While the TEREX TITAN was the largest truck of it's time (1970's) at 350 tons there are considerably larger vehicles being built now, including the CAT 797 at 400 tons.
I find Tugboats interesting and every year I purchase the special AMERICAN TUGBOAT REVIEW issue of PROFESSIONAL MARINER magazine which covers the industry. I just got the new edition and was interested to note that many of the larger boats built recently have MTU 4000 series engines which are a higher speed (RPM wise) design. Remanufactured 645 engines are also still popular for new built vessels but I get the strong impression that MTU/Detroit Diesel is making some serious inroads into the market dominated by CAT and the EMD 710 series....
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
trainfan1221 The original engine that started it all, the Winton 201-A, was actually a marine engine. It just wasn't what was needed for a railroad engine, but apparently it was a good start. The regular EMD diesels, in a modified form, are also used in marine applications. Actually, I visited a display tug once, forgot where it was, but when I checked the engine room the power sitting there was definitely some form of 567 type diesel. Looked slightly different but the basic design was there. As long as this is being mentioned I'll throw in that the world's largest dump truck, the Terex Titan, used a 645 engine for power. It was essentially a diesel-electric locomotive in truck form, at least operating wise.
The original engine that started it all, the Winton 201-A, was actually a marine engine. It just wasn't what was needed for a railroad engine, but apparently it was a good start. The regular EMD diesels, in a modified form, are also used in marine applications. Actually, I visited a display tug once, forgot where it was, but when I checked the engine room the power sitting there was definitely some form of 567 type diesel. Looked slightly different but the basic design was there.
As long as this is being mentioned I'll throw in that the world's largest dump truck, the Terex Titan, used a 645 engine for power. It was essentially a diesel-electric locomotive in truck form, at least operating wise.
The only difference between most marine 567s and 645s, and locomotive 567s and 645s, is the oil pan, which in the marine application is designed to ensure the oil pump pickup still is immersed in oil even when the engine is rotated significantly from normal position, as when the ship or boat pitches or rolls. Approximately 1/3 of the worldwide tug fleet is powered by EMD, 1/3 by Cat, and the other 1/3 by everyone else. Similarly, 1/3 of the 1,000-foot lakers are EMD powered (by 20-645E3s). Many marine operators derate the 16-567C to 1,500 hp and 800 rpm, and under those conditions they virtually will last forever. The machinist I apprenticed to as a pup in the shop came out of marine. He once told me, "Thank God for Alco, because I've made a living for 30 years bolting them back together when they fly apart. If I'd had to feed my family repairing EMDs, we'd have starved."
The Terex Titan was a flop, but that was mostly due to tire problems (the tandem rear axles scrubbed the tires excessively) rather than deficiency with the drive train. Electric transmission earthmoving machinery dates to Robert Le Tourneau in the 1930s. Terex simply borrowed the EMD drive train because it couldn't afford to develop an electric-drive truck on its own. During the early 1960s Unit Rig, Wabco (the former LeTourneau line), and Wiseda developed the electric-drive trucks that are now manufactured under the Komatsu, Liebherr, and Hitachi brands. Terex wanted to break into that market but didn't have the capability. For what it's worth, Caterpillar for several decades has owned about 2/3 of the world market for large trucks, manufacturing only all-mechanical drive, but it's been developing an electric-drive large truck in the 797 class for several years and prototypes are testing in the oil sands. Cat also has the first really thought-out diesel-electric dozer in end-user testing now, the D7E, and early reports indicate it's a world-beater.
RWM
JayPotter oltmannd We had trouble with the SD60MACs we tested at very low speeds. What type of low-speed trouble did they have? Thank you.
oltmannd We had trouble with the SD60MACs we tested at very low speeds.
We had trouble with the SD60MACs we tested at very low speeds.
What type of low-speed trouble did they have? Thank you.
