Sunday, January 28, 2018

Mark Wallace's Black Skiff

If you want to build a classic (Scandinavian roots) oar powered, beautiful boat that is a more challenging build, then Black Skiff may be your ideal. 

Specifications:

  • Length: 14' (4.3 m)
  • Beam: 4' 4" (1320 mm)
  • Water Line Length: 11' (3/4 m)
  • Water Line Width: 33" (838 mm)
  • WLL/WLW Ratio: 4:1
  • Hull  Speed: 4.4 knots, 8.14 kph, 5.1 mph
 “Glued lapstrake ply with sawn frames. Bottom and first strake are sheathed in glass for abrasion resistance. She is strictly for rowing and not suitable for a sailing rig. Medium skill level required to build. Lofting skills needed. (From Mark Wallace’s website)
Plans are free, available here.

Mark Wallace's Black Skiff

...Layout...

...Offsets

Summary-Pros:

  • Will keep you safe in very rough conditions.
  • Easy to row at slower speeds.

Summary-Cons:

  • Limited top speed due to short WLL.
  • High windage would make rowing in a crosswind difficult.




Sunday, January 21, 2018

Skulldugery

"This is a boat that is moved slowly and smoothly through the water towards raft of waterfowl with the hunter lying in prone position in the bottom of the boat. Propulsion is a single oar that extends out through the stern (transom) of the boat and thru a waggling motion the boat moves silently and smoothly forward. When the raft of ducks is closed to a shooting distance, the hunter then sits upright in the boat, ostensibly at this time the ducks take off in flight and with some fine shooting a limit of ducks can be paddled or sculled out to and picked up." (Excerpt from Skulldugery write-up)
Skulldugery in it's Designed Environment and 'Dress'

“Wait…” you’re thinking…  “I thought this blog was about cruising in oar powered boats, not about gunning skiffs.”

It is.

And Skulldugery would make a really nice oar cruiser for protected waters.

Why?

Because it has VERY low windage, easy to row with its V-bottom, roomy enough for comfortable sleeping on the (padded) floorboards, lots of  storage space for supplies, stable enough to stand up.

The modifications I would make in order to provide a sleep-aboard oar cruiser would be:

  • Rather than double layer of 1/4 inch plywood bottom, use just one layer (this MAY decrease the number of sheets of 1/4" plywood needed).
  • Eliminate the cutout in the transom
  • Add a rear deck
  • Move the 6' 3" cockpit opening forward to enable a 2' (610 mm) rear deck  to provide storage.
  • Increase the height of the coaming
  • Provide for a 4 foot span to the oarlocks using one of the designs shown here: 
  • For a shelter from rain/bugs, the ‘PDR Tube Tent’ pictured below would be one solution.


The "PDR Tube Tent"


 Lines of Skulldugery

Construction Detail: Requires 4 Sheets of 6 mm/ ¼ inch plywood

Specifications:

  • Length: 15' 6" (4.7 m)
  • Beam: 38" (965 mm)
  • Water Line Length: 15' 3" (4.65 m)
  • Water Line Width: 26" (671 mm)
  • WLL/WLW Ratio: 6.9:1
  • Hull  Speed: 5.2 knots, 9.6 kph, 6.0 mph

Summary-Pros:

  • High WLL:WLW ratio (6.9:1), V-bottom and very low windage all maker her fast for her length.
  • The very low profile assures she will be little affected by crosswinds.
  • Storage space for supplies in multiple waterproof storage bags under the decks.
  • The added high coaming, splash guard and after-deck provides added protection from boat wakes and storm waves.

Summary-Cons:

  • The foredeck, as designed does not provide enough room for sleeping (thus the recommendation for longer cockpit and/or higher crown to the decks.)
 

Sunday, January 14, 2018

L. Francis Herreshoff 17' Pulling Boat


L. Francis Herreshoff (LFH) 17' Pulling Boat was originally presented in Sensible Cruising Designs by LFH. Later, John Gardner formalized the design in his Building Classic Small Craft, Vol 2.


Lines of the LFH 17' Drawn by John Gardner

Later, Jim Michalak, using Gardner's lines, drew a plywood on frame version. Comparing the set of lines above by Gardner to those of Michalak below, the most noticeable difference is the shape of the sheer line and that in Jim's version both (fore and aft) halves are identical.

Lines of LFH 17' Drawn by Jim Michalak

Stewart River Boatworks sells a slightly modified LFH 17' based on the Gardner version. The modification adds slightly more flair to the topsides at the bow than Gardner's lines call for.

A Finished LFH 17' Offered by Stewart River Boatworks

Chris Jones built the boat pictured below. This was his first boat and he built it based on Gardner's plans and instructions in Building Classic Small Craft.

Chris Jones' LFH 17' He Built

I've read about people who have built the LFH 17' as a skin-on-frame (SOF) using Jim Michalak's plans. However, I could not find any photos nor the articles about them.

Specifications:

  • Length: 17' (5.2 m)
  • Beam: 45" (1134 mm)
  • Water Line Length: 16' 6" (5 m)
  • Water Line Width: 36" (914 mm)
  • WLL/WLW Ratio: 5.5:1
  • Hull  Speed: 5.4 knots, 10 kph, 6.2 mph

Building LFH 17' Skin on Frame:

I bought Jim's plans and made a scale model with 4 modifications:
  1. Built it SOF
  2. Made the bottom panel of plywood rather than SOF
  3. Added 2 bulkheads approximately 7' feet apart for a central cockpit
  4. Added framing for SOF decking at each end and along side of the cockpit opening. 
The photos below show the build process, which is quite straight forward using Jim's plans.


Scale Model of LFH 17' with Plywood Bottom and First Ribands Installed

All Framing Installed, ready for "Skin"

Skin Started...

...and Showing SOF Deck Partially Completed...

...and What Happens When the 'Heat Gun' (for shrinking the skin) Gets Too Close

Summary-Pros:

  •         A tested design originated by one of the premiere boat designers (L. Frances Herreshoff) and  then modified by Jim Michalak for building with modern materials and techniques.
  •         Seaworthy due to flare in hull and added decking.
  •         Low windage means she will not be overly affected by cross-winds.
  •         Decking and flotation as suggested make her safer in most any weather.
  •         Light enough to car-top. Very light if built SOF.
  •         Adequate storage space for supplies. If built SOF, water-proof bags would be needed for perishable supplies.
  • Fast due to high WLL:WLW ratio (5.5:1).

Summary-Cons:

  •         Narrow hull makes her tender and confining.
  •         Flotation would need to be added to make her safe in rough water, regardless of how she was built.

My opinion is that the LFH 17', using Jim's plans, would make an outstanding oar cruiser. She would be light, very sea worthy, fast and very pretty.