Pound Sand, Sucky Motor Club

[mathnerd]

Yeah, I knew a lot of the electric/hybrid cars used regenerative braking, but I'm really not well versed with the topic. It's still somehow more exciting when linked to trains.

[dalesys]

My daughter's first Prius could store about 1200 watt-hours or so in the battery pack... sounds like a lot... just a little less that 2 horsepower for one hour... If, and only if, they got 100% conversion efficiency.

[ADeMartino]

Yeah, I knew a lot of the electric/hybrid cars used regenerative braking, but I'm really not well versed with the topic. It's still somehow more exciting when linked to trains.

Well, trains ARE pretty cool. I especially loved playing with the big EMD 645-seres diesel engines. HUGE things, just a massive rush of power and noise. Make the decks quake at full output. It always fascinated me how something so big and heavy could get moving so damned fast and NOT jump the tracks every eight seconds.

If you like the tech of trains, check out this link about some of the engineering behind Japan's high speed trains:

http://www.youtube.com/watch?v=ulDhklLJxZc

[protege]

Well, trains ARE pretty cool. I especially loved playing with the big EMD 645-seres diesel engines.

I've never played with the prime movers, but I have been in several shops over the years--the most recent tour was at NJ Transit's Kearny (NJ) facility in 2012. One thing I've always been in awe of, was just how *big* everything is. Take the 645, for example. The pistons on that are about the size of gallon paint cans!

[ADeMartino]

I've never played with the prime movers, but I have been in several shops over the years--the most recent tour was at NJ Transit's Kearny (NJ) facility in 2012. One thing I've always been in awe of, was just how *big* everything is. Take the 645, for example. The pistons on that are about the size of gallon paint cans!

I probably should clarify. I never worked for the railroads (but believe me, I would have LOVED the opportunity!). The EMDs I played with were 16-645s aboard a tow boat. Same basic plant as a railroad locomotive uses, just adapted for marine use. Yes, the pistons were massive - the 645 had a 9-1/8" bore and 10" stroke, if memory serves, and aboard my boat, 'redline' was just 900 rpm - with the combined output of the two EMDs being in the 6000 shaft horsepower range. The noise and vibration was pure nirvana for a power freak like me! The sweet spot was standing directly between those big mills at anything above right around 80 percent throttle.

And my boat was a puny li'l thing that operated on the Ohio and Illinois rivers. The really big boats were in the lower Mississippi - HUGE boats, FOUR 16- or 20-645 units for power. Think of all that power - up to 80 massive cylinders hammering away, not counting the generator sets! And the whine of those huge turbo/supercharger assemblies.....

It's been 25+ years, and I still get all tingly inside just thinking about it! Tim Allen, eat your heart out!

Sadly, that 'career' came to an abrupt end due to a drought, which forced the company I worked for to lay up four of its boats for a season, with the subsequent and inevitable layoffs. By the time they were back in operation, I was already working elsewhere.

Boy, did THIS thread ever go 'off track'.

[dalesys]

...Boy, did THIS thread ever go 'off track'.

We've had the loco motive pushing it.

[wolfie]

If you really want to have fun...electric locomotives have regenerative braking. That is, unlike the diesels with dynamic brakes...which *waste* the energy produced...electrics can actually send the energy back into the power grid.

Fun fact: What most people would call a diesel locomotive is actually an electric locomotive which, in order to run on track without an overhead electric wire, carries an on-board diesel generator.

My daughter's first Prius could store about 1200 watt-hours or so in the battery pack... sounds like a lot... just a little less that 2 horsepower for one hour... If, and only if, they got 100% conversion efficiency.

That's a SMALL battery pack for a hybrid electric. For comparison purposes, a Group 31 battery is rated at (typically) around 100 amp-hours. Since it's a 12 volt battery, it would have the same rating as the battery pack on that Prius - and a semi normally has 4 of them.

The EMDs I played with were 16-645s aboard a tow boat. The really big boats were in the lower Mississippi - HUGE boats, FOUR 16- or 20-645 units for power.

Were these 2-cycle Detroit Diesels? Sounds like the naming convention they used. For the uninitiated, a 2-cycle Detroit's model number X-Y meant that it had X cylinders, each displacing Y cubic inches.

[Chromatix]

I believe the EMD engines are indeed 2-stroke. EMD refers to the Electro-Motive Division of General Motors.

It's incorrect to say that electric locomotives in general can do regenerative braking. Some can, but more often they can't. AC overhead systems in particular tend *not* to be able to do it - there are twin problems of matching the locomotive's supply of current to the frequency of the line, and of ensuring that the energy goes somewhere sensible if there are not enough other trains consuming power on the same piece of line. Even on DC systems, the latter problem is still an important one.

