A crazy question? HEP, etc.

[DryCreek]

OK, lookng at the new locomotives that are being used by Amtrak, a crazy question popped into my head.

First, for a little background; my Grandfather was an engineer (first steam, then diesel) for the Rock Island Line, and then Burlington. He was based out of Teague, Texas. My uncle followed in in footsteps and is currently employed by BNSF. He no longer is on the road, but I think that he works in a yard due to injuries (dispatch?).

Anyway, growing up in I remember seeing the big EMD E-Series locomotives* (don't really remember any Alcos) passing by on the freights and some passenger traffic. The EMD's always seemed to be MU'd with an "A" unit followed by however many "B" units were required for the conditions. The brakemen and conductor could pass between the lead unit and the MU'ed B units through doors and passages over the couplers.

So, on these newer units, I guess that there is no way for anyone to pass between the locomotives - is there? Is each one crewed? Even if it is only providing HEP (hotel loads) and not traction? That seems like a redundancy in staffing. Even when they MU'ed two EMD E series "A" units, they had one facing rearward so that the train crews could pass between locomotives - and only the crazy or brave (you pick) would even consider going out the trapdoor on the nose if they wanted to get to the car immediately behind the last locomotive.

Why don't they have one of the locomotives facing to the rear when paired?

* E-7, E-8 and E-9's

 

[Shortline]

If the consist is a pair, and they are back to back, the engineer or head end crew can go from one locomotive to another. Just can't go through the nose anymore to the train, or to a 3rd locomotive in the consist.

No, all loco's are not manned, they're coupled electronically with an MU (Multiple Unit) cable that transmits signals for the trailing unit operation, from the single engineer on the head unit.

Even if they DID have one facing backward, coupled to the cars, unless it is a single engine, still couldn't get through the whole consist that way through to the loco cab, the nose problem is now in the middle, instead of on the rear of the consist. Just really is no reason anymore to need to access the engines from the cars.

 

[cirdan]

You don't need to put a human on every locomotive. The second (and any further) locomotives are controlled remotely from the first and don't require direct supervision.

I don't know how often you would actually need to send staff from one locomotive to another or from the locomotive to the train while the train is moving. Staff changeover usually happens at scheduled stops.

The old E-Units had a door in the nose, so even if an A-unit was sandwiched between other locomotives, you could walk through. I don't know often this was done in reaility though, but possibly on the older style of locomotives you needed to inspect more often.

 

[zephyr17]

Only the lead unit is manned. They wouldn't tend to go between the units while underway in any case, and on a lot of runs there is only one engineer in the cab (under 6 hours?).

I think any of the units can provide HEP. The P42s have a separate HEP generator, unlike the F40s.

 

[jis]

Only the lead unit is manned. They wouldn't tend to go between the units while underway in any case, and on a lot of runs there is only one engineer in the cab (under 6 hours?).

I think any of the units can provide HEP. The P42s have a separate HEP generator, unlike the F40s.

Really? Here is what is said about HEP generation in P40/42/32ACDMs in Wikipedia:

All Genesis engines can provide head-end power (HEP) to the train drawn from an alternator or inverter powered by the main engine at a maximum rating of 800 kilowatts (1,100 hp), making each unit capable of providing HEP for up to 16 Superliner cars. The P40DC and P42DC power plants can supply 60-hertz head-end power either from the HEP alternator with the engine speed-locked to 900 rpm (normal mode) or from the traction alternator with the engine speed-locked to 720 rpm (standby mode). In the latter case, traction power is unavailable. The P32AC-DM powerplant does not have to be locked at a certain rpm because it utilizes an HEP inverter, which allows the prime mover to run at 1047 rpm when providing both traction power and HEP, and to idle at 620 rpm (or notch three) while still providing HEP for lighting and air-conditioning when not providing traction power.

Seems like the same prime mover is used to provide HEP as is used to provide traction. HEP may come from either a dedicated alternator driven by the same prime mover, or from the traction alternator via one of the traction inverters from the DC link.

 

[Bob Dylan]

What are these two engines that you speak off? LOL My home train, the Texas Eagle, ( and several other LD trains)operates with only one P-42 and one engineer in the cab!

 

[Devil's Advocate]

What are these two engines that you speak off? LOL My home train, the Texas Eagle, ( and several other LD trains)operates with only one P-42 and one engineer in the cab!

Now that right there is a genuine mystery. Has Amtrak lost too many genesis locos and now they're just plain out?

 

[neroden]

Amtrak has stated that there's an actual shortage of Genesis locomotives, yes. This will be alleviated somewhat when California, Illinois, Missouri, and Michigan finish buying their own locomotives (currently being manufactured).

 

[BCL]

Amtrak has stated that there's an actual shortage of Genesis locomotives, yes. This will be alleviated somewhat when California, Illinois, Missouri, and Michigan finish buying their own locomotives (currently being manufactured).

I'm seeing quite a few of the P42DCs being used on Capitol Corridor. Seems kind of strange given how I'm hearing about shortages.

I saw the photo of 196, but this says it was returned to service in May 2012 after a Jan 2011 fire. So it would take that long to fix?

Also - nobody needs to be in the locomotive. I ride on trains regularly that are in push configuration - remotely operated by the engineer in a cab car. I don't suppose that there are many trains in a push configuration with two locomotives.

 

[DryCreek]

Well, I am familiiar with how they MU locomotives for traction. I was just wondering if they had some way to gain access while they were moving. I work at a power plant. Most of our systems can be remotely monitored and controlled, but there is always someone available to run down and get "hands-on" with our equipment. In the old days of the E and F unit EMD's, I had heard that it would sometimes be necessary for the lead brakeman (or assistant engineer) to head into one of the B units to shift a fuel oil filter or adjust a cranky steam generator, or just perform any of a myriad of quick fixes on aging equipment. Sometimes just being able to get your hands on a minor problem before it worsens can save much down time.

It's not very encouraging to see so many photos of burned out road traction units like that! Have they determined a common root cause of those fires? They all seem to be in the area of where the alternator or exciter controllers may be. I don't guess that it would have been an issue with the dynamic braking system as those normally set the roof on fire, don't they?

 

[CCC1007]

The first one was a wreck...

 

[Bill]

I have wondered this,lead unit is facing forward and second is facing to the rear does the mu automatically "know" which way to go or does the engineer push a button to let it know if it is not elephant style?

 

[Shortline]

I have wondered this,lead unit is facing forward and second is facing to the rear does the mu automatically "know" which way to go or does the engineer push a button to let it know if it is not elephant style?

Yes, it's automatic. The pins on the MU cable indicate which way it's facing and automatically "reverse" the signals for rear facing units.