A lot of us choose to model the transition era because it allows us to run both steam and diesels on our layouts. However my limited reading tells me it was quite common for railroads to dieselize an entire division at once and that this could happen very abruptly, sometimes seemingly overnight. Was that the rule or the exception. How commonly would an entire division be operating both steam and diesels concurrently? I've also read that even after completing dieselization, some railroads kept the steamers around as reserve power, just in case.
In my case, the principle city on my layout is a division point at the easternmost modeled portion. East of there, toward the staging yards, diesels are run exclusively. West of there, it is predominantly steam, but some through trains, both freight and passenger, will keep their diesel power for their entire run. Other westbounds switch from diesel to steam and westbounds originating from there run primarily steam.
Very common on the PRR although minimal in the electrified area except for steam coming off the PRSL into 30th Street station.
I can only speak with some accuracy about the three roads I model, and even then I don't know every detail. Here are few facts about the B&O.
The B&O dieselized from east to west - BUT, they dieselized passenger service before freight almost everywhere.
On the route directly west, the old mainline, they dieselized helpers before they dieselized road power.
So on the eastern half of their entire system, there was a fairly long period of steam and diesel.
ABBA diesel lashups helped steam powered freight trains over the major grades for quite a while, I woud say a 5-10 period starting in the late 40's. I have a series of photo books on the B&O that is full of pictures of steam and diesel working side by side and diesel helpers pushing steam powered trains.
The B&O moved the better steam westward as they completed dieselization in the east.
But by the end of the 50's steam was mostly gone. I have limited B&O steam on my layout, even in 1954, there would have been more diesels here in the east than steam.
My fictional ATLANTIC CENTRAL set in 1954 is about 60/40 in favor of diesels, with all passenger power being diesel or oil burning steam.
Sheldon
John-NYBWHowever my limited reading tells me it was quite common for railroads to dieselize an entire division at once and that this could happen very abruptly, sometimes seemingly overnight.
I think it was more the other way around...that is, a railroad that had become say 80% diesel might choose to assign all their remaining steam to one division. Steam engines required a lot of maintenance, so it made sense to put them all together with all the required infrastructure (backshops, coal, water, etc.) in one area.
Remember too that different diesels came along at different times. A railroad's first diesels were often yard switchers, starting in the 1930's. After that, they might buy passenger diesels for their top passenger trains in the '40's, and mainline freight diesels and road switchers in the early '50's. I don't know of any large railroads that made an 'overnight' transition from all-steam to all-diesel.
In actuality it was many years for the change. Some coal hauling roads were slower to dieselize than others. Roads operating in more arid areas took to diesels faster than areas with abundant water and fuel. There were crew training, shop forces, and facilities to consider also. Roads like the PRR were reluctant to buy ready made locomotives and even wanted to build their own.
Some diesels didn't live up to expectations. The Baldwin centipedes for example. Originally bought to power the blue ribbon passenger trains were quickly found to be unreliable and downgraded in horsepower and geared for freight speed. Some of them were assigned to push 30 year old steam locomotives up the curve. Others were more successful and assignment to occupations were changed over time. The railroads experimented with diesels a lot in the early years of the transition.
Pete.
I believe CN and CP converted by division, switchers being the exception. But steam pulled passengers up until 1960 in many divisions.
Simon
Steam and diesel together? As with so many things, it depends on time and place. I am a UP fan and one of the incentives to model the mid-1950s is that I can run steam, diesel and gas-turbine power on the same division. The UP tended to dieselize from west to east, the former Los Angeles and Salt Lake got diesels early because of water problems on that line. The Pacific Northwest was next with the Nrbraska and Kansas divisions being last. As diesels replaced steam in some areas, certain older, but viable steam power came east. As newer diesels replaced early models the older power was moved east. So in the mid 1950s one could see UP mainline freights with F-units or Alco FAs, some with GP92 and some with $=6-6-4 Challengers (early types east of North Platte, later ones to the west of North Platte). Some branchlines still had old 2-8-0s for power and some had Alco roadswitchers. Some through freights had 4500hp gas-turbines from Council Bluffs to Ogden. As time went on, more steamers were relegated to storage as more diesels arrived. Steam was also the first power shut down during seasonal lulls or downturns in business. The summer of 1958 was the last "big" year for steam and by 1959 only a few runs were made, and steam was done. So, yes, steam and diesel ran across the Nebraska Division of the UP in the 1950s.
Apparently the Reading put T-1s back into service due to a surge in traffic
greg - Philadelphia & Reading / Reading