Friday, December 31, 2010

General Electric Wheel Slip U25-U36

{I originally wrote and disseminated this document in mid-2005. At that time, I placed it on file in a number of locomotive forums. I have updated the information in this document and it appears here in this form only; consider this version to supersede others extant.}

Wheel slip control in the General Electric Universal Series.

When General Electric began demonstration of the U25B, it was already aware that the railroads would have concerns about adhesion, considering the high power per driving axle. In order to mitigate these concerns, and give the locomotive true drag capability, GE chose to employ a piece of equipment which had already independently been under test in the US for several years (both by Westinghouse Air Brake and by New York Air Brake) as standard equipment.

This device was known as the Slip Suppression Brake Valve, or SSBV. The principle of the SSBV was that wheel slip could be corrected not by reduction of power and application of sand, but by an extremely quick application and release of the independent brake on the locomotive wheels. This device had already been installed experimentally on EMD units on the Western Maryland and had shown an ability to allow increased tonnage ratings in drag service, due to its ability to arrest slip with the locomotive still producing full power. The idea was that any brief track perturbation or weight transfer between axles which caused the slip would be passed fairly quickly, and so simply identifying the slip condition and arresting it without reducing power would not allow speed to drop further, as it would if excitation were reduced, albeit temporarily.

GE also chose to employ a new speed sensing system on the U25B which could provide better monitoring of axle speeds, through individual direct measurement. Normally, wheel slip relays in locomotives were picked up by voltage imbalance between traction motor leads. The new Axle Alternator system used a journal-box-mounted alternator on each axle, whose output was then conditioned into a usable signal for detection of slip, and for transition control as well. This system, with theoretically more rapid detection of slip / incipient spin, coupled with the SSBV to stop it, was supposed to allow unusually high factors of adhesion. Tests with the U25B prototypes actually did show much better adhesion (over the normal 18-20%) in drag service.

With this system, there was a backup; if the slip continued for longer than three seconds, then sand would be applied, excitation reduced (through action of relay and energizing of the ORS solenoid on the governor, which moved the load regulator toward minimum field position,) and the warning light and buzzer sounded. Incidentally, this was not the original design; General Electric 751 and 752, when operating in 1960 as the experimental, prototype U25B locomotives had the slip suppression brake equipment but did NOT reduce main generator excitation upon detection of wheel slip {ref. GEJ-3807, Operating Instructions General Electric Model U25B 2500 HP Diesel-Electric Locomotive - for road no’s. 751-752, page 44.} These units only gave a light and buzzer indication of slip coupled with SSBV operation, without sanding or generator excitation reduction. This design didn’t make it to production units.

Early on, each railroad buying the U25B also bought it with the Slip Suppression equipment since it was standard. However, some roads began to complain of pinion slippage and worn wheels. In brief, the operation of the U25B in mountainous terrain did actually lead to still-unfavorable wheel slip conditions, even with Slip Suppression. In the cases where Automatic Power Matching was employed, this condition was made less severe, but as this system derated the locomotive when excessive traction motor field temperature was reached, the advantage of the high horsepower was lost. The problem continued, and worsened with the U28B, especially on the Pittsburgh & Lake Erie, where U28B units were often used in drag service. General Electric was already aware that refinement was necessary. (It also developed an optional Pinion Slip Alarm at the request of the Louisville & Nashville, although GE’s stated opinion on the subject was that properly applied traction motor pinions did not slip -- a statement condemning the maintenance performed by the railroads.)

In 1964, GE began using new control equipment in the U25B. A new Type FL7 Adhesion Loss Detection Panel replaced the original 17FM190 panel; a new Type FL10 Speed Sensing Panel replaced the original 17FM191 Automatic Transition Control Panel. It appears that the purpose of the new equipment was performance related, although details are not given; these changes are found only by comparison of a number of manuals. One alteration is the addition of circuitry in the FL7 panel that attempts to detect synchronous slip, not addressed with the earlier model, and which only operates upon a simultaneous high speed signal from all axles. This particular protective feature would be improved upon in later locomotives.

During late U25 production, GE had made available an optional All-Electric Wheel Slip System. This was basically the same as the original system without the SSBV, and included instant triggering of the slip relay. One GE representative noted, a few years later, that the actual air valve in the SSBV system was “like any other air component -- you have to maintain it properly or it isn’t going to work.” It seems clear that GE felt that the original idea was still good enough to retain, but also noted that some railroads had continued to buy the system on later units (U28, U30) and that some did not, and might have credited improper maintenance of the equipment with its operational shortcomings.

In the U30, GE kept the options of either Slip Suppression Wheel Slip Control, or else All-Electric Wheel Slip Control, but augmented both with new circuitry designed to detect and correct conditions not detected or corrected by the early U25/U28 systems. The new system could detect synchronous slip of all driving axles simultaneously at low locomotive speeds, and could detect simultaneous high-speed wheel spin of all axles as well. Two different circuits were used, one for each condition, while retaining the Axle Alternator detection system to monitor axle speeds.

With the new system, normally fitted without the SSBV, the ORS solenoid on the governor was not used in conjunction with the wheel slip detection to reduce excitation and thus power. Instead, the completely new excitation system (developed for use with alternator-rectifier transmission) employed inputs from the wheel slip circuit cards to immediately reduce excitation by action of reducing the output of the pulse-width modulator used to supply field to the exciter. This system was both more sensitive and much faster. (With the SSBV, only a slip condition longer than three seconds duration would trigger excitation reduction, sanding and operator warning; without, either in U25/U28 or the new U30 units, these latter actions were immediate.) In later U23 units with GT-581 (U23B) or GT-586 (U23C) generators, the new system was altered to, in fact, return to use of the ORS solenoid.

One of the features of the Universal Series locomotives from nearly the beginning was a system called Automatic Power Matching which reduced locomotive output under adverse operating conditions, which theoretically also had the advantage of reducing wheel slip. In the U25 and U28, this system was not triggered until an over temperature condition was detected in the traction motor shunt field windings (indirectly, by voltage drop.) This system pulsed the ORS solenoid on the governor to force the load regulator wiper arm to assume, on average, a lower field strength position; the pulses or cycles occurred at about 15 times per minute. The Power Matching Panel for the U25B was part number 17FM211C1, and our shop manual for the NYC’s U25B units instructs the setting of the resistor on this panel to correspond to a generator load of 700V / 2000A or about 1876 horsepower. The system remained operative until a timer circuit cleared, which ran seven minutes. Engine speed remained responsive to throttle setting allowing full ventilating air to the traction motors.

Statements by GE engineers at the time indicated that this Power Matching was as much to protect their warranty-covered traction motors on the U25B as it was to match the units to those with which GE units would operate. Regardless, this was the first system of its kind in the USA. This system was standard equipment on U25 and U28 units.

In the early U30 units for what appears to be several months of production, this system may have been retained. Mid-way through 1968, the locomotive manuals begin to describe the addition of a further static control panel in the electrical equipment cabinets: the 17FL24 Power Matching Panel. This panel was used to condition the reference signal for the aforementioned pulse-width modulator to effect a (constant, non-pulsed, non-timed) reduction in power at lower speeds when the locomotive was operating in series-parallel only. It appears by mention in the manuals, and in various statements by GE officials, that on the U30 the system was optional; on later U33B units it was standard, and optional on the U33C. U36B and U36C units followed the same pattern.

This card caused a limit of reference current with decreasing speed down to about 8 MPH in the U33B, below which the full normal range of current limit was available for starting. Above this speed, the reference current was limited essentially until the locomotive made transition to parallel. (Field shunting was not used on these locomotives, but transition was employed.) GE felt that no limit was necessary at speeds above that required for transition, and in fact, the temperature-triggered system on early units was also nullified at the time the locomotive made the transition from series-parallel to series-parallel shunted field (which for the U25B typically occurred at about 19 MPH with standard gears.) In the early system, if the time limit for power reduction (7 minutes) was not expired and the locomotive made forward transition to series-parallel with shunted field, and then back, the limit was still present; if the time had expired, and speed increased and then dropped, it would be necessary to have another over temperature condition to trigger the Power Matching again. In the later units, the system always operated (if fitted) in series-parallel. Both old and new systems could be adjusted, by rheostat, to finely tune the desired amount of power reduction and thus the actual minimum continuous speed.

One further feature included in the U33 (and added to the U30 after this) was the introduction of a rate of change limit on excitation. With this circuitry, there was a limit on how fast the excitation signal could increase, and was in effect at all times, and for any action (throttle manipulation, slip recovery, load regulator action.) One GE representative referred to this as “rounding off the notches,” meaning that no abrupt increase in excitation, and thus alternator output, was possible. This further improved (theoretically) the ability of the locomotives to hold the rail, especially the four-axle units.

