How the trucks are mounted on Locomotives? Are they pin mounted or are they bolted solid to the frame? Art.
Art, as near as I can determine from a 1938 loco book, the trucks under diesels are rotated around a pin in a center bolster. Steam engine Pilot and trailing trucks were also pined to swivel, while all the drivers were hung on equalizing linkages in such a way that some side end-play was allowed, but no swiveling. (That would have damaged the side rods). [ 24 December 2001: Message edited by: watash ]
They're pin mounted. See if you can moe up with a copy of the Trains magazine GE special edition, they had some pics of DASH 9s being set down on their trucks as part of the assembly process.
Depends, On newer designs like the EMD HTCR and both version's over GE Steerables there Rubber Pads that hold the truck to the frame, on all other trucks they use a pin called a "Bolster"
Now that we have determined that the trucks are pin(bolster) mounted. I see no reason that EMD and GE canot use the long porch version of the 20 cylinder SDs and use two sets of two axel truckd on both ends with 750 hp AC Traction Motors. Lead ballast could be used over the front set of trucks to give an equal dead weight load on each axel. With a decent wheel slip device and throttle these big units should make teriffic mountaid units without taring the rails and wheel flanges up. And not have the extra cost of the hydrolics and controles. All comments good or bad are welcome. Art [ 27 December 2001: Message edited by: Art ]
Here's why Cost and Maintance, It cost a more to have those 2 extra traction motors, and a larger truck assembly's , And second, it was finally accepted that 20 cyl prime movers, arent practical, the SD80MAC are geting more troublesome by the day. There have been 2 massive engine failures already. Its not the crankshaft with the problems, but the crank case and Power assembly's I have trouble explaining why this is due to the fact that that EMD's 16V710G3B and 20V710G3B both produce the same HP per cyl. Part of the reason is beleved to be due to the flexing of the block while on the locomotives chassis, Contray to popular belif a locomotive frame is not as rigid as one would think it is, Theres quite a bit of flexing and bending due to all the bangs and bumps in railroad use, The SD80MAC did have one addvancement to try and overcome this, the Prime Mover was mounted to a seperate chassis which was mounted to the frame, but this in reality has helped little. GE on the other hand has never even attempted to produce a 20 cyl FDL. or HDL it would require massive amounts of R&D, and with GE modifying the HDL to met Tier 2 requirements, I am doubtful of that happening. These next few months should be intresting for EMD, Rumor has it there up for sale. [ 27 December 2001: Message edited by: ConrailHaulic ]
Could the block failure be due to the high boost of the dual Turbos causing block flexing and failure. The ductile iron casting may not be as strong as the steel fabricated block of the two strokers. Art.
I wasn't refering to using the 20 cylinder prime mover. I was refering to the16 cylinder 6000 hp unit mounted on the long chassis with 4 sets of two axel trucks. One test unit would give them the answer on tractive force. Art [ 27 December 2001: Message edited by: Art ]
Well the H engine's problems are nemous, but not turbo related, most of the problems are related to the design of the power assemblys and cooling systems, plus inconsistancys in the cast iron blocks EMD's using, this is a first for EMD, all other EMD blocks are wielded, GE's FDL is cast but has a lower failure rate due to the fact that GE has much tighter control than EMD.. I dont know what effect the flexing has on a 16 cyl prime mover, I havent heard any satistics about failures that could be contributed to that. Your Idea is sound about the use of 8 axles, and it has been brought up before. But the main reasons it isnt being used is 1. Cost of the 2 extra traction motors and the truck assemblys 2. these units would have to be ultra reliable to be practical, they would likely be used alone or in pairs, and to lose a unit that big in a consist would be a problem 3. Maintance How hard/costly would it be to maintain the monstroicty of the truck assembly used, Then you got all the related equipment to go with them, extra inverters, larger Alternators, or dual Alternators, computer equpment to drive it all, more High Voltage equipment, not to mention the wiring, the DD35's/DD40s on UP were always pluaged by wiring issues, and electronic issues, and several experments were done to see if these could be remedyed.
