Originally just plain straight rods oars eventually developed to have paddle ends known as blades. These blades improved the oars ability to grip in the water reducing the length required and making them easier to manage. The design of the blade has been the most obvious development in oar design but all aspects of the oar have developed enormously over the last few decades.
Oars can be broken down into their component parts. Blade, Shaft and handle.
Wooden construction – Shaft – Originally a solid length of wood by the 1940s hollow wooden shafts had been developed to reduce weight and improve flexibility. The shaft was made by cutting a deep channel in the wood and then inserting and gluing in place a flat insert. This produced the same solid looking shaft but this now had a hollow core.
The blade was initially a flat straight piece of wood. Eventually a slight curve was put onto the blade so that it locked into the water better and was also easier to extract at the end of each stroke. Changes in blade design have let to asymetric big blades, hatchets, Sharpies and apex spoons, each designed to be the most efficient method of propelling a boat in given conditions. Contrary to popular opinion the oars does not move in the water but merely acts as a fulcrum or pivot point to lever the rowing boat past.
The handle again was originally wood. In an effort to balance the weight of the longer outboard end of the oar wooden handles have continued to be used even in high performance modern rowing circles. In most cases though they have been replaced by carbon fiber handles with rubber grips.
Fibre Glass and Carbon Fiber – Modern composite materials have revolutionised oar design. Modern designs for blades plus more rigid shafts have seen improvements in efficiency of oars. At the forefront of this revolution was the European manufacturer Braca also using the technology for kayak and canoe paddles. Modern oars have adjustable handles to change the overall length plus the inboard and outboard from the oarlock can be adjusted for optimum performance. Shafts in various degrees of stiffness to suit different boat types and athletes are also available providing once unheard of performance for racing boats. The greatly reduced weight afforded by modern materials has made recreational rowing and sculling more affordable and enjoyable. Oars now last longer, are lighter and more affordable thanks to the advancements in material science.
Glossery of terms –
Oar – Used by crews in rowing boats, one person, one oar
Sculls – Used by individuals in sculling rowing boats, one person, two sculls.
Blade – The end of the oar that grips in the water
Oarlock – The holder for the oar on the side of the boat
Outboard – The portion of the oar outside of the oarlock
Inbiard – The portion of the oar inside the oarlock
Gearing – The ratio between a number of points on the oar and boat including inboard, outboard and span.
Span – in a sculling boat the distance between the oarlocks
Pitch – The angle on the blades. Pitch helps the rower maintain the oar at the correct depth in the water.