You may say “Cale, you are a NG Steam fan why do you care?”…I don’t know, but it has been bugging me of late.
Why do the new Diesels look far more like bricks than the early ones? Even the late steamers were streamlined to some accord…
The Genesis that Amtrak uses is pretty streamlined, but the new GE offering looks like the rest of the diesels to me>!?
so enlighten me if you please…
cale
The amount of effeciency added by “streamlining” a locomotive compared to the drag exerted by the mass that they usually haul around hanging on the drawbar so closely approaches zero as to be indistinguishable. Streamling was a marketing tool used to convince the rubes (you and I) that the new dismals were ever so much more efficient than that ancient technology called steam. The late steamers were “streamlined” for the same reason.
And, we bought it. Or at least our parents did. But then they bought the Edsel, too, for a while.
Latest locomotive I’m familiar with IS streamlined…and in my opinion a beaut. Those that model modern European trains will recognize the face. Seems it has the same daddy that the DB 101’s have. But mama was born in the US. The carbody is pure Alstom but the guts are EMD. As a side note to the DB 101, Alstom is manufacturing it here in the US as an ALP46. Meet the PL42AC
And for those not familiar with the ALP46
Warren
The drag suffered by any body moving through the air is not quite as straightforward as it may at first seem .
The two fastest steam locos in the world were streamlined , the difference in the two speeds achieved is minimal , but if either of them had not been streamlined , it would have missed the record by a substantial margin .
If a body has a drag of 10 pounds at 10 mph , at 20 mph it has a drag of 100 pounds --double the speed , square the drag .
So , at 40 mph it has a drag of 10,000 pounds . Over 40 it starts to get complicated by the air forming a wedge in front of the body , thus streamlining it a little .But it does drain power .
If you want to feel just what air drag is like , take a sheet of ply and try holding it at two adjacent corners and swing it over your head against the drag . Then imagine the frontal area of a loco trying to do 60 mph and you may appreciate that drag is a serious problem . Whether it is cost effective to build streamlined as opposed to square is a different matter .
Maybe the square diesels don’t need to go very fast ,or other factors govern its top speed . Like track condition .
But ya can’t dismiss drag out of hand , the car outside your house would cost a lot more in fuel if it were square .
And hurricanes wouldn’t blow houses over if they were streamlined .
Warren Mumpower said:
Latest locomotive I'm familiar with IS streamlined...and in my opinion a beaut. Those that model modern European trains will recognize the face. Seems it has the same daddy that the DB 101's have. But mama was born in the US. The carbody is pure Alstrom but the guts are EMD. As a side note to the DB 101, Alstrom is manufacturing it here in the US as an ALP46.Warren
The company is called ALSTOM, the company name is always written in CAPS. 
Ok, so I stuck an extra “r” in there. Sheesh, nobody told me I had to be a spelling genious to qualify to post here. As for all caps, or just the first letter cap’d, I might suggest you tell Google, Wikipedia, Railpictures.net and the rest of the world because only you and [color=blue]ALST[/color][color=red]O[/color][color=blue]M[/color] seem to know that! 
Oh, well, I still like the locomotive 
Now, if they would just make their locomotives in 1:29 I would be a whooooooole lot happier.
Streamlining was more for looks, not efficiency. It was born in the days of art-deco. If it looked fast, it must go fast. Like the autos of the 40’s and 50’s.
The present day boxes are a lot more fuel efficient than the F’s and P’s of old.
Just my observation…
Warren,
Not to worry.
Even their own website http://www.alstom.com/home/ They only use all caps in a couple places.
jb
In those days effeciency for locomotives was unnecessary…or so they thought. But in today’s market it’s everything. If you note though, even though the locomotives look boxy they are all coming with a wide cab which is angled to break through the wind far more effeciently than the older -2 series locomotives. Passenger locomotives benifit more towards streamlining because the cars are more aerodynamic by nature. I have seen articles discussing the benifits of streamlining freight…but it includes the cars as well as the locomotive which would have to be done to have any benifit. Also freight trains seldom run at speeds that streamlining would benifit whereas passenger trains running at 100mph+ need it. The main reason road switchers were more popular was because they were far easier to service than a cowl unit. Up until this recent surge in oil prices any $ saved in fuel costs because of streamlining was lost in extra cost of servicing the locomotives.
Warren
A point to ponder when thinking about wind effects .
Road going trucks , sideways on to the wind , are better able to stay upright by simply having round edges on all corners , than those with a square box body . So a container truckwill roll over before a fixed body truck with even minmal rounding of the body .
