A few questions regarding realism

[The_Garbear]

I posted a thread about this last week in the Scenario Creation subforum about a week ago to no response, I guess that one is more for problems regarding the scenario editor, and I don't feel this really belongs in The Jungle. Anywho, as the title states I've got a few questions regarding realism. I'm by no means a rivet-counter but I do like to have the scenarios I make be at least plausible (I.E. no trains on the Cajon Pass pulled by three SD40-2s pulling a random assortment of hoppers with some double stacks mixed in *glares at RSC*). This brings me to the questions.

1. What quantity and distribution of motive power would I typically see on the Cajon Pass, Horseshoe Curve and Donner, respectively? I've seen discussions on here where people have mentioned 8 locomotives as kinda a bare minimum, and then I see pictures of actual trains on the Cajon Pass led by just two or three ES44s/Dash-9s/ACXXXXCWs(I can never tell the things apart, heh). Wikipedia is of little help in this regard and to be honest I don't really know where else to look.

2. What kind of consists would I typically see on each route? I know Cajon sees a lot of intermodal traffic and Horseshoe gets a lot of coal, but what else? Do they get a lot of mixed freight, TOFC, etc? What about unit trains?

3. Would I see any freight on NEC, and if so, how much? Would P42s be a common sight on the NEC? Would common use of GP9s really be accurate for a 1990s rendition of Donner?

Sorry if any of these are silly questions, I figured there'd be few better places to go than here to get answers for them. Thanks in advance!

[Chessie8638]

1. What quantity and distribution of motive power would I typically see on the Cajon Pass, Horseshoe Curve and Donner, respectively? I've seen discussions on here where people have mentioned 8 locomotives as kinda a bare minimum, and then I see pictures of actual trains on the Cajon Pass led by just two or three ES44s/Dash-9s/ACXXXXCWs(I can never tell the things apart, heh). Wikipedia is of little help in this regard and to be honest I don't really know where else to look.

2. What kind of consists would I typically see on each route? I know Cajon sees a lot of intermodal traffic and Horseshoe gets a lot of coal, but what else? Do they get a lot of mixed freight, TOFC, etc? What about unit trains?

3. Would I see any freight on NEC, and if so, how much? Would P42s be a common sight on the NEC? Would common use of GP9s really be accurate for a 1990s rendition of Donner?

Sorry if any of these are silly questions, I figured there'd be few better places to go than here to get answers for them. Thanks in advance!

1. Distribution of motive power really depends if a train picks up locomotives that need to be moved to another area of the railroad. That's why you sometimes see 8 or more locomotives on a train (I've seen 13 on the head end once). Each railroad has it's own way of using locomotives on a train. I can tell you UP likes to put DPU's before any empty trailers or containers. So you'll see maybe 10 trailers behind a DPU. BNSF seems to have 2 DPU's on trains. Sometimes operating in a 2 x 2 set up (2 on the head end and 2 DPU's). For Horseshoe Curve (Modern Day NS) they use manned helpers. And in the PRR days it would be also, manned helpers. PRR rules prohibited locomotives from pushing on cabooses. So they would be cut in ahead of the caboose.

2. Donner see a lot of Intermodal now since Union Pacific cleared the tunnels for the stacks and manifests. Horseshoe Curve (modern day NS) sees everything. PRR Horseshoe Curve; well; it was THE mainline of the PRR. Cajon sees everything also except coal (that I know of). Right now Intermodal is leading everything. Carloads in general are down around 5% but Intermodal is up 14% since this time last year. So you'll be seeing lots of containers on these routes.

3. On the part of the NEC that's modeled there is no freight except small little locals that putt around and try not to get in the way of everything. Freight trains use every part of the NEC EXCEPT the NYP (New York Penn Station) to PHL (Philadelphia 30th Street) part of the line. If you can back date the NEC to the 1980's and before you would see freight trains.

P42's can't be used on NEC trains since they can't be used in the confines of Penn Station, diesel fumes and such. But having one DIT (Dead in Tow) is possible. But a variation of the P42; the P32AC-DM; can since it uses a third rail shoe when it comes down from Metro North on the Hudson Line. They are only used on these trains since the NEC doesn't have third rail.

