Western Railroad Discussion > Why would railroads order SD40-2s without dynamic brake

The discussion of the suitability of a non-dynamic braked SD40-2 for a RR museum in the mountains got me thinking.

Suppose you start with a GP40-2 with no dynamic breaks. Then, you consider the two "upgrades:"

1. Dynamic brakes are mainly for train handling on long, steep grades, right? Air brakes work fine if your grades are short, because you can recharge the air pressure between grades. But on long grades, it's nice to have the flexibility to adjust dynamic braking up and down as conditions warrant.

2. Six axle units are for climbing long, sustained grades. SD40s and GP40s have the same horsepower, but SDs have two more traction motors to spread the electricity out to, and 50% more locomotive weight to improve adhesion. Less slippage, and more sustained traction at the rail at low speeds

So, these two "add-ons" to a GP40-2 make it a real mountain goat.

I can see getting the dynamic brakes without the extra two axles. Dynamic brakes probably help trian handling all the way around, reduce wear on the equipment, etc.

Put getting the extra axles without the dynamic brakes? You could climb hills better, but your mountain railroading abilities would be significantly reduced because you'd have to play it extremely cautiously coming down the grades.

Any thoughts?

Ted in Davis

The railroads that ordered non-dynamic SD40's -- and in fact, those that ordered non-dynamic units of any stripe -- have tended to be flatland railroads. Major buyers of non-dynamic SD40/SD40-2's were the Grand Trunk Western (flat), the Illinois Central (flat) and the Missouri Pacific (mostly flat). The IC even removed the dynamics from second-hand SD40s it bought during the early 1990s.

If I recall correctly, all of the New York Central's diesel purchases were four-axles, and mostly if not entirely non-dynamic. And that even though some of the NYC's secondary mains had some decent grades on them.

Add Soo Line and FEC guys. FEC had all four axle EMDs and no dynamics except for GP40-2s 430 and 431 built in 1984, and the secondhand UP SD40-2s, which have kept their dynamics and are FEC's first six motor locos. They almost got 4 conventional cab SD70s in 1995 but cancelled the order. Soo had a good sized fleet of non dynamic SD40 and SD40-2 locos and didn't get dynamics until the 1987-1989 SD60 and SD60M units.

Some railroads--CNW, MILW, and RI--were saving money anywhere they could, so no dynamic brakes on their units. CNW got them on SD40-2s so they were more compatible with UP's units (that was the same reason MP and MILW first got them, too).

FECSD40-2 Wrote:
-------------------------------------------------------
> Add Soo Line and FEC guys. <SNIP> Soo
> had a good sized fleet of non dynamic SD40 and
> SD40-2 locos and didn't get dynamics until the
> 1987-1989 SD60 and SD60M units.

When the Soo took over the remains of the Milwaukee they inherited some healthy grades, yet they persisted in remaining non-dynamic, and rarely ran Milw units in the lead even if equipped with dynamics. This earned them an unoffical nickname "Flat Wheel Central". At that time I was living less than a block from the BN mainline in St. Paul, and Soo had trackage rights. I could easily tell by the sound of the flat wheels on trains passing by that they were Soo, while BN trains were quieter.

When Soo finally started getting dynamic brakes on units, and training engineers to use them, I heard Soo train crews remark "So THAT's how ya run trains!"

gobbl3gook Wrote:
-------------------------------------------------------
> The discussion of the suitability of a non-dynamic
> braked SD40-2 for a RR museum in the mountains got
> me thinking.
.
>
> 2. Six axle units are for climbing long, sustained
> grades.

OR, for pulling long transfer drags across town, pushing long cuts over the hump or out of the bowl in yards or on tonnage trains across generally level terrain. No DB's (or even 16 cyls or turbos) required in such cases.