As we can see, the systems fitted to the GE U-series evolved over time, and the changes did not necessarily exactly coincide with model changes either. At the time that the above improvements were introduced, one further addition was in the works as regards the wheel slip system, which first appears in manual GEJ-3868, an electrical equipment manual which is the first to cover models U23, U30 and U33. This addition is sometimes referred to as the Rate of Change system, and is also sometimes referred to (especially by GE engineers and representatives) as the Power Tie Circuit. These terms are proven synonymous by this manual.

Around the time that EMD introduced its new 645 line of locomotives, there had still been outside research going on not directly connected with the locomotive manufacturers. One such concept was the use of direct measuring coils, mounted on the traction motor leads, which could detect small but instantaneous changes in actual traction motor current. This system was developed and tested by outside companies and various railroads, but EMD essentially adopted it about one year after the new 645-powered locomotives were introduced, as its IDAC Wheel Slip Control System.

General Electric was still employing the same axle alternator units as primary detection as had been used since the U25. However, the challenges of maintaining adhesion with the U33B were proving daunting, and GE added a similar system in concept sometime around the middle of 1968 in its ROC or Power Tie system. This required the addition of yet another static panel, the FM262 ROC panel, and ROC slip sensing transformers. The power tie was connected between the midpoints of pairs of motors when in series-parallel; because of this location, with all axles rotating at the same speed, there should be either a tiny amount of current flowing through this cable, or else (usually) none. If one axle begins to slip, the amount of current drawn by the sets of motors will change relative to each other, and this would then cause current to flow in this power tie. The detection of slip by this indirect method was more sensitive than the axle-alternator detection. The normal wheel-slip system as previously described was still retained, but special circuitry was included to reduce the effect of the relay normally operated by the old wheel slip system when the ROC system relay was picked up. The new system also included the design consideration that rapid and frequent small slips would cause a proportional slight lowering of excitation (and an even more tapered power recovery) which would allow the unit to maintain the highest possible power in the given rail condition. In parallel transition, the ROC system was completely cut out.

This new system did not in any way require the use of axle alternators. Within several years, GE had developed it to the point that the old axle alternator system was deleted, along with its supporting circuitry, and all wheel slip detection performed by coils; this was the Current Measuring Reactor system, or CMR system, and while this system is normally associated with the later “Dash 7” units, one will note that a number of orders of late Universal Series locomotives completely lack axle alternators (except one for speed indicator/recorder drive.) This indicates application of this CMR system. Reportedly, this system could react in one thirtieth of one second.

This concludes our investigation of wheel slip control as applied to the General Electric Universal Series. GE entered the market with the advantage of high horsepower per axle, and in a sense bet its fortune on the concept of high haulage capacity combined with high power and nominally similar weight. The one Achilles heel of this concept was the ability of design engineers to cope rapidly enough with adhesion difficulties as the horsepower race accelerated between the builders, and we have seen that GE was more than mildly active concerning modifications to the U-series over time to address this problem. While many have faulted GE for locomotive quality issues in this early period, it is clear that GE was making every effort to correct the problems and still move ahead in power, allowing it to retain a competitive position -- which in the end helped to drive ALCO out of the business.

Source material for this document includes not only a number of GE locomotive maintenance manuals, but a series of lectures delivered to conventions of the Railway Fuel & Operating Officers' Association by GE engineers over a span of years covering models U25 through U33.

Tuesday, December 28, 2010

Lima's mythical 2-12-6

Here, for the first time anywhere, we present the rumored but never seen legendary Lima Locomotive Works proposal for a 2-12-6 locomotive. Often cited as the genesis of the awesome 2-6-6-6's of the Chesapeake and Ohio and the Virginian railways, this design has remained an unprovable myth. No longer.

Presented during the above group's meeting in Chicago, the report was written by none other than W.E. Woodard, legendary locomotive designer, and at the time Vice-President, Lima Locomotive Works. Unable to attend due to poor health, the report was actually presented by Mr. H.W. Snyder, Mechanical Engineer of the Lima Locomotive works.

Many aspects of super-power locomotive design were covered in this thorough and intelligent presentation, but what interests us here is the section about reduced locomotive maintainance. Woodard, and Lima, were advocating unitary machinery supports, and tandem rod drives. These served to reduce the distance between cylinder centers, thus greatly reducing the bending forces on pins, rods, and frames. A 4-6-4 and a 4-8-4 are shown using these principles, but below we see the ultimate extrapolation of 2 cyl. power, the 2-12-6. Cylinder centers as shown are only 88 inches, with bending forces well within curent limits, and actually less than some locomotives already in service.

The grate anticipated was 151 sq. ft., needed to supply the enormous cylinders. Their goal was to be able to replace 2-8-8-2's with such an engine, developing more power on less fuel and water. This 2-12-6 embodied all the then current super power features. By estimate, it would have evaporated a very impressive amount of water for 1928, and with limited compensated cutoff would have been able to use that steam to provide power at speed. It is the natural progression from their 2-8-4 and 2-10-4 engines, without articulation.

So here it is. It wasn't just a type discussed somewhere. This was presented in front of the leading motive power men in the railroading world. This presentation was followed by another given by A.W. Bruce, Designing Engineer, American Locomotive Company, on "The locomotive of today and the future as a factor in fuel economy." Excellent company to be in, and in front of which to present this awesome design.

The table above was given in the report after the drawing. This table shows not only the capabilities of the proposed engine vs. that which it was designed to replace, but Lima's design philosophy at the time. The new engine might not be able to start a heavier train than the Mallet, but it could move the same trains much faster on less fuel and water. The concept of power at speed was well understood by this time, and just as 2-8-4's were made to replace 2-8-2's, and 2-10-4's to replace 2-10-2's, providing more boiler capacity than the previous types, so was the 2-12-6 designed to replace an even bigger type, providing the same power at speed increase.

A major consideration in locomotive design used to be "clearances". Probably still is! That is, how big a locomotive could be and still fit everywhere on the railroad that it needed to go. Very accurate measurements were taken by the railroad along their right of way, and these were supplied to the locomotive manufacturer. A template was made, and the finished locomotive had to pass through it in order to be accepted by the railroad.

Virginian's famous 2-10-10-2's actually were too large to be shipped on most railroads. They had to be partly disassembled for their trip. The reason was their enormous low pressure front cylinders. Their total width was too big for many roads. This was in some cases the limiting factor for compound locomotives. Simple articulateds solved the clearance problem of the big cylinders, but 2-cylinder simple (non compounded) locomotives like 2-10-4's could press clearance limits with their large cylinders too.

Lima's unitary machinery support concept, used on the 2-12-6 proposal shown above, lessened the distance between cylinder centers. This allowed very large cylinders, in this case actually well forward of the first pair of drivers AND THE LEAD TRUCK (!!) without having an overly wide locomotive. Without this innovation, such a locomotive would have been impossible.

Another thing this design accomplished was to reduce the bending forces exerted on the cylinder saddle and main drive axles. This is because the main rods are closer to the wheels themselves, using shorter journals than would otherwise be possible. As the report states, reduced forces lead to reduced maintainance, an important factor in railroading. Locmotives in the shop can't make any money hauling trains. Lima's design innovations not only allowed for bigger, more powerful locomotives, but also ensured they would be out on the road hauling trains more often than not.

Would these locomotives have been successful if they had been built? We can look at Union Pacific's 4-12-2's for an answer. Built to replace compound Mallet locomotives, the 4-12-2's were expected to haul about the same trains as the Mallets, but faster and on less coal and water. They did indeed prove that they were able to do so. In this case, an unorthodox wheel arangement (the 4-12-2) was the right machine for the job. One can expect that had the 2-12-6 been made, and used in a similar way (as Lima's comparison targets) to replace Mallets, the results would have been at least the same if not better.

Sunday, December 19, 2010

General Electric FDL Diesel Engines - 4


This engine seems the hardest to quantify in terms of initial changes using the available manuals although some things are fairly clear. What seems clear is that by at least 5-70 a new engine cross section drawing (GE E-16188) has appeared in the manuals; the new Diesel Engine Mechanical Service Manual GEJ-3869 contains this drawing at that date for, we believe, the first time and this manual is the first to cover the 3600 HP 16-cylinder engine for the U36 series; thus the first and most obvious change is the increase in fuel rate for the FDL-16F at 3600 HP.

