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.
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.
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.
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.
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.
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!
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.
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.
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".
rcdryeThe 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.
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.
rcdryeThe SDP40F's big failure was in placing all of the water space above the frame
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