Branch falling off old apple tree

Its always sad when apple trees shed branches. Our old apple trees were planted for the War Effort apparently, so nowhere near as old as yours. They used to lean over regularly and we would brace them with a notched length of timber - to make a sort of tripod. Some of the heavily laden branches here are supported in the same way - its the only way I can walk beneath them!
Hope you can find a way to save yours.