Adhesion. They wouldn't get a grip below 5 mph or so. Above 5 mph, they'd run at 35% or better, but below, they couldn't grab and hold even 30%.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Railway Man P.S. -- Earlier I see you'd asked why EMD designed a V-engine instead of an in-line engine. The answer is because it needed to fit the engine into the carbody, RWM
P.S. -- Earlier I see you'd asked why EMD designed a V-engine instead of an in-line engine. The answer is because it needed to fit the engine into the carbody,
I thought EMC designed their original engine to meet Navy specs to fit inside a submarine. The big RR design problem was to get a radiator big enough to replace the ocean.
Phil
Timber Head Eastern Railroad "THE Railroad Through the Sierras"
Murphy Siding More questions, based on finishing the book:Solomon says that the SD45 had 20 cylinders, giving it 20% more horsepower than a 16 cylinder diesel. ? 20 is 25% more than 16. How daoes that math work?Conrail was the only railroad to order 5,000 H.P. SD80MAC. Why?Is the 6,000 H.P. EMD diesel engine dead?Thanks
More questions, based on finishing the book:Solomon says that the SD45 had 20 cylinders, giving it 20% more horsepower than a 16 cylinder diesel. ? 20 is 25% more than 16. How daoes that math work?Conrail was the only railroad to order 5,000 H.P. SD80MAC. Why?Is the 6,000 H.P. EMD diesel engine dead?Thanks
Comparing the contemporary EMD locomotives/prime movers the 16-645 SD40 was rated at 3,000HP and the SD45 at 3600. 3,000 divided by 16 is 187.5 per cylinder which multiplied by 20 is 3,750(although note that in both cases the diesel engine output is actually somewhat higher but the additional HP is needed to run the auxiliaries). I believe the reason that the 20-645 was slightly derated was to increase engine reliability. EMD built several SD45X demonstrator units rated at 4200HP and planned to build a production SD55 but there were reliability issues and the test units were eventually derated to 3600 HP.
My understanding is the CONRAIL wanted a higher horsepower locomotive using an evolved 710 engine rather than the unproven 265H and history has shown they made a wise choice.CP also ordered a small number of SD80MACs but switched the order to SD90s by the production time.
All of the 265H powered SD90MAC-Hs built (UPs fleet and the 2-3 that CP had) have been retired although some are in EMDs lease fleet.EMD is supplying 265-H engines and other components to Dalian Locomotives works in China who are building approx. 200 5,900 HP locomotives for the Chinese railway of a somewhat different design..
Murphy SidingConrail was the only railroad to order 5,000 H.P. SD80MAC. Why?
We were smarter than everyone else!
Most RRs wanted a high horsepower, AC locomotive as a replacement for the existing fleet of 3600/3800/4000 HP six axles. They took the TE at MCS from 90-100,000 up to 147,000 and HP from 36-4000 up to 5000-6000. They held the promise of being able to replace these locomotives roughly 2 for 3 in the fleet. They looked even better against the 3000 HP six axle fleet, replacing them 1 for 2.
Generally, fewer locos = lower ownership costs and AC traction = lower maintenance costs.
Conrail had a pretty well defined set of "tonnage rating" tables for various service types that were based on HP and scheduled running times and the ruling grade on that route. Using these and actual sample of trains on various routes, it was possible to determine what overall replacment ratios would be achievable.
The SD80MAC turned out to be a great match for the Pittsburgh Line between Enola/Harrisburg and Conway for general freight and drag service. Since there was a high frequency of trains on that line, you could keep them productive. They weren't a bad fit elsewhere, but the AC traction was more or less "wasted" on the flater portions of the system. So, the order that was going to be some GP60s (including some B units) and SD70s was converted to SD80MACs.
Why the 20-710 instead of the new 6000 HP engine? There were two factors. The primary one was concern about the reliability of any new engine design. The CMO - Locomotives at Conrail came from GE and had spent quite a bit of time at Conrail fighting problems with even small changes to engine designs. So, he was rightfully leary of the new engines, knowing that each being offered was a "rush job". He was also leary of the 20-710 but EMD had demonstrated the reliablilty of the design to some degree by a number out running in marine service with a pretty good record, so this opiton was less scary.