SD's are best for low to medium speed tonnage hauls regardless of whether the pull on the drawbar is tonnage or gravity induced. Bob

With straight air, stretch braking, and no dynamics, you can wear down the brakeshoes on everybody else's equipment while you keep the engine pulling and independent brakes bailed off or actuated, and defer that train-handling cost of running your railroad off to some other road, utility or car leaser with deeper pockets. It gave the all-too-self-important conductor in the caboose a better ride, keeping him happy, and the old-head engineers could utilize the same familiar stretch braking practices they utilized with steam locomotion, keeping them happy. This also avoids the up-front extra cost to equip diesel locomotives with dynamic brakes in the first place and day-to-day incremental cost of electrical maintenance of this sometimes trouble-prone brake system. This inefficiency was acceptable until diesel fuel prices went through the roof. Then the cost turned around and came back at all the carriers, marginal performers or not, and train-handling practices were modified to utilize "bunch" braking with dynamics when they were available (including, especially on poor roads, purposely placing foreign power so equipped on the point, again to defer that cost of running your railroad off to the other railroad.). These were real considerations and practices, ask any old midwestern yardmasher, road foreman or roundhouse foreman! Interesting also as a side note that today's hybrid gas-electric automobiles are utilizing computer-regulated regenerative(dynamic) braking to assist in keeping their propulsion batteries charged!- - - - - - - - - JLH

Also the Candian National. Didn't understand why they would have so many with dynamics and so many without. The western profile is 'nearly' flat but that would seem to be the best place to use them. If I understand what has been posted on TO in the past, the train tonnage is not based on dynamic brake capacity, it's only based on air brake system. Not my field of knowledge though.

Seems like somebody from the donor RR should have figured out which was the representative home town locomotive. In dem old days, all the UP SD40-2s going through that town would have had dynamic brakes. My two cents thinks a non-dynamic brake SD40-2 woulda/shoulda been donated to a Missouri Pacific town.
It's good that somebody wants it, it's good that the RR is civic minded.

Remember, NYC GP40's had dynamic brakes, but I don't know about their other power. Flatlander(Granger) CB&Q bought all their freight power except the GP7/9's, a few SD7's and F3's (ex-passenger) with dynamics. MoPacs 6000 series SD40-2's were the only ones with dynamics because they were in run-through service on coal trains with BN/UP.

It was mostly how much a unit cost and what type of service it was in. I've seen ATSF SD's drag a intermodal train down to a complete stop with dynamics (Ft. Madison Iowa crew change point), and I mean a complete stop (Their extended range dynamics were set up to cut out at 2 MPH IIRC).

IC removed the dynamics from the Ex-BN SD40-2 fleet they acquired and now CN is putting it back in during their SD40-3 upgrade program. CP RAIL added dynamics to their Ex-SOO SD40's to make them more versitile.

It took awhile for some roads to figure out the fuel economy of the use of dynamics over air brakes, and yes it is substantial as well as cost effective in the savings of wear and tear on the air brake system (Shoes, Wheel trueing/ replacement, brake valve servicing, etc.).

I never understood till later why UP didn't add dynamics to their Ex-MoPac SD40-2's till I saw how much the retrofit would cost. At first it wasn't cost effective.

Just my opinion.

Thanks

Q-GP30

Some of IC's bought new SD40s had dynamics, as did their 4 bought new SD40-2s and their last new power, the 40 SD70s. I believe some GP40s also had them as well as some GP38-2s.

To add to this discussion, didn't the UP add D/Bs to former MP GP50s? I believe so.

As a proud 26-year veteran of my beloved Soo Line, I can and will take exception to just about every point made in this post.

A. While working for, photographing, and being around the Soo for the aforementioned 26 years, I have never once heard anyone use the term "Flat Wheel Central" to refer to the Soo Line Railroad. And what does that have to do with power-braking trains anyway? How are you going to flatten out wheels using 6-12 pounds of air on an 10000+ ton train? Not very likely. Sheesh. Where do people come up with this garbage anyway?

B. In the immediate Soo/Milw post-merger years of '85-'89, the ex-Milw SD40-2's which were dynamic brake-equipped were freely mixed and matched with any and all Soo road units on the roster in prety much any mainline or secondary line assignments. There was NO preference given to ex-Soo or ex-Milw units, whether dyno-equipped or not, to lead or trail. None whatsoever. The ex-Milw Dash-2's lead just as many trains as the ex-Soo units in the post-merger timeframe.

C. As for the final comment.... Some of the BEST hogheads I've ever had the priviledge of knowing, training under, or working with were the guys we had on the old Soo, who ran trains over a RR with a roller-coaster profile using nothing the but the automatic brake valve and the seat of their pants. Most of these guys could control the slack on a 120 car, 18000 ton train using nothing but air, over hogbacks that would scare the pants off the kids coming on-line nowadays, and never even spill a drop of coffee on the control stand. And they could power-brake that same train to a stop within a car length of where they wanted it, no matter if they were going uphill, downhill, or a combination of both at the same time!! Our guys didn't want to use they dynos even when we got the Milw units in the lead after the merger. They were used to running with just the air, and that's the way they liked it.

