The ironwork in the composite construction was such that some of the older yards could reasonably tackle it. The only flat plates of any size or awkward shape were the floor plates. The angle irons were bent and bevelled to shape without the necessity of any heavy machinery, and the tie plates, sheerstrakes etc. could be fitted almost as supplied by the iron foundry, leaving only the floor plates with shaped contours to present any difficulty, especially if the edges were curved convex or concave. One way this was done in a poorly equipped yard was to punch or drill a series of overlapping holes to perforate the edge almost like a postage stamp.

The pink bottoms, also popular and quite successful, were simple mixes basically of tallow and red lead. Pale green bottoms were copper arsenate based paints, which on models are not to be confused with the green colour modelmakers used to imitate copper sheathing.

While iron ships were inexorably superseding wooden ones, and supplies ofgood timber were becoming more difficult to obtain, there appeared on the scene a compromise which for a brief period was to produce the finest tea clippers ever built. These were the composite ships, which had a basic skeleton of iron covered by a wooden skin. Many combinations of iron with wood skin structure had been tried in the early part of the 19th century; also iron beam knees, then iron beams, and next iron beams and iron upper frames, but all with wooden skins which could also take the copper sheathing so much in favour for speed.

It was this latter fact which provided some shipowners with an excuse not to go all out for an iron hull, which of course could not take copper sheathing. Speed of building and cost also often influenced the decision. Those shipbuilders whose yards could not be economically converted to build complete iron hulls for the reasons mentioned earlier were also glad to take up the challenge.

Among the many ingenious ways of planking externally over an iron framework, that ofa MrJordan of Liverpool, invented in 1849, was the best, and with minor changes was the system used for the majority of the more famous tea clippers up to the end of this era in Britain {America never went in for composite building).

The drawing of composite construction shows the final development of this system {24). A number of schooners, barques and ships were built in Liverpool in this manner in the decade following the invention, and the first tea clipper to be built under the same patent was the Taeping by Robert Steele on the Clyde in 1863.

Another system closely following normal wooden construction was MacLaine's, whereby angle iron frames had a complete iron-plated skin on the inner sides like an iron hull turned inside out. Between these exposed frames, which were spaced in pairs, additional wooden frames were bolted, to which a longitudinally planked wooden skin was bolted. This was a wasteful arrangement which did not survive very long.

The only other system which could compete with Jordan's was that introduced by Thomas Bilbe on the Thames in 1856. Iron channel bar frames were used with the two flanges pointing outboard. The bosoms of these channels were filled with wooden chocks or frames, usually teak, standing proud of the flanges and on which the external planking was bolted. The bolts passed through the webs of the frames, through enlarged holes so as not to touch the frame, and the inner end of each bolt was then tightened up on the inner wooden ceiling. Two tea clippers built by Bilbe in this fashion were the Red Riding Hood {1857) and the Lauderdale {1858), the latter having the diagonal system of external planking also.

In all these systems the keel, stem, sternpost, and usually the waterways were of wood, with the side framing, floors, keelsons, stringers, sheerstrake, deck beams, diagonal straps and deck tie plates of iron. The greatest problem was to avoid contact between the copper sheathing and any ferrous metal where salt water could touch both and set up an electrolytic action. For this reason Lloyd's suggested that the bolt fastenings of the external planking be made of yellow metal or copper. If of iron, preferably galvanized, the external heads had to be sunk below the face of the planks and covered with a wooden dowel or cement mix and in addition covered with a minimum of 1.25 in. of wood sheathing on top of hair felt. These latter measures could considerably alter the lines of the hull and the displacement. Internally, with the Jordan system, the bolts were tightened up directly on the iron frames, but if of copper or yellow metal they were insulated to some extent by a coating of guttaperch a or red oxide paint. Despite the fact that bilge or condensed water could make contact with these fastenings, they seem to have successfully stood the test, as those on the existing Cutty Sark bear testimony.