Muzzle Not The Ox

[M636C]

I should have added that the T-1s at the time were showing very poor availability, according to the "Trains" article, and the diesels were new and were less affected by the cold winter (except for the fuel in the steam generator to counter the effects of cold, of course.

So while the availability was much better than the T-1s, this was because the E-7s were a bit better than the best steam performance and the T-1s were a lot worse than the best steam performance (and sadly remained so to varying degrees for their whole lives).

The article commented upon the diesel maintainer asking the harrassed foreman for wheel turning, and the foreman refusing to believe that the E-7s had run the quoted mileage because it was several times more than the best of his recalcitrant T-1s.

M636C

[M636C]

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by Leon Silverman

I recall reading about the PRR's experience regarding their E-units versis the T-1's they replaced. It appeared that the wheels of the diesels were requiring replacement far more often than the steam engines. Then they discovered that the diesel engines were accumulating mileage five times faster than the T-1's. How could this occur if the diesel's availability was less than the steam engine's? The T-1steam engine was considered state-of-the-art technology after WW II.

Not real clear here if you mean wheel rotations, or miles. According to published statistics, the E Units had about half the diameter of the T-1, so it had to rotate twice as many times to achieve the same distance. For a unit to do the same work, on a rail-horsepower basis, the E-7 had to go 4 times farther to achieve the same amount of work as a T-1. That is, if a T-1 moved a given tonnage of freight 1,000 miles, then in order for four of the FT units to achieve the same movement, the total of four locomotive units is 4,000 miles, each unit traveling 1,000 miles.

If it is wheel rotations alone, then the T-1 would have approximately 262,000 wheel rotations, while the FT units, with half the diameter wheel, would have approximately 2.24 million total rotations to haul the same tonnage the same distance.

I can see why they had to replace the wheels more often.

You can see that the wear and tear on the E-7 diesel, to achieve the same amount of work as something like a T-1, was relatively high.

Herein, as well, is the "trick" of why measuring unit maintenance costs on a locomotive mile basis, which was a favorite methodology in certain kinds of studies, was much preferred over a unit maintenance cost per ton mile of freight moved, which you will almost never see in those "studies". Steam could always generate good numbers on a ton miles basis compared to Diesel, poorer numbers on a locomotive miles basis.

The article was in a past (1970s?) Trains Magazine (with a colour photo of the "Train of Tomorrow" E7 on the cover).

The article clearly stated that the E7s were running a much greater distance than the T-1s rather than referring to wheel revolutions. The article referred to the period in 1946 when the Baldwin built T-1s were being introduced. The T-1s proved very unreliable when new, partly due to their unfamiliar and difficult to access Franklin poppet valves with inside bevel gear drives. As a result of these problems, a T-1 was rebuilt with piston valves and another with outside drives to poppet valves. Apparently the problems were worse in winter 1946-47.

Compared to the new T-1s, the E-7s were a well tested locomotive, with ten years of development going back to the B&O EA locomotives. The units concerned in the comparison had been purchased for use on a paticular streamliner, (and this is from memory) the "South Wind" to Miami (?) as part of an agreement between PRR and the other operating railroads. There was some through working involved, and the E7s were able to run long distances on the designated train, but were able to be used on PRR "internal" trains.

One other comment was that the E7s used more fuel keeping the steam heating boilers going than they did on their propulsion engines, particularly when they were standing between trains in winter, and special arrangements had to be made to refuel them in a steam depot with only coal burning locomotives.

This was not a "fair" comparison, since only two E-7s working particular duties were being compared with 25 T-1s working general traffic, and suffering from problems of introducing new technology, while the diesel was an accepted and well proven design at the time.

However, in the view of the article's author, it was clear that the diesels were much more useful as traffic moving locomotives, and were a clear indication that the PRR had made a poor investment in the T-1s, which never really proved to be successful. It was the two E-7s, ignored by the mechanics trying to keep their unreliable steam locomotives working, that were earning money for the railroad quietly and without any fuss. Of course, in time the E-7s and their successors took over, because they were much less trouble to operate, as well as costing less to fill with fuel.