Other locomotives already in production soon changed to use of the F engine, including the U23 and U30.

In terms of manufacturing alterations in the "F", one change that clearly was due to the uprating of the engine was the provision of a second oil drain hole in the underside of the piston crown cavity on the pistons fitted to these engines. GEI-81976, Instructions for Connecting Rods, Bearings and Pistons (and which is a component part of large binder GEK-30130A) instructs that earlier engines should be modified by drilling the second set of drain holes into the piston crowns. These pistons, it is important to note, are NOT yet steel-capped pistons.

A new heavy walled cylinder liner also appears in this time frame, omitting an external jacket (the old style is called "belly band liner" in GE manuals) and thus making the cylinder assembly essentially revert to a wet block construction, since the outer water boundary is again the inner boundary of the cylinder assembly. In the same parlance this new liner is called the "Annular Groove" liner, and on this style the interior was either chrome plated (requiring iron piston rings) or Tufftrided (requiring chromed piston rings.) Further, it appears that on the "F" the change to holding the cylinder head in place using the liner, instead of bolts from the head to the cylinder jacket or cylinder assembly, was made (although this may have occurred late in "E" production and during overhaul GEK-61273 instructs for the omission of these bolts on all engines... Note twice now the instruction to make alterations to in-service engines that essentially convert them to "F" engine features.)

At least one railfan oriented publication stated (quite some years back) that the U34C introduced steel-capped pistons. This may in fact be the case, especially since the U34 is listed in GEK-30130A as being equipped with the FDL-16F. However, since the date of publication of this particular table is 2-76 and reprinted 9-77 this may also reflect upgrading of all of the engines in this model of locomotive to "F" status. One cannot be sure, at least from this material.


According to the manuals, a number of changes were made to the production FDL diesel engines in 1973. This appears not to have made a difference in the letter designation of the diesel engines, however. These changes are spread throughout the various instructions and descriptions and appear to be a number of small refinements all essentially implemented at one time.

Up until mid-1973, all FDL engines had incorporated intake valves with 45 degree intake valves (the angle of the seating surface to the valve centerline.) Apparently, according to a GE technical paper in our collection, valve seat recession was experienced. The modification to remedy this was to alter the intake valve design to 15 degree seating surfaces and this occurred in mid-1973 on some engines, and by the 10-78 print date of GEK-61273 all production engines incorporated this change. This same instruction orders that no exhaust valves with a date stamp prior to 8-68 (and those with no date stamp at all) should be remanufactured, but instead scrapped due to questionable quality.

A modification to the governor drive assembly occurred at this time, and the new drive with an adaptor was then furnished any time the complete previous assembly was requested as a replacement or spare for engines in the field.

Steel crown pistons, using a steel cap bolted to an aluminum body, probably appeared in testing applications on production engines near the inception of the "F" series initially, as hinted at by the fact that the GE illustration number for the steel crown piston is fairly close to the illustration for the new diesel engine itself (which does NOT include these pistons.) It seems that by the 1977-1978 general date of the Conrail manual that is our primary source, these were production standard for all FDL engines in 8, 12 and 16 cylinders.

Also at this time all FDL engines were changed to a fuel header pressure of 39-41 psi. These used the same (large) fuel pump system as previously employed. Older locomotives could be altered to use the new pressure but had to have the fuel racks reset; the locomotive had to be on a load box if the low pressure, large pump system in more recent locomotives was to be converted.

There appear to be numerous other small changes; these are only a few at the time. We'll now turn briefly to a look at the FDL-12 series in domestic U-series locomotives.


The FDL-12 in all references had no lower model delineation than "B" - so that the first FDL-12 model in GE locomotives by these tables (which never give dates) is FDL-12B. This seems to correlate in some way to there being no sixteen cylinder engine with the letter "B" so that in the early days of the Universal series (for export) and then the U25B, the A engines were 16 cylinders and the B engines were 12 cylinders. (Interesting that the "A" variant was for the domestic U25, which appeared later - giving some further credence to the wide assertions that GE intended to enter the domestic market from the start.) This slightly complicates correlation of engine models, though. It appears that after the early production, the FDL-12 used the letter B and D for export models U20 and U22, model C and F for domestic U23 models, and model D for export models of U23 and U26.

Item: The engine model listed for the U50C is FDL-16D, at 1050 RPM maximum.

Further Item: We know from manual evidence that the U50C, and from first hand operator evidence (thank you, Noel Weaver) that some of the Penn Central U23B units used a modified engine speed schedule whereby the engine operated at half speed in notches 1 through 4 and full speed in 5 through 8, with variation in tractive effort by excitation only. This engine speed schedule or description of any such NEVER appears in this Conrail manual; we imagine this variation to be quite rare as a result of this finding.

Whatever the case, the 12-cylinder engines are covered by this same large manual and delineations are almost never made in the material so that we can be sure the same lineage of modifications occurred to the FDL-12 (and also the FDL-8) even if the engine model letters did not match up, at least for the first few years.

We hope you've enjoyed this series on the known (or rather, UNknown until now) model delineations of the GE FDL series engines. I have many engine illustrations to show and those will be coming along shortly.

Wednesday, December 15, 2010

Baldwin - BLH Diesel Engines in photos -2

If you haven't seen our first installment in this series, please take a few minutes to find it and read it to get the whole story -- and the piece (all text) on the mechanical history of the 600 series engine won't hurt either. We are not going to show EVERY photo in our whole collection, but will show the majority.

Let's pick up our study of engine photos with the beginning of 600 series engines that were released for service .. in other words, right after the prototype engines.

This photo comes from the Baldwin magazine, first quarter 1946 in which the new 3000 HP locomotive for the Seaboard Coast Line is announced. The photo is of one of the two 1500 BHP 608SC engines constructed for use in this locomotive; this shot appears to be the only shot we are using here that is duplicated anywhere. (Kirkland's book uses a copy from the same negative, apparently.) Again, notable are the lube oil filters mounted to the side of the engine.

Bulletin 249 (no date) was an advertising brochure produced by Baldwin for its 600 series engines for all types of service. Even with no date, it's easy to tell that it's early because the two engine shots depict the engine-mounted lube oil filters like we've been seeing all along. This engine is the production version of the 606NA, which was rated 660 BHP.

Here, also from Bulletin 249, is the short-lived production 608NA engine, rated 1000 BHP. This engine was not built for long before Baldwin decided that a six cylinder turbocharged engine with identical rating was a better choice than this eight cylinder normally aspirated engine.

This smaller image is from Baldwin DE-100, Diesel Engine Manual / 600 Series. This was the very first manual for these engines, and shown is the early production 608SC engine identical to that shown earlier as depicted in the 1st quarter 1946 Baldwin magazine. 1500 Brake Horsepower, eight cylinders, turbocharged.

Now, we'll end up our look at these engines - at least externally - with the final round of engines built by Baldwin, which of course by this point was Baldwin-Lima-Hamilton. (Note; The company did build the Hamilton T69SA and T89SA engines after the merger, and also used Superior engines for export locomotives; we'll be showing those engine ranges in future articles.)

Baldwin 606 engine. Six cylinders, normally aspirated. 875 brake horsepower; 800 horsepower for traction.

Baldwin 606A engine; 1315 brake horsepower, 1200 horsepower for traction. Six cylinders, turbocharged. Final turbocharged six-cylinder variant shown in final Baldwin 600 series manual, DE-111A.

Baldwin 608A engine; 1750 brake horsepower, 1600 horsepower for traction. Most powerful engine employed in any Baldwin or BLH diesel locomotive.

SO, there's our quick look - mostly externally - at the range of Baldwin / BLH diesel engines to go along with the posted discussion on the development and progression of the 600 series engines. I hope you've enjoyed it.

Baldwin - BLH Diesel engines (VO, 600 series) in photos 1

Yesterday, I made a post about the mechanical progression of the Baldwin 600 series diesel engines, which really is an updated post of a piece I wrote about five years ago or so and put on my original website. I've reproduced it here, minus the photos as I mentioned -- but today I've got FAR MORE photos ready than that original site ever had.

One note - These photos come from a variety of sources in our collection, namely the VO Diesel Engine Maintenance Manual, BLW/BLH manuals DE-100, DE-104, DE-111 and DE-111A (600 Series Diesel Engine Maintenance Manuals), a Baldwin Magazine from 1946, an undated Baldwin-Westinghouse sales brochure, and BLW Bulletin 249 which is a sales brochure for the 600 series engine for various kinds of applications (in other words, not just for locomotives but for stationary power.) All original source material.

