Dave H. Painted side goes up. My website : wnbranch.com
QUOTE: Originally posted by dehusman You can MU almost any modern units together. Not so on older units due to different control systems in some pre 1960 deisels. You do have to be careful of gear ratios. Put a passenger (or high speed) engine in with a "regular" engine on a drag freight and you will burn up the passenger engine's traction motors. Often switch engines with AAR type B switcher trucks (a normal "switch engine" truck) have a speed restriction on them because the truck isn't as stable at higher speeds. Those switchers with road trucks (MP15's, SW150's with Flexicoil trucks) are designed to operate at road speeds. There are also restrictions on engines with non-alignment controlled drawbars. The alignment control keeps the drawbars in line during buffing (shoving) forces. If you have too much tonnage behind engines without alignment control couplers, applying the brakes or shoving the train could cause the drawbars to skew sideways and derail the train or engines. For example Amtrak F40's used in freight service have to be on the point because they have non-alignment control drawbars. Same with mixing AC and DC traction. You have to be especially careful if the AC is in the lead. An AC will keep on pulling down to low speeds that will fry a DC traction motor (why AC's are used on coal trains).
She who has no signature! cinscocom-tmw
QUOTE: Originally posted by kevarc NS has issued guidelines on what unit can be mu'ed together. They want each consists to be like units. They do not what different HP engines together, mixed 4 and 6 axle units and AC & DC units together. Chessie ran anything over Sandpatch, they would use GP's on coal drags down Sandpatch.
QUOTE: Originally posted by dekemd CSX doesn't seem to care about what's lashed together. ACs, DCs, four axles, six axles, it don't matter as long as it runs. It's very common to see two AC4400s and a SD40-2 behind them on coal freights. Saw one the other day that had two sd40-2s with a four axle GE between them. NS does seem to keep like units together. The odd thing NS does is use SD80MACS for locals! Never heard an explanation why. Derrick
QUOTE: Originally posted by dharmon Only reason I'm aware of Derrick is the fact that NS does not like AC motive power and keep them segregated from the rest of thier DC fleet. I travel thru PA on the weekends near Indiana, and usually see 2 pairs of the 80MACs in coal service on a branch line. I live above the gallitzin tunnels in PA, and quite often see a set of them delivering the local, as you have mentioned. They get serviced in town next to me, Cresson, PA, and I frequently watch 4-8 of them there. Also NS will put them on thier local work trains. Sil
Deshler Ohio-crossroads of the B&O Matt eats your fries.YUM! Clinton st viaduct undefeated against too tall trucks!!!(voted to be called the "Clinton St. can opener").
USAF TSgt C-17 Aircraft Maintenance Flying Crew Chief & Flightline Avionics Craftsman
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