A 17-foot Seabright skiff

Happy clam is the latest of over 65 boats having this unusual hull form that have come from the Atkins family during the past 25 years.

They have varied in size from the 17 footer shown here to a 305 foot shallow-draft tanker developed during the past war.

Each has proven seaworthy and successful in attaining high speed with low power.

Among the inherent advantages of this hull form are its shallow draft, great stability, and low center of gravity.

Full protection for the propeller is provided by the box keel.

Flow of unbroken water to the propeller is made possible by tapering the keel to the propeller post.

The relatively wide, flat keel maintains the boat in a level position when beached or trailer borne.

The nearly level shaft angle, which is of value in performance, is not possible to achieve in any other hull form.

Edgar Davis of Whitemarsh, Pa., commissioned us to design and build the original Happy Clam.

An accounting of material costs and time involved was kept and accurate speed and performance trials were made with the completed boat.

All of this, I am sure, will be of interest and value to prospective builders and owners of Happy Clam.

The principal dimensions of this little hooker are 17 feet over all, 16 feet on her designed water line, 5 feet 6 inches wide, and 11 ½ inches draft.

Her ample freeboard of 28 ½ inches forward and 19 5/8 inches at her stern assist in making her a dry boat.

Her speed came up to full expectations.

She was accurately clocked over the official measured mile off Lloyd’s Neck in Long Island.

Sound, making 14.8 mph with a Palmer 5-hp.

Baby Husky marine engine turning 2,250 rpm.

The Columbian type E two-bladed propeller is 10 inch in diameter and has a 6 inch pitch.

Happy Clam was built right side up and I suggest future models should be built in the same position.

Her 1 ½ inch keel, cut to the widths shown at the stations on the full-sized lines, should be laid on suitable building stocks with the amount of drag that’s indicated on the lines drawing.

Build her at least 18 inches above the floor as there is considerable fitting to do in het bottom planking and the room will come in handy.

Apron pieces of ¾ x 2 ½ inch stock are screw-fastened to the top of the flat keel.

The bevels of the rabbet formed by apron and keel must be taken from the full-size body plan.

The aprons are in single lengths.

Mark the 16 inch frame spacing accurately on the flat keel.

Affix the frame gussets and floor timbres to the forward sides of the frames forward of station 6 and to the after sides of the frames aft of station 6.

In the process of making up the ¾ x 1 5/8 inch frames, take all dimensions from the full-size body plan.

Assemble them with glue and screws.

Notch out the 1 1/8 x 3 ½ inch floor timbres to fit over the apron pieces.

Drive screws up through the keel into these floors.

A stretcher of ¾ x 3 inch scrap wood must be screw-fastened to the heads of each frame at the sheer line.

Pick up the water line, the sheer line, and the center line from the body plan and transfer these accurately to each finished frame.

The stem is made in two pieces and shaped as shown in the lines and construction drawings.

Bolt the pieces together.

A template must be taken from the lines to locate the proper positioning of the rabbet, back rabbet, and bearding lines.

When these are transferred to the actual stem, the work of cutting the rabbet may proceed.

Further details on this phase of construction can be found in any book on the subject.

Secure the completed stem to the keel with four bolts.

See that the stem is plumb and brace it in a secure fashion to overhead members in the building shed.

A great amount of strain is to put upon the stem, frames, and transom when bending the planking and other members into place, so care in bracing the framework must be taken.

The propeller post and horn timber come next.

Bore a hole 1 inch in diameter through the propeller post to take the ¾ inch shaft.

The after face of the post is square with the shaft center line, so the work can be placed on a drill press and accomplished with little difficulty.

Use a bare-foot auger rather than a earpenter’s bit the latter has a strong tendency to follow the grain in the wood rather that to bore a straight, square hole.

Secure the horn timber to the propeller post with drift bolts and screws.

Cut a rabbet in the horn timber to take the bottom planking of the box deadwood.

Particular care must be given this part of the work.

Fasten the propeller post and horn timber to the keel as shown in fig. 1.

The 7/8 inch transom is built over a ¾ x 3 ½ inch frame.

Secure the transom to the frame with 1 ½ inch no.10 screws.

Make the stern knee, which is shown in fig. 1, from a ¾ inch natural crook if available.

There may be some difficulty in securing natural crooks for this member and the breast hook and quarter knees.

