Little question about Gaff Rigs Topsail

[srm]

Seems to me a better question would be: What is the purpose of having just one big sail instead of breaking the sail plan up into bits that are easier to handle and serve specific purposes

If you look at cruising boat designs and rigs from the 50's in to the 80's that was the trend. Larger boats, and some smaller ones, often had a ketch or yawl rig, though the yawl gave 'free' extra sail area under some racing rules. The Nantucket Clipper was a nice looking two masted boat, though the hull was basically the same as my old Trintella 29 sloop with a 'beak' added to extend the sail plan. Early fully crewed Whitbread round the world race boats had ketch rigs. Then from around the 80's modern sail handling technology started to develop leading to big sloop rigs on large cruising boats. Looking through a copy of "Bristows Yachts" 1971, listing all the production boats available in the UK then there are a lot with ketch rigs, either as standard or as an option.

 

[srm]

I can't do that nicely/effectively on mine.
The topsail is sheeted to the end of the gaff.

I think the trawlers were able to partly lower the topsail so it would still set as the main was reefed. Pictures of the big racing yachts of the early 20 century seem to indicate lowering the topsail was their first reef.

 

[Chiara’s slave]

I think the trawlers were able to partly lower the topsail so it would still set as the main was reefed. Pictures of the big racing yachts of the early 20 century seem to indicate lowering the topsail was their first reef.

That is certainly the case in my gaff experience. All on early 20th century racers.

 

[srm]

No thread drift intended what came first. Gaff Rig or Gunter Rig as they are both simula.

I am not a historian but would suggest gaff, as a development from square yards swung fore and aft giving a lug sail. Move the sail area and yard aft and you have a more manageable gaff sail. I have seen diagrams of a diagonal deep reef from the jaws of a gaff sail. It looks odd until you imagine the gaff parallel to the mast and the reef along the boom giving a triangular sail. Basically a gunter rig. For small boats the gunter allows short spars that can be stowed inboard so may well have had a role in rowing/sailing workboats long before the Drascombe range adopted the rig.

As steam slowly took over the fishing industry a number of the Scottish east coast sailling drifters were sold to Shetland. These boats had big dipping lugs as they sailed out on one tack and back on the other, in theory anyhow. A significant number were lost as their predominantly agricultural crew, employed to work the nets, could not quickly dip the lug and tack it so they tried to get back in to harbour with the sail backed against the mast in a rising wind and often failed, running aground. Once these luggers had Shetland owners they were invariably converted to a 'smack' rig with gaff on the main and possibly a standing lug on mizzen as the islands and coastline was such that tacking was frequent, and missed stays could quickly become fatal in the sounds.

The Swan was built in Lerwick with an east coast Fifie hull and and lug rig. However she was soon given a Shetland 'smack' rig.
She has been restored, the web site is worth a look, but better still get to sail on her:
The Swan Trust - Classic Sailing on a Traditional Shetland Sail Boat