M636C

[MichaelSol]

QUOTE: Originally posted by Leon Silverman

I recall reading about the PRR's experience regarding their E-units versis the T-1's they replaced. It appeared that the wheels of the diesels were requiring replacement far more often than the steam engines. Then they discovered that the diesel engines were accumulating mileage five times faster than the T-1's. How could this occur if the diesel's availability was less than the steam engine's? The T-1steam engine was considered state-of-the-art technology after WW II.

Not real clear here if you mean wheel rotations, or miles. According to published statistics, the E Units had about half the diameter of the T-1, so it had to rotate twice as many times to achieve the same distance. For a unit to do the same work, on a rail-horsepower basis, the E-7 had to go 4 times farther to achieve the same amount of work as a T-1. That is, if a T-1 moved a given tonnage of freight 1,000 miles, then in order for four of the FT units to achieve the same movement, the total of four locomotive units is 4,000 miles, each unit traveling 1,000 miles.

If it is wheel rotations alone, then the T-1 would have approximately 262,000 wheel rotations, while the FT units, with half the diameter wheel, would have approximately 2.24 million total rotations to haul the same tonnage the same distance.

I can see why they had to replace the wheels more often.

You can see that the wear and tear on the E-7 diesel, to achieve the same amount of work as something like a T-1, was relatively high.

Herein, as well, is the "trick" of why measuring unit maintenance costs on a locomotive mile basis, which was a favorite methodology in certain kinds of studies, was much preferred over a unit maintenance cost per ton mile of freight moved, which you will almost never see in those "studies". Steam could always generate good numbers on a ton miles basis compared to Diesel, poorer numbers on a locomotive miles basis.

[Anonymous]

Here's a couple of observations to keep everybody red in the face.

Water for steam locomotives does not just appear in the trackside water tower. RR's built resevoirs and water treatments plants in many places. There were places such as the southwest where water wasn't plentiful. The FT solved this problem. This was not why steam was replaced but it is a factor even it was a small one. The point is that steam required a considerable infrastructure to supply the elements it needed to operate.

Everybody is looking at crew size wrong. The conductor and two brakemen have nothing to do with operating the engine. The brakemen, myself among them, were replaced in the 70's and on by EOT's and roller bearings and defect detectors and such. This corresponds with the observation that crew sizes decreased faster after 1972. But we were discussing locomotive technologies. It takes two people to run a steam engine, it takes one to run a diesel. It takes six people to run three steamers, it still takes one to run the diesel (not including helpers, I saw that coming).

The number of miles travelled by a locomotive is also limited by how fast trains get over the road. The figure quoted earlier for diesel is about 250 miles a day or two divisions in the east. That doesn't sound too bad. I've had days I didn't get over one division in twelve hours. Also milage presumes that locomotives of any type are trying to accumulate as much milage as they can in a day. Not always so.

OK, please continue the entertaining yet essentially pointless debate.

[Leon Silverman]

I recall reading about the PRR's experience regarding their E-units versis the T-1's they replaced. It appeared that the wheels of the diesels were requiring replacement far more often than the steam engines. Then they discovered that the diesel engines were accumulating mileage five times faster than the T-1's. How could this occur if the diesel's availability was less than the steam engine's? The T-1steam engine was considered state-of-the-art technology after WW II.

[edblysard]

Keep in mind that even with the lead, or A unit dead, the B unit still responds to the control surfaces in the A unit...many times I have run on a train with the lead unit dead, and the trailing units still powering the train.
One dead diesel in a consist dosnt mean you have to stop the train, even if it is the lead unit.
Ed

[M636C]

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by M636C

QUOTE: Originally posted by MichaelSol

Well, for TomDiehl's example, since 50% of the units were different, A & B, if an A unit failed, bringing out a B unit didn't do much good. So, the redundancy had to be double that of Steam right off the bat.

That isn't quite true. In general, you only needed one A unit per set of locomotives. So if an A unit failed, you could couple up a B unit (even with FT units, as long as they had couplers and not drawbars).

