Almost every video of legacy steamers shows a modern diesel-electric locomotive, with dynamic braking, in consist, ostensibly to provide braking on down grades.
Why?
Back in the day, before the diesel-electric locomotive was available, the steamer provided it’s own braking, assisted by the air brakes in the train. What changed to necessitate the addition of the extra locomotive ?
Because those steamers are older than you Steve! It’s pretty much a safety and “save the steamer” type of situation. They do provide power now when the train is underway also. Plus with the upcoming requirements for PTC, it is easier to have a dismal already equipped in the train.
Back up in case the steamer fails
Power braking eats up brake shoes
Steamers break down
PTC and other safety requirements
Because the class I said so.
HEP
Repeat above list…
Yes they do look out of place. (https://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-undecided.gif)
Craig Townsend said:
- HEP
In the case of the Union Pacific several of the cars are equipped with their own power source. There are also special build HEP cars that are carried on the train. The dismals on their trains are not used for HEP.
And STEAMER’S DON’T BREAK DOWN CRAIG!!! They just slow down so the dismal can keep up.
I think the main reason is the host railroads require it, to get the “trash,” off the mainline when the steamer blows a gasket. SP&S 700 blew a gasket on a piston going up the old SP&S mainline from Portland to Spokane (now BNSF), a few years ago, and had to be disgracefully towed to Spokane. The horror!
Braking is just an excuse to make everybody feel better about themselves.
I thought dynamic brakes are better on long downhills, as opposed to real brakes that can overheat?
Greg Elmassian said:
I thought dynamic brakes are better on long downhills, as opposed to real brakes that can overheat?
Yes. Power braking down a mountain grade chews up brake shoes, where as dynos allow a less application. Say a minimum set (7-8 psi) vs a full set (15-18psi). I pulled a few trains down the mountain when learning how to run because; I made too deep of an initial set. And the most memorable was when I was about 1/2 down the mountain and the engineer who was teaching me, reached up from the 2nd unit and turned the dynos off to simulate a failure. Good lesson and good teacher (when he was a smoker and I’m a non smoker and he personally trained me on half the territories required because I liked the way he taught).
All of the above. It’s an insurance policy should the crap hit the fan.
Greg Elmassian said:
I thought dynamic brakes are better on long downhills, as opposed to real brakes that can overheat?
Also, on long downgrades, the air can leak off in the tanks, causing some brakes to release or reduce their braking power. Not an issue with dynamic brakes.
Craig Townsend said:
Back up in case the steamer fails
Power braking eats up brake shoes
Steamers break down
PTC and other safety requirements
Because the class I said so.
HEP
Repeat above list…
So, given all the above, how did steamers make it to the bottom of the hill without smoking the brakes?
Steve Featherkile said:
So, given all the above, how did steamers make it to the bottom of the hill without smoking the brakes?
They smoked the brakes…
And set retainers…
Neither of which happen much today.
As an aside to this discussion about using a diesel electric loco in a steam powered “heritage” consist might I add an apparent oddity currently seen when London’s Underground system run special steam hauled services on their tracks. Both over and underground.
A number of steam locos have and are run on these lines for celebratory purposes but always present in the train is either a vintage electric Underground loco, a 90 year old Bo-Bo knowns as “Sara Siddons”, or a 60 year old early type main line diesel electric, a type 20. Why ? Well, while there is always the need for a backup in case the steam loco fails, especially when you are running in the tunnels under London, there is another more pressing need - braking.
In the main most locomotives and their passenger coaches of the steam era in the UK when built were vacuum braked. However, due to the heavy influence of US practices, in the main due to the promoter of underground railways American Charles Yerkes air braking and electric traction took precedence on our Underground system at an early stage and became the norm over 100 years ago. Hence, when these vintage excursions are run, there is a need for an air braking source - the addition loco. The steam loco still has its own brakes but nothing to slow up its following cars that are in the main air braked fitted - Yes, cars, again the US influence, all coaches that run on the London Underground are cars not coaches (unless built before Mr Yerkes got in on the act)(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)
Steve Featherkile said:
So, given all the above, how did steamers make it to the bottom of the hill without smoking the brakes?
On the Cass, brakemen set the brakes on each car, making sure they don’t lock the wheels. That way the train can descend from the top of the mountain, down into the switchbacks. In each switchback, the brakemen will release, or partly release the hand brake, since the track is on an upgrade in the tail of the switchback. Then when they start descending again, they tighten up on the brakes.
Back in the day brake shoes for locomotives were a common service item so no big deal to replace, today they try to get as much mileage out of them as possible as replacing is a much more expensive proposition.
Gary Buchanan, FOG said:
Back in the day brake shoes for locomotives were a common service item so no big deal to replace, today they try to get as much mileage out of them as possible as replacing is a much more expensive proposition.
It’s not the locomotive brake shoes that need replacing, it is every single car after the locomotive. When you apply air brakes to the entire train you have to “bled” off the locomotive brakes. Otherwise, your locomotive will have flat spots. Brake shoes are cheap compared to wheels.
We went on a steam excursion in the snow years ago and a diesel followed along behind the train but was not part of it which was great when we all piled out for the photo run bys.
I would say the diesel was following us just in case something happened to the steamer. I don’t know if it was a requirement for insurance or safety.
Is putting a diesel on the train behind a steam loco something that is only done if the train is going to use a main line with other traffic? On the trains that our own Dave Taylor runs on they aren’t doing that. (https://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-undecided.gif)
Joe Zullo said:
Is putting a diesel on the train behind a steam loco something that is only done if the train is going to use a main line with other traffic?
No it’s called a Class I railroad vs. a Class III railroad (if they are even listed as a Class III RR)
