VGN JessWould it violate patent rights to have used those same cylinder dimensions of 12.75" x 15.75" and operated at 625 RPM? I didn't realize that cylinder sizes or operational RPM could be patented.
Bore & Stroke dimensions are not patented, nor is operational RPM. Other technical manifestations of the machine can be patented - such as, but not limited to, cylinder top design, combustion chamber shape, the specifics of the fuel injection system - and on and on and on.
Never too old to have a happy childhood!
Would it violate patent rights to have used those same cylinder dimensions of 12.75" x 15.75" and operated at 625 RPM? I didn't realize that cylinder sizes or operational RPM could be patented.
I guess short answer to the original question would be EMD didn't copy Baldwin because (besides issues of patent rights) Baldwin's product was inferior to theirs. By 1970 if you saw a Baldwin diesel locomotive, it either had been retrofit with an EMD engine, or it was in a scrap line.
Overmod The CB has an arrangement where two lighter pistons bear on one large crank throw, but only one connecting rod has the 'whole' journal area on the crank (the other one bears on a pin in that rod, similar to the master rod in a radial) and hence combines large bearing area (including in tension) with lower reciprocating mass allowing what can be alarming working speeds at high developed mep.
The CB has an arrangement where two lighter pistons bear on one large crank throw, but only one connecting rod has the 'whole' journal area on the crank (the other one bears on a pin in that rod, similar to the master rod in a radial) and hence combines large bearing area (including in tension) with lower reciprocating mass allowing what can be alarming working speeds at high developed mep.
On first reading the above, it occurred to me that sounded like a "master rod in a radial" - then noticed that you beat me to it... The Master rod on a Wright Cyclone must have been impressive as the nine cylinders connecting to it added up to almost 1700 cu in.
One of the advantages of a single in-line engine (e.g. straight 6 and straight 8) is that the connecting rod and bearing can be made much beefier than a V type with the same cylinder spacing. Cummins has fun illustrating that with their ~6L inline 6 compared with the Duramax and PowerCerebralVascularAccident rods...
A few years back I made a comment about how a straight 8 diesel engine (ISTR GE EVO) was almost the same weight as the V-12. A reply was that the weight was still usefull for traction.
Erik_MagThe problem with the heavy Baldwin engines is that a pound of crankshaft is a LOT more expensive than a pound of ballast.
Yes, but take even rudimentary care of the engine and it will last essentially forever.
There is a problem, of course, if you don't. I don't remember offhand if the problem with one of the Sharks is a scored crank or camshaft, but it's a big thing to repair (pun intended) and not really 'worth it' for 1500hp.
Note the difference between the generous crank-throw area in this engine and the one in the Cooper-Bessemer engine (which could be boosted to far more hp and still be reasonably reliable). The CB has an arrangement where two lighter pistons bear on one large crank throw, but only one connecting rod has the 'whole' journal area on the crank (the other one bears on a pin in that rod, similar to the master rod in a radial) and hence combines large bearing area (including in tension) with lower reciprocating mass allowing what can be alarming working speeds at high developed mep.
If I recall correctly, the highest power from a 608A was Cockerill's 2150hp, achieved in part by pushing the engine to 650rpm. You would not get much more no matter how jewel-like the superfinish on the throws...
Overmod The Baldwin is built as a large, heavy engine, with very generous main-bearing areas and an almost incredibly stout crankshaft (you almost wouldn't believe how big it is until you see one). To an extent this represented sound philosophy for an American locomotive, where there is little point in weight-saving when it will only have to be made up in ballasting, but as previously noted a significant consequence was low maximum 'safe' rotational speed.
The Baldwin is built as a large, heavy engine, with very generous main-bearing areas and an almost incredibly stout crankshaft (you almost wouldn't believe how big it is until you see one). To an extent this represented sound philosophy for an American locomotive, where there is little point in weight-saving when it will only have to be made up in ballasting, but as previously noted a significant consequence was low maximum 'safe' rotational speed.