This was proven by Santa Fe who purchased many of their early FT sets as A/B/B/B, at least until they could reach an agreement with the unions that a crew wasn't needed in the rear cab, at which stage they purchased a lot of A units to make up A/B/B/A sets.

Following was the actual production:

555 A units, 541 B units

If four unit sets, this suggested that 97% of such sets had an A unit on each end.

No,

Using that logic there were 270 A/B/B/A sets
One A/B set
and 13 A units which could be made up into three A/A/A/A sets with one spare!

The point you were making referred to redundancy:
I said that only one A was REQUIRED per set.
ATSF proved this by purchasing and running A/B/B/B sets.
The FT diagram in E.D. Worley's "Iron Horses of the Santa Fe Trail" shows the A/B/B/B configuration, as do several early WWII photographs.

I did know, and said, even in your quote, that ATSF subsequently bought nearly matching numbers of A units.

Your 97% figure would apply only if there were more B units than A units!

M636C

[MichaelSol]

QUOTE: Originally posted by M636C

QUOTE: Originally posted by MichaelSol

Well, for TomDiehl's example, since 50% of the units were different, A & B, if an A unit failed, bringing out a B unit didn't do much good. So, the redundancy had to be double that of Steam right off the bat.

That isn't quite true. In general, you only needed one A unit per set of locomotives. So if an A unit failed, you could couple up a B unit (even with FT units, as long as they had couplers and not drawbars).

This was proven by Santa Fe who purchased many of their early FT sets as A/B/B/B, at least until they could reach an agreement with the unions that a crew wasn't needed in the rear cab, at which stage they purchased a lot of A units to make up A/B/B/A sets.

Following was the actual production:

555 A units, 541 B units

If four unit sets, this suggested that 97% of such sets had an A unit on each end.

[M636C]

QUOTE: Originally posted by MichaelSol

Well, for TomDiehl's example, since 50% of the units were different, A & B, if an A unit failed, bringing out a B unit didn't do much good. So, the redundancy had to be double that of Steam right off the bat.

That isn't quite true. In general, you only needed one A unit per set of locomotives. So if an A unit failed, you could couple up a B unit (even with FT units, as long as they had couplers and not drawbars).

This was proven by Santa Fe who purchased many of their early FT sets as A/B/B/B, at least until they could reach an agreement with the unions that a crew wasn't needed in the rear cab, at which stage they purchased a lot of A units to make up A/B/B/A sets.

The Santa Fe units were called model FS by EMD during this period (for Fourteen hundred horsepower Single units). There were some minor differences to allow the B units to run on their own, standard FTB units lacking some equipment (possibly batteries, but I don't recall right now) in the standard bar coupled sets.

Most locomotive terminals had some means of turning locomotives in steam days, so an A/B/B/B set wasn't a big problem, although ATSF clearly were happy to get A units on each end when it became cost effective to do so.

But you did need at least one A unit in every set!

M636C

[MichaelSol]

Well, for TomDiehl's example, since 50% of the units were different, A & B, if an A unit failed, bringing out a B unit didn't do much good. So, the redundancy had to be double that of Steam right off the bat.

[TomDiehl]

QUOTE: Originally posted by futuremodal

Tom,

I think that steam had less likelyhood of road failure than the early diesel consists, precisely because steam utilized more preventive maintenance as part and parcel of regular maintenance. Conversely, those diesels had many more "maintenance free" parts that, due to the lack of *required* maintenance, were more likely to fail out in the middle of nowhere, e.g they didn't bother to check every wire and relay everytime, did they?

And again Dave you missed the point completely. Failure was the reason to break up a set of diesel locomotives to repair the failed one. The other units would still be operable and would not be dropped from availability. In this case, or any other where a single unit needed to be serviced, the multipler Michael applied to the diesel availability figure stated above would not be valid.

