I was not sure about the length of the oars on a cutter I am building so started doing some digging. David Steel gives a little information as follows:
The problem for me is more to do with the length of the boat. Using this formula, a a cutter with a 6 foot beam that is 18 feet long has oars that are longer than the boat. This may very well be correct, but I wondered about variations. I found the following AI response which was more liberal in its findings but was still close.
A precise oar length for 18th-century cutters with specific dimensions (single-banked, 6 feet broad, 18 feet long) isn't directly available in historical records with a definitive, single answer. However, historical sources and general boat design principles offer a way to estimate the appropriate oar length based on the boat's beam and intended use.
One guideline suggests that oar length could be approximated as 2.5 to 3.5 times the boat's beam. Given the cutter's beam of 6 feet, this would mean the oars were likely between 15 feet (6 feet * 2.5) and 21 feet (6 feet * 3.5) long.'
Lastly, I also found the following that may be of help to other members.
Shaw and Tenney Oar Length Formula 1858
Measure the distance between the center of the port and starboard oar sockets, which hold the oar locks on each gunnel. This is called the “span” between the oarlocks. Divide the span by 2, and then add 2 to this number. The result is called the “inboard loom length” of the oar. Multiply the loom length by 25, and then divide that number by 7. The result is the proper oar length in inches. Round up or down to the closest 6” increment.
For a boat with a six foot beam (6/2+2) X 25/7 = 17 feet 10 inches which fit in with the other two sources. The oars I will make for the model will be just short enough to fit in the boat for display, about 17 feet.
Looking at contracts, I found no information on oars but if anyone has more information, it would be very helpul.
Allan
The problem for me is more to do with the length of the boat. Using this formula, a a cutter with a 6 foot beam that is 18 feet long has oars that are longer than the boat. This may very well be correct, but I wondered about variations. I found the following AI response which was more liberal in its findings but was still close.
A precise oar length for 18th-century cutters with specific dimensions (single-banked, 6 feet broad, 18 feet long) isn't directly available in historical records with a definitive, single answer. However, historical sources and general boat design principles offer a way to estimate the appropriate oar length based on the boat's beam and intended use.
One guideline suggests that oar length could be approximated as 2.5 to 3.5 times the boat's beam. Given the cutter's beam of 6 feet, this would mean the oars were likely between 15 feet (6 feet * 2.5) and 21 feet (6 feet * 3.5) long.'
Lastly, I also found the following that may be of help to other members.
Shaw and Tenney Oar Length Formula 1858
Measure the distance between the center of the port and starboard oar sockets, which hold the oar locks on each gunnel. This is called the “span” between the oarlocks. Divide the span by 2, and then add 2 to this number. The result is called the “inboard loom length” of the oar. Multiply the loom length by 25, and then divide that number by 7. The result is the proper oar length in inches. Round up or down to the closest 6” increment.
For a boat with a six foot beam (6/2+2) X 25/7 = 17 feet 10 inches which fit in with the other two sources. The oars I will make for the model will be just short enough to fit in the boat for display, about 17 feet.
Looking at contracts, I found no information on oars but if anyone has more information, it would be very helpul.
Allan