Even though we didn't discuss the VO engine in the previous post, let's start with a few views of this engine.

Here is a three quarter shot of an eight cylinder, 1000 BHP Baldwin VO engine. Note that this engine uses the main production version of the engine frame that only includes a half-circle mounting for the main generator, which Baldwin found problematic and changed after the war when it was allowed to do so. Note also the two lube oil filters on the side of the engine; these are a hallmark of VO and early 600 series engines.

Here is a cross section view of the Baldwin VO engine. Readers should immediately examine the cylinder head, and notice the ovoid (egg-shaped) combustion chamber contained entirely within the cylinder head, and connected to the cylinder working volume by a cylindrically shaped passage. All of this is cast into the head. This antiquated design came from the days when atomization of fuel was problematic; this could be remedied by forcing all the air into a small volume, with induced swirl, which would start combustion in the small chamber upon fuel injection and heat all of the mixture to the point that any larger fuel droplets would hopefully both atomize and burn completely as they spread into the working cylinder. What this means, though, is that a large amount of heat is liberated in the cylinder head - given to lube oil and cooling water - and that it's impossible to cool this combustion chamber with intake air. This makes the heads run hot and makes a definite ceiling on fuel rate due to liberated heat. This is why Baldwin had to convert to (more modern, more conventional) open combustion chambers with its new 600 series engine in order to get any increase in power.

Next, at left, we have a late VO series 8-cylinder 1000 HP engine. Note the late-model alteration to include a main engine bed that has large extensions or arms to mount the generator much more solidly than the half-circle flange used previously. Note also the lube oil filters. This engine looks very much like the later 608NA but the sure way to tell is to look at the fuel pumps and push rod tubes. On the VO engines, the fuel pumps are on the cam deck between the intake and exhaust valve push rod tubes. On all 600 series engines, the fuel pumps are BESIDE the push rod tubes. This always works as an ID feature.

Baldwin developed its new 600 series engines while the war was in progress, using some new components and some VO components. Two fascinating shots are found in a Baldwin-Westinghouse sales brochure we have. One of these engines has been seen before in Kirkland's book in a different shot; the other one has not.

This is the shot we're sure hasn't seen light yet. This is certainly the prototype 608NA engine. Note the clear 600 series fuel pump and push rod arrangement, but note the use of the half-circle flange mount for the generator and the two lube oil filter tanks. Note also the four exhaust stacks. We can guess a bit more after seeing the next picture.

This is the prototype 608SC engine. This engine is shown, in a different picture, in John Kirkland's book and in that book Kirkland mentions that only this engine was built this way - with a mix of old VO style and new 600 style components; again note the half-circle flange mount for the generator. Surely the previous photo contradicts this unless we assume that the engine was first built and tested as a normally aspirated, 1000 BHP unit and then altered and turbocharged to produce the 1500 BHP prototype seen here and in Kirkland's book. This assumption seems safe enough, but again it is only my assumption. From an engineering standpoint it would make perfect sense.

Next post in this series will continue with the 600 series engines in every variant we can get a photo of, so keep looking back.

Tuesday, December 14, 2010

Baldwin - BLH 600 series engine history

THIS CONTENT was originally published on my locomotive site a number of years ago. I've decided to put it back on the net on our new site. I have totally cut and pasted it from my own site page at the internet archive but the PHOTOS are not included. I will try to get all of those, and some more, including shots we have of some of the prototype engines that haven't seen the light of day before, up on this blog in the near future. So please ignore photo references in the text.

Baldwin / Baldwin-Lima-Hamilton 600 series diesel engines 1946-1956.
Following the failure of its multi-engined road locomotive concept, which effectively ended the Baldwin 400 series engine's future, the company decided to center future locomotive production around a thoroughly redesigned version of the VO engine, to be known as the 600 series. Paramount to the new engine's design was the ability to accept turbocharging; the cylinder heads had to be totally redesigned to eliminate the integral combustion chambers of the VO in favor of the modern open chamber design (in which fuel is injected directly into the cylinder volume.) New, saucer-top pistons were developed. The entire engine structure was redesigned and reinforced, including much heavier crankshaft and connecting rods; the new engine would be required to develop a rated 1500 HP, which was 150% of the rating of the previous 8-cylinder VO.

The new engine series was phased into the various locomotive lines in a slightly hodge-podge manner. The basic details of the new engine lineup immediately after the end of the Second World War are seen below. Note that all 600 series engines were 12.75" bore, 15.5" stroke and ran at 625 RPM maximum.

606NA 6 cylinders, normally aspirated. BMEP = 70.6 psi. 660 brake HP.

608NA 8 cylinders, normally aspirated. BMEP = 80 psi. 1000 brake HP.

608SC 8 cylinders, turbocharged (Elliot BF44.) BMEP = 120 psi. 1500 brake horsepower. (This engine is pictured at left, in its earliest production configuration. From Baldwin Diesel Engine Manual DE-100, published 1946 and revised 3-26-47, 4-9-47, 2-1-48, 5-1-48.

Baldwin decided, shortly, to replace the 608NA engine with a new, turbocharged 6-cylinder engine. This engine is added to the aforementioned DE-100 manual in the 3-26-47 revision; details for it are as follows.

606SC 6 cylinders, turbocharged (Elliot BF40, known as "two exhaust pipe" type, or Elliot BF34, known as "three exhaust pipe" type.) BMEP = 106.7 psi. 1000 brake HP.

It should be noted at this time that Baldwin was advertising and rating its locomotives based upon the brake horsepower rating of the diesel engine. ALCO-GE was also using this system with its locomotives powered by 539 engines, but had decided to rate its road locomotives, powered by 244 engines, using the "horsepower for traction" rating which indicates power delivered to the generator. This theoretically placed Baldwin at a slight power disadvantage, which it eventually corrected later.

The original DE-100 manual stipulated that main bearing alignment be checked at intervals of once per year, or every 300,000 miles. The revision of 5-1-48 shortened this to every six months or 50,000 miles. The 5-1-48 revision becomes more specific about procedure of mounting the generator to the engine and checking its alignment. The engines were still using shimmed main bearings at this time; drawing D-1004 in DE-100 shows the comparative placement and thickness of the bearing shims. Some of the locomotives still used lube oil radiators; some used the full flow oil filters, some the bypass type. The 2-1-48 revision appears to be the one to include the three-pipe, or BF34, turbocharger for the 606SC. In general, it is clear that, at this time, the engine had been improved from the VO, but many design details were being altered in the period 1946-1948 and that some of the original sources of complaint (oil radiators, shimmed crankshaft bearings, for example) had still not been eliminated when the 600 series engine appeared.

Baldwin Diesel Engine Manual DE-104 was the next manual issued, and while the first printing date is not known, it was revised in 5-15-50 and 11-1-50. It is assumed that the original printing was likely in late 1949 or early 1950. In this manual, it is made apparent that numerous changes have been made to the engines. Probably the most important to modern railfans, and the least known, is the fact that Baldwin changed over at this time from rating its locomotives by the brake horsepower of the engine to rating the locomotives using the newer "horsepower for traction" method. Baldwin increased the actual power output of the engines without altering the advertised ratings of the locomotives. Below are the 1950 specifications for the three engine models in production (first built in January 1950 and contained in DE-104 on a revision page dated 5-15-50.)

606NA 6 cylinders, normally aspirated. BMEP = 88 psi. Compression ratio 14.88:1. 825 BHP. HP for traction 750.
606SC 6 cylinders, turbocharged (as before.) BMEP = 120 psi. Compression ratio 13.45:1. 1125 BHP. HP for traction 1000.
608SC 8 cylinders, turbocharged (as before.) BMEP = 130 psi. Compression ratio 13.45:1. 1625 BHP. HP for traction 1500.

New, Tri-Metal shimless crankshaft bearings replaced both the (shimmed) gridded and babbitt types used prior. Bearing dimensions remained the same, as did valve dimensions in the cylinder heads. The following are the given cylinder conditions at full load: 606NA max compression pressure 540 psi, max firing pressure 1015 psi. 606SC max compression pressure 720 psi, max firing pressure 970 psi. 608SC max compression pressure 750 psi, max firing pressure 1000 psi. Maximum exhaust elbow temperatures in the same order were given as 950, 850 and 900 degrees; thus, the normally aspirated engine had the highest exhaust elbow temperature. Valve timing for the engines depended upon whether or not they were turbocharged, and also upon whether or not the engines had the older "Saucer top" pistons with a concave piston crown, or the new "Hesselmann" pistons, sometimes referred to in the field as "Mexican Hat" pistons, as these had a depressed top portion with a pointed, raised center. Fuel injection timing also differed between piston types as well. Thus, for six-cylinder engines there would have been four different camshafts available (normally aspirated with saucer pistons, normally aspirated with Hesselmann pistons, turbocharged with saucer pistons, turbocharged with Hesselmann pistons.)

