rcdryeThe SDP40F's big failure was in placing all of the water space above the frame
Overmod rcdrye The SDP40F's big failure was in placing all of the water space above the frame with little baffling. A major contributing factor was the shape of the tank, too.
rcdrye The SDP40F's big failure was in placing all of the water space above the frame with little baffling.
A major contributing factor was the shape of the tank, too.
rcdryeThe SDP40F's big failure was in placing all of the water space above the frame with little baffling.
Passenger F-Units had water tanks under the frame with the fuel tanks. Since the fuel tank was limited to 1200 gallons in this arrangement, the lack of water capacity wasn't an impossible problem for many railroads. A contemporary E-Unit had the same 1200 gallon fuel capacity, but could carry about twice as much water.
There were a number of ways to stretch the water capacity of an F-Unit. A 600 gallon tank could be ordered to replace the dynamic brake hatch. B-units had an interior tank where the cab would be on A-units. Many railroads general policy was to require an A-B pair, with the S/G on the B unit (All FTs, Santa Fe, B&M are examples). Santa Fe did have some F7As with boilers, but mostly relied on the S/Gs in F7Bs - hence the famous A-B-B-A warbonnet strings.
The entire four foot extension of the FP7 body was devoted to water space. As in the F7, the dynamic brake could be given up for water as well.
Southern modifed some F3/F7 units with "Torpedo Boat" air reservoirs on the roof to get additional water capacity.
The most innovative approach was by Northern Pacific, which purchased or rebuilt "water baggage" cars which were trainlined with the locomotives for extra water capacity.
And both C&NW and CRI&P put HEP generators in the S/G space - in C&NW's case in former freight units.
The SDP40F's big failure was in placing all of the water space above the frame with little baffling. 3500 gallons of water weighs 28000 pounds - significant once the tanks emptied part way and began sloshing. In the words of a former Amtrak employee "that's all it took to make good track bad".
Considering a typical steam generator was rated around 2,000 to 2,250 lbs/hr, that's about 250 gal/hr at full output. Don't remember the F units having a reputation for gargantuan tankage.
My understanding is that the first railroads to request what would become the FP engines - F-style A units stretched out several feet to allow the same water storage as an F-style B unit - were northern railroads like CP, NP and CN who needed the water for steam heating passenger cars in the dead of winter. It apparently was realized quite quickly that an FP could also be used by themselves on a medium-length passenger run where normally railroads had to run an A-B set just to get the extra water tanks of the B unit.
Overmod MR STEVEN AROESTY For the sake of completeness, let's also mention the FL9s because there are many preserved. This is a F unit (only one diesel inside) but with a rear three [axle] truck (with front two [axle] truck) and longer than a normal F but shorter than an E unit. For further completeness we should also mention the FP7 (and FP9) which were built with a 4' longer carbody to optimize steam generation for passenger work. Since over 300 FP7s were built, this is at least as significant a variant as the FL9. Note that there were no 'FP' B-units, and the demonstrators were both built as three-unit "locomotives" (with just the one cab and a pair of near-normal F7Bs) probably for the same reason ATSF went to A-B-B-B consists for a while.
MR STEVEN AROESTY For the sake of completeness, let's also mention the FL9s because there are many preserved. This is a F unit (only one diesel inside) but with a rear three [axle] truck (with front two [axle] truck) and longer than a normal F but shorter than an E unit.
For further completeness we should also mention the FP7 (and FP9) which were built with a 4' longer carbody to optimize steam generation for passenger work. Since over 300 FP7s were built, this is at least as significant a variant as the FL9.
Note that there were no 'FP' B-units, and the demonstrators were both built as three-unit "locomotives" (with just the one cab and a pair of near-normal F7Bs) probably for the same reason ATSF went to A-B-B-B consists for a while.
B&O bought F3 units equipped for passenger service as the power for the streamlined, vista-dome equipped Columbian in 1948. The problem the the B&O had with these engines were their limited water capacity. The train was assembled in the Robey Street coach yard and backed down to Grand Central station a the proper time with the locomtive consist fully serviced - with the time required from leaving Robey Street to arrival at Garrett for watering the engines - in many case the engines were out of water. After a period of time shorter passenger runs were assigned to these engines. I suspect the additional 4 feet in the FP-7 and FP-9 were to allow for additional water capacity.
Never too old to have a happy childhood!
MR STEVEN AROESTYFor the sake of completeness, let's also mention the FL9s because there are many preserved. This is a F unit (only one diesel inside) but with a rear three [axle] truck (with front two [axle] truck) and longer than a normal F but shorter than an E unit.