The 1990 roster of SP / SSW / DRGW locomotives show 106 GP9E's on the roster (the GP9E was a rebuild SP did). These were used on locals and NOT on Donner except in a power move. But then again SP was in such trouble at the time they sometimes would use anything they had available to move trains. Example: This little GP9 working it's guts out with big six axle power: http://www.youtube.com/watch?v=ByoZNudQ_hw

pulling a random assortment of hoppers with some double stacks

I wouldn't say that. This year in Rochelle, IL I witnessed a UP train pulling grain hoppers and double stacks. Here's the proof: http://youtu.be/XyKTkwgmr60?hd=1&t=15m8s

You never know what you may see! Haha.

[Kali]

NEC local freight? is there somewhere I can find out more?

I presume there's still limits for the number of powered axles at the head of a train?

[The_Garbear]

Wow, that was a fantastic response, thanks! That pretty much clears everything up for me. And I was a bit curious about the GP9 thing because all of the scenarios for Donner that involve being a helper crew include GP9s somewhere and I thought that seemed a bit...Off. I may use RWtools to replace those with SD40-2s or tunnel motors. And the bit about hoppers and double stacks was a comment about the general absurdity of most of the consists in scenarios on the US routes, haha. Not to say it's not possible but you wouldn't see it as much as in the game.

[Chessie8638]

NEC local freight? is there somewhere I can find out more?

I presume there's still limits for the number of powered axles at the head of a train?

Yes Conrail Shared Assets handles local frights between Trenton, NJ and Newark, NJ. Since Amtrak owns the track it's by trackage rights. Most of the North Jersey Shared Assets Area is operated over the NEC. One area to see some kind of local is the Metuchen, NJ area. CSAO (Conrail Shared Asset Operations) has a yard along the NEC and use a remaining yard from when there was a FORD plant nearby.

Most of what info is available is spaced out far and few between on many sites. Here is some info:
http://www.railroad.net/forums/viewtopi ... 27&t=60865
http://www.railroad.net/forums/viewtopi ... t#p1060535


As for the limits of powered axles on the head end it differs between railroads and what type of freight cars are being hauled. For example, on Union Pacific there can't be more then 8 units on the head end of a train (powered, isolated, dead) unless authorized by Train Management. Power moves between terminals are limited to 25 locomotives unless otherwise authorized.


Take Rule L-207 on Norfolk Southern for example.

Rule L-207 deals with Locomotive Axle Limits Under Power and it states...

Except on designated trains, no more than the equivalent of 24 conventional (non-high adhesion) axles may be operated under power on the head end of a train. (Designated trains are solid loaded 100 ton cars equipped with high tensile (Grade E) knuckles and couplers.)

High adhesion axles are equivalent to 1-1/3 conventional (non-high adhesion) axles.

Alternating Current (AC) traction motor-equipped axles are equivalent to 1-1/2 conventional (non-high adhesion) axles.

(So in Laymen's terms it simply means an SD40-2 = 6 axles, SD70M-2 = 8 axles & SD70ACe = 9 axles)

Our L-210 Rule deals with the use of the Dynamic Brake and it states...

If a locomotive consist includes one or more units equipped with STANDARD dynamic brake, not more than the equivalent of 20-axles of dynamic braking may be used on the head end of a train. If ALL UNITS in the consist are equipped with EXTENDED RANGE dynamic braking, not more than the equivalent of 18-axles of dynamic brake may be used on the head end of a train. (Exception - The equivalent of 24-axles of dynamic braking may be used for designated trains handling only loaded 100 ton cars equipped with high tensile (Grade E) knuckles and couplers.)

And here is CSX definitions for dynamic brakes:

For Dynamic Brake calculations the following values are used

All 4-axle units except B40-8 4
B40-8-- 5
All 6-axle units except SD60/M/I, SD70M, C/CW40-8, CW44-9, and ACs-- 6
SD60/M/I, C/CW40-8, CW44-9 ES44DC-- 7
SD70AC, SD70M-- 8
SD80AC, CW44AC, CW44AH, ES44AC-- 9
SD70ACe-- 10
CW60AC-- 11

Maximum Dynamic Brake Axle Value
Do not exceed the maximum dynamic brake axle value for the locomotive consist. Those maximum values are:
•
24—when all units have alignment control couplers.
•
20—when any unit has coupler limiting blocks.
•
Do not use dynamic braking when any locomotive in the locomotive consist does not have alignment control couplers or coupler limiting blocks.