It has also been well proven that a truck with a roof spoiler uses 12,5%less fuel than the same truck without , even when they are limited to a top speed of 55mph by governers .
But , bear in mind what was stated earlier , is it cost effective ? With a truck , yes , the fibreglass spoilers can recoup their fitting costs in 12 months easily on an average working truck . If the truck’s life is three years , you’re on a winner for two years on fuel saving .
With a train , it has to be going well up into the 90’s before problems of drag creep in .
One of the worst problems suffered by trains at high speed is the Pantograph Buffeting , streamlining in this case has the added benefit of blasting the air up clear of the pantograph . On trials , European High Speed Trains have had pantographs losing contact with the overhead wires big time ,leading to the rear pantograph usually being used for pickup . So there is more to streamlining than the simple "looks nice " qualification .
John Bouck said:
Warren, Not to worry. Even their own website http://www.alstom.com/home/ They only use all caps in a couple places.jb
I noticed; what a bunch of slackers who don’t adhere to their corporate identity!
Mind you on their “About us” page they get it right. Probably the only one the Chairman and CEO got to proofread.
OTOH Warren wouldn’t worry about that in the first place.
On another note, OK the prime mover is made by EMD, whose electrics do they use? Couldn’t find a reference so far.
An intelligent guess would say that the guts of the locomotive (PL42AC) are pure EMD. I say this because the layout of the external visible components (placing of fans, exhaust, filters, battery boxes, fuel tank etc. are identical to the F40PH. Now, the trucks are a different matter. I don’t recognize them at all. Now that EMD is it’s own separate company located in Canada they might become more progressive and competitive. They may have a whole gaggle of new stuff we are not aware of under the hood of that thing. My railroad wants a whole fleet of those for both passenger and freight service. Nah, I’ll just use them for freight service. I’ll use the ALP46 for passenger…
Warren
Warren,
My guess is the prime mover and generator are from EMD. The rest is most likely from ALSTOM i.e. the ONIX system
BTW I just came across a reference that some EMD prime mover is supposedly built in Poland by GE!?!
Railroad.net forum said:I guess everyone is outsourcing. ;)
The Caltrain MP36's and the Metra's both have the same 645F3B, a older EMD design with flaws, that GE bought the patent to and modified to overcome the issues EMD had. The prime movers are built by GE of Poland, the 710G's are just too inefficent I'd say, I've heard of the Amtrak California units having nothing but problems with theirs.
Curious. Neither the PL42AC nor the ALP46 (isn’t that a printer?) look particularaly streamlined. Yes, the nose is canted back to shed some of the wind, but there are enough things hanging off both of them to make an aeronautical engineer’s soul cringe. Look at all of that induced drag!
Even the induced drag produced by the handrails is enough to take off several degrees of efficiency!
Wouldn’t they be better served by putting everything under a fairing, if they are trying to achieve efficiency? Or are they just trying to go after looks? Personally, given the amount of induced drag I see just in those pictures, I think they are just going after looks.
madwolf
Parasitic drag , if you please .
Induced drag is the one caused by lift .
Careful , I’m a Drag Queen
Steve,
Both engines have European design.
One item that is taken into account in Europe is air displacement in tunnels - the older tunnels have a track running in either direction.
When they first started doing tests with two trains meeting at speed in a tunnel it was noted that the front windows had a tendency to dislodge. This was with windows that had only a slight incline from the vertical.
I don’t remember reading anything on the “behaviour” of the windows of the French engines which had a negative rake, but I can imagine the pressure wave in front of those.
Steve, the initial contact with the air is the important thing. These locomotives are designed in the front end to deflect the air away from the sides of the locomotive…and cars. Generally there is a vacuum next to the train itself.
Back when the Metroliners first came into being the problems with the vacuum created alongside the cars became very apparent. It seemed that when they passed another passenger train it sucked all the windows out…
HJ, it’s hard to really say. The suspecting thing that says you may be right is the trucks, but on the other hand, everything else from the cab back is pure EMD. What would lead me to believe that most of the electronics would be EMD is the fact that this locomotive will have to meet the new “EVO” standards that all new locomotives in the US have to meet. I’m not sure that a European manufacturer would be ready to or willing to meet those standards alone. Also for inventory reasons of NJT I would think they would want off the shelf EMD parts. Don’t think this is important…take a look at the new SD70’s. They have rectangular windshields for a reason…railroads demanded that GE and EMD locomotives share a common windshield…to minimize inventory.