Baldwin issued its Diesel Engine Manual DE-111 on 9-15-50, which covered the next round of revisions to the 600 engine. The largest change was the inclusion of a substantially larger and heavier crankshaft; all of the bearing bore sizes increase, and lifting weight of the crankshaft increases as well. It appears that upon issuance, Baldwin was beefing up the bottom end of the engine to accept a further power increase. This happened shortly thereafter. The following ratings are included in this manual, on a page dated 6-15-51.

606 6 cylinders, normally aspirated. BMEP = 93.5 psi. 875 BHP. HP for traction 800.
606A 6 cylinders, turbocharged (Elliott H503.) BMEP = 140 psi. 1315 BHP. HP for traction 1200.
608A 8 cylinders, turbocharged (Elliott H704.) BMEP = 140 psi. 1750 BHP. HP for traction 1600.

Cylinder conditions at full load are given as follows: 606 max compression pressure 540 psi, max firing pressure 1120 psi. 606A and 608A max compression pressure 690 psi, max firing pressure 1120 psi. Max exhaust elbow temperature 1000 degrees F for normally aspirated engine, and 925 F for turbocharged engines. The increases in power over the time the whole 600 series was in production had been produced by increase in fuel injection amount, involving both volume and timing, as well as boost pressure and thus scavenging effect and compression pressure. No increase in engine speed was needed to increase from the 1000 brake horsepower of the 608NA all the way up to the 1750 brake horsepower of the 608A.

At the very late date in Baldwin history of 2-1-55, manual DE-111A was issued to cover further revisions to the engine. These changes were very slight -- including changes to the crankcase breather design, engine air filter design, and others. One change of note was that the engines themselves became several hundred pounds lighter, for reasons which are not explained. This manual is also the first to contain a complete section on engine speed control applicable to all optional setups, including both types of air throttles available (D-1 and CE-100) as well as the 8-step electric throttle, and also includes data for the UG-8 and PG types of Woodward engine governors. (Most Baldwin manuals are specific, and thus there is a wide variation of manuals --- this is why this one, applicable to any optional combination, is unusual.) Looking through this manual reveals that the vast majority of important changes had already occurred prior to a date of 1953 (some of the pages in this manual carry this date) and most likely all of the last-generation changes physically date to 9/50, with the last uprating likely 6/51.

There you have it -- the complete breakdown of important evolutionary changes to the post-War Baldwin / Baldwin-Lima-Hamilton 600 series diesel engine. It is apparent that Baldwin continuously tried to improve their product, but for too many railroads it was not enough. Even though the late locomotives were greatly improved in reliability, the serious shortcomings of the VO and very early 600 engines caused many railroads to abandon Baldwin as a serious supplier of diesel locomotives.

Westinghouse Gas Turbine - Electric Locomotive 3

Here's our final look at the Westinghouse Gas Turbine locomotive which was first operated in road service in May, 1950. Our primary source is a previously described (see older posts on this blog) specification book produced by Westinghouse in June 1952.

Westinghouse drawing number 55-J-87, described below.

It appears that in terms of test or prototype gas turbine powerplants for locomotives, Westinghouse was first out of the box with its 2000 HP prototype being operated from September 1946 until December 1948 at its plant before being shipped out to the field, modified, as a stationary plant for further evaluation (which Westinghouse of course monitored.) General Electric's prototype gas turbine plant for locomotive service operated at its plant in Erie from September 1947 until August 1948. Westinghouse indicates that its test unit operated 1500 hours; Railway Age reported in 1949 that GE's test unit operated 700 hours. Unlike Westinghouse's test unit, though, the GE unit was placed immediately in a newly-designed locomotive, lettered and numbered as "ALCO-GE 50" and placed in test operation very shortly. Extensive testing of this ALCO-GE prototype on the Union Pacific in 1949 revealed that the locomotive worked; according to Don Strack, UP had already ordered a production batch of locomotives before the end of 1950. The first was delivered in January of 1952, several months before this specification book was issued by Westinghouse covering its gas turbine locomotive.

It would then appear that Westinghouse re-issued the specification with slight revisions (the book indicates that the diagrams and line drawings supersede previous data) and put this binder out to the railroads in hopes of getting some action, as it were, before it was edged out of the gas turbine locomotive market. The fact of the matter was that all of the members of this locomotive family (Westinghouse, offering straight electric locomotives including Ignitron rectifier units, Baldwin and Lima-Hamilton, and Whitcomb) were essentially only marginal players at this point. Further, GE had an advantage with the gas turbine locomotive in simplicity and very likely in fuel economy in developing 4500 HP for traction with a single gas turbine powerplant while Westinghouse chose to use two powerplants to develop a total of 4000 HP for traction.

AS AN ASIDE, a very interesting notation appears on Westinghouse Drawing Number 55-J-87 which is included in the specification book. This drawing is labeled as "4000-4500 Locomotive Arrangement." If this carries any weight it would appear that Westinghouse was considering a 2250 HP net output for its gas turbine plant. However, Railway age reported in 1949 that while the locomotive rating ALCO-GE was publishing was 4500 HP, the gas turbine's nominal rating was 4800 SHP at highest normal altitude (for railway service) and temperature, and 5000 SHP at sea level but that the unit could possibly tolerate operation with higher turbine inlet temperature at 6000 HP and finally that in testing in cold weather the unit had actually been tested at 6400 HP. Clearly then, while it is possible that Westinghouse may have uprated slightly to match the as-built 'first generation' GE turbines, GE also had plenty of horsepower growth available - far in excess of what Westinghouse could have matched, without major redesign.

Getting back to our story line, having covered much of the operational data and the developmental story all that's left is to describe the mechanical layout of this prototype gas turbine locomotive. For that we'll use Westinghouse drawing 57-J-844 from the specification book, which is the Layout & Servicing diagram.

Starting at the left side of the drawing, we note that there are two large air brake equipment racks in the nose of the locomotive, flanking the vertically mounted front traction motor blower serving both front trucks. The blower motors are Westinghouse Y-400A units; each blower was rated 12,000 cfm air flow. Central also is the heavy fuel filler pipe, above which is a hinged door in the top of the nose. Also present in the front compartment is the UE-23 Traction Motor Blower Alarm relay, warning of blower shutdown. In the cab, the engineer's position is fairly typical for road locomotives of the time, including a pneumatic throttle. In front of the fireman's position are a remote steam generator control panel and a hand brake.

Moving into the engine room through a centerline door we find, each side, a large 5000 gallon water tank and behind these two electrical equipment cabinets. Outboard of these, and accessible are various control and indicating panels and the TS-31-D Load Regulators, part of the complex load control scheme required by the nature of the gas turbines' load profile. The front end of each powerplant is a Westinghouse 2-cylinder air compressor; inboard of these, flanking the central walkway are the operating handles for the two XC-623-H Starting Controllers. We imagine these are used only for individual powerplant startup. Outboard and below the air compressors are the YG-53-A Pilot Exciters, which have mounted on front shaft extensions A-80 Tachometers. Behind these we see the large auxiliary generators mounted directly to the front of the main traction generator groups, and on top of these are the four exciters. On top of the front end of the actual gas turbine compressor housings are turning gear motors, used to operate the turbine shafts at very low speeds (required during cooldown for prevention of rotor bowing) and alarm lights indicating dirty intake air (probably a D/P cell.) While the locomotive has three engine room ventilating fans, the larger one over the turbines is a Y-44D motor providing cooling for the turbine lube oil. Below the turbines are Y-109A auxiliary lube oil pump motors and Y-202A fuel pump motors. Overtemperature thermostats, with resets, are located in the engine exhaust pipes; under the left-side exhaust elbow is an auxiliary air compressor driven electrically by a Y-204-A motor. The unit on the left of the engine room behind the left turbine is a standard Vapor steam generator, and on the right is a Babcock & Wilcox custom exhaust heat generator; water is supplied to the exhaust steam generator by a Y-109-B motor driven pump.

Next are two further large water tanks, with the rear traction motor blower at center, sanitary facility at right rear, 75 HP auxiliary diesel left rear, and auxiliary and signal power cabinet at centerline. Item 65 on the drawing is a TK-168-A Hostling Switch, probably used to direct power from the auxiliary generator to a traction motor or pair of them for hostling moves.

