• Engine dimensions 16-645E3

  • Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.
Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.

Moderator: GOLDEN-ARM

  by GoranH
 
What are the dimensions of the EMD 16-645E3 engine (length, height, width), and why do 16- and 20-cylinder engines have a two-piece crankshaft?
  by AllenHazen
 
If no one else has answered in a day or two, I'll try to look up the dimensions. My recollection from the 1970s is that the 20-645 of an SD-45 was shorter and narrower, but maybe a bit taller, than the 16 cylinder "English Electric" engine (CSVT?) used on the British Rail Class 56. And that it was lighter in weight than the 18-251 used on the MLW M640.

(And do they really have a two-piece crankshaft, or is it the camshaft that's divided?)
  by Pneudyne
 
The attached excerpt from Jane's 1969-70 might help with the dimensions, at least.

Jane's 1969-70 p.218.gif

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  by GoranH
 
Thanks for dimensions
  by GoranH
 
16 and 20 cylinders have a two-part crankshaft, in the middle is a flange that connects the two parts
  by Pneudyne
 
That a two-piece crankshaft was used for the 16-cylinder engine is noted on page 52 of the famous 1951 Kettering paper, attached, although it does not say why it was done that way.

EMD 567 History and Development 1951 p.52.png

That no technical advantage for so doing was imputed, it might have been that it was a case of production economics, at least in the early days of the 567 engine, and once chosen, became embedded, in part to retain backward compatibility of later developments. Judging by the above paper, backward compatibility was a major issue for EMD.

The conventional wisdom is that the crankshaft is the single most costly component of an engine. Not only that, but when it comes to spare/replacement parts, shipping very long crankshafts around the world is a specialist and expensive operation. So in that sense, having the 16-cylinder crankshaft in two parts might have been advantageous.

Re dimensional comparison with other makes of engines, the attached compilation of excerpts from Jane’s 1969-70 gives a snapshot of the relativity as it was at that time.

from Jane's 1969-70 p.191.pdf




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  by GoranH
 
Thanks for this valuable information. In Croatia we have locomotives EMD G16, G26CW, GT22HW and GT26CW-2. These are very high quality and durable locomotives! Yes, it may have been about production economics. I guess in the event of a crankshaft breakage, only that part was replaced, while the other part remained old. It seems cheaper to me than replacing an entire crankshaft.
  by AllenHazen
 
I didn't realize that EMD 16 and 20 cylinder engines had two-piece crankshafts. Thank you for educating me!

As for dimensions... My usual source (the Diesel engine manufacturers section of the 1986-1987 edition of Jane's World Railways) let me down: the entries for many other manufacturers have dimensional information, but EMD's doesn't. So thank you (once again!) Pneudyne for finding it!

(I did find a list of dimensions for the 710 engine. Linear dimensions, other than height, are very similar (the 16-710 is 4 inches longer and one inch wider than the turbocharged 16-64), and the weight a bit higher: the 16-710 is shown as 18,000 kg / 39,685 pounds, as opposed to 15,646 kg / 34,500 for the turbocharged 16-645. The 710 is taller (108 inches as opposed to 98 inches), but I suspect this is largely a matter of the supercharger mounting, and might be modifiable for clearance-limited applications.

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On the tangent of comparison with the British Rail Class 56... The only dimension on which the 20-645 exceeds the engine on the Class 56 is height, but looking at the table Pneudyne has posted, the Roots-blown engines are significantly lower. So a 20-645 engine might have been squeezable into a Class 56 engine room with a modified turbocharge mounting: if you look at the GE table, the 8 cylinder FDL is only 84 inches tall, as opposed to 89 for the 12 and 16 cylinder versions. This, I think, is entirely a matter of turbocharger application, and the 12 cylinder engines on non-North American locomotives had the same height as the domestic 8 cylinder engine. ... I first visited the British Isles about the time the Class 56 was introduced in the 1970s, and was intrigued by the comparison between British and American "Second Generation" diesel locomotives. (Note that, in terms of power, the Class 56 would have been the equivalent of a North American locomotive with a 16 cylinder engine: its nominal 3250 hp is in terms of the British and European conventions, which give about 10% higher ratings than those used in North American, so a 16-645 powered locomotive like an SD-40 would bd rated 3300 hp in Britain, as the Class 59 a few years later was.)
  by GoranH
 
Greeting! Is there any data on the efficiency (in percent) of EMD 645 diesel engines?
  by AllenHazen
 