Warren
Warren,
The vaccuum that you speak of is the Venturi effect, the same thing that creates lift on a wing. Airplanes really don’t fly, they are just sucked into the air. It has nothing to do with drag. Google “Venturi effect” for a more complete discussion than I can give.
The same thing occurs with ships when they get too close. Once, while I was conning USS Vincennes alongside USNS Cimmaron during a FAS (Fueling At Sea), an odd set of waves pushed one or the other of us, or perhaps both, into the Venturi effect, and the distance between us suddenly went from 150 feet to 90 feet and closing fast. It took some handy use of the rudder to break us out (full rudder at 20 knots only 90 feet from another ship will definately get your attention and increase the pucker factor, not to mention bringing all 4 sweat pumps on line!). Cimmaron by custom had to maintain course and speed, but I would not be surprised if they didn’t apply a little judicious use of the rudder, too.
Mike, I had a feeling someone was going to call me on that. I’m trying to remember from high school studies from longer ago that I care to admit! I’m sure that on this side of the pond we didn’t call it parasitic drag, though! My memory of that time resembles a moth eaten cloth. It was the 60’s, don’t you know!
If these locomotives are to be steamed at 100 knots or more (sorry), they probably should be aerodynamically streamlined. That means being designed by an aeronautical engineer, not a mechanical engineer. The ME can design everything inside, except the stuff needing an E.E., but the outside needs the A.E. If the windows are not going to be sucked out when two trains pass eachother at a closing speed of 100 whatever (mph, kph, knots), then they are either going to have to have beefier mountings, or the tracks will have to be farther apart to defeat the Venturi effect.
At one of my rare rail fan days, I saw a guy who was too close to the tracks get pushed away by the leading edge effect, only to have to fight being sucked into and under the train by the Venturi Effect. Spooky!
madwolf
Well , Steve , I learned to fly in '51 , and back then and ever since , it’s parasitic drag . All Air Forces use the term , or did do until recently . Obviously , it’s the drag caused by bits that stick out into the airflow .
Induced drag is just that , you get lift which induces drag , which has to be overcome by either the engine , or falling rapidly to produce laminar flow.
But , the application of this to locos is a bit too advanced , they don’t fly yet . Nearly , but not quite .
If you look at the aerodynamics of the French TGV’s , the airflow is arranged to produce a high pressure area in front of the pantograph , which then does not suffer bounce effect . The aerodynamics of high speed trains is very important , the negative sloped windscreen on the French and other Continental engines was a serious attempt to reduce the side vacuum effect which has been mentioned previously . There were other considerations as well , but they don’t seem to have pursued it . Ugly things .
The fluid effect drawing ships together , isn’t that called “Canal Effect” ? When you are gliding happily along the canal , the low pressure caused by the acceleration of the water causes the boat to move into the canal bank . Twice as bad if you have two bodies moving side by side . More than twice if one is bigger than the other . I prefer to fly , myself . Boats is wet . Pretty , but wet .
If you’re in a canal, then it can rightly be called Canal Effect. The scientific Principle is Venturi Effect but we are probably getting a bit esoteric for this lot.
That afternoon on the Vinnie-Maru was one of the most memorable of my 22 year career in the Naval Service, and one that I’d rather not repeat.
You are right about induced drag, oh Drag Queen! I don’t remember parasitic drag, but then as I said, my memory resembles a moth eaten cloth.
When I ride my bicycle at 5 mph, 85% of the effort goes into moving the bike over the ground, and 15% into pushing the wind out of the way. At 15 mph, the ratio is reversed, 85% goes to pushing the wind out of the way, and 15% of the effort goes into moving the bike over the ground. The same applies to trains, but in spades.
Still, if two trains pass eachother at speed, on adjacent tracks in opposite directions, the Venturi effect will suck the windows out if you are not careful.
The only wind I really know anything about is the excess wind caused by the pressure of too many beans in one place. So I will for the most part not blow off any more hot wind on the wind subject.
Metroliners were the first attempt by the US at high speed railroading…a snails pace compared to Europe and Japan. Also remember that the NJT is a commuter line. They spend more time starting and stopping than running. Call them the “Jackrabbit Line”.
Steve, as for the poor chap that almost got sucked in, I can fully understand what he was going through. When I was a teen I stood out on the walkway of a GP9 one evening to watch the Montrealer come through. Even though he was only doing about 35mph when he passed and we were standing still I decided I didn’t want to do that again!! I think I left permanent hand grip marks on the railing…
Warren