- The background to the tea trade
- Chinese silver
- Treaty of Nanking
- British-built clippers
- Ocean Steam Ship Company
- The homeward passage
- Development of the ships
- The way of a ship
- A comparison of hull forms
- Development of the clipper bow
- Development of the upper stern
- Headworks and upper stem
- Disadvantage of Aberdeen clippers
- Comparison of sizes
- Hull Construction
- Construction of iron hull
- Composite construction
- Proposed tea clipper
- Ornamental deckwork
- Ornamental deckwork
- Miscellaneous fittings
- Full deck height poop
- Sail plans
- Details of tops
- Masts and spars
- Iron yards
- Steering Gear Arrangements
- Windlass and Forecastle Arrangement
- Fife Rails and Bitts
Masts and spars
Wherever possible wooden lower masts were made from a single tree which was first squared down to the maximum square possible and then into the round, leaving only the head and possibly the heel square. The mizzen mast, being relatively small, was usually a single tree. Its smooth surface was also convenient for the hoops of the spanker sail to ride up and down on, as also the gaff jaws if so rigged.
If the fore and main masts could not be taken out of a single tree, owing to their size, it was necessary to build up each mast to its required diameter by joining or splicing a number of smaller timbers longitudinally. The minimum number was known as a five-piece mast, which meant that a central spindle was made out of one piece in a square taper extending for part of the upper length, and then each face built up with separate lengths, rounded on their outer surface and long enough to make up the full required length, as shown.
The central spindle extended above the level of the trestle trees to form the masthead, with two of the side pieces reduced in size to strengthen it. To provide rigidity to the whole mast it was necessary to prevent the longitudinal abutting surfaces from sliding against each other, which would happen if the whole mast was allowed to bend. To stop this, each of these surfaces was carved out (tabled) in alternating raised lips and sunken mortices (coaks) which interlocked when bound tightly together.
The binding was done by iron hoops put on hot while they were in an expanded condition, shrinking tight when cooled. A very large mast could be made up by this process, using as many as fourteen pieces for the whole. In the five-piece mast the side pieces were known as 'side trees' and the fore and aft pieces respectively as 'fore side fish' and 'after side fish.
British ships' masts made this way, with five or more pieces, had the appearance of a plain round mast hooped at regular intervals, the hoops usually distinctively painted black or white (yellow in the Royal Navy after Trafalgar). Many of the American masts elaborated the process by not making up a full circular section. Instead the edges of the outer pieces were chamfered off, leaving four vee-shaped grooves running up the mast, and in order to make a solid bed on which to tighten up the iron bands a small wedge piece was fitted in each groove under the band. The ends of these wedge pieces were sloped to prevent water lodging against them. The idea of the grooves was to eliminate feather edges on the side timbers and allow air circulation nearer the heart of the mast, thus reducing the possibility of rot, which is alwa ys a danger when timbers are buried inside other timbers.
These grooved masts looked quite handsome, especially when the grooves were picked out in a different colour, say black or white, or sometimes red. Some of the masts on the steamship Great Britain were made in this manner, and possibly on some sailing vessels too, but usually it was an American characteristic.
If spencers or trysails (the small fore and aft sails with gaff, on the fore or main masts) were fitted on large hooped masts, the mast would be too large to conveniently take the gaff jaws or the hoops on the luff of the sail, so a much smaller mast was stepped close to the larger with its head let into a chock between the trestle trees and its foot stepped in a socket on deck or to a mast band with an eye or socket a foot or so above the deck. This small diameter mast took the gaff jaws and also the wooden hoops seized to the sail. If the mizzenmast was considered too large it also would have a try sail mast, which served the same purpose as the extra mast which distinguishes a small craft called a snow. A vertical iron rod jackstay bolted to the aft side of the mast with a gooseneck fitting on a band for a hooked iron on the end of the gaff, served the same purpose as the trysail mast and by mid-century seems to have been fairly common on wooden masts and was carried on in the same fashion for iron masts. The gaff of course was the non-lowering type, and the head of the trysail ran on hoops along it with an outhaul and inhaul, the body of the sail being brailed from blocks attached to the jackstay or mast.
Iron masts were built intermittently from early in the century, especially for steamships, but it was in the 186os, with the composite clippers, when they became the general rule, at first for lower masts only and then for topmasts as well. The lower yards and bowsprit were also of iron, and the lower topsail yards, if large enough. The extra strength of iron masts coupled with the more rigid iron wire rigging encouraged a greater spread to the courses which was apparent in the later clippers.
Iron masts, however, had their problems too, and many collapsed, chiefly due to localized bad riveting and insufficient internal stiffening. The restricted space inside the masts made it difficult for rivets to be held up efficiently while being hammered on the outside, and if a small man or boy could not do it, a long rod was used as a lever to hold up a heavy iron dolly like along mallet fitting against the rivet head, which was inserted from the inside.
I recall an incident during the reconstruction of the Cutty Sark involving one of these dollies, with near-fatal results. One of the ship's masts, which had been a replacement after a dismasting, was found to be some feet too short, and in consequence I suggested adding the requisite length to the heel, thus avoiding altering the top and its cheek plates. This meant raising the mast by chain hoists inside the hold, seized around a heavy iron bar which passed through two holes burned out of the mast. The mast had a full-Iength vertical diaphragm plate as a stiffener, and a manhole was cut into the mast near the holes so that the diaphragm could be penetrated also. After the strain had been taken on the hoists, a shipwright put his head into the manhole to see if all was correct and as he withdrew it, a loud clatter was heard as a heavy iron dolly came hurtling downwards and bounced upwards again from the keel.