how did they hollow a stay mast

[Magenta]

Topmast x2 Hollow Sitka Spruce
Gafff: Hollow Sitka Spruce
Jack Yard: Hollow Sitka Spruce
Club yard: Hollow Sitka Spruce
Spinnaker pole: Hollow Sitka Spruce

https://www.boats.com/sailing-boats/1911-william-fife-125-classic-sloop-5678264/

[Chris249]

Well trained termites.

[John B]

Drill bit.

[Chris mcm]

Check out this 1918 Patent # https://patents.google.com/patent/US1314007A/en
McGruer made spars for yachts and aircraft. I investigated this when double planking a hull from 1/4 +NZ Kauri planking. The idea was to save backing out the carvel planks. I tried to steam the compound curve but failed. I am sure it is possible. Maybe using a different species of timber. I read somewhere W/B ? Rowing skiffs are made from 1/4 sawn ceder steam bent. Each side in one piece. I am sure Herreshoff Manufacturing Co used steam to shape at least the inside planks of their light hulls. I will never build a boat that way again. Your note reminded me of the research I did at the time. Pleased to share it.
Chris McMullen Auckland NZ

[HCR]

As early as 1891 for the famous Gloriana the Herreshoffs built hollow spars for clients who desired this. Gloriana's spars (all except her solid mast) were specified as "hollow" or "hollowed out" and the drawings suggest that a solid spar was lengthwise cut into two halves which were then hollowed out. Gloriana's owner specifically ordered these spars to be doweled and then glued together with pot cheese (i.e. casein) and lime --- an old and tried glue for woodwork. These early hollow spars may have been experimental, for the plans also show extra and spare spars which were solid.

In later years N. G. Herreshoff tested different glues to destruction and carefully noted the glue recipes and the loads at which the samples broke. In 1903 he wrote that glues had improved and they were able to build stronger and lighter and nearly as stiff spars as ones made of steel for large racers but complained that they were not as durable, as the glue often failed or a check in the wood developed.

Most or all of the company's later America's Cup boats and other important large racing yachts had hollow spars, often of rectangular section with rounded corners, the sides then glued back together. Round spars were usually glued together of eight staves (not birds mouth). Usually these were tapered spars made in tapered moulds.

Plans show strategically placed vertical grain bulkheads for strengthening inside the spars. These were bored with holes to provide for ventilation inside the mast.

There is no evidence to suggest that the Herreshoffs ever bored out spars to hollow them. There is correspondence from 1896 by a friend of NGH describing to him a method to do so, but it is not known if the recommendation was ever taken up or even taken seriously.

By 1905 (and possibly earlier) the Herreshoff Manufacturing Company employed a large molding machine for its hollow spar work.

Hollow spars were not uncommon by the early 1900s as is suggested by a price list printed in 1907 by the Pigeon-Fraser Hollow Spar Co. of East Boston for all sizes of hollows spars measuring from 16ft to 85ft long.

[John Meachen]

Gouges,templates and hollowing planes before the advent of large stationary moulding machines.

[Woxbox]

Going back to the early 17th century, possibly earlier, ship masts were made up of staves and were hollow. The staves were held together with heavy line known as woolding. Easier to source the wood this way, plus if struck by a cannon ball there was at least a chance one stave would splinter and leave the rest standing. Wood hoops top and bottom protect the woolding from chafe. Shown here on the Kalmar Nyckel.

[Canoeyawl]

I have mades several masts hollow by sawing them lengthwise after shaping and hollowing them out with a combination of tools. A small circular saw set to specific depths then finishing with big heavy gouges worked pretty well. This had the advantage of leaving material nicely tapered in at the partner and down to the step. Then again at the hounds, gaff , its associated blocks, spreaders and the truck