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New Member
Not exactly "what is the ideal diesel roster"; that could be a subject for another thread. From your railfan perspective, what is the ideal way for a railroad to dieselize?

To get the big question out of the way, let's ignore when dieselization takes place, in absolute terms at least.

Do you prefer when steam and diesels are bought/built alongside each other for some time (B&O, most national railways) or those where the first diesel comes after the last new steam (South Africa, N&W, C&O if you exclude PM)?

Should dieselization be fast (N&W, Clinchfield) or slow (extreme cases - Italy and Switzerland, ~50 years from last new steam to last steam operation. Even longer for some developing countries, ~60 years for Burma)?

In cases of overlapping orders and slow transition, it's common for the first diesels to be retired before the last steam. This even occurred with British Railways, though it's one of the fastest among national railways. In some cases (DB, China), the first diesels are retired while steam is still being built.

We're used to railways where passenger generally goes diesel earlier. What about railroads like GTW, which had no passenger diesels until the mid-50s? Or India and Poland, where most steam operation in the last years was passenger? N&W qualifies for both this and the opposite. First diesels mid-55, no passenger diesels until early 57, but no regular steam-hauled passenger after 1958, with remaining passenger steam downgraded, including streamlined steam still in that form on freights.

China ran out of dedicated passenger steam long before the end of steam, and pulled passenger trains behind freight steam afterward. East Germany was similar.

What should the last steam services be? Sporadic use of heavy modern steam on mainline freights (UP)? Sporadic use of heavy modern steam in helper service (ATSF)? Old steam on branches (Wabash)? Switchers (SP, N&W)? Road power as switchers, old (Japan) or newer (Zimbabwe)? Some manage regular mainline freight steam to the end (DB, South Africa, NKP).

If all the heaviest jobs are dieselized, should you keep older, lighter steam for the remaining ones or use overqualified modern steam (NdeM 4-8-4s on locals)? In a similar fashion, though there was mainline freight service to the end, South Africa retired its last dedicated steam switchers around 1986. Switching by 4-8-2 tender engines - overqualified and inappropriate switchers by any standards - was already common, and it only increased. Even 4-8-4s were seen as switchers in their last years.

Should older steam go first (N&W, China, India) or should most types last near the end (CN, CP, British Railways)? There are some railways where it seems at first glance like most major classes last near the end until you remember that all newer/larger classes were made in smaller numbers and vanished early (PRR, DB).

What about major rebuilds of steam after the last new steam? DR is the best-known example.

Some railroads bought used steam after their last new steam, NdeM and DM&IR being familiar cases. In the Missabe case, this was before their first diesels. With Mexico, it was after.

Zimbabwe is famous for its unusual case of reversion to steam. Guatemala, Ecuador and some small railways and industrial operators are similar, though. The usual reason is inability to maintain diesels. Clearly not perfect from a management perspective, or for anyone who likes to see plans carried out.

Do you like to see periods of experimentation (most national railways, British Railways being a famous case) or getting it right the first time (most railroads that dieselized with a single generation of power: N&W again, DM&IR, Wabash)?

Note the assumption in several of these questions, that the newer steam is larger and/or faster. This is not true everywhere. Possible dieselization is influenced by what the steam fleet contains and what services it must perform. Sometimes, for example, there is a need for power to fill new services. In India, diesels were assigned to new trains, faster than any regular steam trains (it helped that India had no true expresses to begin with). In China, famously, the average length of passenger trains increased during the transition era. Until enough diesels were available, this meant an increasing number of passenger trains needed high-tractive-effort freight power, which slowed their schedules.

I have opinions on some of these, but I won't say anything until some of you have.


Photo Critiques Welcome
Perfect dieselization from the railfan perspective? That would be no dieselization at all. Consider the definitions of perfect. Perfect as an adjective meaning to conform absolutely to a description. That would eliminate a partial dieselization. It’s all diesel or all steam to be perfect dieselization to be perfect and conform absolutely. Perfect can also mean to be excellent beyond improvement. From the railfan prospective the steam locomotive is far more dynamic in sight, sound and photo than the diesel. So to conform absolutely and be excellent beyond improvement it has to be total steam.


New Member
British Railways was a perfect example of how not to dieselise. The original plan of building protypes and testing them for two years was sensible. Orders could then have been placed for suitable types which in turn would have been cascaded as the promised major electrification programme materialised. There were plenty of modern steam locos about that could have held the fort until the early 1970s to allow this to happen The political decision to scrap this plan and the mass ordering of untested designs was a complete shambles and many were scrapped at a very early age Of course steam had to go, sad though it was but if there had been a more orderly change from steam to diesel and electric traction an enormous amount of waste would have been prevented and the money spent on keeping electrification promises. The Swiss knew what they were doing and cut out mass dieselisation by electrifying everything in sight and simply kept a handful of steam to quite a late stage on minor duties they were capable of doing. No pressing reason other than maintenance to do otherwise. Ditto Italy and Austria to a large extent. Rebuilt steam in East Germany gave them the time needed to electrify although it didn't stop them building and importing many diesels that were not needed long term.

I can remember fifty years ago all the talk was that diesels were only a provisional stopgap on heavy use lines until electrification and on the whole this has proved to be the case in most European countries although the UK now lags behind.

I very much enjoyed a visit North Platte a few months ago and seeing the volume of traffic but without any overhead wires in sight. I was impressed by the efficient use of diesel power and the turn round times but still found it odd Of course everything is on a different scale, it's not just a matter of electrifying a couple of hundred miles as in Europe and there are no comparable passenger services to share the cost but it still felt strange bearing in mind that fossil fuels will not last forever. Then perhaps the question will be what will the perfect replacement for traditional diesels and how quickly to go about it. Perhaps the experiences of the transition from steam to diesel will help. There again who bothers to learn from History is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to - An online railroad bookstore featuring a curated selection of new and used railroad books. Railroad pictorials, railroad history, steam locomotives, passenger trains, modern railroading. Hundreds of titles available, most at discount prices! We also have a video and children's book section. - An online model railroad bookstore featuring a curated selection of new and used books. Layout design, track plans, scenery and structure building, wiring, DCC, Tinplate, Toy Trains, Price Guides and more.

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