I've lost one of the oars for my tvåmänning. As the aft pair weren't built for the boat I decided to make two new oars and keep the remaining aft oar as a spare.
First a picture of the boat we're talking about
These oars are very simple and robust and very well suited for rowing in hard wheather. The boat is a Gotlandic 20' double ender with two sets of rowlocks, it's 6,5' wide.
You start of by getting two 12' pieces of 2X4 dimensional lumber, which in my case would be 45X95mm.
The measurements here could hardly be critical, I've made a drawing in imperial dimensions because the tolerances could scaresly be better that the odd inch here and there so no need to talk about half a mm.
Ive managed to find two heavy pieces with straight fibers that run all through the entire piece. All construction lumber here in sweden is spruce.
They smell heavily of resin, enough to make your eyes water when you cut it with the Skil saw, so they ought to hold up for a long time, be very choosy when you pick through the pile!
I've used one of the original oars as a template and just marked of the different measurements, the drawing is a bit tidied up to give you easier numbers to work with.
Then we just start cutting away the bits that aren't part of the oar.
The original oars are 3" wide in the blade, I thought that I should keep the the whole 4" to see of I get some more power from these oars. If not they will be reduced.