[Anonymous]

Tom,

I think that steam had less likelyhood of road failure than the early diesel consists, precisely because steam utilized more preventive maintenance as part and parcel of regular maintenance. Conversely, those diesels had many more "maintenance free" parts that, due to the lack of *required* maintenance, were more likely to fail out in the middle of nowhere, e.g they didn't bother to check every wire and relay everytime, did they?

[Anonymous]

One of the big reasons for decreasing RR employment in the period 1947-72 was the disapearance of the passenger train.

[TomDiehl]

QUOTE: Originally posted by FJ and G

"goodyear and big oil crushed the interurbans and trolley's"

they didn't?????????????????????

[?][:(][:O][8)][:D]

And GM had nothing to do with crushing Tucker or DeLorean. [:0]

[FJ and G]

"goodyear and big oil crushed the interurbans and trolley's"

they didn't?????????????????????

[?][:(][:O][8)][:D]

[wallyworld]

It wasnt a conspiracy but there was very good, in fact, excellent salemanship by EMD, which, at times, make the facts of the transition period take second place, in hindsight. Selling the public first on diesels via the Zephyr was a tactic, which, in turn gave them a foot in the door to upsell freight power. It was'nt the hands down conclusion that diesels were superior when the transition began, although, in retrospect, it appears to be. Everyone draws their own conclusion as to the why and how, or for that matter, if the picture was as rosy as it appeared to be.

[youngengineer]

this thread is sounding a lot like a conspiracy theory, just like the one were goodyear and big oil crushed the interurbans and trolley's

[wallyworld]

Sometimes where the rubber of theory meets the road of reality made all the difference in the world when the first diesels were put into service. The theory of multiple units failed by the fact that the design of FT's did not provide for the isolation of an individual traction motor. This was especially true on grades where the loss of 1300+ hp made the difference between a four unit mu'ed consist being able to continue with three units. Individual isolation switches didnt arrive until 1946 with the F3.

[PBenham]

Michael Sol makes a telling point, as have some others which gets back to just how primitive diesels were in their early days. The difference in manpower attention needed by an FT versus an F7 is telling. The F7 had automatic engine temperature control versus the FTs manual controls( We can partly blame wartime priorities which limited the supply of thermostats to non-war applications until well into 1945), then there are the V-belt driven auxiliaries that were dropped by EMD after the experience gained on the FT(and early Es) showed up the weak link a v-belt represented. Now, carloadings did go down after WWII, but NET tonnage went up! How? heavier/higher capacity cars. A pre WWII car could hold 50 tons of revenue freight. By 1948 the average was on its way up to 70 tons by 1950, and 80 tons in less than a decade. In the 60's 100-ton capacity cars began to be introduced, along with Hi-cubes,and auto racks, which actually held lighter loads than grain or coal hoppers and gons, which have added on average 1940-1970, 10 tons capacity per decade. This was offset some what by roller bearings on all axles of all equipment, but that took time due to the resistance to roller bearings, which was stronger than the steam vs diesel battle/showdown.

[MichaelSol]

QUOTE: Originally posted by balboa110
Train crew size dropped dramatically also, but occurred over a longer period of time. What was the train crew size with triple headed steam? 10?
With three diesels? 2?

Where did you get your information?

According to Kent Healy's Performance of the U.S. Railroads Since World War II: A Quarter Century of Private Operation, the smallest decrease in railroad employment, 1947-1972, of all classes of railroad employment, were the engine crews.

Indeed, crews decreased by a percentage most closely resembling the drop in carloadings over the same period, almost zero correlation with engine type. Engine crew employment decreased by 48%, carloadings handled decreased by 43%. It is arguable that it might have been no different, under steam, with the lower carloadings with the natural consolidation of trains to handle fewer rail cars.

The crew number decrease compares highly unfavorably to the between 84% and 95% improvement in virtually all other categories of railroad employment over the same time period.

Best regards, Michael Sol

[TomDiehl]

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by TomDiehl
[The statistic being quoted wasn't "failure" it was "availability." In my example, the one unit that failed was in its 13% non-available range, while the other 3 units, since they could be operated without the one that failed, were in their 87% available range. The use of the unit quantity multiplier was, therefore, not valid because the other three units could still do their job.