Erik_Mag zardoz Once we get the F and E debate settled, we can start on whatever happened to the E1, E2, E3, E4, F1, F2, F4, F5, GP25, GP1, GP2, etc? And will we ever see a SD100? IIRC, a few F2's were made between the end of FT production and the start of F3 production.
zardoz Once we get the F and E debate settled, we can start on whatever happened to the E1, E2, E3, E4, F1, F2, F4, F5, GP25, GP1, GP2, etc? And will we ever see a SD100?
Once we get the F and E debate settled, we can start on whatever happened to the E1, E2, E3, E4, F1, F2, F4, F5, GP25, GP1, GP2, etc? And will we ever see a SD100?
IIRC, a few F2's were made between the end of FT production and the start of F3 production.
That's right. The F2 used the new F body design that became pretty much the model for all later F's (trucks more centered, not offset towards one end which had created the signature FT overhang at the other end). It was supposed to be the 1500 HP replacement for the 1350 HP FT. However, due to a shortage of a particular part in 1945, they had to make the F2s with only 1350 HP like the FT. Once the necessary part became available after a few months, they were able to incorporate the power increase and changed the model number to F3.
D.HearneI see everyone here missed the obvious. The E's never had dynamic brakes. The F's did, That is why the F's were preferred by the western roads for passenger service in the mountains.
For the sake of completness, let's also mention the FL9s because there are many preserved. This is a F unit (only one diesel inside) but with a rear three wheel truck (with front two wheel truck) and longer than a normal F but shorter than an E unit. It also was delivered with third rail pickup and could operate for short periods without the diesel on electrified third rail and was used to go into Grand Central and Penn Station by the New Haven. Believe the extra length/wheel was to support the additional equipment required for the third rail and to spread the weight out a bit on the Park Avenue viaduct (Grand Central line). These were passenger units. Many survived because a dual mode was a handy thing to have and served well into the Amtak era (NH, PC, CR, Amtrak and CDOT).
zardoz oltmannd I would expect an E unit to ride better at speed due to its longer length, but probably not a huge difference. Actually, at least on jointed rail, the ride difference was huge. On welded rail the difference was not nearly as significant, but there was still a difference. The F's trucks would beat the rail from side-to-side, as well as readily transmit the joint impacts. The E's ride was vastly superior, similar to the difference between a GP9 and an SD9; there was a reason the SD9's were refered to as "Cadillacs".
oltmannd I would expect an E unit to ride better at speed due to its longer length, but probably not a huge difference.
Actually, at least on jointed rail, the ride difference was huge. On welded rail the difference was not nearly as significant, but there was still a difference.
The F's trucks would beat the rail from side-to-side, as well as readily transmit the joint impacts. The E's ride was vastly superior, similar to the difference between a GP9 and an SD9; there was a reason the SD9's were refered to as "Cadillacs".
Comparing assumes that there are two units in view. Looking at a single unit or from a distance, the number of axles and side door placement are hard to miss.
NickPThe cheap and easy way to distinguish E's and F's is: E's were 6 axle, F's 4 axle. If you have a side view, the side door on the E's was half way down the carbody, on the F's the door was at the end.
rcdrye E-Units have two 12-cylinder engines while F-Units have a single 16-cylinder engine. The door on E-Units is between the two engines, while the rear door on F-Units is behind the engine. Apparently no one saw a reason to put another door behind the second engine on E-Units. E-Units and passenger-equipped F-units have the train heating boilers at the rear of the carbody. Since some E-Units had two boilers back there I'm kind of surprised no version had a second carbody door.
E-Units have two 12-cylinder engines while F-Units have a single 16-cylinder engine. The door on E-Units is between the two engines, while the rear door on F-Units is behind the engine. Apparently no one saw a reason to put another door behind the second engine on E-Units.
E-Units and passenger-equipped F-units have the train heating boilers at the rear of the carbody. Since some E-Units had two boilers back there I'm kind of surprised no version had a second carbody door.
Opening the carbody doors on a locomotive (whether they be an E, F, SD, GP, etc.), will have a negative effect on the cooling system, as the motors will suck air from the location with the least resistance (the doors) rather than through the cooling system's radiators.
Both the E and F units had the HEP Cummins engine located in the rear, mounted transversally from the prime mover motor(s).
I believe that "F" actually stood for "Fourteen hundred" in the same way that "E" stood for "Eighteen Hundred". The first F unit model was the FTs (an even more literal abbreviation for "FourTeen hundred". Its actual horespower was 1350, but who's counting.
The other EMD first generation models were designated by horsepower too. The S units were Six hundred, and the N units were Nine hundred.