The drawing indicates a total capacity of 3850 gallons of heavy fuel in main, or underbody tank, and I-beam tanks. Total diesel fuel capacity 500 gallons. Traction motors labeled as model 370K. The rear traction motor gear cases, #7 and #8 were using an experimental lubricant (Sinclair Jet Lubricant TM) in place of the normal prescribed lubricant. The cab was heated only by steam.

THAT about covers the Westinghouse 4000 HP Gas Turbine Electric Locomotive in as much detail as we need to get a good idea of its design, history, construction, and competitive position in the field at the time. I hope you've enjoyed it!

Sunday, December 12, 2010

Even MORE General Electric brochure photos

Yet another round of GE sales brochure photos. Hopefully this will help occupy our many snowed-in friends in the Eastern half of the US.

Let's lead off with another view of the locomotive that heads this blog, namely the experimental General Electric road locomotive no. GE 750.

General Electric 750. Four unit experimental road locomotive, built in 1955. Length overall 212 feet, weight in working order total 490 tons- all on drivers. Rated 6000 horsepower. Operations totaled over a million unit miles under testing, mainly on the Erie Railroad (for which the locomotive was painted.) Two units contained Cooper-Bessemer FVBL-8T engines rated 1200 HP for traction; two units contained Cooper-Bessemer FVBL-12T engines rated 1800 HP for traction.

Chicago, Rock Island & Pacific No. 206, General Electric model U25B.

Assembly of FDL-16A diesel engines. General Electric decided immediately upon separating from the old ALCO-GE agreements to develop the Cooper-Bessemer F series engine for locomotive service, namely in 1953. In 1954-1955 GE built a diesel engine lab at Erie, and in 1958 took design and development responsibility for the FDL diesel series from Cooper-Bessemer, who still built the engines for GE at its Mount Vernon, Ohio plant until early 1963 when assembly was transferred to Erie, Pennsylvania at GE's plant. In this illustration the nearest engine frame lacks cylinder assemblies; a technician appears to be checking or finishing the bores for pushrods and fuel pumps. The next most distant engine is having its last cylinder assembly installed in the frame by overhead hoist.

Cylinder assembly, seen in cutaway. From sales brochure for U30 locomotives; depicts FDL-16D assembly. Note valve box on top, with valve spring visible; steel cylinder head is visible in center, containing valves and injector nozzle (hidden inside) while removable cylindrical cylinder liner is seen at bottom.

Detail of (circular) cover illustration for U33 sales brochure. Unit closest camera is GE 301, one of the original four U30 test/prototype/demonstrator units that was converted to U33 by the time of this brochure's printing. More interesting is the unit at left, obviously another U33 but numbered "308." There was no GE 308 that we know of; either this number was applied (very well) by an artist for this photo and perhaps the unit was built for, perhaps, NYC or perhaps there was going to be a GE 308 which ended up being one of the two pre-production U33 units built for NYC that were mixed right in with a large order for U30 units. Pure speculation, but this illustration has puzzled me for years.

MUCH more to come!

Saturday, December 11, 2010

More GE pictures, and a cab shot as well

I hate to just put up technical jargon - so it's time for a few more pictures, as always from actual sources. Let's use some of the early GE sales brochures.

At left is a small shot included in the 1960 brochure announcing the U25B locomotive. This shot is of unit 751 coupled to what appears to be an ERIE F3B, obviously during the testing period that preceded announcement of the model. Note the original configuration with no front rails or platform. GE 751 and 752 carried the designation "FG-24" under their road numbers during this period, indicating "Freight, GE, 2400 HP." That FG-24 label is clear in another detail shot we won't show here, which was meant to show under-cab compartment details.

Here are GE 751 and 752 together, after modification and during the period in which they were demonstrating as U25B units, prior to construction of the four-unit set of production U25B demonstrators, units 753 through 756, in early 1961.

At left is a great color shot included in a large binder that GE issued to advertise the U25B, showing the lowest numbered unit of the 1961 U25B demonstrator set. GE seems to have used this shot with at least one other airbrushed background. This large binder includes a sales brochure, a specification booklet, and several transcripts of technical lectures delivered concerning the U25B and its development. In the sales brochure is an interesting illustration, shown next.

This shot seems to depict a control stand and instrument layout between two of the previously shown ones (see the older post on GE control stands.) Judging by the layout of switches, the addition of a power limit switch but the placement of the ammeter on the bulkhead instead of in the instrument panel below the front window, it would appear that this exact control stand and instrument layout would apply perhaps only to the four-unit demonstrator set 753-756 considering that the operating manual shows the layout with ammeter in the front panel. This might be splitting hairs, but it's sensible guesswork and provides an interesting in-depth addition to our study of early GE control stand layouts.

Stay tuned to our blog for MANY more materials from all of the locomotive builders.

GE FDL Diesel Engine - Installment 3

FDL-16D... There is evidence to suggest that the C and D engines are for all practical purposes identical, with the exception of governed engine speeds (the A and C engine both had idle speed set at 400 RPM and full speed at 1000 RPM) with an increase in full speed to 1025 RPM. Idle speed remained the same.

While I'm at it, I should mention that all FDL engines from A through F series had a compression ratio of 12.7:1. We cannot be sure as to when or how camshaft profiles may have changed; this is not referred to generally and you'd need a parts manual to get that detailed information.

Returning to the near identical features, mechanically, of the C and D engines: An interesting blurb in The Railway Gazette, October 1, 1965 (provided us by Steve Palmano) announces the introduction, expected in May 1966, of the GE models U28B, U28C and U56. The short article states that while these models will be introduced at a 2800 HP rating, due to the limits of DC transmission (in particular generator size) GE was developing an AC/DC transmission to be employed at first in test units and then later in production locomotives (which we now know to all have been pre-production U30 units.) At that point, ALCO had developed, and EMD announced, 3000 HP units. What's important here is to note the concurrence in development of the 2800 HP powerplant and the 3000 HP powerplant, and considering the lack of any hard data in our mountain of manuals to indicate that other than governed speeds and fuel rack settings there's a difference of any significance between the "C" and "D" engines, we'll have to assume they were just different designations for essentially the same engine.

The sales brochure we have for the U30 actually for once mentions engine model by name, calling the engine "FDL-16D." Interestingly, the brochure also says that the engine's fuel-air ratio was properly maintained by monitoring the engine air supply - but we cannot find any such indication in either the Diesel Engine manual for the U30 (we have several, the earliest being GEJ-3847 printed 3-67) or the Educational Manual for the U30 (our earliest being GEJ-3849, printed 4-67.) This sounds like either a reference to an early two-slope pressure-bias engine control governor or to the overspeed / derater link which both actually appeared on production "E" engines, which we'll describe shortly. The sales brochure is, by the way, GED-5646 dated 2-67.

A large number of changes were introduced with the "E" engine. Following the introduction of the "E" engine, the same engine was used for both the new U33 locomotives and for the already in-production U30 locomotives. Up until this point, GE had dropped lower horsepower models when higher power units were developed, but popularity of the U30 caused it to remain in production alongside newer models. Thus, while the U30 began production with the FDL-16D, it progressed to the FDL-16E and later even the FDL-16F all the while being rated 3000 HP for traction. This may be the root of the old railfan saw that says that all GE models were alike except for fuel rack settings, but as we see now the situation was far more complicated.

FDL-16E This engine was that developed for production use at about the time the U33 was introduced, and apparently it included a very large number of test-proven developments GE had been working on in a wide variety of areas. We will not attempt to list these in any specific order but will use first the U33 sales brochure we have, printed 11-67 to hit key points that GE thought worth advertising heavily.

The "E" engine finally did away with the original overspeed protection system, in which an overspeed governor caused, on trip, a butterfly valve to shut in each intake manifold to cut off intake air. On the "E" and later engines, an overspeed - derater link is installed in the linkage between the governor control arm (or mechanical output) and the fuel rack linkage. On this device, trip of the overspeed governor will dump oil from this large, more complicated than it looks inside than out, coffee-can shaped link device causing it to expand under its own spring pressure (which the governor oil was overcoming) and pull the fuel rack linkage in the "less fuel" direction. This motion is enough to kill the engine. With oil pressure applied the device was a simple mechanical link. The other function of the device was to derate the engine if intake manifold temperature was too high (signaling a turbo problem, or plugged intercoolers, etc.) Wax filled actuators, inside the unit and supplied with a bleed of intake air, served to expand the actuator and reduce fuel rack setting if intake manifold temperature was too high.