Doesn't work that way.

Three units as a "locomotive" would have a 65% availability. However, in this instance, the failed unit is still part of the statistical pool. The availability rate is still 57%. If there is a backup unit sitting somewhere, then that is part of the statistical pool and the availability rate is 50%.

Now, the flaw above is the artful conversion of the economic impacts of the statistical problem into a practical problem on the road, for which, as was pointed out, very little data exists to form a conclusion.

However, we do know exactly what the economic data is, and we have a compelling statistical explanation for it.

Interestingly, the industry has a practical experience as well, shown by railroads attempting to get back to the road Steam model -- as much horsepower as possible in single units and as few "building blocks" as is feasible on the trains.

Because they learned the hard way that they couldn't fight the statistical inevitability of the original MU model of low horsepower units.

"Availability" means just that, how often the unit is available to do its job. Since one unit can be removed from the set and the rest of the set operated without it, there is no practical reason to say that the other units are not "available" for use. Whether the railroad decides to mix and match another unit into the set, or operate the set as a lower horsepower unit doesn't change the fact that its still available for use.

[wallyworld]

Found at EMD-Field Technician Notebook: The early days.

A Diesel engine is an amazing assortment of bolts, nuts, valves, heaters, coolers, expanders, contractors, and other gadgets too numerous to mention here. All of these are screwed and welded together to form a single unit. This resulting unit is expected to start out with below the usual grade of fuel oil and change it into BTU - then the BTU into MEP - the MEP into RPM - the RPM into BHP - the BHP into KWH. Then the electrical gear takes over and makes a BHP out of KWH and RPM out of BHP, and then, if everything is in working order, you finally get MPH. All of this takes place in a fraction of a second in the confines of an all-too-small engine room. This gives you a rough idea of the confusion characteristic to all Diesel Freight Units.

The Diesel engine was invented by a man named Dr. Diesel. The Writer has checked back into his life and character, and is satisfied that this was not done with any malicious intent, as he was a very fine man and loved the human race. Had the idea been left as he left it, nothing would have happened to it. The responsibilities rest upon the shoulders of certain individuals and corporations and Diesel Engine manufacturers, so do not hold it against Dr. Diesel. The names of these men can be furnished during the discussion of this paper, if anyone feels that they might want them.

There are three main classes of Diesel engines. Namely, High-speed Diesels, Slow-speed Diesels, and No-speed Diesels. The principal difference is that the High-speed Diesel runs faster than the Slow-speed Diesel, and they both run faster than the No- speed Diesel. The High-speed Diesel makes noise faster than the Slow-speed Diesel. A Slow-speed Diesel can become a High-speed Diesel by the simple act of speeding it up. Either a High-speed Diesel or a Slow-speed Diesel can become a No-speed Diesel by merely shutting the fuel oil off. This is accomplished very easily. None of the Diesel engines invented up to now will run without fuel oil. This seems to be a characteristic of a Diesel engine. The engine can also be shut down by placing a monkey wrench in an appropriate place so as to jam the gear train, but as this method is not recommended by the manufacturer's association, we will omit it in this paper.

A Diesel engine has several important parts that should be mentioned, among them is the cylinder. This is a long round hole filled with air that is covered on one end with a cover full of holes containing valves that admit fuel, air and sometimes water and carelessly placed tools. These valves open and close according to a predetermined sequence of events. The other end is plugged with a movable plug called a piston. This is free to move up and down within certain limits and would come out altogether if it were not for the connecting rod. This connecting rod is important, too, as it is what changes MEP into RPM, and without it we would be stuck with the MEP, which no one knows how to use up to now. This whole assembly is held in place by crab studs and nuts to prevent it from joining the bird gang. Each cylinder has four crabs, so we might be more considerate of the noise that the engine makes, considering the noise that you would make if you had the same number of crabs.