The UP drawings of their E8s and E9s (in Kratville books and maybe elsewhere) show "dynamic brake resistors and blower" at roof level between the two exhaust stacks. Might be a 48-inch fan on E9s, if not E8s?
M636C timz Don't SP E9s (and UP I assume) have an extra fan on the roof for the dynamic brake? So if you compare pics of an SP E9 with most other RRs... Only the SP E9s had dynamic brakes. No UP E8 or E9 had them and neither did SP's one E8. Peter
timz Don't SP E9s (and UP I assume) have an extra fan on the roof for the dynamic brake? So if you compare pics of an SP E9 with most other RRs...
Don't SP E9s (and UP I assume) have an extra fan on the roof for the dynamic brake? So if you compare pics of an SP E9 with most other RRs...
Only the SP E9s had dynamic brakes.
No UP E8 or E9 had them and neither did SP's one E8.
Peter
The E8/E9 roster in issue 43 of Extra 2200 South shows the SP E8A and E9As had dynamic brakes. All UP E8s and E9s had dynamic brakes. Dynamic brakes were also found on the EMD E8A demonstrator, all Milwaukee E9s, and Southern E8As #6906-6915.
The dynamic brakes were removed from the E8 demonstrator before it was sold to Rock Island. Dynamic brakes were removed from all Union Pacific E8s and E9s sold to C&NW and Rock Island.
Ed in Kentucky
This may, seem obvious but other the 2 vs 3 wheeled trucks it's easy to spot. The E units have a door into the cab then a door in the middle of the car body. While the F's have the cab door and then one at the back (still on the side) Not sure the reasons but maybe some of the other well informed know why.
SSW9389 rcdrye SSW9389 was the lead unit one time in March 1974. The subject unit was built in April 1975. See http://www.trainweb.org/emdloco/74696.htm
rcdrye SSW9389 was the lead unit one time in March 1974.
SSW9389 was the lead unit one time in March 1974.
The subject unit was built in April 1975. See http://www.trainweb.org/emdloco/74696.htm
Typo. March 1976 !
very interesting stuff, I am like DPool original poster, but for us all vacation travel was by train as Dad would not drive a long way and we never even considered flying. Train travel was free with Dad's pass, but we never got to ride the classy trains, except UP/SP City of St. Louis. Dad had to pay half fare for us to ride that one, I knew I liked the engines, but until I got on Facebook, had no idea what they were. I first learned about E and F and some of the differences. I just know what I liked, and it was always a comfort to see the wigwag of the headight down the track on a dark night. Some of our train transfers were at midnight or 4 am, the perk of riding on a pass. Sometimes we could step from one train to another like at Lake Alfred, FL or Cairo, IL which was easier.
SD70Dude D.Hearne I see everyone here missed the obvious. The E's never had dynamic brakes. The F's did, That is why the F's were preferred by the western roads for passenger service in the mountains. E8 and E9 could be ordered with DB. E7 and earlier did not have it. PA's had pretty good DB too, which was a big deal for roads like Santa Fe and Southern Pacific.
D.Hearne I see everyone here missed the obvious. The E's never had dynamic brakes. The F's did, That is why the F's were preferred by the western roads for passenger service in the mountains.
I see everyone here missed the obvious. The E's never had dynamic brakes. The F's did, That is why the F's were preferred by the western roads for passenger service in the mountains.
E8 and E9 could be ordered with DB. E7 and earlier did not have it.
PA's had pretty good DB too, which was a big deal for roads like Santa Fe and Southern Pacific.
BLS53 D.Hearne I see everyone here missed the obvious. The E's never had dynamic brakes. The F's did, That is why the F's were preferred by the western roads for passenger service in the mountains. To me, and most casual railfans, the number of wheels is the obvious identifier. I've watched trains for over 60 years, and still can't identify dynamic brakes. Dynamic brakes, number of radiator fans (that one can only view from an overpass), all that stuff, I reserve for the aficianados.
To me, and most casual railfans, the number of wheels is the obvious identifier. I've watched trains for over 60 years, and still can't identify dynamic brakes. Dynamic brakes, number of radiator fans (that one can only view from an overpass), all that stuff, I reserve for the aficianados.
BLS53 To me, and most casual railfans, the number of wheels is the obvious identifier. I've watched trains for over 60 years, and still can't identify dynamic brakes. Dynamic brakes, number of radiator fans (that one can only view from an overpass), all that stuff, I reserve for the aficianados.
On GP60 and older EMD hood units the DB grid is quite obvious, directly above the diesel engine. On other units it is more difficult to identify.
All North American road units built since the early 1980s have DB.
Greetings from Alberta
-an Articulate Malcontent
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