Pusher diesel engine on August Trains Cover...

…Could someone elaborate what the Diesel pusher engine number 5681 is rounding the Curve west bound on August cover…I may have known it’s identity in the past but if so I have forgotten.
Center cab and appears to have 2 engines [prime movers], 4-axle and non roller bearing trucks.

Lima T-2500 transfer loco?

Yeah it’s a LIMA, that’s about all I got on it. LOL!!!

…Did a little checking on the above mentioned engine…It for sure is a lima T-2500 engine containing 2 inline engines with a total of 2500 hp. I was wrong in my above mention of a 4-axle unit as it has 3-axle trucks each end. Found a full screen photo of it and details are shown very clearly. The picture I found was taken in Indianapolis and as it turns out not more than 65 miles from me…but of course back around 1965. That sounds like a rather powerful engine for that era. Must have been a pretty good unit for pusher duty up from Altoona, around the Curve and on to Cresson, Pa. One item I notice it is missing is dynamic braking…At least I don’t see any cooling fans in the top where they are normally located on most units.

PRR got two orders of these locomotives from Lima. The other order had dynamic brakes, which added large boxy housings next to the cab (on both hoods).

2500 horsepower may have been a lot in those days, but PRR also had the Baldwin Centipedes by around this time (1950-51)…3000 horsepower, and usually used in pairs.

…Interesting…I would think the ones with the dynamic braking may have been used on the downgrade with the heavier trains…such as coal drags. With the high horsepower figure on the Centipedes, they must of had 2 engines per unit too. Believe they are shown in one of the current pic’s of the Horseshoe Curve article.

I’m wondering if the grades on Horseshoe Curve and the high power engines used there caused some of the operational problems I hear about nowadays- busted coupler knuckles, runaways, and derailments. The maps seem to have towers every fifteen feet or so and I bet the operators were busy checking trains for the above… were there any speed limits on the curve?

Erik

The LT2500 model was unique to PRR and was Lima’s last locomotive production. The only comparable model was Baldwin’s various centercabs.

…I can’t give any numbers on freight train restrictions for the decent of the east downgrade and down around the Curve but I know they do exist. I remember traveling down through the curve some years ago [on a passenger train], and I heard the contuctor say we were under a 35 mph limit down through that area. Years ago there used to be "horns’ near the summit and trains that started down too fast and through a measured space the warning horns would sound for the engineer to get his train under control before it went any farther…It is a critical area.

Broken knuckles and runaways have been with the railroad since the invention of the Janney coupler and the occurence of downgrades. As the railroads master getting each size train accross their specific territories they begin increasing train size to the point the begin having consistant trouble then work on the causes of the trouble.

Over the years they have developed high-strength knuckles, extended range dynamic braking, mid train remote controlled helpers and various other levels of technology.