To start a Diesel engine it takes a certain amount of knowledge, steady nerves, and a certain amount of bravery. First, you set all of the switches in the correct position, with the fuel pump shut off. Then open the relief valves and pu***he starter button all of the way in. If nothing happens, call a Road Foreman, and he will call a Diesel man to put the starter fuse in for you. Then try again. Let the engines turn several revolutions in this way. The primary purpose of this act is to clear the cylinders of any water that might have leaked in through the above-mentioned holes, or any other holes that were not mentioned. But it also serves another purpose, and that is helping the engineer gain a little confidence before giving it the works. It also adds prestige on the part of the onlookers that might be standing around-namely, the fireman, brakeman, and any laborers and EMD men (if it isn't too early in the morning). After closing the relief valves and turning on the fuel pump, you shut your eyes and pu***he starter button again. If everything is as it should be, everything about you will begin to tremble and then shake and the ***edest noise that you have ever heard will begin, and then you release the starter button, for this noise and commotion are a sure sign that the engine has started. When the smoke has cleared away and the onlookers have returned, look wisely at the engine oil pressure - then drop the isolation switch a few times to hear it spit. This never fails to impress the fireman and brakeman. Of course, this will not impress the EMD men, because by this time they will have already gone back to their hotel so that they will not be around when the floating pistons let go. Then, before you forget it, go up into the cab and open the throttle to see if the traction wheels will turn over. It is most embarrassing to be out on the main lines, running 60 miles per hour, and find out then that the traction wheels are not revolving.

There are many confusing things about a Diesel engine that you will learn as you gain experience. Among them is the indicator. It is considered a good practice to take indicator readings at regular intervals. An indicator is a gadget consisting of strings, levers and pulleys. The idea is to get a diagram drawing on a piece of paper. This diagram has to do with MEP mostly. To obtain this diagram, the instrument is screwed into a hole in the cylinder cover, mentioned before. It is connected by strings and other suitable gear to an oscillating part of the engine. Here, again, steady nerves and patience is necessary. The idea is to engage a loop on the end of the oscillating string to a hook attached to the indicator. The best way to describe this operation is to compare it with attempting to thread a sewing machine that is underway. If you are lucky and manage to engage a loop in the hook, the string is usually broken. The hook has never been known to break. After breaking a number of strings, one's patience is sure to wear out. Then the proper thing to do is to take a clean card and draw in a diagram like the one in the instruction book. This card is called an inphase card. With much less effort, you can make a hand-drawn card known as an out-phase card. But the out-phase cards are practically useless. So are the in-phase cards.

Another confusing thing about a Diesel freight unit is the interlocks. It is fairly infested with interlocks. There is one that keeps the unit from backing up while you are going forward. This, incidentally, is the only useful one up to now. But there should be another lock on the unit, and that is on the door between the engine room and cab, so that when the Road Foreman goes back into the engine room to see if there is any water in the toilet water tank, the fireman can lock this door and keep him back there where he belongs, but will never stay. After all, the engineer was put on the unit to run the train, so why not let him?

Another confusing so-called interlock keeps you from starting the engine with the overspeed trip kicked out. Here, a word of advice - when you fail to start an engine on account of someone having stopped it by tripping this device, phone the yard office at once and report water in the fuel oil. While you are draining the water out of the lines, filters, pumps, tanks, and so forth, someone is sure to discover this thing tripped and he will, of course, reset it. Then you are ready to try again. However, don't forget to notify the Road Foreman that you are now ready to go, otherwise he might get tired of waiting, get disgusted, and go up town and get drunk.

There is another interlock on the starting contactors that keeps the engine from loading up when the starting contactors are stuck. For some unknown reason this contactor seems to be unusually hard to locate, but there is a movement afoot to have a seeing eye dog assigned to each unit to lead the engineer to the contacts, so that he can tell the fireman to tell the brakeman to get him a flagstaff so that the fireman can break the stuck contacts loose.

Meanwhile, the conductor will be walking many miles up and down, up and down, the tracks and wearing out his shoes, so it is important to hurry. If he is afflicted with high blood pressure, it is very important that you hurry, and if he has already used up his shoe coupon, it is most very important that you hurry.

