I was in Altoona early in August 09 and I noticed
something different on the mountian
What is the significance of the SD 40-E’s over
the SD 40-2’s thanks
Yardmaster JOE
Stand by…I’d wager when Dave see’s your question, he can answer it…
Norfolk Southern has been undertaking several major rebuilding projects recently including the SD40E program which involves remanufacturing SD50 units into microprocessor equipped 3,000 HP locomotives. NS is utilizing 16-645E3 engines “harvested” from retired SD40s. There are major problems with the 16-645F engines so NS is rebuilding the SD50’s with a more reliable engine.
SD40-E units are former SD50 (&50s) units. The horsepower on the former SD50 was downsized to 3000HP, new microprocessors installed, cab signals, auto detach device and other small changes. This occured from Nov of 2008 into Aug 2009 and are assigned numbers 6300 to 6319 (so far). Just making some good use of a disappointing engine that never lived up to expectations, many were retired in 2000 and 2001.
Are you sure they aren’t remanufactured F crankcases. Get a reading off the data plate and report back.
Following are a couple of links for specific information regarding the NS SD40-E model rebuild program:
http://www.nsdash9.com/rosters/6300.html
http://www.altoonaworks.info/rebuilds/ns_sd40e.html
From what I understand, these units have been rebuilt with 16-645F engines which have been de-rated to a more reliable 3000 HP.
From what I have read. The oil return to the sump is external to the crankcase and there are problems with broken pipes. The 645E;s have the oil return internally so there is no problem with oil leaks.
I called up a buddy at RELCO yes they normally only rebuild switchers. However even they know why they 645F was the Biggest DOG that EMD ever came out with even larger than the H-series of the SD90. The Oil return for the Turbo was a Copper line that ran outside the block instead of being a internal return. They would snap off like a twig next thing you knew low oil SHUTDOWN and dead-in tow unit. Between that and the Electrical issues those are the biggest reasons the SD50 and the GP50 series are being retired and the SD40-2 is still going strong. Now if the Engineers had not screwed witht he design they would have a sound design. However we know how Designers think even if it isn’t broke we need to fix it anyways.
If that’s true why are CSX and NS doing major rebuild programs on 25 year old locomotive to get another 25 years out of them. They are replacing the wheelslip/engine control with Q-tron in CSX’s case and EMD’s latest version for NS. Part of the reason for the 3000 hp rating may be to take advantage of improved bsfc at the lower engine speed and it reduces stresses on parts top extend service life. In NS case they are going to use them in helper service that would be 95% power factor uphill and nothing downhill. There should be a lot of fiddling to optimize for that service.
“bsfc” = ?
I think no fiddling would be needed. Set 'em up to optimize for the 95% power factor uphill, and call it ‘Good !’. Since they’re not under power downhill, there’s nothing to optimize, other than the idle and dynamic brake, right ?
- Paul North.
bsfc = Basic Specific Fuel Comsumption
Actually its brake specific fuel consumption and the english units would be pounds of fuel per horse power hours. Engine manufacturers like to publish the best number but it rarely occurs at the rated horsepower. The F engine is better at lower rpm and power. For instance the rating for marine engines at 800 rpm is better than at 900 rpm. There standard designs that were built over the years that were designed around the E engine rating of 2875 hp at 900 rpm with the advent of the F engine the new tug was built with an F engine turning 800 rpm with a different gear ratio so that the propeller turned the same speed as the previous tug for the same power. The benefit was a big reduction in fuel consumption for the same work or horsepower-hours over a several day voyage. I don’t have the engine curves for the locomotive version of the F engine but it will almost certainly more fuel efficient at 900 rpm than 954 it had at the 3600 hp rating. Pushing up hill will burn a lot of fuel but not much runnig light downhill for a load factor of about 50%. The offshore marine units are running over 90% load factor. Moran Towing has been building a series of tugs for their ATB (articulated tug-barge) and now that EMD stopped building 12-645F’s they are using 12-710G rated at the same 2550 hp but at 800 rpm So it will interesting how it works out when it goes into service this fall.
The biggest problem we had with the SD50s at Conrail were head pot seat ring wearing out - the 954 RPM had the heads dancing on the top deck - new crab stud and plate designs notwithstanding. The second biggest problem was keeping the radar for the Super Series wheelslip system happy. The face plate would get dirty or snowy, so compressed air was aimed at it. Then it got covered with oil from the air system and really crudded up with dirt. I imagine at 900 RPM and 3000 HP the engine is much happier. If they were for road sevice, you wouldn’t even need a WS system any better than a WS10 - the extra adhesion just puts you in the “red”. But for pusher service a little extra grip for a short period of time might be just enough to get over the hump.
GE still produces a copy of the 645F in Europe that is used in MPI’s MP36-series commuter locos. The GE 645Fs must be better than the EMD’s since MPI is using them, and the MPI locos are supposedly Tier-2 compliant. Besides MPI, has any builders/rebuilders used these improved 645Fs? I guess GE’s 645F could be put into GP/SD50’s, though other work would probably have to be done to make them tier-2 compliant like the MP36.
The 645F copy was actually designed by MK Rail(who sought to build
Getting back to EMD SD50’s, the F engine was supplanted for locomotive use back in 1985 by the 710G so all engineering time has been allocated hopefully to the new engine. Running the engines at 954 rpm caused the head ring wear problem that was fixed by the new design plate crab with the necked down bolt. Maintaining bolt tension has a lot to do with bolt stretch so with a smaller diameter bolt and higher bolt torque (2300 ft-lb instead of 1800 ft-lb). This greatly increases the clamping force to hold the power pak in the engine. The Motive Power version of the engine has this feature. The main difference is that the fabrication of the crankcase uses different structural shapes so that automated welding can be used and I understand the complete crankcase is substantially heavier than EMD’s version. The Motive Power engine achieves it 3600 HP at 920 rpm not 954. EMD did sell 645F engines in the power product line (all rated at 900 rpm or less) up until a few years ago but dropped due to low sales. Since both the 645 and the 710 can use the same cylinder heads and hence the same fuel injectors all the do-it-yourselfer’s shouldn’t have any trouble creating a Tier 2 version for railroad service.