I visited local apple orchards for the ones in Happy Clam and the time spent proved well worthwhile.

Practical substitutes for natural crooks are laminated oak knees of the same size and shape.

Several laminations of 3/8 x ¾ inch wood can be bent to shape and tied together with waterproof glue.

Secure the stern knee to the transom framing and horn timber with bolts and screws.

At this point, the completed frame should be faired up, checking with long battens tacked temporarily to the stem, frames, and transom.

Any irregular hollows or hard spots must be built up of planed down to assure the planking being smooth.

When this work has been completed, brace each frame to overhead members.

Each 1 ½ x 1 ¾ inch chine log is in a single length.

Cut the proper bevels on each, the place it on a table saw, as shown in fig. 2, and cut the rabbet depth by slowly turning the chine as it passes over the saw so the cut is kept square with beveled surface.

The balance of each rabbet is cut with a chisel and a rabbet plane.

Since the forward end of the chine’s take a considerable twist, they’ll require steaming.

Inwales, or sheer clamps, of 5/8 x 2 inch material, are fitted at the frame heads.

As shown in the construction section, the frames must be notched out to take these.

Because of the amount of sheer and the coming together of the sides at the stem, it is necessary to saw these inwales to shape prior to fitting them.

A template is taken from the boat and the required shape determined from this.

It is not possible to bend in these sheer clamps from straight stock.

After installing the inwales, add the breasthook and quarter knees, Happy Clam’s topsides are planked with ½ inch white cedar in lapstrake fashion.

This manner of planking, reminiscent of the New Jersey Seabright skiffs, is stronger than controversial smooth planking and is easier for amateurs to apply.

The lapped surfaces may vary as much as an eighth of an inch with no one being the wiser, while a smooth planked boat must have carefully made, evenly spaced, properly outgaged seams.

The 5/8 inch bottom planking is smooth.

Intermediate 5/8 x 1 ½ inch frames extend from the apron to the chines.

The run of planking on the bottom of Happy Clam is a little out of the ordinary.

In addition to the regular boards, stealer planks must be installed.

The garboards and the planks just outboard of them are cut and crewed to the frames in the convetional manner.
These run from the rabbet in the stem to the rabbet in the propeller post.
The stealer planks, fitted against the horn timber and alongside the top of the box deadwood, go in next.
Each is about 2in. wide at its forward end and fitted with a butt block.

While this part of the work is difficult to describe, fig 3 illustrates the stealer planks and you will find the work quite clear on the actual hull.

Once the stealers are properly fitted, the rest of the bottom planking will go on as easy as in any V-bottom form.

Calk the seams in the bottom planking by rolling in a strand or two of cotton wicking, using a regular calking wheel.

Pay the seems with thinned-out white lead and then putty them with Kuhl’s flexible seam compound.

Nicely shaped 1 x 1 ½ inch guards will prevent the boat from becoming damaged as she lies in a slip.

These must be steam-bent around the forward part of the boat.

Screw them to the frame heads and drive 2 inch no 10 screws through the sheer clamps and planking into the guards.

Slightly round off the heads pf the frames.

Her rudder is hung on the transom.

A galvanized shoe projects from the underside of the box deadwood to take the heel fitting of the rudder.

Standard rudder hangers are installed on the transom and n the rudder.

A 3/8 inch bronze rod runs between these.

A long tiller provides a simple, inexpensive, and completely practical manner of steering the little boat.

The engine floor timbres are heavier than the ones secured to the frames, being 1 ½ x 6 inch material.

The fore-and-aft beds are 2 ½ x 3 inch stock lying on the flat.

A copper gasoline tank is installed under the bow seat.

It may be necessary, because of the forthcoming difficulty of securing copper, to substitute galvanizes iron.

Details of the tubing and various fittings for the gasoline and the sea-water lines are shown in fig 4.

A ¾ x 1 ¼ inch seat riser is screwed to the insides of the frames on each side from station 2 to station 11. The three ¾ x 10 inch thwarts are fastened to the risers.

Secure the floor boards to floor beams set 6 inch above the keel.

The beams are ¾ x 1 ½ inch and the floorboards are 5/8 inch stock about 4 inch wide.

A small hatch immediately forward of the engine allows convenient use of a rope starter.