Crab claws on ice

03 February 2017    Editor    6 Comments

A report by Peter Adrian from Sweden on his crab claw rigged iceboat:

Am sailing my second season my modified iceboat: an Isabella Classic with 5m2 (54 sq. ft.) crab claw sail. Just a win-win over all compared against the same boats with conventional Bermuda rig. Just one thing I’ve noticed is she no longer lifts the windward runner at over 60km/h (37 mph).

The yard is made fast to the apex of a bipod mast and fixed to the hull at the bow, so it cannot move. Like the traditional oceanic rig, only the boom is free to sheet in and out. Iceboats are sailed close-hauled at all times, and tack downwind, so the narrow sheeting range between the bipod is no problem.

The sail is cut dead flat, so it is the simplest of rigs for the home builder. Another advantage is the iceboat can be parked in its box more or less completely rigged. Pull the sack off the spars/sail, lift the yard and clip it to the bipod mast. Install the runners and the sled is ready to go in 5-6 minutes, while the Bermudas are still still fighting to get their stuff ready in 20-30 minutes, and even longer if minus 5C.

Peter’s Isabelle Classic fleet: The G-Flyers

Peter also sails a Viking ship. Really.

 iceboats / crab claw 


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06 Feb - 04:38

Janusz Ostrowski

brilliant simplicity smile Are you satisfied with the sail cut ? in terms of wrinkles etc.

08 Feb - 13:29

Peter Adrian

Hej, Thank you, that was the target (!) making one of the most increasing free isboat class >the Isabellas</Bernd Stymer Design and in this case his >Classic< even better and simpler. We are now close to target. Everything can be made by a someware handy person at home to a functional iceboat that can sail when others has to tear down their sheets and give up. all according to KISS Keep It Stupid Simple When this photos were taken the sail was not optimal set and fixed at the >ears</spare ends. Now it is OK and the trim has to be adjusted because she is going to much windward's meaning however, is falling because of the v.s. reaction of the steering runner. 15 cm affront and she will be fine. Trim moved because of the sail maker enlarged the ears and curve as you can see. His company >Latsch Speedsails< in Germany can do their job and we are doing experiments and are not ready yet. Peter

09 Feb - 04:54

Janusz Ostrowski

Hej Peter, I'm asking specifically about sail cut effects, because I design CrabClaws for over 12 years now smile and the cut I see here is suitable for different kind of stretches then happens with CrabClaws. Would you notice wrinkles along rear leech we can come back to the subject matter wink

09 Feb - 11:40

Peter Adrian

Hej Janusz, nice getting your questions because it was you and your proa and Marchaj of course who triggered me trying a CCS on an iceboat. Thank´s for this. ..... different kind of stretches then happens with CrabClaws. What do you mean with this? .....wrinkles along the rear leech..... I have no wrinkles at all now since the sail is adjusted on what I call >antenna<, the top spare of a Latin rigged ship. Can you explane your questions further? Would like to learn of your long experience. You may also give me a mail. Welcome. I am just trying to make a movi of the last scence taken on the ice and tried to put one of the test sailings on youtube you may find it soon under Peter

15 Feb - 11:02

Janusz Ostrowski

Peter, please write to me at: .(JavaScript must be enabled to view this email address). The case is worth discussing in such detail which is hardly of interest to regular sailors smile Janusz

15 Feb - 15:50


Janusz, I can forward your email on to Peter. Apparently the system thinks sharing email is forbidden!!!