Diesel engines have innumerable troubles. They have combustion trouble, lubrication trouble, and smoke trouble. It has also been reported that they have female trouble -- this report, however, was checked by the writer, and it was traced to a typographical error where the word "engineer" was misspelled "engine." It would not come within the scope of this paper anyway, so it will be omitted. It might be taken up a little later in the course of conversation when we try to determine why are Road Foremen necessary and what do EMD men put on their expense accounts.

The power of a Diesel engine is measured in horsepower. Why, no one seems to know. Therefore, if you want to measure the power of an engine, the natural thing to do is to find a horse, hitch him to the engine and see which could pull the most. Here a word of caution is necessary. First, horses are scarce, and even if you could find one, it would be another problem to hitch him up to the locomotive - for with so many Road Foremen around who resemble the south end of a horse headed north, it would be very easy to hitch the Road Foreman up to the locomotive and put the horse in the cab with the engineer. Not that the engineer would mind, because he would be much better off with a whole horse in the cab with him than with just the worst part of one. But if there was no Road Foreman in the cab, who would ever think to look back in the log book and report everything that the man in front of him reported. And, after all, that is the only way that the Company can tell if the Road Foreman has ever been on the locomotive, so it is very important that he do this so that the Company will remember to pay him each month. Anyway, getting back to the horse, it would be very hard to find one that wouldn't be scared by the faces of the EMD men around, and he would probably end up by kicking the nose of the unit in and going home.

So it would be much better to rely upon the instruments that the electrical men have invented. They will indicate this power in terms of Amps, Volts or Kilowatts, depending on the individual whims of the electrical designer. With a little arithmetic these values can be converted to HP as nearly accurate as by using a horse. Of all the power generated, some goes to work, some goes to friction, some goes to heat, and the rest goes to hell, which is all that you could expect under the circumstances.

The writer recommends that the prospective Diesel engineer does not take these engines too seriously, or study about them too much in trying to learn all about them. By the time that he becomes familiar with one particular type of engine, it is obsolete, because the designer has the thought of some more interlocks to incorporate into the engine. It has also been noted that once an engineer gets to spending too much time thinking about this Diesel, it is almost impossible to get him off of that track. The best way discovered so far, to prevent this mental derangement, is to lay off as often as possible. A dimly lighted bar is the best treatment for this type of sickness. If the bar is frequented by blondes or brunettes, the treatment is double effective.

[MichaelSol]

QUOTE: Originally posted by TomDiehl
[The statistic being quoted wasn't "failure" it was "availability." In my example, the one unit that failed was in its 13% non-available range, while the other 3 units, since they could be operated without the one that failed, were in their 87% available range. The use of the unit quantity multiplier was, therefore, not valid because the other three units could still do their job.

Doesn't work that way.

Three units as a "locomotive" would have a 65% availability. However, in this instance, the failed unit is still part of the statistical pool. The availability rate is still 57%. If there is a backup unit sitting somewhere, then that is part of the statistical pool and the availability rate is 50%.

Now, the flaw above is the artful conversion of the economic impacts of the statistical problem into a practical problem on the road, for which, as was pointed out, very little data exists to form a conclusion.

However, we do know exactly what the economic data is, and we have a compelling statistical explanation for it.

Interestingly, the industry has a practical experience as well, shown by railroads attempting to get back to the road Steam model -- as much horsepower as possible in single units and as few "building blocks" as is feasible on the trains.

Because they learned the hard way that they couldn't fight the statistical inevitability of the original MU model of low horsepower units.

[wallyworld]

Holding a screwdriver on a relay makes all the difference on theoretical availability as it did in the transition era.

[Murphy Siding]

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by Murphy Siding
My point is, MichaelSol is stretching things a bit to just disregard this little point .

Disregard? To the contrary, it was my exact point: what is the economic gain if the assembly line product costs more per rail horsepower to buy and costs more to maintain than the "custom" product?

Exactly what is the benefit of the assembly line in that instance?