The problem with the heavy Baldwin engines is that a pound of crankshaft is a LOT more expensive than a pound of ballast.
VGN JessI can certainly understand the concept that less cylinders equals less reciprocating mass, but how could 16 cylinders weigh less than 8 cylinders? Given the 8 cylinders greater size over the EMD 16 cylinder, I don't see how they would weigh more.
There are at least three separate things involved here.
1) Displacement per cylinder is different
2) Engine construction much, much heavier (including component weights) for the Baldwin
3) Operating speed. (This is the most critical thing involved).
As an initial question: which is larger, the 12-cylinder engine in a BMW E38 or the 8-cylinder 8V71 in a MCI bus? The purpose of the additional cylinders is not just to provide 'extra power'; a V12 in particular has very good balance characteristics, and may be considered over a V8 of equal swept volume.
Note that I left out the truism that the EMD, as a two-stroke engine, has twice the nominal power strokes as a 4-stroke diesel of equivalent displacement. That certainly doesn't result in the engine making 'twice the power' (Don Oltmann will have the precise amount, which I dimly recall being somewhere in the range of 1.4 times for a Roots-blower scavenged engine) but it does give more output power for a lighter engine, as is the case for two-stroke engines elsewhere like lawnmowers or motorcycles.
The eight 'cylinder bores' in, say, a 608a are larger than their counterparts in 567 or 645 power assemblies, but the surrounding block is far heavier, as are the pistons and rods that run in them. And it's the reciprocating mass that is most significant here.
Meanwhile, the EMD engines, from early on, featured welded construction for lightness (there was at least one article in Trains on this in the 1960s) and so weighed less than even a modern (and, as Peter Clark notes, frequently crack-prone) cast counterpart as in, say, a GE FDL.
Another factor to consider was that the De La Vergne engine was an inline 6 or 8 cylinder arrangement while the various 567 engines were V-6 through V-16. That would cause differences in the stresses on the crankshaft and main bearings.
De La Vergne engines were also notorious for being high-maintenance and really bad oil leakers.
Pi. The De La Vergne engine had a bore of 12.75 inches and the 567 8.5 inches. Stroke was 10" vs. 15.5".
I can certainly under stand the concept that less cylinders equals less reciprocating mass, but how could 16 cylinders weigh less than 8 cylinders? Given the 8 cylinders greater size over the EMD 16 cylinder, I don't see how they would weigh more. ??
Smaller pistons and cylinders equal less reciprocating mass and less weight.
Thank to all who responded. As an aside, I didn't expect anyone to know the actual reasoning behind EMD using 16 cylinders to get the BHP of an 8 cylinder Baldwin. I was looking for speculation. oltmannd: Baldwin didn't start with a clean sheet of paper did they? The DelaVergne engine company had been around for decades. Yours is still the best speculative answer I read-thanks.
You need to remember that after WW2 companies were buying anything that was powered by a diesel engine in order to replace steam engines. Where EMD had the edge was most Navy ships that had been powered by diesel engines were powered by the same 567 series engines that were in the EMD engines. So the machinsts that worked on them that had served in the war on those ships were like hey same engine I know how to make this thing work. Every LST was powered by a quartet of 567 engines.
oltmannd Because they weren't starting with a clean sheet of paper. EMD started as a relatively small company, EMC, that built self-propelled rail cars. They purchased/licenced an existing engine design that they modified for locomotive application. Their expertise at the time was not engine design, but locomotive building - more of a system integration job than component manufacturer.
Because they weren't starting with a clean sheet of paper. EMD started as a relatively small company, EMC, that built self-propelled rail cars. They purchased/licenced an existing engine design that they modified for locomotive application. Their expertise at the time was not engine design, but locomotive building - more of a system integration job than component manufacturer.
May be more accurate to say that EMC/EMD got into the locomotive business as a progression in making larger, more elaborate and more powerful rail cars, e.g. the Pioneer Zephyr and UP City of Salina. The first E's built for the Santa Fe and B&O were a bit like a rail car with the engines taking up the interior space.
