Originally Posted by GrahamHO
I always thought the ama were meant to be kept light with boyancy as the designer
Sure, we have to follow the ideas of the designer. A truck is a truck and cannot be used as a formula1 racing
car. Same with boats.
But there are parameters we can handle flexible. E.g. calculate that many of the Trimarans have to 4-6 birth. Its part of the stability and sailing plan.
Lets say we take a 35 or 40 foot Trimaran, regularly 6 birth, e.g. 1 double bed
in astern cabin
, one double cabin in foreship and two single beds each in the wings beside the saloon
So the construction itself is designed to transport maximum 6 people... with all the personal stuff (weather clothes, luggage etc. ...) and food
capacities (water + regular food) I suppose we can calculate minimum 100 kilogrammes each person, right ?
Not to mention, that during day sailing
we see 8-10 people hanging around on the trampolins of such boats :-) Never heard about that one of the amas has broken off. :-)
Even on a small 24 Foot Trimaran, e.g. a Kurt Huges Design which is used in Italy
, there hang around 6 people on board with all that stuff (e.g. surf boards)... and they sail very tough MUFFOLO as you can see in the vid... no problem with stability...
If you reduce the crew for a regularly crusing to a two handed one, which is in tendency very typically nowadays... we get free 4 birth = 400 kilogrammes "trimming weight"... to invest in other equipment
or to manage the storage places differently. Right ?
Naturally it is a very normal thing for a designer, that he expects these 6 people jump around on board as they like, not all sit all time in the cockpit. Some hang around on the trampolins, another sits on the bow to enjoy watching dolphins
etc. .... very normal way for leasure sailing on Multihulls.
So the boat itselfs has a stiffness to handle such crew weight of more than 500-600 kilogrammes easily.... not loosing its sailing ability.
If I take such kind of boat, reduce it to a maximum crew of 2-3 people I get free 200-300 kilogrammes of weight I can use differently, e.g. storage of batteries into the amas...
I am very confident about that in very close future, we will see such kind of concepts, to have electro motors in the amas and the whole battery
In small there exist already a US patent for an electro motor
driven Trimaran designed by inventor Ronald A. George
(owner of company THE OCEANSCIENCE GROUP which shortly was sold to TELEDYNE RD INSTRUMENTS, INC. in California)
Patent US20140158037 - Trimaran having outriggers with propulsors - Google Patents
The Finnish company OceanVolt installed shortly a pure electro engine
into a bigger Cruising Trimaran... it has a water cooled sail drive, too (only 44 kgs weight). More details here: The yachting future is silent… new & powerful Electro Motor Systems from Finland
I am in contact with the folks of OceanVolt and waiting for some more details... will report as soon I have more details.
We just need to become flexible in our mind to handle the parameters given by the Multihull
designers... and find a good way for compromize: Speed + Space. :-)