Steam whistle repair project
Hello All, I thought I'd post a few pics of my current project. I am in the process of building a new bell to replace a damaged one. I purchased a whistle on Ebay and it had some damage done to the bell at some point in it's lifetime. The pics are of the newly machined pieces that are ready for brazing. The original bell is a single note and the new bell will have three notes (or chimes) in a single bell so I need to form three chambers of differing length within the bell. The rectangular pieces form the dividers between the bell and the pie shaped pieces are the stops that give the three chambers the different lengths which determine the pitch of the chamber. The assembly will be silver brazed in stages. More pics as the project progresses Cheers for now Ken

I've been doing some research into whistles and came accross this website which gives you the basic calculations: http://rjweisen.50megs.com/fluepipe1_001.htm The general point whistle designers keep pointing out is that its the speed of the air moving past the flute which is important and not the pressure they run at. Further investigation into steam whistles shows a general trend of resticting the steam before the slit on the whistle to reduce the pressure and provide the right speed of steam. Steam whistles are also a bit longer than air whistles for the same note due to the higher speed of sound through steam.

I made some more progress on the whistle over the weekend and thought I'd share. This pic show the vane assembly silver brazed with the chamber stops in place and the outer tube with the arches. I have done some clean up after brazing but still need to clean up some more before final brazing. Here is the two parts placed together for a fit up. Some more cleaning up and then off to braze these parts together. It's going to be a challange as it's a big assembly, the joints are all inside and there needs to be a good seal between the chambers. Leaks between chambers will affect the sound. Good steaming! :D