16/10/2025
An interesting study in construction detail here,the two Portrush DB21 keels have well cut dovetail sockets in the keels to accept the mainframe heels,their iron strap floors were fastened to the keel with two 5/8" bronze bolts,the steam bent timbers were not fastened to the keel at all,merely sitting into a shallow cutout,I would guess this was just to locate them.The near keel is almost certainly greenheart,I haven't scraped away at the second Portrush keel to determine what timber it is but I suspect it may be oak.
Hollweys of the Liffey did something different,their keel has no dovetail for the mainframe heels,just a bevelled socket with no apparent fastening,iron strap floors again with just a single bolt through the keel,5/8" again i think,however the steamed timbers are fully socketed into the keel and fastened with a single bronze screw.
All three boats sailed successfully for near enough 80 years,whatever your thoughts on the merits of one method over the other this fact might say enough?