The "E" engine also included a two-slope pressure-bias load control scheme governor, which simply means in GE parlance that the governor was able to control load on the engine, and fuel rate if needed, based on the actual intake manifold pressure. This both reduced engine wear and reduced smoke. The governor was set up so that if limit were needed, the load regulator would be operated to reduce load before the governor acted to reduce actual fuel rate. This type governor was capable of reducing both to the point that engine operation with a totally failed turbocharger was possible without engine overheating.

It appears that on the "E" engine, the Elliott H581 turbocharger was replaced with the Elliott BCO65, and that intercooling capacity was increased. A new cam profile was introduced on the "E" engine, according to the sales brochure: "New valve timing and new high-lift cam contour to improve engine breathing and reduce temperatures." On the fuel side, a new high-capacity fuel pump was included and this forced a change in the engine frame deck design to accomodate it. This is always called the "large fuel pump" or "large style pump" in GE literature. Engines were now also set to use a lower fuel header pressure (33-37 psi tolerance for old 'small fuel pumps' with the new "E" "large" pump system using a fuel header pressure of 22-24 psi.)

THAT'S IT for this installment. In the next, and final, installment we'll detail the upgrade to the "F" engine, and some later changes as well as trying to detail the confusing and non-matching progression of FDL-12 model numbers.

Thursday, December 9, 2010

Early General Electric Control Stands

Yesterday's post on the FDL engine progression was a bit dry.. so today let's have some pictures! We'll examine the early control stand setups of the U25, U28 and U30 locomotives.

Many people are not aware (anymore) that the U25 locomotives that had high short hoods used controller cabinets that were mounted very high up on the cab wall, leaving space BELOW the controller for the brake equipment. This design was not used on any of the early Universal series locomotives that we know of; rather, it was introduced on the test U25 prototype units numbered GE 751 and 752 along with the new 16-notch KC-99 Master Controller that it contained.

We have here with us a rare find - and a large one! It's a huge GE manual titled GEI-92215A Maintenance Manual Model U25B Diesel-Electric Locomotive 2500 HP. This manual is specific to the New York Central System, and covers road numbers 2500-2529 and 2530-2559. Publication date is 12-64 and only 50 copies were made. We'll use this to give details on the controllers (such as can be found, anyway) after we see the pictures from various operator manuals.

First up.. GEJ-3807, covering prototype U25B locomotives 751 and 752.

Here is the first of two control stand illustrations from this manual. Units 751 and 752 had both different control stand arrangements and different air brake equipment. The manual (oddly) doesn't tell which was which, so we'll just describe this as the first illustration, which of course it is. This unit had 24RL brake equipment, operating handles of which are seen at lower left. Note the controller cabinet location, with throttle handle on the right and selector on the left. The reverser handle protrudes from the slot below and to the left of the speed recorder. Note overhead horn cord. Note also the load meter located on bulkhead, below throttle; the panel below the front window contains brake gauges only. Sand, and slip suppression button, on right below side window. Now let's see the second unit's control setup.

The other unit of this pair was equipped with the new panel mounted No. 26L brake equipment, clearly visible to the left of the engineer's position. Note the many small changes overall that give this the look of being a different model locomotive; while the controller is in the same location essentially, almost all of the other controls have been moved around. Gauge locations are the same; this photo for some reason was taken with the air brake panel's front cover opened and pulled down, but the panel is the same as that shown above. Major controls, including throttle, selector lever and reverser remain the same - and on this unit, as well as the other, and all U25, U28 and U30 units using this controller, the throttle handle controls both power in motoring and braking effort in dynamic braking.

At this point there's no way to tell if originally both units had control setups that were identical, and we might suspect they were. Perhaps one unit was modified with improved control layout and the new brake equipment at the same time, or perhaps not. We don't know. Date of this manual is 5-60.

This illustration is that found in manual GEJ-3810, issued 12-60 which covers high-hood production model U25B locomotives like those furnished to Union Pacific and the Frisco. Note the overall more "finished" look that this illustration shows - no doubt, some further changes as a result of having worked out the design with the experimental 751/752. Most important to note is the addition on this picture of a "Power Limit Switch" (on front of controller, next to the two black headlight switches) that limits the unit to Notch 7 output even if the throttle is above this setting to limit slip on the unit while trailing units respond to the full throttle range. Note also that the load meter has joined the air brake gauges in the panel below the front window.

This setup naturally wouldn't work with a low-nosed or "low short hood" unit. GE then redesigned the whole control setup to not only get everything mounted on the floor but also to provide a totally unobstructed view through the very large one-piece windshield it originally fitted to the U25B and U25C locomotives. Originally this stand had a very short, stubby throttle lever but this was quickly changed to a much longer design more suited to the extreme stiffness associated with the strong latch spring fitted to the controller. It is this slightly later design we'll show now.

This illustration would be generally typical for late U25, all U28 and many U30 locomotives. It is taken from GEJ-3834, the operating manual for the U28 when built in the U25 style carbody, and which was printed 1-66. This is essentially the "classic" early GE control stand since as we know the vast majority of units were NOT high-short-hood. Although it's obvious, we should note that high-hood U28 and U30 units (Southern, N&W) had floor-mounted stands. We also are almost certain that the few PRR U25B units that had dual controls used two floor mounted stands.

What's not too obvious here is that there were several submodels of the KC99 controller differentiated by their mounting and internally contained equipment. This is where the aforementioned NYC manual comes in handy with this description of the various models of KC99 controller, at least as of 9-63 when this manual's section CE-1 / Master Controller was printed. Remember that sometimes these manuals foreshorten model numbers for ease of reference, and officially the "KC99" controller is GE model series 17KC99. Here are the model delineations:

17KC99A: This controller is overhead mounted. Braking and accelerating is controlled by one handle (THROTTLE). The controller housing contains the control switches, circuit breakers, lights, and braking-throttle control resistors.

17KC99B: This form has a different cover and wiring, and it contains three more resistor tubes than the form A controller. The form B controller is wall mounted.

17KC99C: This controller has no resistors. It is floor mounted.

17KC99D: This controller omits the console, the switches, and the resistors. It is floor mounted.

17KC99E: This controller is floor mounted. It contains switches which are designed differently than those found on other forms of this controller.

17KC99F: This controller omits the console, is overhead mounted, and contains a dynamic braking commutator and resistor as shown in figure 1.

The above is RIGHT OUT OF THE MANUAL, word for word. We won't show "Figure 1" here but I can tell you, looking at the illustration that it's my best guess that this controller was for use in either the UP's or the Frisco's U25B units for controlling field loop dynamic brake systems in EMD locomotives. (Normally GE units were potential control.)

If we look at the first two pictures of 751 and 752's cabs, we might guess that these are showing two different mounting styles and might be the A and B models of controller -- although that's a very hazardous guess. What seems clear is that between the illustrations I've shown, and those I haven't, there are more than enough to cover all of these stated model changes in the U25 series alone.

I hope you've enjoyed this little in-cab look - when we return to GE locomotives it's back to the FDL engine series.

Wednesday, December 8, 2010

GE FDL Diesel Engines - installment No. 2

In our first installment, we noted that the differences between GE prime movers employed during the production of the Universal series are rarely discussed and gave as a matter of introduction the briefest of tables indicating what the letter submodels were and in which locomotives they were used. There are exceptions of course, and we'll go into that and more in some further detail in today's installment.

Keep in mind that there is not a lot of data to be found - but also know that we have practically all that CAN be found. While this description isn't all inclusive, it will probably be more complete than anything in print or on the net so far.

FDL-16A This is the engine that GE used to power the production U25 locomotives. It is known that there were further sub-variations of the model numbering that correlated to modifications; for example, the engine model given in manual GEJ-3814 is 7FDL16A1. None of the exact breakdowns are known as far as the sub-letter number designations and these are almost never seen. In general it's very safe to say that in any GE manual, drawing numbers E-9900, E-9900A and E-9900B cover the "A" model and that it was production standard during all of the U25 and U50 runs. There were numerous changes in the engine during this time- most important was a change in firing order that appears to have occurred between 2/62 and 5/63. Perhaps concurrent with this was a switch in orientation of master and articulated connecting rods; at some point during "A" production, the rods were changed from master rods in the right bank of the engine to master rods in the left bank; E-9900B reflects this change which occurred before 10-64. Also at some point during "A" production, small check valves in the oil passages in both master and slave rods were omitted; E-9900B is also the first to show this change as well. Another alteration in the "A" series was the change from individually replaceable, keyed camshaft lobes on the camshafts to sectionally replaceable camshafts with non-removable lobes and again E-9900B is the earliest to reflect this change; a GE service bulletin in our large U25B Maintenance Manual (issued to the NYC) indicates this change occurred 5-64. Sometime before 5-62 the early one-piece crankshaft was changed to a two-piece design and mounting of the vibration damper was altered. In 1-64 a low water pressure shutdown was added to the engine governor. In 2-64 the Elliott H-588 turbochargers began to be delivered with increased thrust bearing area to extend service life. Also in 1-64 improved radiator panels, with improved core and tube design began to be applied to new production U25 locomotives; there were two different types of improved design, both interchangeable with the original. These radiator units appear to have been designed to reduce leakage due to expansion and shock. In 2-63 a field modification order was issued to change the setting of the lube oil pressure regulating valve, and later all engine made after August 15, 1963 had a new style lube oil pressure regulating valve. In 6-64 a new style of engine and generator hold-down attachment was employed, designed to reduce transmission of shock from the underframe to the diesel engine.

