I have been studying photos of a number of British six drivered tank steam locomotives, and note that they have connecting rods, but no steam chests or main rods. How do these locomotives actually work?
The cylinders are inside, with the main rods connected to the cranks on one of the the axles (something like a crankshaft in a car). Three and four cylinder steam engines have two outside cylinders, such as you are familiar with and a similar setup for the inside cylinder(s).
John
With the last of the 9F Decapod 92220 Evening Star having been delivered in 1960 British Rail decided to abandon steam as quick as possible or impossible - no matter what ever!
So, scrapping sometimes tended to be quicker than service and thus it happened that certain engines still needed had to be retrieved - if possible - from the torch already starting to take it’s bite.
As long as the boiler had not been touched, some engines were put back to work without con rods and even without cylinders. Of course such engines could only do light secondary work, such as picking up parcels and goods carriages or - as it was often called in - minerals. Probably this was essential as I would imagine these poor hard bitten engines suffered severely from lacking minerals.
To Juniatha: Well done, M’Lady! I got a good laugh out of this one, and after the week I had I sure needed one! Look, my stomach’s settling down, I’m regular again, ahh, life is good!
The book “How Steam Locomotives Really Work” by Semmens & Goldfinch, Oxford University Press, may be of some help to you. It’s mostly about Euro locos. I’ll sell my copy if anyone is interested.