And I do think it is stretching things to ignore that particular point.

Michael: I went back and re-read your post. I now believe I misunderstood it the first time. Thank you for clarifying that for me.

[TomDiehl]

QUOTE: Originally posted by wallyworld

The root of statistical evaluation in this case is failure-whether it is steam or diesel motive power. I know of no statistics available of road failures comparing the percentage of each. I do know that in the early days of diesels, regardless if it was Alco-EMD-Baldwin-road failures were not an uncommon event. That is why field technicians were the norm on road units. It also depends on the quality of maintenance of steam the quality of which deteriorated in the transition period. PRR is the most notorious example. So with all of this in mind-both sets would be skewed.

The statistic being quoted wasn't "failure" it was "availability." In my example, the one unit that failed was in its 13% non-available range, while the other 3 units, since they could be operated without the one that failed, were in their 87% available range. The use of the unit quantity multiplier was, therefore, not valid because the other three units could still do their job.

[wallyworld]

The root of statistical evaluation in this case is failure-whether it is steam or diesel motive power. I know of no statistics available of road failures comparing the percentage of each. I do know that in the early days of diesels, regardless if it was Alco-EMD-Baldwin-road failures were not an uncommon event. That is why field technicians were the norm on road units. It also depends on the quality of maintenance of steam the quality of which deteriorated in the transition period. PRR is the most notorious example. So with all of this in mind-both sets would be skewed.

[TomDiehl]

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by TomDiehl
[One thing not considered in this statistical exercise is the fact that the failure of one of the locomotive units did not sideline the entire set, what the diesel manufacturers called the "building block concept." The failed unit could be uncoupled, leaving the rest of the set to operate, or have another unit substituted. Another advantage of the MU concept.

Adding a unit to the pool as backup does not improve the failure rate. Rather it required increased redundancy, at extra cost, and only degraded the overall availability statistic even further because then you have five units instead of four in the statistical pool, and the availability statistic drops to 50%.

Try as you might, you can't beat the statistical odds which worked strongly against the economic efficiency of the multiple unit concept in attempting to replace high horsepower single unit motive power.

The failed unit was rarely sitting in a yard, conveniently announcing in advance it was going to fail. It usually occured in service. Not too many standby units sitting on sidings along the way waiting to serve.

The "statistical odds" don't need to be beat. A single 5400HP steam locomotive has a failure, the entire locomotive is out of commission until it is repaired. A single 1350HP unit of a 5400HP locomotive set has a failure, the rest of the 4050HP of the set is still fully operational. If the failure happens on the line (which most do) the failed diesel can be isolated in a few minutes and towed dead in consist to the nearest terminal and set out. It will probably not be able to maintain the speed as if it had all units operational, but it still can clear the line faster.

If the same failure happens to a single 5400HP steam locomotive, it stops and stays there until it, and its train, can be towed by another locomotive dispatched from the nearest terminal. And towing a dead steam locomotive has to be done at restricted speed.

And you're right about one thing: there's "Not too many standby units sitting on sidings along the way waiting to serve," steam or diesel.

So, statistically speaking, which one will tie up the line the longest?

[MichaelSol]

QUOTE: Originally posted by TomDiehl
[One thing not considered in this statistical exercise is the fact that the failure of one of the locomotive units did not sideline the entire set, what the diesel manufacturers called the "building block concept." The failed unit could be uncoupled, leaving the rest of the set to operate, or have another unit substituted. Another advantage of the MU concept.

Adding a unit to the pool as backup does not improve the failure rate. Rather it required increased redundancy, at extra cost, and only degraded the overall availability statistic even further because then you have five units instead of four in the statistical pool, and the availability statistic drops to 50%.

Try as you might, you can't beat the statistical odds which worked strongly against the economic efficiency of the multiple unit concept in attempting to replace high horsepower single unit motive power.

The failed unit was rarely sitting in a yard, conveniently announcing in advance it was going to fail. It usually occured in service. Not too many standby units sitting on sidings along the way waiting to serve.