To limit draft forces, the maximum trailing tonnage for a train handled with only head-end power will be restricted as follows:
1. For loaded unit trains (coal, grain, potash, etc.) the maximum tonnage will not exceed the tonnage determined by the tonnage rating for two (2) AC4400 and one (1) C40-8 or CW40-8 locomotives.
2. For other trains, (Trains not qualifying as unit trains), the maximum tonnage will not exceed the tonnage determined by the tonnage rating for three (3) C40-8 or CW40-8 locomotives.
On grades where this tonnage limitation will be exceeded, trains will have a rear-end helper or appropriately positioned in-train helper, or the trailing tonnage must be reduced.
3. The number of powered axles in use must not exceed:
• 24—for the operating locomotives that are pulling a train or cut of cars.
• 15—when all operating locomotives are shoving a train or cut of cars totaling more than 50 cars, and every locomotive in the consist and within twenty cars of the consist are equipped with alignment control devices. If any locomotive in the consist or within twenty cars of consist is not equipped with alignment control devices, comply with Paragraph B(1) below.
• 12—on a helper locomotive when the helper locomotive is shoving a train.

When calculating powered axles, count AC locomotives as 9 axles.
When a reduction of powered axles is necessary, isolate locomotives from the rear of the consist forward.
4. ABTH rule is modified for Express Train Service only.
ABTH rule is modified for Express Trains Q090 and Q091 only, to enable the locomotive operator to use 3CW44AC locomotives or 27 powered axles.

The full discussion can be seen here: http://cs.trains.com/TRCCS/forums/t/200 ... ageIndex=1

Somewhat confusing when you get right down to it.

[MattW]

To add a bit, you'd also see P42s in and around the Philadelphia area. The Pennsylvanian changes locomotives from an AEM-7 on one end to a P42 or P40 on the other before heading west. Sometimes the long distance trains will change engines here too, but it's rare. Train 66 and 67 for a time (and they still might) always operated with a P42 somewhere in the consist, usually leading, to allow Amtrak to shutdown the New Haven to Boston catenary to perform maintenance, and sometimes the AEM-7 wouldn't be cut off in Washington, so it was possible to see electric locomotives as far as Newport News, VA!

[_o_OOOO_oo-Kanawha]

The most interesting to me of all the locomotive traction and braking ratings is that is clearly shows the superiority of AC traction.

Also it shows that modern AC units are actually so powerful the whole train needs strengthened couplers and some slack reducing device (I think). Static pulling and buffeting forces are one thing, they can be calculated and controlled by the engineer and tractive electronics. Slack action of course is different and still mostly uncontrollable. Experienced engineers with knowledge of the lines they drive trains over are better than rookies in preventing slack action. But when a train goes into emergency, there is still the chance of couplers breaking.

I shall try to make sense of the figures and give ES44AC and ES44DC different adhesion factors. It is a pity we don't have high adhesion trucks, otherwise we could give locos on these larger adhesion factors.

The real NEC might never see large/long/unit freight trains, but there is nothing that prevents us from running them. There are lots of industries that can be served by local freights. IIRC, there are no freight scenarios with the NEC and I believe even having read that not all of the freight only track and industrial spurs are safe to use.

[Kali]

AC units are about 36% adhesion or so - however they basically do the same thing as EMD's supercreep ( and I presume GE also has a similar thing ) so I'm not actually that sure why there's such a big advantage. I guess they just do it better.

RW has massively variable adhesion anyway, don't even bother trying for now...

[PapaXpress]

I thought it was a matter of cost between AC and DC units.

[arizonachris]

AFAIK, difference with AC and DC traction is the starting power/ torque/ whatever you call it. AC has better low end power, DC not so much? (I'm not an expert so no quotes here)

[Chessie8638]

Simple Answer:

AC locomotives are better at getting heavy trains (IE: Coal, Iron Ore, etc) started at lower speeds and maintain the effort at the lower speeds. The traction motors won't burn up like in a DC locomotive. Notice that DC locomotives have the Green / Yellow / Red Amp meter (at least in EMD models). Keep a DC unit in the red for to long and you'll burn up the traction motors.

