Sunday, August 20, 2017

Selway-Fisher's Windrush

Selway-Fisher's Windrush is a long narrow lightweight rowing boat that would make a beautiful oar cruiser. 

Specifications:

  • LOA.......................................................18' (5.49 m)
  • WLL.......................................................16' 6" (5 m)
  • Beam......................................................2'9" 0.85 m)
  • WLW......................................................30" (762 mm)
  • WLL/WLW Ratio...................................7.2:1
  • Hull Speed..............................................5.4 knots, 10.0 kph, 6.2 mph
  • Hull Mid Depth.....................................13" (0.32 m)
  • Draft.......................................................4" (0.1 m)
  • Approx. Dry Weight...............................66 lbs (30 kg)
  • Hull Shape..............................................4 planks per side with wine-glass transom
  • Construction Method..............................Stitch and tape
  • Major plywood requirements for hull.....6 x 4, 5 or 6 mm exterior or marine plywood
  • Guidance Use..........................................3 adults or single use
  • Drawing/Design Package........................4 x A1 drawings + 5 a A4 instruction sheets

Selway-Fisher Commentary:

"This skiff has been drawn up for a client who specifically wanted to develop a design optimised for the "Frontrower" rowing system which allows the rower to face forward. For those who do not want to use this system we have included details for the skiff to be fitted out with conventional fixed seat and outriggers—she could also take a sliding seat if required. 
Construction is simple stitch and tape using 4 planks per side but we also include the jig and mould details so that she may be built using clinker ply construction."
 
Windrush...

...under construction...

...clam's eye view.

For oar cruising, including sleeping onboard, the following would need to be done:
  • Provide floorboards that span the (slight) V-bottom.
  • Provide shelter for sleeping, cooking, etc.
  • Provide fore and aft, and possibly side, decks which could be skin-on-frame to minimize weight.

Summary-Pros:

  • Windrush's almost round, narrow, V-bottom minimizes skin-friction leading to her being one of the fastest Oar Cruisers.
  • A cruising speed of 4.5 mph (7.2 kph) for ten 45" sessions per day results in 34 miles (54 km) a day cruising.
  • Addition of decks, coaming and water-proof compartments make her more seaworthy.
  • Relatively low windage reduces impact of cross-winds.
  • Sufficient storage for extended cruises.
  • Boats this long can be car-topped by one person.

Summary-Cons:

  • The narrow hull makes Windrush tender. Consequently, interior space is limited as well as the ability to move around in the cockpit.

Windrush, with minor additions, would be a beautiful, fast oar cruiser... and without these additions, a beautiful fast day boat for one rower and one or two passengers... or for two rowers (and a passenger). 

Sunday, August 13, 2017

Jim Michalak's Oracle

Jim's Oracle is similar to Jim's most popular design, Toto.

Max Wawrazyniak's Oracle

Plans Overview...

...and an End View


Specifications:

  • Length: 15' 6" (4.7 m)
  • Beam: 45" (1143 mm)
  • Water Line Length: 13' 10" (4.2 m)
  • Water Line Width: 37" (944 mm)
  • Weight: 80 pounds (36 kg)
  • WLL/WLW Ratio: 4.5:1
  • Hull  Speed: 5.0 knots, 9.3 kph, 5.8 mph

Jim, using a GPS found the speed to be 4 mph (6.4 kph) at a 'cruising pace', and 5+ mph (8+ kph) when he pushed hard.

Max Wawrzyniak published an article in Duckworks focused on building Oracle.

Max's Oracle under Construction

Gerry L. also has an Oracle build documented on his site.

Jim has a good article (Rowboat Setup) on setting up the seat and oarlocks to get the correct trim on an Oracle or any other rowboat.

Steve Chamber's Oracle

Oracle would make a fine oar cruiser without affecting the hull design which has proven to be very effective. Possible modifications to create a 'sleep-aboard' oar cruiser include:
  • Fore and aft decks made either with plywood or skin-on-frame
  • Floorboards to provide dry sleeping platform and attachment points for rowing seat and foot braces
  • Temporary shelter.

Summary-Pros:

  •         Oracle is easy to build, based on the very popular Toto design of Jim's.
  •         Large enough to move around in and to carry all the equipment/supplies you'll need.
  •        With the changes noted above, able to deal with any reasonable weather conditions likely to be met.

 

Summary-Cons:

  •         Her wider beam slows her speed slightly compared to that of Larsboat.


Oracle, another great design by Jim Michalak: easy to build, good looking, fast.