we al should never forget, that Germany, as many other countries in europe had an other focus on steam engines. Also, I would remember to the fact, that steam locomotive development after WW2 was on a dying branch. The rise of Diesel and electric traction made further development obsolet in the eyes of many person in responsibility.
We can remember, that bevor WW2 enough facts about the draught systems of Kylchap and Lemaître, same with Giesl have existed, as well as with water tubes and combustion chamber expansions or limitations. Also iron casting was highly developed, that main frames on weldet or riveted basis would not allways represent the state of technology. Also roller bearings and further feedwater development was still very good understood...
If we look in the development of steam locomotives after WW2 and their improvements, based on this know improvments, we will find, that with the exception of full welded boilers with combustion chambers nothing really was spread on a large scale basis. New build locomotives lack all those improvements, thus being often in power and efficiency compareable to the former locomotives - mostly as a consequence of the regulatories within the board of engineering in the federal railways of germany.
Thus, I am museal club railroader and often we struggle with those misconceptions done in the past, and now lead to some difficulties - difficulties also very viewable in service in the past, but: As more and more engines got replaced with Diesels and Electro locomotives, these things didn't count anymore.
I do not only act as fireman, we also serve in the shop.We do most maintainance at ourselfes, also many of the main repairs. So we have a gret insight into the technology and the "how to's" of the steam engines - and I personally watch over the borders.
I am a fan of the 4-8-4 US Steam locomotives, like the UP844 or the so called Niagara locomotives of the New York railroads... I am so interested in technical details, but usually: It seems, there is nothing!
We in Germany got loads on this, like material descriptions, boiler describtions, maintainace rules and repair guidelines. We use this for doing the maintainace and repairs, thus we depend on those drawings, descriptions and measurements. So we understand in the work in the shop, how the parts work and work together. For example how the steam pump for feedwater works, or how an injector is maintained and why.
So when I visit another steam railroad... I try allways to increase and exchange knowledge. Increase my own and learn from the others. So the Riggenbach counter pressure brake, as translated word by word from german name, I first encountered in Austria - on the famous cog railroad from Jenbach to Achensee. On the 160‰ ramp up to Achensee the engine goes at maxium power output.... but downhill, I watched engineer and fireman enjoying the sunny day, because the Riggenbach brake was in operation, so both had the time to watch and to chat, while only certain views on pressure gauges and temperature controls were need. It was amazing, that the brake itself was able to hold the train down, without any additional brake, and taking advantage of the same structures as on the climb. Thus there was no additiona wear, no additional duty, nor was there any additional work to do... simply, set the brake in operation, adjust it and let the machine do the rest... Only on the stops, they need to increase the brake force to slow down, and in the moment of very, very slow to turn the spindle of the handbrake to hold the train astop!
On restart, they simply turned the spindle, open in this way the hand brake and let the engine start to roll. On the desired downhill speed they adjusted the Riggenbach brake and again: It did the job on it's own.
The piston the rods and the cogwheel did the same job... now not driven by steam force - now driven by gravity and retarded by aspiring and compressing air in the cylinder.
If you want to see and hear, watch my you tube Video on:
The second time I was in Austria, I visit the cograilway to Schafberg - which starts on St. Wolfgang at lake wolfgang. The 1992 by the swiss DLM AG biuld steam engines do a great job on the railway and push nearly three times the load on double speed as the old steam engines. Downhill again, the engineer only controls the speed by adjusting the compressed air pressure and the ride is smooth and relaxed. Also here:
For a stop, the engineer increases the retard of the Riggenbachbrake to maximum, the engine get nearly so slow that it's standing still, in this moment the hand brake is tied up by a spindle and the engine is hold with the train astop... Start: Open the handbrake, let the engine get rolling and adjust the Riggenbach brake by increasing the counter pressure and so increase the retard... after: Enjoy the downhill ride.
There is no real noise downhill, it's a silent sound of rushing steam and air...
On both trains, the fire wasn't maintained downhill. The Achensee railway did a resting fire in the firebox, just to keep the boiler alive. On Schafberg the oil burner was shut down and the boiler kept the pressure because of proper insulation to restart the oil burner on the climb tour again without more to do.
Try this on diesels... No one will shut down the diesel on downhill travel. Only the electros can go here, they switch from motor to generator and feed the power generated during the downhill ride into the main grid...
But, I anyone has something about US steam locos, espacially details: Please, remember me
Allways keep two-thrid level in gauge and a well set fire, that's how the engineer likes a fireman