The 201/201A engines were a product of the GM era, with Kettering directing the devlopment of the unitized injectors used on the various Winton/EMD diesels as well as the Detroit Diesel line. The smaller cylinder size, higher engine speed and use of two cycle design was done to make an engine with much pounds per HP than existing diesels, with one very large non-RR customer in the form of the USN.
"System integrator" is a very apt description of pre-GM EMC.
VGN Jess That may be true, but companies bought the Baldwin 8 cylinder engines despite the simplicity of the EMDs.
That may be true, but companies bought the Baldwin 8 cylinder engines despite the simplicity of the EMDs.
Not many.... EMD pretty much owned the market by 1960.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
VGN Jess That answered my 1st question, but my 2nd question was why didn't EMD use the larger cylinders to get an 8 cylinder engine vs 16 cylinders. ??
That answered my 1st question, but my 2nd question was why didn't EMD use the larger cylinders to get an 8 cylinder engine vs 16 cylinders. ??
As time went on, they got more and more involved in engine design. But, the current 710 engine is nothing more than the evolution of the Winton design they started out with. Designing an engine from a clean sheet of paper is quite a task. Not something EMC/EMD could afford to do. Better to take a proven "off the shelf" design.
VGN Jess That answered my 1st question, but my 2nd question was why didn't EMD use the larger cylinders to get an 8 cylinder engine vs 16 cylinders. ?? the people that know the answer to that died a long time ago and their secret died with them.
The development of remarkably high power out of the Cooper-Bessemer design is an interesting thing - Will Davis and I believe Don Strack have researched the period in the '50s where it began to appear as if the rotating assemblies in the engine design could produce (and tolerate) vastly more horsepower than previously expected.
This was most obvious in 1952. One of the first examples of a GE road locomotive was sold to Queensland Railways in late 1951, a locomotive that even looked a lot like the mid 1950s export U-boats, with a 12 FVBL rated at 1100 hp input to the generator. A year earlier, the New South Wales railways had purchased RSC-3s from Montreal which provided 1600 HP from an engine of the same nominal displacement.
GE had a line of shovel nose units that sold well in Argentina, but only the first batch had the Cooper-Bessemer, the others using the higher rated Alco 244.
So at this time, GE presumably realised that if they were to separate from Alco, the C-B had to at least match the 244, and later the 251.
The cast crankcase of the C-B, and the FDL was well designed and could take the higher forces of the greatly increased BMEP required to get 2500 HP, and later 4400 HP out of a 16 cylinder. But fatigue cracks appeared and as the power went up, the life of the crankcase reduced.
In 2004, when BHP purchased a number of forty year old secondhand SD40s to meet rapidly increasing demand for iron ore, Rio Tinto had replaced the crankcases on all of their first batch of C44-9Ws which were just ten years old.
Argentina remained a big market for GE who purchased many of the early export units, eight cylinder U12s and U13s and twelve cylinder U18s. By 2003 (so more than 40 years) while some of the old GEs were still running, crankcase cracking was taking its toll and striped GE crankcases could be seen stacked behind many locomotive workshops. But the oldest C-B engines had been replaced by locally built Alco 6-251 D engines of the same power.
The Pilbara replacement of crankcases after ten years is an extreme example, and Rio's track is harder on locomotives than BHPs, but the ex SP SD40Rs with not much more than a minor overhaul and a coat of paint went straight into the heaviest service straight off the boat. BHP, who'd had an all GE fleet were a bit appalled by the fuel consumption of their not so new EMDs, but were happy with the performance. They now have only SD70ACe units, nearly two hundred of them...
Pacific National's intermodal trains rely on 120 Cv40-9i units. These received new FDL-16 engines after 15 years, along with a much needed update of the electronics which were becoming unreliable.
Locomotives are still being built with FDL-16s for use in Australia, three being delivered at the end of last year.
