I thought the cooling problems with the 265H related more to the intercoolers. These were placed on each side of the crankcase and fed the air directly into the cylinder heads. I believe the intention was to keep the engine as short as possible, which has always been an EMD desire. These tended to leak coolant and needed continuing attention.
While none are in use now, SD90MAC-H were used by Fortescue Metals in the Pilbara and they apparently held up under those conditions. The first batch were refitted with 710G3 engines and the second batch were put into storage after demand for iron ore fell.
There were some 5300 HP SD80ACe units built for Brazil. I don’t think they had bigger radiators than the SD80MAC units.
I was under the impression that the WDG5 was 5500 Brake HP, so around 5300 HP input to the alternator. Export locomotives are often described by the Brake HP which is commonly used outside the USA.
Since WDG5 has radiators more like a GE ET44 than an SD80MAC, we are none the wiser as to the capacity of the 80 line radiators to take higher power, unless they are the same as the SD90MAC fit.
I wonder why they didn’t offer 90 series “convertibles” with 20-710s…?
I was around the 8500’s for just a small amount of time, but from what I gathered the cooling system was almost as secure as a colander. In addition the locomotives used antifreeze, (I dont know why we couldn’t just use water like every other locomotive we owned) so they were also a giant pain to refill properly.
Is there any way you can find exactly where the colander leaks were springing up, and what was causing them? This would be enormously valuable even if only ‘hearsay’…
Did the convertibles have issues with the cooling system? Or is that a component that would’ve required replacement had they ever repowered them with the 6,000 hp power plant?
I think they could use water though, couldn’t they? I seem to recall that being an issue with the H-engined units. Shop personnel would top them off with water like they were accustomed to, and once the mix changed too much away from antifreeze, they were at risk of freezing up when shutdown in cold weather.
And that of course negates the environmental/economy feature that was one of the selling points of that engine.
My recollection is that they were specifically designed to require as little modification as possible to take the ‘new’ engines (the primary difference being the shape of the short part of the hood over the engine proper).
Part of the problem was not in the ‘cooling system’ proper, but in the structure of the H-block crankcase. This being a thin-wall casting and not fabricated, it contained many areas that if frozen would produce damage that would be difficult to repair and likely disabling to operation. Meanwhile, as I recall, some of the issues of spot heat uptake required ‘water wetting’ for proper heat transfer, which were provided by additives in the coolant, and may have required some of the additional characteristics of an antifreeze azeotrope for reasonable performance especially at protracted WOT.
Not sure ‘negate’ is the word you mean – it reduced the economy somewhat, but if there were any concern with actual antifreeze concentration a relatively simple hydrometer-like test would reveal the situation as easily on a locomotive as for an automobile … with the option being either to use an additive package or do a partial drain and refill to restore the integrity of the thermal protection.
In any event the cavitation issues far outweighed anythi
I just meant that the fuel economy advantage of being able to be shut it down in cold weather isn’t an advantage if shop personnel didn’t correctly fill the cooling system with antifreeze and a freeze up occurs.
None particularly. Service experience with an engine design is really important. EMD really rushed the 265H to production. It began as a smaller bore and stroke 4 cylinder test engine squirrelled away in LaGrange. When the push for 6000HP occurred, they scaled it up and ran with it. (slight exageration, I’m sure - but the point is that there weren’t any of them running around doing anything - and everything was new - a clean sheet of paper.)
Knowing what trouble can occur with modest changes to existing designs, I’d be really skeptical of trying more than a very small handful of a brand new design.
For example, when EMD went from 645E3 to 645F3, they raised the engine speed from 904 to 950. Big deal, huh? Ugh. Headpot seat rings “unseating” all over the place. A “proven” design pushed just a bit…Led to total redesign of crab studs and plates in the 710 engine.
Of course, it would immediately occur to me that you could still run the autostart a bit more frequently, or longer, with the water coolant, and that a considerable amount of the theoretical fuel saving over the course of a calendar year would still be available. That should be something that could be calculated for a given usage profile.
The ‘other shoe’ in that, however, is that additional sensors might (and very probably would) have to be incorporated at ‘key’ points to trigger the more frequent start, and we know that it isn’t the as-built integrity of that sort of system that determines its long-term effectiveness.
Don, do you remember the specific heat rejection in the H-block compared to the 710 equivalent at comparable rpm or fuel rate?
VERY big deal, looking at it from the perspective of an equivalent cyclic-rpm change on a reciprocating steam design. That is a nontrivial change in inertial forces. However, in my next breath I’d have to say I would NOT expect a primary result of the higher speed to be loosening of the power assemblies.
Can you tell us more of the mechanism of failure, and how the redesign addressed it?
My experience was limited, and almost 15 years ago, but I recall a lot of piping leaks where the they connected to the engine, I would assume those were predominantly related to vibration, the charge air coolers also always had streaks running down them where they had leaked, particurlarly where the two sections connected.
Yeah. Forces up by speed squared… Bronze head pot seat rings were getting “chafed” between head and top deck to the point they started leaking. EMD replaced whole crab stud system with stronger bolts (rolled threads, smooth thread to neck transition) and crab plates replacing individual ones.
Also, added Viton seal to head pot seat ring…more of a band-aid.
Can you tell us more of the mechanism of failure, and how the redesign addressed it?
Yeah. Forces up by speed squared… Bronze head pot seat rings were getting “chafed” between head and top deck to the point they started leaking. EMD replaced whole crab stud system with stronger bolts (rolled threads, smooth thread to neck transition) and crab plates replacing individual ones.
Also, added Viton seal to head pot seat ring…more of a band-aid.
Presumably all of the 645F changes had been incorporated in the early 710G engines anyway and those engines were suitablr for the in
Those crankcases came from Engine Systems (Latham, NY) which eventually became owned by GE. The crankcases were fabricated by Zgoda in Poland. Far as I know the only user of them is Metra in Chicago, IL.
This is coming back to me now. But didn’t EMD decide that they had best derate the engine to something like 930rpm at some point, officially? When did they fix things definitively ‘enough’ to go back to full power?