Enough said.....

Soo Line Hoghead
Working on my 3rd decade of sittin' in "the" chair.





MTMEngineer Wrote:
-------------------------------------------------------
> FECSD40-2 Wrote:
> --------------------------------------------------
> -----
> > Add Soo Line and FEC guys. <SNIP> Soo
> > had a good sized fleet of non dynamic SD40
> and
> > SD40-2 locos and didn't get dynamics until
> the
> > 1987-1989 SD60 and SD60M units.
>
> When the Soo took over the remains of the
> Milwaukee they inherited some healthy grades, yet
> they persisted in remaining non-dynamic, and
> rarely ran Milw units in the lead even if equipped
> with dynamics. This earned them an unoffical
> nickname "Flat Wheel Central". At that time I was
> living less than a block from the BN mainline in
> St. Paul, and Soo had trackage rights. I could
> easily tell by the sound of the flat wheels on
> trains passing by that they were Soo, while BN
> trains were quieter.
>
> When Soo finally started getting dynamic brakes on
> units, and training engineers to use them, I heard
> Soo train crews remark "So THAT's how ya run
> trains!"

I wish on downgrade instead of making heat on the grid, I wish they had catenary and the juice would flow into the power network instead of just wasting it, like the Milw electrics.

soolinehoghead Wrote:
-------------------------------------------------------
> Some of the BEST
> hogheads I've ever had the priviledge of knowing,
> training under, or working with were the guys we
> had on the old Soo, who ran trains over a RR with
> a roller-coaster profile using nothing the but the
> automatic brake valve and the seat of their pants.
> Most of these guys could control the slack on a
> 120 car, 18000 ton train using nothing but air,
> over hogbacks that would scare the pants off the
> kids coming on-line nowadays, and never even spill
> a drop of coffee on the control stand. And they
> could power-brake that same train to a stop within
> a car length of where they wanted it, no matter if
> they were going uphill, downhill, or a combination
> of both at the same time!! Our guys didn't want
> to use they dynos even when we got the Milw units
> in the lead after the merger. They were used to
> running with just the air, and that's the way they
> liked it.

That's why railroads retrofitted DB to locomotives, and insisted that the crews use it. Power braking often added 15 or 20 percent to the fuel use, not to mention the extra wear on brake shoes and wheels, all of which cost a significant amount of money. I can recall riding with one locomotive engineer who notched up to eight while departing the initial terminal, then left the throttle there and used the automatic for all slow orders, downgrades, and stops.

Some railroads were fairly draconian in their rules about DB. They insisted that the throttle be in idle before making any automatic appllications. Some engineers got so good that on relatively flat terrain they could operate the train over their territory without the use of the automatic, except to make the initial squeeze, and to set the brakes on arrival at the destination. They'd use the DB for all slow orders, downgrades, and meets.

You make some good points run8. I agree. However, back in the 70's and 80's most RR's weren't nearly as concerned about the fuel usage factor as they are now. Look at the EMD cataloge from about 1965 to 1980. 20-cylinder SD45's, DDA40X's, DD35's, SD45X's and SD45-2's, and so forth. If I remember correctly, a lot of the retrofitting of non-dynamic units on various RR's didn't start in earnest until the late 80's and early 90's.

Be that as it may though, power-braking a long and heavy tonnage freight over a hogback-profile pike is indeed an art form, so to speak. It may indeed use more fuel and be harder on brake shoes and such as you stated, but those old hogheads were good. They knew how to control those trains whether they had a leaky automatic, bad trainline, cold weather issues, and so forth. No extended-range, high-capacity dynos to fall back on to stop if the air was horses**t in those days.

I learned a lot from those oldheads, and still hold them in high regard.

Take care and be safe.