DC locomotives are just as good and work just as good as AC locomotives in applications that need horsepower but little brute force pulling power. Example being Intermodal trains.

DC locomotives cost relativity cheaper then AC locomotives.

[Kali]

AC motors work totally differently to DC ones; you can apply full power to an AC motor without it even turning, irrespective of the load on it. The advantage is the computers tell the motor precisely how fast to turn by changing the frequency of the supply to the motor independently of current, so you turn the wheels so they slip just a little; that is actually more grip than if they didn't slip at all. EMD's Supercreep does the same thing, but I presume it doesn't have anything like the same level of control. So, they get better starting adhesion which is what matters in the end; no point putting bigger traction motors in if you can't put the torque down.

The motors are simpler, but then you have all the control electronics which I presume bumps the cost up again...

[TrainMaster1]

The real advantage of AC over DC motors is on very heavy tonnage. Think coal trains on a grade. DC motors have an LCS rating known as Lowest Continuous Speed. If you were looking in an actual cab, this is where the hours of service meter would be pegging in the red zone. If you stay there too long, DC motors begin to overheat and can be come useful only as paperweights.

AC motors do not generate the same heat level and there can tolerated lower speeds better. They also tend to have a higher adhesion ratio (holds its grips on the rails better). This is also a function of properly weighting a locomotive as well. The first GP 30's for instance had too much rear weight so when the engine was under load, the front wheels would lift from the tracks. Popping a wheelie is not something you want your locomotive to do and many were reweighted to correct this.

I have extensive research on how power is assigned, including adjusted tonnage ratings on many North American routes. This determines the number of engines and the type best suited to get the job done. I also have access to railroad SSI (special system instructions) that tell how to properly block a train (assemble it in the proper order) and how to handle that train (all automatic, independent an dynamic) braking systems.

There are many parts you can do in a simulator but no sim gets really close to actual performance without tons of work. I know we have done this on Cajon where we created an virtual version of a an actual train and ran them side by side. Virtual matched the real one right down to the speed on the grades. Took many hours to pull that off but kinda nice when it happened.

Keep at it! As in my estimation, running a railroad is far better than playing a sim. There 's a lot to learn and I would be happy to work with anyone who seriously wants to know how to get more out of their simulator.

Nick

[_o_OOOO_oo-Kanawha]

In search of the facts concering AC traction I came across the world's first engine, I think, with more then 2000 hp continuous per axle: BLS RE465 class Bo'Bo' electrics. 320 kN maximum tractive effort, which is a record for 4 axle locomotives with the European axle loading limits. It used to take a 120 tons 6 axle loco with conventional switchgear and single phase traction motors to achieve that pull.
http://en.wikipedia.org/wiki/SBB-CFF-FFS_Re_460
http://4rail.net/reference_switzerland_locos_electric1.php#class465bls
http://bls.ch/e/bahn/charter-fz-re465.php
http://www.rrpicturearchives.net/Locopicture.aspx?id=144397
http://www.youtube.com/watch?v=vcjDCuGRyBo

Technical article on the pro's and con's of energy saving by switching individual traction motors on/off according to load. Main concern: lack of electric braking power and idling of roller bearings: http://www.railway-energy.org/tfee/index.php?ID=220&TECHNOLOGYID=31&SEL=210&EXPANDALL=3

Mighty fine looking machine, and with a BLS route in the works who knows? SBB-CFF RE460 already available in TS2012 and not a slouch either: 7500 hp, 240 km/h.

Data, facts and figures vary according to source but since this is a whole family of locomotives in use all over the world, variations do exist.

So if UP decides to electrify their transcontineltal mainline we can see a new generation of locomotives, one electric capable of the same power as two or two and a halve ES44AC Diesels.

[Kali]

http://en.wikipedia.org/wiki/EuroSprinter - that one is on the way for RW too. Stick "Taurus locomotive" in youtube, lots of entertaining video there. Acceleration is a bit nuts, too.... Just remember it's in km/h, still quite ridiculous for a train.

I'm not actually sure what six axle electrics anyone's building anymore; we have some relatively new ones here with AC motors & 400kN TE, but they were meant for cross-channel work so they're basically two entire engines in one shell. Alstolm have a proposal for a 12,900bhp one.