The information Wesley has posted (from this website, I might add) is very correct.
The current calliope aboard the Str. Belle of Louisville features whistles built as replicas of Thomas J. Nichol (the premiere builder of steam calliopes, based on Vine Street in Cincinnati 1890-1935) style of whistle.
What makes the Thomas J. Nichol style markedly different is the use of copper for the "bell" of he whistle. Most other builders used brass for the entire construction. The copper is said to have a "more pleasant" ring to it.
The Str.Delta Queen calliope whistles are Thomas J. Nichol originals. However, they have been gold electroplated to reduce labor of polishing. The calliope I perform on, the Indiana Ujniversity Steam Calliope is one of the "Three Sisters", of which the Str. Delta Queen is also a member.
The "Three Sisters" are 3 virtually identical Thomas J. Nichol calliopes built in the winter of 1923 at Cincinnati, OH. They were the first 32 note Thomas J. Nichol steam calliopes. Each of the "sisters" has a unique "chiff". The Str. Delta Queen's "chiff" is her middle "C", the Indiana University has her's on "D" above middle "C". I do not know where the Str. Avalon (the other of the "Three Sisters")chiff was/is (maybe we can get Capt Gabe on here to tell us?).
The calliope currently on the Str. Belle of Louisville was patterened after measurements taken from the Indiana University Steam Calliope and the Sparks Bros. Circus Steam Calliope (a later built 32 note Thomas J. Nichol original).
David Morecraft, of Peru, IN. and I became friends through the process of getting the sale for the Str. Belle of Louisville and worked together to install the instrument. The whistles were installed on 18/April/1988. We had a great time performing at the "Tall Stacks" festival that year. The new whistles added a pride to my performing, I can assure you!
Over the successive years, I can say this. The instrument has functioned flawlessly. The tone is pure Nichol and cannot be beat!
I worked on Str. Belle of Louisville from 04/81 - 09/95. It was a great pleasure to perform on that calliope. To this day, I remain proud of that instrument and visit her regularly. I know of no serious maintenance has been performed on the whistles since I left the vessel. It is a testament to the builder. They truly are fine work!
I would be glad to answer any other questions you might have about this fine instrument. Please feel free to ask. I guess you can tell I still have a deep respect for not only the instrument...but, the boat as well!
By the way..the "chiff" was thought to have been exorcized out of the Str. Belle of Louisville calliope. However, I can state with authority she has one....it's in the "F#" 1 1/2 octaves above middle "C".