GoranH--
The truth may indeed be out there, as the saying goes, but that doesn't mean a layman like me can easily find it.
Note, as a complication, that the 645 engine was used in new locomotive construction for something like two decades, and fuel efficiency was improved over that period -- sometimes by improvements to the engine itself, sometimes by improvements to other parts of the locomotive. So any answer will have to be relativized to a date.
Which said... I have a booklet, "Fuel Conservation from an operating viewpoint," published by the "Railway Fuel and Operating Officers Association" (a U.S. organization: place of publication shown as a suburb of New Haven, Connecticut) in 1980: the title page says it was "compiled" by H.C. Eck, a member of the executive committee). About 20 pages of text on various aspects of locomotive fuel conservation, with, at the end, tables of the fuel consumption (at different throttle settings) of some then-current American locomotive models.
So, one testimony, from one particular time.
(I can give some more information from this booklet if it seems useful, but for the moment, a sample.)
The GP40-2 or SD40-2 (so, 3,000 horsepower (on the American convention: rated horsepower is power delivered by the engine to the traction generator) units with turbocharged 16 cylinder 645 engines), running at full power (Run 8) used... And here there is a sample of the complications about date! For older units the Run 8 fuel consumption is given as 167.7 (U.S) gallons of diesel fuel per hour, but "units built after 6/79 have model 645E3B fuel economy Diesel engines," and for them the Run 8 consumption is given as 164.4 gallons per hour.
And, to compare this with the fuel consumption of non-turbocharged 645 engines, the Run 8 fuel consumption of a GP38-2 or SD38-2 (2000 hp units with Roots blown 16 cylinder 645 engines) is given as 122.4 gallons per hour.
(All at specified atmospheric pressure and temperature, with fuel of a specified specific gravity: details on request.)
---
(And, for comparison with GE FDL engine, the Run 8 fuel consumption of a U30B/U30C/B30-7/C30-7 --- similarly 3000 hp locomotives with 16 cylinder engines --- is given as 149.2 gallons per hour.)
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And, no, I don't know how much faith I should put in the figures from this booklet, or how to translate "gallons per hour" used by a locomotive into other measure of engine efficiency.
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One further example of the complications. The EMD 3000 hp units are shown s using 21 gallons per hour --- 18.4 for units with the newer more efficient variant of the 645 --- in dynamic braking, whereas the GE units are shown as using 26 gallons per hour in dynamic braking. Obviously, this doesn't reflect a difference in the engines, but rather other aspects of the locomotive design. EMD units had dynamic brakes with grids cooled by separate electric-motored fans. GE, in contrast, had from the U25B on sought to simplify the locomotive design (with an eye to simplifying maintenance) by having dynamic brake grids cooled by the same fan as the radiators, a fan power by an extension shaft from the engine. Evidently GE's system required running the engine at a higher speed -- equivalent to somewhat less that Run 3 in fuel consumption -- while dynamic braking than EMD's (fuel consumption in d.b. a bit less than that in Run 2). By the 1980s, fuel was more expensive than it had been in the 1960s, so the trade-off between maintenance-oriented simplicity and fuel efficiency had changed: late GE Dash-7, and later, locomotives, have dynamic brakes cooled by separate, electrically motored, fans.
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All of which does not give a direct answer to your question. I hope it is at least somewhat interesting/useful!
  by GoranH
 
Thanks for explanation! Now i understand fuel efficiency. I am interested in whether there is any information about the thermal efficiency of the EMD645 diesel engine. I read somewhere that a large marine two-stroke diesel engine (Wärtsilä RT-flex96C) has a thermal efficiency of up to 50%.
  by AllenHazen
 
