The Merlyn was launched on 6 and 12 volt winches with 150 lb test tow line, that were in use at the time Ken was flying his Merlyn. The design is an enlarged Aquila and the airfoil Ken used was the original Aquila's airfoil. A thin flat bottom.
It does not need a special winch to launch.
Wing loading per sq foot is the way to tract a sailplanes flying weight. Most unlimited size class RC sailplanes are in a range of approx. 8 - 10 oz per sq ft. Ken Bates AMA magazine Merlyn construction article is a great read and very educational.
I have started my Merlyn and will have a building tips photo catalog to document my modifications, it will be available on my web site when completed and is being sent to Merlyn builders as I progress. A build thread has been started on R C Groups.
Ray ... LSF 803
Sky Bench ... Woodys Forever
http://www.skybench.com