What didn't work out very well was somewhat less thoughful application of the SD80MACs once they arrived. The "old school" railroaders ran them all over the RR in every kind of service to "see what they could do". We really already knew what they could do and where they fit best. HP is HP and TE is TE. The only real question we needed answered was if they could really achieve the 35% adhesion under 5 mph. We had trouble with the SD60MACs we tested at very low speeds.
In then end, they wound up on the Boston Line, which wasn't too bad a fit, except the utilization of power on that line was traditionally bad and the service demands of the line would have been satisfied with 4000 HP AC locomotives. Had Conrail stayed in one piece, you'd have seen follow on orders of SD80MACs. In fact, there was one on the books, ready to go that got converted to NS SD70s and CSX SD70MACs at the end of Conrail.
There was always hope, confirmed by EMD, that the 20-710 could be boosted up to 5500 HP or so as the 16-710 had been boosted from 4000 to 4300 HP.
In hindsight, was this a good choice? Mostly yes. The SD80MACs certainly proved more reliable than their 6000 HP cousins with only the CSX fleet of AC6000s surviving in spite or engine woes.
However, Conrail had been pursuing a split fleet philosophy. High HP four axles for intermodal and six axles for everything else. By the early 90s, the four axle fleet was in decline. The GP40-2s could still go, but their fuel efficiency was poor. The B36-7s were a mess. They ran good for about a year, then started failing and rough ride compliants started coming in in droves. The B40s were good, but there were only 30 of them.
In order to keep the intermodal trains running on time, the newer C40-8Ms and SD60Ms were bumping the B36-7s and many of the GP40-2s from this service. The decision to purchase some GP60s and SD70s would have continued the split fleet philosophy and bumped some of the six axles back to the general freight service they were purchased for.
But the AC power looked like a game changer and Conrail wanted to play.
Murphy:
Horsepower is not always linear with number of cylinders for several reasons, such as not necessarily proportional increases in parasitic loads (some are fixed), the poor economics of designing peripherals 100% matched to the individual engine instead of one-size-fits-all, the requirement to live within the capabilities of the electrical transmission. Using hp available at the flywheel for traction, note the step-wise decline:
I think Don can offer more incisive insight on the SD80MAC; suffice it to say it was a locomotive that didn't fit the operating paradigms of other Class 1s. But remember, when we're talking a universe of only 10 or so Class 1s, versus half a hundred Class 1s a half-century ago, only "one railway ordering" is statistically much less meaningful: the difference between random chance and actual correlation disappears when the sample size becomes very small.
I have heard no plans from anyone to employ the 6,000 hp EMD engine in the North American market. But that doesn't mean I know the future. I hardly know what the future holds for my own job.
P.S. -- Earlier I see you'd asked why EMD designed a V-engine instead of an in-line engine. The answer is because it needed to fit the engine into the carbody, and build an engine that wasn't so long that it got into excessive deflection problems, which are ruinous to the life of crankshaft, bearings, and crankcase. It's certainly possible to build a crankcase that's stiff enough to not bend as the locomotive flexes, or build a locomotive stiff enough to not bend, and bolt the crankcase firmly to the engine bed, and also beef up the crankshaft so it doesn't flex or twist excessively, but then the weight and depth of the locomotive frame girder, and crankcase girder, and overall crankcase size, no longer fits within the loading gauge, or exceeds maximum axle load, or makes the locomotive too long and thus exceeds axle loading gauges, or all of the above. The engineering solution was to use a V design to shorten the crankcase length and reduce the bending moment and reduce the size of the crankshaft, and live with the complexities a V design creates. These complexities were much easier to solve than trying to build a stiffer crankcase, crankshaft, or locomotive frame and add enormous amounts of weight, which were insuperable problems.
If materials had different properties, e.g, steel was much stronger than it actually is, and diesel fuel had more BTU per gallon, then things could have worked out differently. Materials properties and physical size limits force the engineer into a narrow pathway. The differences between one manufacturer's design and the other manufacturer's design is like choosing to start walking on a tightrope with your left foot first instead of your right foot first.
