Definitely, GE and EMD have been doing well in building large road hauling locomotives. But I have been wondering, why have they both stopped manufactuing switchers. There's obviously still a market for switchers to shunt cars around within yard confines.
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The market kind of disappeared in the 1970s when GP7/9s began to be cascaded down to yard service. GE decided when they entered the locomotive market in the 1960s that they weren't even going to bother. Railroads were increasingly looking for locomotives that could also do secondary road work if need be. Yard power is increasingly EMD Dash-2 power including SD40-2s and GP38-2s that also see local service. Most of the gensets are similarly sized. The switchers currently on the market are smaller and designed largely for industrial applications. EMD (well, really Progress Rail) are offering switchers in the forms of the PR20B and the PR24B, which are about the same size as a GP40-2, as well as the 12-710 ECO repower line.
NorthWest wrote:The market kind of disappeared in the 1970s when GP7/9s began to be cascaded down to yard service. GE decided when they entered the locomotive market in the 1960s that they weren't even going to bother. Railroads were increasingly looking for locomotives that could also do secondary road work if need be. Yard power is increasingly EMD Dash-2 power including SD40-2s and GP38-2s that also see local service. Most of the gensets are similarly sized. The switchers currently on the market are smaller and designed largely for industrial applications. EMD (well, really Progress Rail) are offering switchers in the forms of the PR20B and the PR24B, which are about the same size as a GP40-2, as well as the 12-710 ECO repower line.Thanks for the feedback. Meanwhile, the other querstion on my mond regarding locomotive use is: With all fur regard to the better 4 axle units that have seen a lot of use, and why hasn't there been more use of 6 axle units? I ask form the point of view that sice a six axle locomotive can generate considerably more tractive effort than a dimilar 4 axle unit with the same horsepower engine, then why not make better use of available engine power by throwing on a couple more traction motors?
It's a combination of things. 6-axles have long been used in heavy yard service such as pushing cars over humps, and several railroads bought SD38 and SD38-2s for that purpose. Slugs have also been used in this service, which is particularly useful if you want a cab on both ends.
Railroads stopped buying and using 4-axles on road trains in the early 1990s, so they were the first to be demoted as their 6-axle mechanical equivalents remained in road service for longer. As the remainder of the Dash-7s and early geeps were retired/sold/shortlined, more 6-axles were cascaded down to secondary service.
Not all switching/local service needs a lot of tractive effort, and 6-axles are much harder to squeak around sharp curves and switches in often dodgy trackage areas, and their added length and truck wheelbases are harder on the track.
Railroads stopped buying and using 4-axles on road trains in the early 1990s, so they were the first to be demoted as their 6-axle mechanical equivalents remained in road service for longer. As the remainder of the Dash-7s and early geeps were retired/sold/shortlined, more 6-axles were cascaded down to secondary service.
Not all switching/local service needs a lot of tractive effort, and 6-axles are much harder to squeak around sharp curves and switches in often dodgy trackage areas, and their added length and truck wheelbases are harder on the track.
Thanks. In addition to what you wrote, which covers most of it, there's also the xost of maintaing extra motors which aren't always needed.
Railfan365--
But your question about why the railroads haven't gone for extra traction motors to use the available engine power at low speeds was a good one. One alternative is to combine a (typically 4-axle) "slug" with a 4-axle unit: this is even better than a six-axle unit for low speed oomph (engine power spread over eight axles instead of just six), with two added advantages: all the axles are in short-wheelbase 2-axle trucks, so you don't have problems with sharp curves and sloppy track work, and slugs are CHEAP: the railroad's own shops can usually do the work of converting a retired 4-axle locomotive to a slug.
But your question about why the railroads haven't gone for extra traction motors to use the available engine power at low speeds was a good one. One alternative is to combine a (typically 4-axle) "slug" with a 4-axle unit: this is even better than a six-axle unit for low speed oomph (engine power spread over eight axles instead of just six), with two added advantages: all the axles are in short-wheelbase 2-axle trucks, so you don't have problems with sharp curves and sloppy track work, and slugs are CHEAP: the railroad's own shops can usually do the work of converting a retired 4-axle locomotive to a slug.
Observation post: Kansas City.
Concur with the above. GPs and -2 era SDs now cover most yard service I see. There are BNSF and UP switch units drifting around, but they don't often leave Argentine or Neff.
Concur with the above. GPs and -2 era SDs now cover most yard service I see. There are BNSF and UP switch units drifting around, but they don't often leave Argentine or Neff.
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John_Perkowski wrote:Observation post: Kansas City.Observation post: Rochester NY.
Concur with the above. GPs and -2 era SDs now cover most yard service I see. There are BNSF and UP switch units drifting around, but they don't often leave Argentine or Neff.
Concur with the above. CSX has been using GP38-2's and GP40-2's as Rochester yard switchers since 1999, and Conrail was doing it before them..
its been a solid 20 years now that GP38-2's and GP40-2's have been the yard power for Rochester..
the yard is the only place I see those Class-1 GP's anymore, Road power is 99% 6-axle.
Scot
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CP has been using 4 axle units in road service frequently. Sometimes the tonnage is just a bit more than an AC can handle, but not enough for two AC units. For a while they were on an EMD kick. We had consists of SD30, 40-2, and 60. The new GP20eco seems to get used in road service frequently too.
Here in the east much of the infrastructure is older. With the high population density, the amount of land for railroad tracks is much more confined. We have lots of places where 6 axle is prohibited.
Here in the east much of the infrastructure is older. With the high population density, the amount of land for railroad tracks is much more confined. We have lots of places where 6 axle is prohibited.
I did not think to add about car weights. Over my 21 year career, we have had the increase of car maximum weight from 263K#, to 268. Now a mile long train typically weighs as much a a 6,000+ train did then. This has forced the move to 4000 hp locomotives predominating on the road. The switching of these trains used to be OK for a geep, but now may require 2, or maybe a SD instead. Old switcher style engines are only good for real light operations, or places where bigger power will not fit.