Large Scale Central

I have a question about diesels in consist with steam locomitive

General Discussion
#1

  1. Sometimes the line is the diesel is there to provide head end power. Ok, I can understand that, newer passenger cars no longer are heated by steam.

  2. Sometimes the line is that the diesel is there in case the steamer breaks down. I can understand that too.

  3. Sometimes, the line is that the diesel is there to provide dynamic braking. Now, that I do not understand. Dynamic braking did not become commonplace until diesels were commonplace, with the exception of electrics. What did steam locomotives do for “dynamic” braking back in the day, before diesels were available to run in consist with the steamer, throw out a sea anchor? To me, this sounds like the modern day Class I RR is really using reason number 2, but publicly saying “Dynamic Braking” to keep up appearances.

#2

The real reasons are 1. to pre-empt a breakdown (delays and blocked tracks are HUGE $$$$$$$$$$). 2. The union rules usually say so. The HEP unit could otherwise be in a tool car. The braking is mostly a canard, except perhaps on huge grades, for insurance reasons, or if they want to make a big show with a light train. A diesel can also help start a super heavy train. (It’s in the mechanics of how the power is produced. A steam engine can pull a train that it can’t start. - While a diesel can start a train that it can’t pull)

You had independent engine brakes and train brakes. You could also set the reverser slightly into reverse and get braking action that way (something like a compression or ‘jake’ brake on a diesel truck)… This takes a deft and gentle touch. Do it too long and you overheat the cylinders (to the point that the steam oil will combust! – ruining it’s lubrication properties), set the reverser too far and the wheels will slide, apply it too quickly and something important may break.

Where it got interesting was with a long train on undulating track…with part of the train needing held back while part needed dragged along… A good engineer could interplay the locomotive, brakes, and slack in the cars to make it look easy. An indifferent one could yank out drawbars or couplers… or put stuff on the ties.

Edit: back to the union thing: This applies especially on excursions with ‘guest’ locomotives: The host RR is usually required (by union agreement or their insurance people) to supply said train with a ‘pilot’ - a railroad (union) engineer familiar with that part of the line. - This guy mostly just gets a well paid cab ride, and will advise the locomotive engineer on various track conditions, etc. if needed… However, should the steam engineer become incapacitated (a heart attack. etc.) Most of these pilot usually AREN’T also certified to operate a steam engine, and probably wouldn’t be familiar with the quirks of THAT one, anyway… BUT, being (union) engineers, they CAN drive the diesel to get the ‘stranded’ (for lack of a steam certified engineer) train the hell off the main… Make sense?

#3

If the Steamer is using class A rails, sometimes the railroad requires a dismal for all the above reasons. Mostly breakdowns.
It all started a while back when, (I forget the particular steamer. it was an Eastern 4-8-4 mountain class) broke down on the BN mainline somewhere in the mid west. The front pilot wheels had a bearing go out. They had to cut the ribbon rail, dig a pit and lower the truck into it. Then off to a BN shop for repairs. The loco sat out on the mainline for a few days, holding up freight.
I have the whole thing on video somewhere in my collection.
After that fiasco, all the railroads started to crack down on steam on the mainlines.

#4
Quote:
... You could also set the reverser slightly into reverse and get braking action that way
In the early days of steam, that's the only way you stopped your locomotive. They didn't have engine brakes. If they needed to slow down, they dropped into neutral and coasted. If they needed to slow down faster, they opened the cylinder cocks, closed the throttle, put the loco in reverse, and opened the throttle again. The cylinder cocks needed to be open because wheel rotation wouldn't allow the steam to escape otherwise, leading to blown cylinder heads. (Which would definitely stop you, but really limit your ability to get going ever again.)

Later,

K

#5
Kevin Strong said:
Quote:
... You could also set the reverser slightly into reverse and get braking action that way
In the early days of steam, that's the only way you stopped your locomotive. They didn't have engine brakes. If they needed to slow down, they dropped into neutral and coasted. If they needed to slow down faster, they opened the cylinder cocks, closed the throttle, put the loco in reverse, and opened the throttle again. The cylinder cocks needed to be open because wheel rotation wouldn't allow the steam to escape otherwise, leading to blown cylinder heads. (Which would definitely stop you, but really limit your ability to get going ever again.)

Later,

K


Wonder how they figured that out the first time?

“Geeze, Harry, You got the train stopped, but what are you gonna do now? The super is gonna be pi$$ed! Maybe some duct tape will help.”