I know that EMD isn't currently using the 6000hp engine in domestic applications, apparently they use it in overseas models. Conrail seemed to make good use of the SD80MACs, they didn't order anymore though. It doesn't look like other railroads were interested.
Thanks to Chris / CopCarSS for my avatar.
The SD45-2 compensated the extra frame length with the long radiator, used apparently so that they didn't have to use the slant of the SD45, considered to be a maintenance issue at the time I believe. Interestingly they are the norm today. The SD40-2 has a slightly longer hood than the SD40, otherwise the porches would have been bigger. Actually the extra porch length on the SD40-2 appears to be all on the back, making it a slightly awkward unit when viewed from the side. But who is gonna argue with success? It certainly worked, and the formula doesn't seem to have been quite captured again since.
The SD40-2 and SD45-2 have longer frames as the HTC trucks are longer than the Flexicoil trucks they replaced. They would have had to reduce the 4000 gallon fuel tanks to keep the same wheebase.
FT's did NOT have any draft gear between the A and B unit. A special curved shank coupler was designed at ATSF's request as they wanted to have coupler on all units. Adding draft gear would have meant a re-design/lengthening of the units. These 'FS' units did not have any draft gear on the front of the B unit or the rear of the A unit. 'FS' was an EMD engineering designation for the ATSF units.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Let me add a bit:
The SD40-2/SD45-2 had a longer frame than the SD40/SD45 to accomodate the HTC trucks with their inboard TM spun around with the nose facing the fuel tank.
Just a guess, but I'll bet you the drawbar on the FT's was connected to draft gear, so while it doesn't have free slack, it has slack from "springiness". The drawbar probably just replaces the couplers not the whole draft arrangement.
Whoever brought up bolting things as opposed to welding, don't forget hot rivets!
I'm not sure that the cast vs. welded frame was because the RR ordered it that way?? I thought the NC/SC came out first, later to be replaced with NW/SW series a little later??
To add some to the welded frame answer. In the 1930's welding was not regarded as reliable enough to be used in a high impact service such as the frame of the locomotive. Cast steel was a known and very well proven technology. Using bolts was an alternative that was used, but bolts come loose.
Additionally the companies who provided the castings could provide the builders with a casting that was not only a frame, but it could have the fuel tank, cooling water reservoir, air reservoir, engine/generator/air compressor mounting brackets, battery box and much more all cast in place with only minor machining necessary to make the casting complete.
Murphy Siding Actually, a bunch of similar questions, all lumped together. I'm reading EMD Locomotives by Brian Solomon. Some of what I read makes me wonder about the following:Some E-8's were built with dynamic brakes. Why would this be needed on passenger trains?
Actually, a bunch of similar questions, all lumped together. I'm reading EMD Locomotives by Brian Solomon. Some of what I read makes me wonder about the following:Some E-8's were built with dynamic brakes. Why would this be needed on passenger trains?
The original FT's had draw-bar connections, mating an A unit to a B unit. Did this connection have slack built into it, like a regular coupler would have?
Why were EMD engines built in in a cylender arrangement divisible by 4: 8,12,16, or 20 cylinders? Why no straight 10, or V-10, or V-14? I recall that Fairbanks Morse had some 10 cylinder units?
Some early switchers were built with cast frames, because the purchasing railroads requested them. Why?
SD40-2's had longer frames, and perhaps the famous porches(?), than SD40's Why?
Actually, a bunch of similar questions, all lumped together. I'm reading EMD Locomotives by Brian Solomon. Some of what I read makes me wonder about the following:Some E-8's were built with dynamic brakes. Why would this be needed on passenger trains?The original FT's had draw-bar connections, mating an A unit to a B unit. Did this connection have slack built into it, like a regular coupler would have?Why were EMD engines built in in a cylender arrangement divisible by 4: 8,12,16, or 20 cylinders? Why no straight 10, or V-10, or V-14? I recall that Fairbanks Morse had some 10 cylinder units?Some early switchers were built with cast frames, because the purchasing railroads requested them. Why?SD40-2's had longer frames, and perhaps the famous porches(?), than SD40's Why?Thanks
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