Rheostatic braking, however, is quite common wherever it can sensibly be fitted into the locomotive's bodywork. Traction motors traditionally have four terminals, not two - two of them goes to the armature windings via the commutator, just like in the small permanent-magnet motors in your Lego set, but the other two go to the stator windings which replace the permanent magnets. For driving, the two sets of windings are connected in series, so the current goes first through one and then the other. For braking, the traction supply is connected to the stator windings, allowing direct control of the field strength, while the armature produces the power which is directed to the resistor grids - or, for regenerative braking, matched in voltage (and if required, frequency and phase) and sent to the line.

Another famous 2-stroke diesel was the Deltic engine. Eighteen cylinders and thirty-six pistons per engine, producing 1650hp in railway service (and often considerably more in marine service). This was an unusually compact and lightweight engine for its power class, being derived from an experimental *aircraft* engine design, and allowed such oddities as a 3300hp locomotive which weighed only 100 tons, and minesweeper ships with ridiculously low magnetic signatures.

[ADeMartino]

Were these 2-cycle Detroit Diesels? Sounds like the naming convention they used. For the uninitiated, a 2-cycle Detroit's model number X-Y meant that it had X cylinders, each displacing Y cubic inches.

Electro Motives, actually, and yes, they were two-stroke. Four valves at the top of the cylinder and mechanical injection. The '645' does indeed indicate the cubic inches per cylinder - (which meant 16-645s were 10,320 cubic inches PER ENGINE, or in metricspeak 169 liters EACH!) Compare that to a modern V6 automobile with usually between 2.5 and 4.0 liters! Even the 'big' Cadillac 500 (8.2 liter) V8s paled in comparison to those EMDs. I loved the enormous scale of 'big iron' diesels.

Even starting those big EMDs up was a power trip. TWO, count 'em, TWO starters per engine, and air-driven! Sounded a little like this:

http://www.youtube.com/watch?v=c_BKrLZTvsI

To get the full effect, play it LOUD through a good, high-powered stereo. He ain't wearing Mickey Mouse ears to be fashionable! In the vid, he's starting up 12s, not 16s. Ours would 'crank' slower and a bit longer before they'd catch, but it gives you a good idea of what it sounded like.

[Shalom]

Just for clarity, while Detroit Diesel and Electro-Motive were both once owned by GM, they were separate lines.

Detroit Diesel powerplants were smaller, primarily used in trucks, tractors, and stationary generators; the largest ones were found in self-propelled railcars like the Budd RDC. They came in 53, 71, 92, and 110 cubic inch per cylinder configuration.

EMD prime movers were much bigger: their smallest units displaced 567 cubic inches per cylinder, later expanded to 645 and finally 710 cu.in.. (They also make one that's 1010 per cyl., but those are 4-stroke engines). These were originally designed for locomotives, also found in stationary power generation, and after WWII began finding installations in marine usage.

GM's Cleveland Diesel Division, formerly the Winton Engine Co., built marine engines that were around the same size as the EMD railroad units (the Winton 16-278A displaced about 631 cu.in./cyl). They were the original engine supplier to EMD until the latter started building their own prime movers, and were very common in marine use before the EMD powerplants began supplanting them. GM apparently used to market matching engine sets for boats, with a Cleveland Diesel engine for propulsion and one or more Detroit Diesel engines for auxiliary power generation.

Here's some good reading on these engines, with some great photographs. More diagrams at here.

[ADeMartino]

and for those who are turned on by sheer scale:
http://www.youtube.com/watch?v=kRwrN6HuBEo

[protege]

Any Alco fans on this board? Those were four strokes, and sound rather different than an EMD. I never got to see them when they were current. The only Alco product I got to hear run, was an RS3 at a museum in Connecticut. But, I'm more an EMD guy anyway--I remember when E units and F40s still called at the station downtown...

BTW, not all diesels have generators to power them. Some small switchers were direct-driven by chains. I actually drove one of these (a Plymouth narrow-gauge switcher) at a museum. How did I manage that? I was there helping to clean up the county's steam engine, and the Plymouth (which owed its very existence to pulling said steam engine out of its shed for festivals) was being driven back and forth by one of the volunteers. I asked for a cab ride, and he let me take over until the fuel ran out. It was like driving a big truck. There were levers for direction, changing gear, plus the brake pedal on the floor. Below that lot, were the chains that powered the axles.

[xxscooterxx]

Oh how much I love this topic. Lol

[Irving Patrick Freleigh]

Not yet, we haven't even gotten to the subject of locomotive dynamic brakes!

*drools* Don't tease me like that!

Ummm, they do fun things sometimes.

[Argabarga]

Mmmmmm.... molten resistor grids, bet that cost some money to fix. The old Seabaord engine vid has been around the internet a few times, but that was the first I ever saw of the UP unit losing it's dynamics with a bang... I mean, it put a hole clean through the engine!

But yeah, that howling noise you hear as that train is coming towards you in the second vid is the sound of the dynamic brakes at work normally, when they don't explode.