FDL-16C No "B" series engines were used in domestic locomotives, although for reference it seems as if the reversal in location of connecting rod mountings (from one bank to the other) happened with introduction of the "B" series. The "C" series powered all locomotives of model U28 in the US; it also was employed on various pre-production, field-test locomotives built in the midst of, or in place of, conventional U25 locomotives prior to the official introduction of model U28. The most important changes on this engine are the alteration of the cylinder unit design to include a removable, steel head section that contains all four valves (two intake, two exhaust) and the injector nozzle. This head was bolted into the cylinder assembly. Also, the exhaust system was altered from a somewhat complicated design of individual pipes for pairs of cylinders to a single-pipe exhaust in which cylinders simply fed a large tubular manifold. Engine speeds for the "C" remained the same as for the "A" although of course there was the increase in rated power, from the 2500 HP for traction / 2750 gross HP of the "A" to 2800 HP for traction / 3050 HP gross for the "C." Increased fuel rack travel was employed with exactly the same fuel system top to bottom. The cross-sectional drawing for the FDL-16C is E-13461. Apparently, the new style of cylinder unit, with steel head, was designed to interchange with earlier "A" units so that it could be backfitted to U25 or U50 locomotives, although one manual notes that old engine frames should be checked for proper depth of bore clearance to ensure that the cylinder units would fully enter into and properly seat in the engine frames; some small amount of grinding of bosses in the frame was all that was needed in some cases to clear this up. It also appears that the "C" model (although it might have been the "B" first, for export) introduced a new style of cylinder liner. The new style - first shown in a manual actually for the U25B/U25C and included after E-9900B - had a jacket applied to the cylinder liner that GE would later describe as the "Belly Band" type of cylinder liner. This was essentially a modification to further reduce exposure of larger engine parts to water; on the A, none of the frame was exposed to water at all, but the inside of the cylinder assemblies along the bore formed the outer water barrier for liner cooling (the liner itself being the inner barrier.) On the "C" engine, or should I say on the belly band liner, the cylinder assembly was protected against water exposure because the cylinder liner now had both inner and outer surfaces to contain cooling water.

That's enough for now on this topic. Next time we'll introduce the FDL-16D that appeared with the U30.

"V" type EMC 201A Diesel Engines

Continuing with our theme of showing diesel engines either never shown anywhere before, or seen rarely, we now bring out (from the David A. Davis collection) EMC Bulletin 118A, with an issue date of February 1, 1941 and which is titled "Operation and Maintenance Instructions for 12-201A and 16-201A Diesel Engines for Railway Equipment." We won't reprint the whole huge thing here but instead we'll give somewhat of a general idea of the nature of these pioneering engines.

Our first illustration is an exterior view of the V-12 version of the 201A.

In this view the engine is sitting on top of some sort of base which appears not to have been for locomotive installation. The near end is the blower and auxiliary end; the far end is the generator end. Note that the water pumps are mounted on the end of the large blower housing, on top of which is the large cylindrical air cleaner; note also the housing at the opposite, or generator, end, for the timing chain and gears. The engine has one exhaust stack for each cylinder, and these can be seen sticking up at the center of the engine. The governor (Woodward SI) is in evidence on the near corner of the engine.

Next, the 16-201A - largest and most powerful of the 201 line.

Clearly evident on the 16-201A are the dual air cleaners, required because of the increase in volumetric flow rate of air. Otherwise, this engine is largely the same except for one very interesting fact: The block angle on the 12-201A was 60 degrees, but on the 16-201A the block angle was 67-1/2 degrees. Surely this was a requirement to balance the engine against torsional vibration. One further interesting difference between the 12 cylinder and 16 cylinder engines was that the 12 cylinder engine had a firing order in which pairs of cylinders fired simultaneously, but the firing order of the 16-201A was individual like you'd find in most other engines.

Basic specifications applicable to both engines are as follows:
BORE 8 inches
STROKE 10 inches
CYLINDER DISPLACEMENT 502.65 cubic inches

RATED POWER OUTPUT 12-201A 900 HP / 16-201A 1200 HP

Here is an overhead diagram of the 12-201A engine. Notable immediately is the staggering of the cylinders, like you'd find in any four-stroke Vee engine. The 201A did not use fork and blade connecting rods, but rather side by side rods as was conventional practice which naturally dictates this arrangement. Note the blower housing on the bottom end of the illustration. Weight figures for the engines are given, although not indicated is whether they're wet or dry: 12-201A, 18,500 lbs; 16-201A, 22,100 lbs.

Here is a fascinating cross section view of the 12-201A. Notable are the flat bottomed cylinder heads; combustion space is in the piston crowns. The original one piece heads were at printing of this manual being replaced with "pot type" heads in which a removable insert containing the exhaust valves and injector nozzle was inserted into the head. This is exactly the kind of modification that General Electric would introduce many years later on its production U28 series locomotives incorporating the FDL-16C engine ("Steel Head / Single Pipe Manifold" variant, which there will be lots more about on this blog in the near future.) At print, the original pistons were being replaced with forged pistons (material is not specified) but the manual states that the difference in mass between the two styles was not enough that pistons could not randomly be refitted as needed to individual cylinders (although it was recommended to fit at least a whole bank at once.)

This brief overview should give all who are interested at least a basic idea of the arrangement and design of the pioneering 201A locomotive engines; we can answer more specific questions using the 'comments' feature on this blog if need be.

Wednesday, November 24, 2010

Westinghouse experimental V-12

It is fairly well known in railfan circles that Westinghouse purchased rights to the Beardmore diesel engine, for use in railcars ("doodlebugs") and locomotives. This engine was originally 8-1/4 inch bore and 12 inch stroke, with exposed pushrods. Westinghouse developed the engine into a 9 inch bore by 12 inch stroke engine, more enclosed, and used this engine in a number of forms - inline and vee.

The largest was a V-12, which was used in three applications; one engine was used in a single-engine steeple-cab locomotive, while two of them were used in the large road switcher that Westinghouse built in the mid-1930's. This engine was as mentioned 9 x 12 inch, four stroke, and normally aspirated.

This photo, from an old and uncopyrighted volume in our collection, is the engine in question. Viewed from the auxiliary or pump end, we can see one of the two sets of ganged fuel pumps (six units here; six units on the opposite side of the engine) as well as the two water pumps. A railway style generator and end-mounted auxiliary generator are just visible. Note that the cylinder head design provides for intake on the outboard sides of the engine cylinder banks; here, a unit intake manifold is seen with air filters mounted at each end. Two exhaust manifolds are visible, one for the forward six cylinders and one for the rear; this matches well with pictures of the CGW center or "steeple" cab unit before repowering. This engine was rated 800 brake horsepower.

Much more interesting is the next photo.

This photo shows what appears to be an identical engine; however, immediately visible is a supercharger mounted above the generator. The intake manifold arrangement has been altered to accomodate feed from this two-rotor, very likely gear-driven blower. An earlier shot in the book labels a very similar looking blower as being a Connell Supercharger; it's unclear if this is that make or not. What is clear is that we've never read of a supercharged Westinghouse V-12 before. Westinghouse did build one unit with a supercharged inline 6, which raised the rating of the six-cylinder engine from 400 BHP to 530 BHP. If that correlates well, then the engine shown here would have been capable of over 1000 BHP. No data are given in this book- just two cryptically labeled photos. Interesting indeed!

Perhaps as interesting is the clear evidence that Westinghouse was using an extended engine bedplate to support, and thus align, the main generator. Had this knowledge been transferred from Westinghouse to Baldwin, the latter might have saved itself numerous headaches, in terms of engine failures in the field and warranty coverage.