Thank you for your comments and for the opportunity for me to expand on the decision I made for the iron strapping.
While it is true that the method of iron strapping used on Young America, built in 1852-53, is uncertain, it is by no means cclear that outside strapping was widely used at the time or that internal strapping was rare. It is true that outside strapping appears to have become more prevalent after the 1850’s. Space did not permit a full discussion of the history of iron strapping, nor was in-depth construction history the primary purpose of the book. I did discuss the decision to use internal strapping in Chapter 8 of the book and quote the relevant passage:
“A lattice of diagonal iron bands came into use in the early 19th century to help stiffen wooden hulls against hogging strains. Young America had such banding. The bands were normally about 4" wide by ¾" thick, spaced on a grid about four feet apart. The lattice extended over most of the hull length between the floor heads and the main deck clamps. The bands were set into scores cut into each frame to provide a flush surface for planking. They were bolted through every frame and where they overlapped. This configuration was documented for Challenge, a similar clipper launched by Webb two years earlier. However, it is not known whether the ironwork on either of these ships was installed inside or outside of the frames. Both methods were in use, with outside installation becoming more common in later years. Although it offered some technical advantage, outside strapping was much more difficult and time consuming to install. After reviewing available information and considering the urgencies of the times on construction schedules, I decided to adopt the internal installation for the model.”
A more thorough discussion of the topic was included by Bill Crothers in his book The American-built Clipper Ship pp 195-196. I believe he summarized the issue quite well – and the uncertainty. As with many of the undocumented details of the model, choices have had to be made – or there would be no model. After reviewing available information on the subject this appeared to indeed be a toss-up issue. I was influenced in my decision by the following factors:
- The internal or “Admiralty” system, developed for use by the Royal Navy was prevalent during the first half of the 19th Century.
- Webb was the first American builder to adopt iron strapping on Challenge in 1851.
- Webb used internal iron strapping on Ocean Monarch in 1856 as referenced by Crothers based on Webb’s published Plans of Wooden Vessels.
- American Lloyds’ Registry of American and Foreign Shipping, 1859 includes the following passage under Rules for Inspection and Classification: “Ships exceeding four times their breadth in length, should be cross(X) iron strapped diagonally on the inside – outside strapping leakage through the seams of outside plank will corrode and destroy the iron. The bolts through the straps either from out or inside should go through and clinch.”
- Speed of construction was a primary driver in the hectic extreme clipper rage of the early 1850’s – driven by the demands of the California gold rush market. Outside strapping was much more time consuming to install, especially in the days before pneumatic drills, chisels and hammers. While not a primary argument for internal installation, it was a factor considered.
On balance, while not being clear cut, I believe the decision to use internal strapping on the model was reasonable and should be considered a more likely actual scenario than a one-off rarity.