SLH




run8 Wrote:
-------------------------------------------------------
> soolinehoghead Wrote:
> --------------------------------------------------
> -----
> > Some of the BEST
> > hogheads I've ever had the priviledge of
> knowing,
> > training under, or working with were the guys
> we
> > had on the old Soo, who ran trains over a RR
> with
> > a roller-coaster profile using nothing the
> but the
> > automatic brake valve and the seat of their
> pants.
> > Most of these guys could control the slack
> on a
> > 120 car, 18000 ton train using nothing but
> air,
> > over hogbacks that would scare the pants off
> the
> > kids coming on-line nowadays, and never even
> spill
> > a drop of coffee on the control stand. And
> they
> > could power-brake that same train to a stop
> within
> > a car length of where they wanted it, no
> matter if
> > they were going uphill, downhill, or a
> combination
> > of both at the same time!! Our guys didn't
> want
> > to use they dynos even when we got the Milw
> units
> > in the lead after the merger. They were used
> to
> > running with just the air, and that's the way
> they
> > liked it.
>
> That's why railroads retrofitted DB to
> locomotives, and insisted that the crews use it.
> Power braking often added 15 or 20 percent to the
> fuel use, not to mention the extra wear on brake
> shoes and wheels, all of which cost a significant
> amount of money. I can recall riding with one
> locomotive engineer who notched up to eight while
> departing the initial terminal, then left the
> throttle there and used the automatic for all slow
> orders, downgrades, and stops.
>
> Some railroads were fairly draconian in their
> rules about DB. They insisted that the throttle
> be in idle before making any automatic
> appllications. Some engineers got so good that on
> relatively flat terrain they could operate the
> train over their territory without the use of the
> automatic, except to make the initial squeeze, and
> to set the brakes on arrival at the destination.
> They'd use the DB for all slow orders, downgrades,
> and meets.

To my knowledge, none of the IC 3100 series GP-40s have dynos! And boy are they junk. Remember, they where all in the deadline at Homewood at the time of the CN/WC merger and for good reason! The WC GP-40s that where rebuilt at LRC in 1990 are MUCH better than the ICs or CN GP40-2W (9400-9600s) also not requiped with dynos...And CN had the WC GP40s in storage for a long time in the past 2 years! What for? They should scrap all those CN IC Geeps and keep the WC's! I don't think a dynamic retrofit is cost prohibitive at all, maybe $10-15K per unit!?! Saves alot of fuel and wear on the wheels and equipment, not to mention possible break in twos
if any one freight car has weak iron or an "old break" (rust buildup) within the knuckle or drawbar! Don't get me wrong, their are situations where I powerbrake in 4-6 notch to make sure they are streched, but having dynamics available makes my job of running and handling a train safer and more efficent. Now, of course if you have emptys, in particular, empty flats on the head end or near the head end, forgot about using the dynamics!
Power braking in 5 or 6 is the norm in that situation! And believe me, CN doesn't have train makeup restrictions or requirements at all, so it does happen on big trains (loads) for time to time, bette rknow how to power brake efficently and warm up the air (brake shoes) well in advance of where you want to stop and watch your amp gauge closely! If your slowing down you better back off the thorttle somewhat, especially if your pulling above 900 amps or you may very well bust a knuckle, or worse, a drawbar! Its happened to rookies out there before! Just my observations!

Rail1

Hi!

I know an engineer who regularly ran trains
in San Diego with the steep hills on the
trolley line without dynamics because of
the slow speed. One day, he went up to
get qualified a CORP, and he of course
continued to control the train with air.
The guys at CORP were amazed that he
could do such a thing with just air!

Tony Burzio
San Diego, CA

MTMEngineer Wrote:
-------------------
> When the Soo took over the remains of the
> Milwaukee they inherited some healthy grades, yet
> they persisted in remaining non-dynamic, and
> rarely ran Milw units in the lead even if equipped
> with dynamics. This earned them an unoffical
> nickname "Flat Wheel Central". At that time I was
> living less than a block from the BN mainline in
> St. Paul, and Soo had trackage rights. I could
> easily tell by the sound of the flat wheels on
> trains passing by that they were Soo, while BN
> trains were quieter.


Sure, you can tell. You can also look in a pail of corn kernels and tell exactly which hybrid produced each kernel, or tell gasoline brands by how your car runs.

Flat wheels - listen to a train of UP & affiliated roads steel coal hoppers. Talk about a racket! Yet, those cars have spent much of their time trailing dynamic-equipped engines. Many flat wheels are created when cars are switched - someone does not bother to bleed the brakes.


>
> When Soo finally started getting dynamic brakes on
> units, and training engineers to use them, I heard
> Soo train crews remark "So THAT's how ya run
> trains!"

They may have made that remark, but that does not give scientific support to your statement.