Peter
oltmannd creepycrank Not if you take the head off the liner first
creepycrank
Not if you take the head off the liner first
Well, let's go the other way, then; you'd need a chain hoist to position the replacement 440# PA correctly over the crankcase and let it down 'easy' without the dangling connecting rod scoring the bore of the liner.
If these were actually installed 'in two pieces' ... how were the liners-with-pistons worked into position, and how quick was it to torque the head to spec?
BTW, for you 'tugboat engine' snobs, the revision of the 608 to the 608A was more or less specifically to make it a good locomotive powerplant -- which it was, for its era and the assumptions Baldwin (and Lima) made about what made for a good railroad diesel engine. The problem was that it was already effectively horsepower-limited by its combination of speed and relatively high boost; there would be vastly self-limiting returns to scale for any particular rotational speed increase, let alone increased MEP per stroke added to inertial loading.
The development of remarkably high power out of the Cooper-Bessemer design is an interesting thing - Will Davis and I believe Don Strack have researched the period in the '50s where it began to appear as if the rotating assemblies in the engine design could produce (and tolerate) vastly more horsepower than previously expected. There is no comparable upside for one of the Baldwin engines (which didn't use as robust a pin and journal arrangement, with 'master' rod, as the CB design did) although there was certainly quite a life for the Baldwin engine design in Europe after BLH threw in the towel post-Westinghouse quit.
creepycrankYou will need a chain hoist to pull the 440 pound PA out of the engine
Not if you take the head off the liner first. I've heard of this being done and a couple of guys wrangling the parts by hand. I wouldn't do it, but.....
You will need a chain hoist to pull the 440 pound PA out of the engine. By the way I timed a National Marine team change a power assembly on the " Sheila Moran" in30 minutes from dumping the water until hitting the start button. An engineer on a McAlister tug said he and a deck hand changed out a PA while the cook was ashore buying food and was ready when the the dispatcher called with the next job. The National Marine guys had all the tools including hydraulic wrenches that speed things up by the tugs engineer had to have at least the fixture that attaches to the cylinder head to allow the hoist to connect up and some pretty large torque wrenches you won't find in your toolbox in the garage.
No mystery at all. You can maintain an EMD engine with simple tools. Changing a power assembly can be done by a couple of guys and the only special tool you'd need is something to torque down the crab studs. Everything else you need is in your garage toolbox.
The "number of parts" argument has merit, but fails when you think about the FM engine. Really simple. No heads! RRs hated them because you had to pull the top crank to replace a liner.
VGN Jess Thank you for the great PDF files; very interesting reading. Even after reading about the 537 development though, I still can't get my head around why a company would build a 16 cylinder engine when a 8 cylinder engine would produce 100 more BHP and would have, (intuitively at least to me) cost less to build (eg..smaller block, less cylinders, etc...) Oh well, some things must remain a mystery to me. :)
Thank you for the great PDF files; very interesting reading. Even after reading about the 537 development though, I still can't get my head around why a company would build a 16 cylinder engine when a 8 cylinder engine would produce 100 more BHP and would have, (intuitively at least to me) cost less to build (eg..smaller block, less cylinders, etc...) Oh well, some things must remain a mystery to me. :)
VGN Jess Ok, thanks. So why do you think that EMD would not have used those same cylinder dimensions of 12.75" x 15.75" and operated at 625 RPM, so they could have reduced their engine size by half (16 cylinders down to eight)? Surely that would have saved EMD a lot of money.
Ok, thanks. So why do you think that EMD would not have used those same cylinder dimensions of 12.75" x 15.75" and operated at 625 RPM, so they could have reduced their engine size by half (16 cylinders down to eight)? Surely that would have saved EMD a lot of money.
Ok, thanks. So why do you think that EMD would not have used those same cylinder dimensions of 12.75" x 15.75" and operated at 625 RPM, so they could have reduced their engine size by half (16 cylinders down to eight)? Surely that would have saved EMD alot of money.
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