives?

After several days of waiting for the manufacturer to get back to me on this promising alternative we learned these drive or not very effective at low speeds so we plan to stay away from them. But, for informational purposes, we share the sites we found while surfing the Internet to learn more about 'surface drive' principles. We came accross another manufacturer, Levi Drives. Their page on design issues is informative and worth reading. And here' another list of surface drive manufacturers we ran into. In the US you will find Arneson Industries. The image below, comparing propulsion systems, is theirs. Pulse Drive Systems Intn'l is another company from the US.
different systems and the drag they create

the very reliable Yanmar engine we are planning to use

the Q-SPD surface drive

New crane solution

using a more traditional solution will look better and save $$Since we eventually would like to be able to carry a 7 ton sub, we need a pretty strong crane.

We've been looking at hydraulic cranes but they are not cheap and the location, while acceptable, did leave us with kind of a big ugly object in the line of sight forward.

Since we have a pretty strong forward mast anyway, our designers at Herman Jansen made this suggestion - a boom - and we like it a lot. It's a lot more affordable while able to carry higher loads. It also looks a lot better we think.

a Bell Jetranger has just landed. Welcome on boardNow we're going to find a way to do the same for the tenders on the platform aft.
We can't use the same set up behind the mast because it would reduce the safe area to land a helicopter. Maybe a small hydraulic low profile (stiff) boom crane after all? We'll figure something out.