http://www.modellbauvideos.de/bootsvideos/segelboot-videos/1-mini-40-treffen-in-deutschland.html
Last few seconds has an interesting shot of a large scale Hobie 16
Dick,
I was impressed with how it was able to tack without a great deal of difficulty. Do you know what hull design they were using?
Bill
I will try to find and send you some links. I can understand/read German - but am very rusty. Can’t write so BableFish is my companion and their forums have a few words that I am lost on. Been trying to find a German who speaks English for correspondence… “Idealist” being excluded of course.
The trimarans are of personal design while the Hobie hulls are a lot more rocker and I think a personal rendition based on the “banana look”. The link I am thinking of has some static photos of the build. Not sure if you noticed, but the Hobie is using movable ballast on top of the trampoline. Covered in what appears to be black and yellow neoprene.
Holiday tomorrow (Veteran’s Day) and no work so I will find and do a personal email to you on Wednesday.
Dick,
just ask me if you need some of the German stuff translated…
the desings visible in the video are a ghost train, a butterfly (manufactured by Graupner, but discontinued), the scaled down Hobie and one construction by an Austrian guy (no, not Idealist).
The ghost train was modified later for more buoyancy in the bow area…
Cord
Thank you for your very kind and generous offer, Cord. I will PM you my personal, off-line contact info.
Visiting the German multihull website, I saw and managed to understand a lot of the new stuff going on over there. I’m sure the French are also doing some new ideas and designs. Being able to tie the US, Britain, Germany, Denmark, Finland, Swiss, France, Spain, Australia and New Zealand together to share ideas and methods has always been a goal of mine. I would guess there is also some multihull activity in Asia and Japan - it’s just hard to catch up and make contacts. We often spend a lot of time trying to do something others have tried and failed. Spending valuable time on a project or idea that has proven NOT to work could be better spent discussing and improving ideas that DO work.
My warmest regards and thanks for your kind offer.
Dick
Cord,
Do you have any specifics on how the Ghost train was modified for more bouyancy in the bow?
Mitch
Hi Mitch,
the owner, Michael Scharmer (German Champion in IOM) reported, that the Ghost Train has to less volume in the bow areas, the result was, that the bow was pressed into the water especially when running.
Several possible solutions where discussed, Michael finally decided to change the shape of the bow area. His idea can be seen in the following post:
http://www.rc-network.de/forum/showpost.php?p=462929&postcount=71
The round shape is the original shape from the Ghost Train, the one with more V-shape is Michael’s suggestion. He first built a version with slightly more freeboard and then made the radical changes seen in the post mentioned above.
By the way, the following link leads to the discussion thread on the Ghost Train and the improvement process:
http://www.rc-network.de/forum/showthread.php?t=48237
It is in German, but there are several pictures which might help you…detailed data on what was done exactly do not exist as far as i know, but i will have a look if i can find something…
if you have any other questions, just let me know…
Cord
Thanks Cord for the reply.
Great information! It was interestig to see the various hull shapes. I had read an article about preventing nose diving in monohull boats a while back and the finding was it was best to keep the deck from submerging. Once the deck goes under your are done. They experimented with tall freeboard bows and deflectors too. I agree with Dick that you want to keep the bow narrow so the boat doesn’t trip, it needs to continue to accelerate.
Wasn’t the old Playstation that had the real high bows?
Mitch
Cord -
of interest - 2 questions if you can find out (or post) to the site…
-
Is the increased height of GHOST TRAIN bows above or below the waterline - or is it in the middle of the bow where height was added? It will make a difference is the bow is deeper in the water - or just higher in the air.
-
Are any of the German/European boats sailing and using modified marblehead (M Class) main hulls competitive? I had correspondence from Australia that the M hulls were OK for local sailing, but were much slower than a purpose-built trimaran with thinner main hulls. In a few photos on the site you provided, the main hull almost looks like a modified monohull.
Thank you
Dick
Hi Dick,
the increased height in the ghost train hulls is above the waterline i guess, so that it just comes into play when the bow comes down when running…but i will read over the thread again to make sure.
I haven’t heard of any M hulls used in Germany. The multihull scene here is not very old, it really started when Michael built his ghost train.
All boats which were built later are constructed as trimarans and are not based on monohulls. I know of one boat which uses scaled down Tornado class hulls on a trimaran.
The boats that were built this year and are currently in process are independent constructions based on the experiences made with the ghost train and the boats built so far…but i will have a look if i can find any information on M hulls used on trimarans…
Cord