GoranH--
I ***think*** my booklet has enough information to allow an estimate of the thermal efficiency of 645 (& FDL) engines, but I'm feeling lazy and will let you do the arithmetic. (It doesn't help that it's an American booklet, and uses Anglo-American traditional units: first task for your calculator is converting everything to SI.)
Now, I think the "thermal efficiency" of an engine is the ratio of the heat energy of the fuel burned to the mechanical energy produced by the engine. (Pneudyne, unlike me, has actual engineering training: I hope he will correct me if I've got this wrong!)
So there is one question of measurement CONVENTION relevant here: what do we take the output of the engine to be? Since thermal efficiency is a general concept, not one restricted to exclusively locomotive application, my guess would be that the relevant rating would be the "brake horse power" rather than the input to traction generator. So the 3,000 horsepower (input to traction generator) SD40-2 and U30C locomotives both have roughly 3300 horsepower engines. Power being energy per unit of time, this should allow calculation of the mechanical energy output of the engines.
For the heat energy... The fuel consumption figures I gave in my last post are a starting point, but I'm afraid there are several further calculation steps. The figures I quoted were in (U.S.) gallons, and heat content of fuel is quoted as energy per MASS of fuel, rather than volume.
Now, the tables of fuel consumption for different locomotive models in the booklet have information provided (I assume) by the manufacturers, and the footnote to the GE table has a bit more relevant information about the fuel used: 7.387 pounds per gallon (so multiply gallons by 7.387 to get the mass -- in pounds -- of the fuel used), and
19,350 BTU per pound. Give or take of things like the conversion of BTU (British Thermal Units) into Joules, I think this is enough data to allow calculation of the thermal efficiency of the engines.
(I assume the fuel assumed in the fuel consumption figures for the EMD locomotives would be pretty close to the same heat content as that used in testing the GE locomotives: in actual railroad operation the two brands of locomotive were fed the same diesel fuel!)
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Comparing locomotive to marine diesels... I think that, other things being equal, a Diesel engine with larger cylinders is more efficient than one with smaller cylinders. (Heat loss through the cylinder walls is a significant factor, and the larger the cylinder the smaller the ration of cylinder wall area to combustion volume: area scales with the square of linear dimensions and volume with the cube.). And Wärtsilä engines have humongous cylinders!
And 4-stroke engines are a bit more efficient than 2-stroke: compare the figure for EMD and GE engines. This is why EMD finally abandoned its 567-645-710 two-stroke engine in favour of a 4-stroke engine for their current production.
  by Pneudyne
 
Engine builders often did provide specific fuel consumption numbers, and sometimes the derived efficiency numbers. I don’t have any such data for EMD engines on hand, but the attached brochures from English Electric/Ruston are indicative as to how these numbers were presented. As may be seen, such numbers are referred to quite tightly controlled conditions, so how they translate into everyday service is difficult to say.
Ruston RK270 Traction Data 198710.pdf
EE RK,V Industrial 1969.pdf
In making comparisons of locomotive and marine engines, it may be noted that the latter category covers a wide range of basic types. One relatively coarse approach to categorization has at the top end, power-wise, the very large low-speed two-stroke crosshead engines, burning heavy fuels, used to power the large ocean-going vessels, tankers, bulk carriers, “box boats: and so on. Then come the medium-speed heavy four-stroke trunk piston types, ranging in bore size from 200 to 600 mm or so, and also usually burning heavy fuels. Still in the medium-speed four stroke trunk piston class are the lighter-built engines, with bore sizes up to around 280 mm, often used as “fast ferry” powerplants, which usually burn distillate fuels, but are sometimes capable of burning heavy fuels. A separate category is usually referred to as “North American inland marine”, covering distillate-burning medium-speed engines, and which historically been dominated by the EMD 567/645/710 two-stroke trunk piston engines. High-speed engines in marine service are usually multipurpose designs and distillate fuel burners. Of the major marine engine builders, Wärtsilä is active in the low-speed two-stroke and medium-speed heavy four-stroke fields, whereas MAN, as well as these, also has a “fast ferry” range. That kind of engine would be closest to the locomotive type in general terms. In fact the MAN 28/33D (https://www.man-es.com/docs/default-sou ... 595f30f6_1) was derived from the Ruston RK280, successor to the earlier RK engines. That category would include the North American locomotive engines when used in worldwide marine service, and also the Caterpillar C280/3600.

Wärtsilä claims that its recent 31 series (https://www.wartsila.com/marine/product ... artsila-31), which falls into the heavy marine trunk piston category, is the most efficient four-stroke engine currently available.

An interesting aspect is the EMD 567/647/710 engine is a rare survivor in the two-stroke medium-speed trunk piston category. Until the late 1960s or thereabouts, the marine heavy medium-speed market was occupied by both two-stroke and four-stroke types, including some basic models that could be configured either way and swung from one to the other without overly major surgery. But in the 1970s, there was a decisive swing to the four-stroke type, and the two-strokes faded away. One of the last, to circa 1997, was the Wichmann.


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  by Pneudyne
 
I have since found this specific fuel consumption chart for the EMD 16-645F3 engine:

EMD 16-645F3 Specific Fuel Consumption.png

It should allow calculation of efficiency at any point on the curve.

The chart is from a 1982 IME paper, “The GM/EMD Model F3A Engine for Rail Application”.


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