DM30 and DE30

What kind of information are you looking for exactly S@fino?

Has there ever been a locomotive made that could be hooked up to a consist of MU's that would supply electric power for both the traction motors on the engine and to the MU's. If not why not? It would seem the perfect engine for the LIRR, if you made a DM type that could do this, it would be able to operate under any conditions, plus do away with the requirment of having 2 DM's on a train because of 3rd rail contact problems....

Mu couplers only have low voltage connectors(32volt) High voltage connections are not trainlined, other than 480 volt HEP jumpers on locomotive hauled cars.

I would imagine that it is virtually impossible to have a heavy enough power linkage. It would have to carry the power for the entire train between the engine and the first car. We're talking amperage in the thousands range?

No way, Jose!

Actually, building a locomotive like that would be technically possible these days with the constantly improving fiber optic technology, which would allow for greater amperage transmittance. However, it would be costly to build, as well as demanding from an electrical engineering perspective. Above all, the market for such a locomotive would likely be quite limited, so i don't see any of the major companies venturing into this area anytime soon.

MP-54s had trainlined power busses, Reading Blueliners did too. Nothing magic about it, just need a cable of suficient capacity and the right connectors. Just no point to it on third rail systems since the conductor size will be so big and high amperage connectors are fun things to have around...

E-33s and Little Joes had roof busses, FWIW. I don't think they ever got much use since it makes coupling things less easy.

The TGV trainlines the 25kv line on the roof because at 186mph, the wave created in the catenary makes contact a bit hard, though the Japanese have had some success with multiple pans at that speed...

In USA high voltage connections other than 480 volt HEP are prohibited on all rail vehicles by FRA unless they are permanently coupled and can only be uncoupled in shops.
Traction power is transmitted from A car to B car on a pair or even MNCR triplets but the cars are drawbar connected, no couplers.

Couple of questions/comments:

Why do the DMs run on their own power for most of the route? Wouldn't it be more efficient and environmentally friendly to stick with 3rd rail power for as long as possible? The Port Jefferson Branch trains could probably switch from 3rd rail power a few miles after Hicksville.


With Metro North and the Genesis series of locomotives, what parts do they run on 3rd rail power? Do they push-pull when they run 3rd rail to provide more surface area contacting the rail? Do they run the Genesis's into Grand Central Station?

Lirr168 wrote:What kind of information are you looking for exactly S@fino?

I'll write You later today. But I'm not sure if You'll understand my translate from Slovak language (the informations I need to know are in Slovak language). But I hope so...

RPM2Night wrote:Couple of questions/comments:

Why do the DMs run on their own power for most of the route? Wouldn't it be more efficient and environmentally friendly to stick with 3rd rail power for as long as possible? The Port Jefferson Branch trains could probably switch from 3rd rail power a few miles after Hicksville.


With Metro North and the Genesis series of locomotives, what parts do they run on 3rd rail power? Do they push-pull when they run 3rd rail to provide more surface area contacting the rail? Do they run the Genesis's into Grand Central Station?

I'm not sure, but I think that on Oyster Bay - Penn Station route there's 3rd rail starting just in Jamaica (?)...

Do anybody know what means "AC" in DE30AC and DM30AC??

AC means AC propulsion as in AC travtionmotots and inverters.
The reason nobody wants to run the DM's at speed in electric is the flashing at gaps and bad contact spots on third rail.
Just like a welder the DC power can cause extensive damage to locomotive trucks if it flashes to ground.

Actually, building a locomotive like that would be technically possible these days with the constantly improving fiber optic technology, which would allow for greater amperage transmittance.

Sorry.. incorrect. Fiber optic cable transmits light, not electricity.

Good catch, scopelliti, my mistake; I meant to say that fiber optics is an example of how we have greatly improved transmittance technology in the past few years, but I wound up losing my train of thought (no pun intended ) Oh well, "to err is human."

Anyway, I do stand by my contention that although difficult and not cost effective at this stage, it is physically possible for something like this to be done.

Why do the DMs run on their own power for most of the route? Wouldn't it be more efficient and environmentally friendly to stick with 3rd rail power for as long as possible? The Port Jefferson Branch trains could probably switch from 3rd rail power a few miles after Hicksville.

Engineers are required to make the transition to Diesel Mode upon exiting the tunnel for Eastbound trains

Engineers are required to make the transition to Electric Mode at Nassau or Port Interlockings for Westbound trains